Spinal Cord Stimulation bei

chronischem Rücken- und

Beinschmerz (Failed Back Surgery Syndrome, FBSS)

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Inhalt (chronologisch)

Spinal Cord Stimulation

Spinal cord stimulation for cancer-related low back pain. Yakovlev AE, Resch BE. Am J Hosp Palliat Care. 2012 Mar;29(2):93-7. Epub 2011 Jun 13. ....................16

Triangular stimulation method utilizing combination spinal cord stimulation with peripheral subcutaneous field stimulation for chronic pain patients: a retrospective study.

Navarro RM, Vercimak DC. Neuromodulation. 2012 Mar;15(2):124-31. doi: 10.1111/j.1525-1403.2011.00422.x. Epub 2012 Feb 13. ......................................................................................................16

Spinal cord stimulation with hybrid lead relieves pain in low back and legs. de Vos CC, Dijkstra C, Lenders MW, Holsheimer J. Neuromodulation. 2012 Mar;15(2):118-23. doi: 10.1111/j.1525-1403.2011.00404.x. Epub 2011 Nov 10. .............................................................................17

Subcutaneous Stimulation as an Additional Therapy to Spinal Cord Stimulation for the Treatment of Lower Limb Pain and/or Back Pain: A Feasibility Study.

Hamm-Faber TE, Aukes HA, de Loos F, Gültuna I. Neuromodulation. 2012 Mar;15(2):108-17. doi: 10.1111/j.1525-1403.2011.00393.x. Epub 2011 Sep 21. .............................................................................17

Back pain: a real target for spinal cord stimulation? Rigoard P, Delmotte A, D'Houtaud S, Misbert L, Diallo B, Roy-Moreau A, Durand S, Royoux S, Giot JP, Bataille B. Neurosurgery. 2012 Mar;70(3):574-84; discussion 584-5. .........................................................18

Is spinal cord stimulation an effective treatment option for discogenic pain? Vallejo R, Zevallos LM, Lowe J, Benyamin R. Pain Pract. 2012 Mar;12(3):194-201. doi: 10.1111/j.1533-2500.2011.00489.x. Epub 2011 Jul 29. ........................................................................................................18

Treatment of Multifocal Pain with Spinal Cord Stimulation. Yakovlev AE, Resch BE. Neuromodulation. 2012 Feb 29. doi: 10.1111/j.1525-1403.2012.00435.x. [Epub ahead of print] ...............................................................................................................................................19

Spinal cord stimulation: a review. Compton AK, Shah B, Hayek SM. Curr Pain Headache Rep. 2012 Feb;16(1):35-42. ................................19

Managing chronic pain with spinal cord stimulation. Epstein LJ, Palmieri M. Mt Sinai J Med. 2012 Jan-Feb;79(1):123-32. doi: 10.1002/msj.21289. .................19

A prospective, open-label, multicenter study to assess the efficacy of spinal cord stimulation and identify patients who would benefit.

Moriyama K, Murakawa K, Uno T, Oseto K, Kawanishi M, Saito Y, Taira T, Yamauchi M. Neuromodulation. 2012 Jan-Feb;15(1):7-11; discussion 12. doi:10.1111/j.1525-1403.2011.00411.x. Epub 2011 Dec 12. ................................................................................................................................................19

Cephalad lead migration following spinal cord stimulation implantation. McGreevy K, Williams KA, Christo PJ. Pain Physician. 2012 Jan-Feb;15(1):E79-87. .................................20

The impact of spinal cord stimulation on physical function and sleep quality in individuals with failed back surgery syndrome: A systematic review.

Kelly GA, Blake C, Power CK, O'Keeffe D, Fullen BM. Eur J Pain. 2011 Dec 21. doi: 10.1002/j.1532-2149.2011.00092.x. [Epub ahead of print] ...................................................................................................20

Costs and cost-effectiveness of spinal cord stimulation (SCS) for failed back surgery syndrome: an observational study in a workers' compensation population.

Hollingworth W, Turner JA, Welton NJ, Comstock BA, Deyo RA. Spine (Phila Pa 1976). 2011 Nov 15;36(24):2076-83. .......................................................................................................................................21

A Unique Approach to Neurostimulation in Patients With Previous Two-Segment Spine Surgery and Obstruction of Epidural Access for Spinal Cord Stimulation: A Case Series.

Mironer YE, Hodge PJ, Parrott JT, Lal S, Latourette PC. Neuromodulation. 2011 Oct 25. doi: 10.1111/j.1525-1403.2011.00397.x. [Epub ahead of print] ..........................................................................21

Invasive brain stimulation for the treatment of neuropathic pain. Nguyen JP, Nizard J, Keravel Y, Lefaucheur JP. Nat Rev Neurol. 2011 Sep 20;7(12):699-709. doi: 10.1038/nrneurol.2011.138. .........................................................................................................................22

Results of neuromodulation for the management of chronic pain.

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Sokal P, Harat M, Paczkowski D, Rudaś M, Birski M, Litwinowicz A. Neurol Neurochir Pol. 2011 Sep-Oct;45(5):445-51...........................................................................................................................................22

Technique for steering spinal cord stimulator electrode. MacDonald JD, Fisher KJ. Neurosurgery. 2011 Sep;69(1 Suppl Operative):ons83-6; discussion ons86-7. ......................................................................................................................................................................22

Automatic adaptation of neurostimulation therapy in response to changes in patient position: results of the Posture Responsive Spinal Cord Stimulation (PRS) Research Study.

Schade CM, Schultz DM, Tamayo N, Iyer S, Panken E. Pain Physician. 2011 Sep-Oct;14(5):407-17. ......23

Epidural spinal cord stimulation for therapy of chronic pain. Summary of the S3 guidelines. [Article in German]

Tronnier V, Baron R, Birklein F, Eckert S, Harke H, Horstkotte D, Hügler P, Hüppe M, Kniesel B, Maier C, Schütze G, Thoma R, Treede RD, Vadokas V; Arbeitsgruppe zur Erstellung der S3-Leitlinie. Schmerz. 2011 Sep;25(5):484-92. ................................................................................................................................24

Retrograde C0-C1 insertion of cervical plate electrode for chronic intractable neck and arm pain. Moens M, De Smedt A, Brouns R, Spapen H, Droogmans S, Duerinck J, D'Haese J, D'Haens J, Nuttin B. World Neurosurg. 2011 Sep-Oct;76(3-4):352-4; discussion 268-9. .............................................................24

Long-term outcome of patients treated with spinal cord stimulation for therapeutically refractory failed back surgery syndrome: a retrospective study. [Article in French]

Abeloos L, De Witte O, Riquet R, Tuna T, Mathieu N. Neurochirurgie. 2011 Jul;57(3):114-9. Epub 2011 Sep 9. ...........................................................................................................................................................24

Spinal cord stimulation versus re-operation in patients with failed back surgery syndrome: an international multicenter randomized controlled trial (EVIDENCE study).

North RB, Kumar K, Wallace MS, Henderson JM, Shipley J, Hernandez J, Mekel-Bobrov N, Jaax KN. Neuromodulation. 2011 Jul-Aug;14(4):330-5; discussion 335-6. doi:10.1111/j.1525-1403.2011.00371.x. Epub 2011 Jul 7. ...........................................................................................................................................25

Percutaneously implanted plates in failed back surgery syndrome (FBSS). Vonhögen LH, Vancamp T, Vanneste S, Pollet W, Dirksen R, Bakker P, Mestrom I, van de Looij T, Plazier M, de Ridder D. Neuromodulation. 2011 Jul-Aug;14(4):319-24; discussion 324-5. doi:10.1111/j.1525-1403.2011.00368.x. Epub 2011 Jul 7. ..........................................................................................................25

Long-term outcomes of spinal cord stimulation with paddle leads in the treatment of complex regional pain syndrome and failed back surgery syndrome.

Sears NC, Machado AG, Nagel SJ, Deogaonkar M, Stanton-Hicks M, Rezai AR, Henderson JM. Neuromodulation. 2011 Jul-Aug;14(4):312-8; discussion 318. doi: 10.1111/j.1525-1403.2011.00372.x. Epub 2011 Jul 7. ...........................................................................................................................................26

Using the SAFE principles when evaluating electrical stimulation therapies for the pain of failed back surgery syndrome.

Krames ES, Monis S, Poree L, Deer T, Levy R. Neuromodulation. 2011 Jul-Aug;14(4):299-311; discussion 311. doi: 10.1111/j.1525-1403.2011.00373.x. Epub 2011 Jul 7. ..................................................................26

Selected interventional methods for the treatment of chronic pain: part 2: regional anesthetic techniques close to the spinal cord and neuromodulative methods. [Article in German]

Böttger E, Diehlmann K. Anaesthesist. 2011 Jun;60(6):571-90. doi: 10.1007/s00101-011-1891-2. ...........27

Failed back surgery syndrome. Chan CW, Peng P. Pain Med. 2011 Apr;12(4):577-606. doi: 10.1111/j.1526-4637.2011.01089.x. Epub 2011 Apr 4. ...................................................................................................................................................27

Prospective, two-part study of the interaction between spinal cord stimulation and peripheral nerve field stimulation in patients with low back pain: development of a new spinal-peripheral neurostimulation method.

Mironer YE, Hutcheson JK, Satterthwaite JR, LaTourette PC. Neuromodulation. 2011 Mar-Apr;14(2):151-4; discussion 155. doi: 10.1111/j.1525-1403.2010.00316.x. Epub 2010 Nov 2. ..........................................28

Spinal cord stimulation in a patient with spinal epidural lipomatosis. Zhang Y, Wood MJ, Gilligan C. Pain Med. 2011 Mar;12(3):377-81. doi: 10.1111/j.1526-4637.2011.01057.x. Epub 2011 Feb 18. ......................................................................................................28

Alternative approach to needle placement in cervical spinal cord stimulator insertion. Zhu J, Falco FJ, Onyewu CO, Vesga R, Josephson Y, Husain A, Gutman G. Pain Physician. 2011 Mar-Apr;14(2):195-210. .......................................................................................................................................29

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Retrospective review of 707 cases of spinal cord stimulation: indications and complications. Mekhail NA, Mathews M, Nageeb F, Guirguis M, Mekhail MN, Cheng J. Pain Pract. 2011 Mar-Apr;11(2):148-53. doi: 10.1111/j.1533-2500.2010.00407.x. Epub 2010 Sep 8. ..........................................29

Combination therapy of radiofrequency lumbar facet joint denervation and epidural spinal cord stimulation for failed back surgery syndrome.

Terao T, Ishii T, Tani S, Abe T. Neurol Med Chir (Tokyo). 2011;51(11):805-9. ...........................................29

Alternative approach to needle placement in spinal cord stimulator trial/implantation. Zhu J, Falco F, Onyewu CO, Joesphson Y, Vesga R, Jari R. Pain Physician. 2011 Jan-Feb;14(1):45-53. 30

Counting the costs: case management implications of spinal cord stimulation treatment for failed back surgery syndrome.

Mekhail N, Wentzel DL, Freeman R, Quadri H. Prof Case Manag. 2011 Jan-Feb;16(1):27-36. .................30

'Hybrid neurostimulator': simultaneous use of spinal cord and peripheral nerve field stimulation to treat low back and leg pain.

Lipov EG. Prog Neurol Surg. 2011;24:147-55. Epub 2011 Mar 21. .............................................................31

Simultaneous intrathecal opioid pump and spinal cord stimulation for pain management: analysis of 11 patients with failed back surgery syndrome.

Tomycz ND, Ortiz V, Moossy JJ. J Pain Palliat Care Pharmacother. 2010 Dec;24(4):374-83. ...................31

Questions about Turner et al. Spinal cord stimulation for failed back surgery syndrome: outcomes in a worker's compensation setting.

North RB, Shipley J, Taylor RS, Eldabe S. Pain. 2010 Nov;151(2):550-1; author reply 551-2. Epub 2010 Sep 9. ...........................................................................................................................................................32

Trial spinal cord stimulator reimplantation following lead breakage after third birth. Takeshima N, Okuda K, Takatanin J, Hagiwra S, Noguchi T. Pain Physician. 2010 Nov-Dec;13(6):523-6. ......................................................................................................................................................................32

The use of spinal cord stimulation and intrathecal drug delivery in the treatment of low back-related pain.

Bagnall D. Phys Med Rehabil Clin N Am. 2010 Nov;21(4):851-8. ...............................................................32

Spontaneous resolution of nausea induced by spinal cord stimulation for failed back surgery syndrome.

Vorenkamp KE, Baker NE. Neuromodulation. 2010 Oct;13(4):292-5. doi: 10.1111/j.1525-1403.2010.00291.x. ......................................................................................................................................33

Spinal cord stimulation for the treatment of chronic pain in patients with lumbar spinal stenosis. Costantini A, Buchser E, Van Buyten JP. Neuromodulation. 2010 Oct;13(4):275-80. doi: 10.1111/j.1525-1403.2010.00289.x. ......................................................................................................................................33

Neurophysiological assessment of spinal cord stimulation in failed back surgery syndrome. de Andrade DC, Bendib B, Hattou M, Keravel Y, Nguyen JP, Lefaucheur JP. Pain. 2010 Sep;150(3):485-91. Epub 2010 Jun 29. .................................................................................................................................33

The cost-effectiveness of spinal cord stimulation in the treatment of failed back surgery syndrome. Taylor RS, Ryan J, O'Donnell R, Eldabe S, Kumar K, North RB. Clin J Pain. 2010 Jul-Aug;26(6):463-9. ..34

An analysis of the components of pain, function, and health-related quality of life in patients with failed back surgery syndrome treated with spinal cord stimulation or conventional medical management.

Eldabe S, Kumar K, Buchser E, Taylor RS. Neuromodulation. 2010 Jul;13(3):201-9. doi: 10.1111/j.1525-1403.2009.00271.x. Epub 2010 Feb 22. ......................................................................................................34

A critical review of the American Pain Society clinical practice guidelines for interventional techniques: part 2. Therapeutic interventions.

Manchikanti L, Datta S, Gupta S, Munglani R, Bryce DA, Ward SP, Benyamin RM, Sharma ML, Helm S 2nd, Fellows B, Hirsch JA. Pain Physician. 2010 Jul-Aug;13(4):E215-64. ..................................................35

Pulse width programming in spinal cord stimulation: a clinical study. Yearwood TL, Hershey B, Bradley K, Lee D. Pain Physician. 2010 Jul-Aug;13(4):321-35. ........................36

Lumbosacral radicular pain. Van Boxem K, Cheng J, Patijn J, van Kleef M, Lataster A, Mekhail N, Van Zundert J. Pain Pract. 2010 Jul-Aug;10(4):339-58. Epub 2010 May 17. ........................................................................................................36

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Comparative effectiveness research and policy: experiences conducting a coverage with evidence development study of a therapeutic device.

Turner JA, Hollingworth W, Comstock B, Deyo RA. Med Care. 2010 Jun;48(6 Suppl):S129-36. ...............37

Treatment of urinary voiding dysfunction syndromes with spinal cord stimulation. Yakovlev AE, Resch BE. Clin Med Res. 2010 Mar;8(1):22-4. .....................................................................37

Ultrasound-guided transversus abdominis plane block for spinal infusion and neurostimulation implantation in two patients with chronic pain.

Asensio-Samper JM, De Andrés-Ibáñez J, Fabregat Cid G, Villanueva Pérez V, Alarcón L. Pain Pract. 2010 Mar;10(2):158-62. Epub 2010 Jan 8. ..................................................................................................37

Clinical applications of neurostimulation: forty years later. Mekhail NA, Cheng J, Narouze S, Kapural L, Mekhail MN, Deer T. Pain Pract. 2010 Mar;10(2):103-12. Epub 2010 Jan 8...........................................................................................................................................38

Spinal cord stimulation as a treatment for refractory neuropathic pain in tethered cord syndrome: a case report.

Moens M, De Smedt A, D'Haese J, Droogmans S, Chaskis C. J Med Case Reports. 2010 Feb 25;4:74. ..38

Modulation of neuronal activity after spinal cord stimulation for neuropathic pain; H(2)15O PET study.

Kishima H, Saitoh Y, Oshino S, Hosomi K, Ali M, Maruo T, Hirata M, Goto T, Yanagisawa T, Sumitani M, Osaki Y, Hatazawa J, Yoshimine T. Neuroimage. 2010 Feb 1;49(3):2564-9. Epub 2009 Oct 27. ..............39

Spinal cord stimulation in a workers' compensation population: how difficult it can be to interpret a clinical trial.

Wasan AD. Pain. 2010 Jan;148(1):3-4. Epub 2009 Nov 11. ........................................................................39

Spinal cord stimulation for failed back surgery syndrome: outcomes in a workers' compensation setting.

Turner JA, Hollingworth W, Comstock BA, Deyo RA. Pain. 2010 Jan;148(1):14-25. Epub 2009 Oct 28. ...39

Novel use of intraoperative dexmedetomidine infusion for sedation during spinal cord stimulator lead placement via surgical laminectomy.

Harned ME, Owen RD, Steyn PG, Hatton KW. Pain Physician. 2010 Jan;13(1):19-22 ..............................40

Spinal cord stimulation for chronic pain. Jeon Y, Huh BK. Ann Acad Med Singapore. 2009 Nov;38(11):998-1003. ..................................................40

Spinal cord stimulation. [Article in Japanese] Fukazawa K, Hosokawa T. Masui. 2009 Nov;58(11):1393-400. ..................................................................40

Spinal cord stimulation: principles of past, present and future practice: a review. Kunnumpurath S, Srinivasagopalan R, Vadivelu N. J Clin Monit Comput. 2009 Oct;23(5):333-9. ..............41

Generating evidence on spinal cord stimulation for failed back surgery syndrome: not yet fully charged. Clin j pain. 2008;24:757-758.

North RB, Shipley J, Taylor RS. Clin J Pain. 2009 Sep;25(7):650; author reply 651. ..................................41

Spinal cord stimulation for control of low back pain after multiple corrective surgeries for severe scoliosis: report of a case.

Canlas BR, Yap AN, Fernando BY, Paiso JM. Pain Pract. 2009 Sep-Oct;9(5):404-5. ................................41

Spinal cord and peripheral nerve stimulation techniques for neuropathic pain. de Leon-Casasola OA. J Pain Symptom Manage. 2009 Aug;38(2 Suppl):S28-38. .....................................41

Spinal cord stimulation: a 20-year retrospective analysis in 260 patients. Reig E, Abejón D. Neuromodulation. 2009 Jul;12(3):232-9. doi: 10.1111/j.1525-1403.2009.00220.x. .......42

Comprehensive evidence-based guidelines for interventional techniques in the management of chronic spinal pain.

Manchikanti L, Boswell MV, Singh V, Benyamin RM, Fellows B, Abdi S, Buenaventura RM, Conn A, Datta S, Derby R, Falco FJ, Erhart S, Diwan S, Hayek SM, Helm S, Parr AT, Schultz DM, Smith HS, Wolfer LR, Hirsch JA; ASIPP-IPM. Pain Physician. 2009 Jul-Aug;12(4):699-802. ........................................................42

Spinal cord stimulation as a novel approach to the treatment of refractory neuropathic mediastinal pain.

Guttman OT, Hammer A, Korsharskyy B. Pain Pract. 2009 Jul-Aug;9(4):308-11. Epub 2009 May 15. ......43

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Pretreatment psychosocial variables as predictors of outcomes following lumbar surgery and spinal cord stimulation: a systematic review and literature synthesis.

Celestin J, Edwards RR, Jamison RN. Pain Med. 2009 May-Jun;10(4):639-53. .........................................43

Demographic characteristics of patients with severe neuropathic pain secondary to failed back surgery syndrome.

Thomson S, Jacques L. Pain Pract. 2009 May-Jun;9(3):206-15. Epub 2009 Mar 5. ...................................44

Nonsurgical interventional therapies for low back pain: a review of the evidence for an American Pain Society clinical practice guideline.

Chou R, Atlas SJ, Stanos SP, Rosenquist RW. Spine (Phila Pa 1976). 2009 May 1;34(10):1078-93. .......44

Rare Side-effects during Spinal Cord Stimulation: Gastrointestinal Symptoms. La Grua M. Neuromodulation. 2009 Apr;12(2):161-3. doi: 10.1111/j.1525-1403.2009.00202.x. .................45

Modern potentialities of minimally invasive management of chronic non-malignant pain. [Article in Russian]

Seeleger A. Zh Vopr Neirokhir Im N N Burdenko. 2009 Apr-Jun;(2):42-6; discussion 46-8. .......................45

Spinal cord stimulation for chronic pain of neuropathic or ischaemic origin: systematic review and economic evaluation.

Simpson EL, Duenas A, Holmes MW, Papaioannou D, Chilcott J. Health Technol Assess. 2009 Mar;13(17):iii, ix-x, 1-154. .............................................................................................................................46

Spinal cord stimulation for patients with failed back surgery syndrome: a systematic review. Frey ME, Manchikanti L, Benyamin RM, Schultz DM, Smith HS, Cohen SP. Pain Physician. 2009 Mar-Apr;12(2):379-97...........................................................................................................................................46

Spinal cord stimulation: a basic approach. Brook AL, Georgy BA, Olan WJ. Tech Vasc Interv Radiol. 2009 Mar;12(1):64-70. .....................................47

Spinal cord stimulation compared with medical management for failed back surgery syndrome. Coleman SD, Mackey S. Curr Pain Headache Rep. 2009 Feb;13(1):1-2. ...................................................47

Spinal cord stimulation for complex regional pain syndrome. Shrivastav M, Musley S. Conf Proc IEEE Eng Med Biol Soc. 2009;2009:2033-6. ......................................47

Generating evidence on spinal cord stimulation for failed back surgery syndrome: not yet fully charged.

Chou R. Clin J Pain. 2008 Nov-Dec;24(9):757-8. ........................................................................................48

Systematic review of the (cost-)effectiveness of spinal cord stimulation for people with failed back surgery syndrome.

Bala MM, Riemsma RP, Nixon J, Kleijnen J. Clin J Pain. 2008 Nov-Dec;24(9):741-56. .............................48

Quality of life, resource consumption and costs of spinal cord stimulation versus conventional medical management in neuropathic pain patients with failed back surgery syndrome (PROCESS trial).

Manca A, Kumar K, Taylor RS, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Buchser E, Fortini G, Richardson J, Taylor RJ, Goeree R, Sculpher MJ. Eur J Pain. 2008 Nov;12(8):1047-58. Epub 2008 Mar 21......................................................................................48

Interventional pain therapy. [Article in Japanese] Hosokawa T. Masui. 2008 Nov;57(11):1379-87. ..........................................................................................49

Efficacy of a Single, Percutaneous, Across Midline, Octrode® Lead Using a "Midline Anchoring" Technique in the Treatment of Chronic Low Back and/or Lower Extremity Pain: A Retrospective Study.

Mironer YE, Satterthwaite JR, Lewis EM, Haasis JC, Latourette PC, Skoloff EM, Diaz RL. Neuromodulation. 2008 Oct;11(4):286-95. doi: 10.1111/j.1525-1403.2008.00178.x. ..................................49

The effects of spinal cord stimulation in neuropathic pain are sustained: a 24-month follow-up of the prospective randomized controlled multicenter trial of the effectiveness of spinal cord stimulation.

Kumar K, Taylor RS, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Buchser E, Fortini G, Richardson J, North RB. Neurosurgery. 2008 Oct;63(4):762-70; discussion 770. .............................................................................................................................................50

Spinal cord stimulation for failed back surgery syndrome--does it work and is it cost-effective?

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Sciubba DM, Gokaslan ZL. Nat Clin Pract Neurol. 2008 Sep;4(9):472-3. Epub 2008 Jul 22. .....................50

Spinal cord stimulation versus reoperation for failed back surgery syndrome: a cost effectiveness and cost utility analysis based on a randomized, controlled trial.

Wilkinson HA. Neurosurgery. 2008 Aug;63(2):E376; author reply E376. ....................................................51

Spinal Cord Stimulation Has Comparable Efficacy in Common Pain Etiologies. Krames ES, Oakley JC, Foster AM, Henderson J, Prager JP, Rashbaum RR, Stamatos J, Weiner RL. Neuromodulation. 2008 Jul;11(3):171-181. doi: 10.1111/j.1525-1403.2008.00163.x. .................................51

Use of spinal cord stimulator for treatment of lumbar radiculopathy in a patient with severe kyphoscoliosis.

Atallah J, Armah FA, Wong D, Weis PA, Fahy BG. Pain Physician. 2008 Jul-Aug;11(4):555-9. ................51

Reassessment of evidence synthesis of occupational medicine practice guidelines for interventional pain management.

Manchikanti L, Singh V, Derby R, Schultz DM, Benyamin RM, Prager JP, Hirsch JA. Pain Physician. 2008 Jul-Aug;11(4):393-482. .................................................................................................................................52

Epidural abscess due to spinal cord stimulator trial. Rauchwerger JJ, Zoarski GH, Waghmarae R, Rabinowitz RP, Kent JL, Aldrich EF, Closson CW. Pain Pract. 2008 Jul-Aug;8(4):324-8. Epub 2008 May 23. ...................................................................................53

A 50-year-old man with chronic low back pain. Rathmell JP. JAMA. 2008 May 7;299(17):2066-77. Epub 2008 Apr 1. ........................................................53

Efficacy of transverse tripolar spinal cord stimulator for the relief of chronic low back pain from failed back surgery.

Buvanendran A, Lubenow TJ. Pain Physician. 2008 May-Jun;11(3):333-8. ................................................53

Spinal cord stimulation in conjunction with peripheral nerve field stimulation for the treatment of low back and leg pain: a case series.

Bernstein CA, Paicius RM, Barkow SH, Lempert-Cohen C. Neuromodulation. 2008 Apr;11(2):116-23. doi: 10.1111/j.1525-1403.2008.00152.x. .............................................................................................................54

Rechargeable spinal cord stimulation versus non-rechargeable system for patients with failed back surgery syndrome: a cost-consequences analysis.

Hornberger J, Kumar K, Verhulst E, Clark MA, Hernandez J. Clin J Pain. 2008 Mar-Apr;24(3):244-52. ....54

Neurophysiological evidence of antidromic activation of large myelinated fibres in lower limbs during spinal cord stimulation.

Buonocore M, Bonezzi C, Barolat G. Spine (Phila Pa 1976). 2008 Feb 15;33(4):E90-3. ............................55

Functional magnetic resonance imaging of cerebral activation during spinal cord stimulation in failed back surgery syndrome patients.

Stancák A, Kozák J, Vrba I, Tintera J, Vrána J, Polácek H, Stancák M. Eur J Pain. 2008 Feb;12(2):137-48. Epub 2007 Oct 30. ........................................................................................................................................55

Lumbar post-laminectomy syndrome: II. Pain management using neuro-modulation techniques. [Article in Spanish]

Robaina Padrón FJ. Neurocirugia (Astur). 2008 Feb;19(1):35-44. ..............................................................56

Using image-guided techniques for chronic low back pain. Boyajian SS. J Am Osteopath Assoc. 2007 Nov;107(10 Suppl 6):ES3-9. ...................................................56

Spinal cord stimulation versus conventional medical management for neuropathic pain: a multicentre randomised controlled trial in patients with failed back surgery syndrome.

Kumar K, Taylor RS, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Buchser E, Fortini G, Richardson J, North RB. Pain. 2007 Nov;132(1-2):179-88. Epub 2007 Sep 12. .........................................................................................................................................................57

Spinal cord stimulation: stimulating questions. Turner JA, Deyo RA, Loeser JD. Pain. 2007 Nov;132(1-2):10-1. Epub 2007 Sep 12. ................................57

Squamous cell carcinoma occurring within incision of recently implanted spinal cord stimulator. Atallah J, Wainscott J, Sloan D, Moore K, Fahy BG. Pain Physician. 2007 Nov;10(6):771-4. ....................57

Spinal cord stimulation with interleaved pulses: a randomized, controlled trial. North RB, Kidd DH, Olin J, Sieracki JM, Boulay M. Neuromodulation. 2007 Oct;10(4):349-57. doi: 10.1111/j.1525-1403.2007.00123.x. .............................................................................................................58

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EFNS guidelines on neurostimulation therapy for neuropathic pain. Cruccu G, Aziz TZ, Garcia-Larrea L, Hansson P, Jensen TS, Lefaucheur JP, Simpson BA, Taylor RS. Eur J Neurol. 2007 Sep;14(9):952-70. ................................................................................................................58

Appetite suppression and weight loss incidental to spinal cord stimulation for pain relief. Pereira E, Foster A. Obes Surg. 2007 Sep;17(9):1272-4.............................................................................59

Spinal cord stimulation versus reoperation for failed back surgery syndrome: a cost effectiveness and cost utility analysis based on a randomized, controlled trial.

North RB, Kidd D, Shipley J, Taylor RS. Neurosurgery. 2007 Aug;61(2):361-8; discussion 368-9. ............59

Effects of spinal cord stimulation on the cortical somatosensory evoked potentials in failed back surgery syndrome patients.

Polácek H, Kozák J, Vrba I, Vrána J, Stancák A. Clin Neurophysiol. 2007 Jun;118(6):1291-302. Epub 2007 Apr 23. .................................................................................................................................................59

Spinal cord stimulation with a dual quadripolar surgical lead placed in general anesthesia is effective in treating intractable low back and leg pain.

Duyvendak W. Neuromodulation. 2007 Apr;10(2):113-9. doi: 10.1111/j.1525-1403.2007.00099.x. ...........60

Neurostimulation technology for the treatment of chronic pain: a focus on spinal cord stimulation. Foletti A, Durrer A, Buchser E. Expert Rev Med Devices. 2007 Mar;4(2):201-14. ......................................60

Interventional approaches to pain management. Markman JD, Philip A. Med Clin North Am. 2007 Mar;91(2):271-86. ..........................................................61

Neuromodulation of the cervical spinal cord in the treatment of chronic intractable neck and upper extremity pain: a case series and review of the literature.

Vallejo R, Kramer J, Benyamin R. Pain Physician. 2007 Mar;10(2):305-11. ...............................................61

Dual electrode spinal cord stimulation in chronic leg and back pain. Rainov NG, Demmel W, Heidecke V. Acta Neurochir Suppl. 2007;97(Pt 1):85-9. ......................................61

Spinal cord stimulation for failed back surgery syndrome and other disorders. Nicholson CL, Korfias S, Jenkins A. Acta Neurochir Suppl. 2007;97(Pt 1):71-7. ........................................62

Management of chronic severe pain: spinal neuromodulatory and neuroablative approaches. Raslan AM, McCartney S, Burchiel KJ. Acta Neurochir Suppl. 2007;97(Pt 1):33-41. .................................62

An introduction to operative neuromodulation and functional neuroprosthetics, the new frontiers of clinical neuroscience and biotechnology.

Sakas DE, Panourias IG, Simpson BA, Krames ES. Acta Neurochir Suppl. 2007;97(Pt 1):3-10. ...............63

Interventional techniques: evidence-based practice guidelines in the management of chronic spinal pain.

Boswell MV, Trescot AM, Datta S, Schultz DM, Hansen HC, Abdi S, Sehgal N, Shah RV, Singh V, Benyamin RM, Patel VB, Buenaventura RM, Colson JD, Cordner HJ, Epter RS, Jasper JF, Dunbar EE, Atluri SL, Bowman RC, Deer TR, Swicegood JR, Staats PS, Smith HS, Burton AW, Kloth DS, Giordano J, Manchikanti L; American Society of Interventional Pain Physicians. Pain Physician. 2007 Jan;10(1):7-111. ......................................................................................................................................................................63

Survey of the practice of spinal cord stimulators and intrathecal analgesic delivery implants for management of pain in Canada.

Peng PW, Fedoroff I, Jacques L, Kumar K. Pain Res Manag. 2007 Winter;12(4):281-5. ...........................64

Patient satisfaction with spinal cord stimulation for failed back surgery syndrome. [Article in Spanish]

De Andrés J, Quiroz C, Villanueva V, Valía JC, López Alarcón D, Moliner S, Monsalve V. Rev Esp Anestesiol Reanim. 2007 Jan;54(1):17-22. ..................................................................................................65

Neurostimulation in patients with chronic neuropathic pain in the so-called failed back surgery syndrome (world and the author's experience). [Article in Russian]

Zeeliger A, Bersnev VP. Zh Vopr Neirokhir Im N N Burdenko. 2007 Jan-Mar;(1):53-7; discussion 57-9. ...65

Spinal nerve root stimulation. Haque R, Winfree CJ. Neurosurg Focus. 2006 Dec 15;21(6):E4. ...............................................................65

Spinal cord stimulation: indications and outcomes. Lee AW, Pilitsis JG. Neurosurg Focus. 2006 Dec 15;21(6):E3. ...................................................................66

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Psychological factors in spinal cord stimulation therapy: brief review and discussion. Doleys DM. Neurosurg Focus. 2006 Dec 15;21(6):E1. ................................................................................66

Lumbar spinal cord stimulation can improve muscle strength and gait independently of the analgesic effect: a case report.

Buonocore M, Demartini L, Bonezzi C. Neuromodulation. 2006 Oct;9(4):309-13. doi: 10.1111/j.1525-1403.2006.00072.x. ......................................................................................................................................67

Failure modes of spinal cord stimulation hardware. Rosenow JM, Stanton-Hicks M, Rezai AR, Henderson JM. J Neurosurg Spine. 2006 Sep;5(3):183-90. ...67

Quantitative sensory testing for spinal cord stimulation in patients with chronic neuropathic pain. Eisenberg E, Backonja MM, Fillingim RB, Pud D, Hord DE, King GW, Stojanovic MP. Pain Pract. 2006 Sep;6(3):161-5. .............................................................................................................................................67

Peripheral nerve field stimulation in chronic abdominal pain. Paicius RM, Bernstein CA, Lempert-Cohen C. Pain Physician. 2006 Jul;9(3):261-6. .................................68

Prevention of percutaneous electrode migration in spinal cord stimulation by a modification of the standard implantation technique.

Renard VM, North RB. J Neurosurg Spine. 2006 Apr;4(4):300-3. ...............................................................68

Neurostimulation for chronic neuropathic back pain in failed back surgery syndrome. Van Buyten JP. J Pain Symptom Manage. 2006 Apr;31(4 Suppl):S25-9. ...................................................69

Spinal cord stimulation in complex regional pain syndrome and refractory neuropathic back and leg pain/failed back surgery syndrome: results of a systematic review and meta-analysis.

Taylor RS. J Pain Symptom Manage. 2006 Apr;31(4 Suppl):S13-9. ...........................................................69

Spinal cord stimulation in treatment of chronic benign pain: challenges in treatment planning and present status, a 22-year experience.

Kumar K, Hunter G, Demeria D. Neurosurgery. 2006 Mar;58(3):481-96; discussion 481-96. ....................69

Neural modulation by stimulation. De Andrés J, Van Buyten JP. Pain Pract. 2006 Mar;6(1):39-45. .................................................................70

Use of a tubular retractor system as a minimally invasive technique for epidural plate electrode placement under local anesthesia for spinal cord stimulation: technical note.

Beems T, van Dongen RT. Neurosurgery. 2006 Feb;58(1 Suppl):ONS-E177; discussion ONS-E177. ......70

Minimally invasive procedures for the treatment of failed back surgery syndrome. Mavrocordatos P, Cahana A. Adv Tech Stand Neurosurg. 2006;31:221-52. ..............................................71

Spinal cord stimulation for axial low back pain: a prospective controlled trial comparing 16-contact insulated electrodes with 4-contact percutaneous electrodes.

North RB, Kidd DH, Olin J, Sieracki JN, Petrucci L. Neuromodulation. 2006 Jan;9(1):56-67. doi: 10.1111/j.1525-1403.2006.00043.x. .............................................................................................................71

Spinal cord stimulation electrode design: a prospective, randomized, controlled trial comparing percutaneous with laminectomy electrodes: part II-clinical outcomes.

North RB, Kidd DH, Petrucci L, Dorsi MJ. Neurosurgery. 2005 Nov;57(5):990-6; discussion 990-6. ..........72

Spinal cord stimulation in Failed-Back-Surgery-Syndrome. Preliminary study for the evaluation of therapy by functional magnetic resonance imaging (fMRI). [Article in German]

Rasche D, Siebert S, Stippich C, Kress B, Nennig E, Sartor K, Tronnier VM. Schmerz. 2005 Nov;19(6):497-500, 502-5. ...........................................................................................................................72

Evaluation of a dual quadripolar surgically implanted spinal cord stimulation lead for failed back surgery patients with chronic low back and leg pain.

De Mulder PA, Rijdt BT, Veeckmans G, Belmans L. Neuromodulation. 2005 Oct;8(4):219-24. doi: 10.1111/j.1525-1403.2005.00028.x. .............................................................................................................73

Spinal Cord Stimulation vs. Conventional Medical Management: A Prospective, Randomized, Controlled, Multicenter Study of Patients with Failed Back Surgery Syndrome (PROCESS Study).

Kumar K, North R, Taylor R, Sculpher M, Van den Abeele C, Gehring M, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Fortini G, Richardson J, Buchser E, Tracey S, Reny P, Brookes M, Sabene S, Cano P, Banks C, Pengelly L, Adler R, Leruth S, Kelly C, Jacobs M. Neuromodulation. 2005 Oct;8(4):213-218. doi: 10.1111/j.1525-1403.2005.00027.x. ..................................73

Interventional pain management: an overview for primary care physicians.

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Boyajian SS. J Am Osteopath Assoc. 2005 Sep;105(9 Suppl 4):S1-6. .......................................................74

Spinal cord stimulation for failed back surgery syndrome: a decision-analytic model and cost-effectiveness analysis.

Taylor RJ, Taylor RS. Int J Technol Assess Health Care. 2005 Summer;21(3):351-8. ...............................74

Association between methodological characteristics and outcome in health technology assessments which included case series.

Stein K, Dalziel K, Garside R, Castelnuovo E, Round A. Int J Technol Assess Health Care. 2005 Summer;21(3):277-87. .................................................................................................................................74

Spinal cord stimulation. Costantini A. Minerva Anestesiol. 2005 Jul-Aug;71(7-8):471-4. ..................................................................75

Spinal cord stimulation for axial low back pain: a prospective, controlled trial comparing dual with single percutaneous electrodes.

North RB, Kidd DH, Olin J, Sieracki JM, Farrokhi F, Petrucci L, Cutchis PN. Spine (Phila Pa 1976). 2005 Jun 15;30(12):1412-8. ..................................................................................................................................75

Dual spinal cord stimulation for complex pain: preliminary study. Abejón D, Reig E, Del Pozo C, Contreras R, Insausti J. Neuromodulation. 2005 Apr;8(2):105-11. doi: 10.1111/j.1525-1403.2005.00226.x. .............................................................................................................76

Do the findings of case series studies vary significantly according to methodological characteristics?

Dalziel K, Round A, Stein K, Garside R, Castelnuovo E, Payne L. Health Technol Assess. 2005 Jan;9(2):iii-iv, 1-146. .....................................................................................................................................76

Spinal cord stimulation versus repeated lumbosacral spine surgery for chronic pain: a randomized, controlled trial.

North RB, Kidd DH, Farrokhi F, Piantadosi SA. Neurosurgery. 2005;56(1):98-106; discussion 106-7. ......77

Interventional techniques in the management of chronic spinal pain: evidence-based practice guidelines.

Boswell MV, Shah RV, Everett CR, Sehgal N, McKenzie Brown AM, Abdi S, Bowman RC 2nd, Deer TR, Datta S, Colson JD, Spillane WF, Smith HS, Lucas LF, Burton AW, Chopra P, Staats PS, Wasserman RA, Manchikanti L. Pain Physician. 2005 Jan;8(1):1-47. ....................................................................................78

Spinal cord stimulation for chronic back and leg pain and failed back surgery syndrome: a systematic review and analysis of prognostic factors.

Taylor RS, Van Buyten JP, Buchser E. Spine (Phila Pa 1976). 2005 Jan 1;30(1):152-60. .........................79

Improvement of muscle strenght independently of analgesic effect following spinal cord stimulation. A case report.

Buonocore M, Demartini L, Bonezzi C. Eura Medicophys. 2004 Dec;40(4):273-5. .....................................80

Multiple lead spinal cord stimulation for chronic mechanical low back pain: a comparative study with intrathecal opioid drug delivery.

Raphael JH, Southall JL, Gnanadurai TV, Treharne GJ, Kitas GD. Neuromodulation. 2004 Oct;7(4):260-6. doi: 10.1111/j.1094-7159.2004.04211.x. ......................................................................................................80

Spinal cord stimulation for refractory angina pectoris: a shocking experience. Murphy PM, Macsullivan R. Neuromodulation. 2004 Oct;7(4):246-8. doi: 10.1111/j.1094-7159.2004.04209.x. ......................................................................................................................................80

Cost-benefit evaluation of spinal cord stimulation treatment for failed-back surgery syndrome patients. [Article in French]

Blond S, Buisset N, Dam Hieu P, Nguyen JP, Lazorthes Y, Cantagrel N, Laugner B, Bellow F, Djian MC, Husson JL, Lapierre F, Blanc JL. Neurochirurgie. 2004 Sep;50(4):443-53. ................................................80

Neuropathic limb pain and spinal cord stimulation: results of the dutch prospective study. Spincemaille GH, Beersen N, Dekkers MA, Theuvenet PJ. Neuromodulation. 2004 Jul;7(3):184-92. doi: 10.1111/j.1094-7159.2004.04198.x. .............................................................................................................81

Do minimally invasive procedures have a place in the treatment of chronic low back pain? Cahana A, Mavrocordatos P, Geurts JW, Groen GJ. Expert Rev Neurother. 2004 May;4(3):479-90. ........81

Safety and efficacy of spinal cord stimulation for the treatment of chronic pain: a 20-year literature review.

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Cameron T. J Neurosurg. 2004 Mar;100(3 Suppl Spine):254-67. ...............................................................82

Prospective study of the success and efficacy of spinal cord stimulation. Allegri M, Arachi G, Barbieri M, Paulin L, Bettaglio R, Bonetti G, Demartini L, Violini A, Braschi A, Bonezzi C. Minerva Anestesiol. 2004 Mar;70(3):117-24. ...........................................................................................82

Spinal cord stimulation for patients with failed back surgery syndrome or complex regional pain syndrome: a systematic review of effectiveness and complications.

Turner JA, Loeser JD, Deyo RA, Sanders SB. Pain. 2004 Mar;108(1-2):137-47. .......................................83

Spinal cord stimulation in chronic pain: a review of the evidence. Carter ML. Anaesth Intensive Care. 2004 Feb;32(1):11-21. ........................................................................83

Spinal cord stimulation for chronic pain. Mailis-Gagnon A, Furlan AD, Sandoval JA, Taylor R. Cochrane Database Syst Rev. 2004;(3):CD003783. ......................................................................................................................................................................83

Spinal cord stimulation does not change peripheral skin blood flow in patients with neuropathic pain.

Ather M, Di Vadi P, Light D, Wedley JR, Hamann WC. Eur J Anaesthesiol. 2003 Sep;20(9):736-9. ..........84

Management of chronic limb pain with spinal cord stimulation. Fogel GR, Esses SI, Calvillo O. Pain Pract. 2003 Jun;3(2):144-51. ............................................................84

The performance and safety of an implantable spinal cord stimulation system in patients with chronic pain: a 5-year study.

Buyten JP. Neuromodulation. 2003 Apr;6(2):79-87. doi: 10.1046/j.1525-1403.2003.03012.x. ...................85

Spinal cord stimulation in chronic lumbar pain. [Article in Italian] Signorelli CD, Lavano A, Volpentesta G, Chirchiglia D, Signorelli F, Sibille M, Ferraro G, Veltri C, Aloisi M, Piragine G, Santangelo E, Pardatcher S, Pardatcher K. J Neurosurg Sci. 2003 Mar;47(1 Suppl 1):41-5. ..85

Spinal stimulation in failed back surgery syndrome [Article in Italian]

Meglio M, Papacci F. J Neurosurg Sci. 2003 Mar;47(1 Suppl 1):32-6. ........................................................85

Acute vs. Prolonged Screening for Spinal Cord Stimulation in Chronic Pain. Weinand ME, Madhusudan H, Davis B, Melgar M. Neuromodulation. 2003 Jan;6(1):15-9. doi: 10.1046/j.1525-1403.2003.03002.x. .............................................................................................................85

Dorsal column stimulation for lumbar spinal stenosis. Chandler GS 3rd, Nixon B, Stewart LT, Love J. Pain Physician. 2003 Jan;6(1):113-8. ..............................86

Spinal cord stimulation for chronic pain of spinal origin: a valuable long-term solution. North RB, Wetzel FT. Spine (Phila Pa 1976). 2002 Nov 15;27(22):2584-91; discussion 2592. ..................86

Spinal cord stimulation: mechanisms of action. Oakley JC, Prager JP. Spine (Phila Pa 1976). 2002 Nov 15;27(22):2574-83. ............................................87

Spinal cord stimulation (SCS) using an 8-pole electrode and double-electrode system as minimally invasive therapy of the post-discotomy and post-fusion syndrome--prospective study results in 34 patients. [Article in German]

Rütten S, Komp M, Godolias G. Z Orthop Ihre Grenzgeb. 2002 Nov-Dec;140(6):626-31. ..........................87

Spinal cord stimulation electrode design: prospective, randomized, controlled trial comparing percutaneous and laminectomy electrodes-part I: technical outcomes.

North RB, Kidd DH, Olin JC, Sieracki JM. Neurosurgery. 2002 Aug;51(2):381-9; discussion 389-90. .......88

Evolving patterns of spinal cord stimulation in patients implanted for intractable low back and leg pain.

Sharan A, Cameron T, Barolat G. Neuromodulation. 2002 Jul;5(3):167-79. doi: 10.1046/j.1525-1403.2002.02027.x. ......................................................................................................................................88

Treatment of chronic pain with spinal cord stimulation versus alternative therapies: cost-effectiveness analysis.

Kumar K, Malik S, Demeria D. Neurosurgery. 2002 Jul;51(1):106-15; discussion 115-6. ...........................89

Four Year Follow-up of Dual Electrode Spinal Cord Stimulation for Chronic Pain. Aló KM, Redko V, Charnov J. Neuromodulation. 2002 Apr;5(2):79-88. doi: 10.1046/j.1525-1403.2002.02017.x. ......................................................................................................................................90

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Spinal cord stimulation. Stojanovic MP, Abdi S. Pain Physician. 2002 Apr;5(2):156-66. ...................................................................90

Current and future trends in spinal cord stimulation for chronic pain. Deer TR. Curr Pain Headache Rep. 2001 Dec;5(6):503-9. .........................................................................91

Patient satisfaction with spinal cord stimulation for predominant complaints of chronic, intractable low back pain.

Ohnmeiss DD, Rashbaum RF. Spine J. 2001 Sep-Oct;1(5):358-63. ...........................................................91

Spinal cord stimulation for nonspecific limb pain versus neuropathic pain and spontaneous versus evoked pain.

Kim SH, Tasker RR, Oh MY. Neurosurgery. 2001 May;48(5):1056-64; discussion 1064-5. .......................92

Epidural spinal cord stimulation with a multiple electrode paddle lead is effective in treating intractable low back pain.

Barolat G, Oakley JC, Law JD, North RB, Ketcik B, Sharan A. Neuromodulation. 2001 Apr;4(2):59-66. doi: 10.1046/j.1525-1403.2001.00059.x. .............................................................................................................92

Outcomes of spinal cord stimulation: patient validation. Anderson VC, Carlson C, Shatin D. Neuromodulation. 2001 Jan;4(1):11-7. doi: 10.1046/j.1525-1403.2001.00011.x. ......................................................................................................................................93

Spinal cord stimulation for failed back surgery syndrome. Leveque JC, Villavicencio AT, Bulsara KR, Rubin L, Gorecki JP. Neuromodulation. 2001 Jan;4(1):1-9. doi: 10.1046/j.1525-1403.2001.00001.x. .............................................................................................................93

The efficacy of spinal cord stimulation for chronic pain. Kavar B, Rosenfeld JV, Hutchinson A. J Clin Neurosci. 2000 Sep;7(5):409-13. .........................................94

Treatment of Chronic Pain in Failed Back Surgery Patients with Spinal Cord Stimulation: a Review of Current Literature and Proposal for Future Investigation.

Wetzel FT, Hassenbusch S, Oakley JC, Willis KD, Simpson RK Jr, Ross EL. Neuromodulation. 2000 Apr;3(2):59-74. doi: 10.1046/j.1525-1403.2000.00059.x. ............................................................................94

Treatment of chronic pain by spinal cord stimulation. Tseng SH. J Formos Med Assoc. 2000 Mar;99(3):267-71. ..........................................................................94

Laminectomy versus percutaneous electrode placement for spinal cord stimulation. Villavicencio AT, Leveque JC, Rubin L, Bulsara K, Gorecki JP. Neurosurgery. 2000 Feb;46(2):399-405; discussion 405-6. ..........................................................................................................................................95

Hardware failures in spinal cord stimulation for failed back surgery syndrome. Heidecke V, Rainov NG, Burkert W. Neuromodulation. 2000 Jan;3(1):27-30. doi: 10.1046/j.1525-1403.2000.00027.x. ......................................................................................................................................95

Spinal cord stimulation for treatment of failed back surgery syndrome--two case reports. Vijayan R, Ahmad TS. Med J Malaysia. 1999 Dec;54(4):509-13. ................................................................96

Multiple Program Spinal Cord Stimulation in the Treatment of Chronic Pain: Follow-Up of Multiple Program SCS.

Aló KM, Yland MJ, Charnov JH, Redko V. Neuromodulation. 1999 Nov;2(4):266-72. doi: 10.1046/j.1525-1403.1999.00266.x. ......................................................................................................................................96

Treatment of failed back surgery syndrome patients with low back and leg pain: a pilot study of a new dual lead spinal cord stimulation system.

Van Buyten JP, Van Zundert J, Milbouw G. Neuromodulation. 1999 Nov;2(4):258-65. doi: 10.1046/j.1525-1403.1999.00258.x. ......................................................................................................................................96

Spinal Cord Stimulation for the Relief of Pain: Proceedings of a Symposium during the 4th International Congress of the International Neuromodulation Society, September 16-20, 1998, Lucerne, Switzerland.

Oakley JC. Neuromodulation. 1999 Jul;2(3):184-7. doi: 10.1046/j.1525-1403.1999.00184.x. ....................97

Spinal cord stimulation for failed back surgery syndrome: technical advances, patient selection and outcome.

North RB, Guarino AH. Neuromodulation. 1999 Jul;2(3):171-8. doi: 10.1046/j.1525-1403.1999.00171.x. .97

Spinal Cord Stimulation: Indications, Mechanism of Action, and Efficacy. Krames E. Curr Rev Pain. 1999;3(6):419-426. ............................................................................................97

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Lumbar and Sacral Nerve Root Stimulation (NRS) in the Treatment of Chronic Pain: A Novel Anatomic Approach and Neuro Stimulation Technique.

Alo KM, Yland MJ, Redko V, Feler C, Naumann C. Neuromodulation. 1999 Jan;2(1):23-31. doi: 10.1046/j.1525-1403.1999.00023.x. .............................................................................................................98

Efficacy of transverse tripolar stimulation for relief of chronic low back pain: results of a single center.

Slavin KV, Burchiel KJ, Anderson VC, Cooke B. Stereotact Funct Neurosurg. 1999;73(1-4):126-30. ........98

Epidural spinal cord stimulation for treatment of chronic pain--some predictors of success. A 15-year experience.

Kumar K, Toth C, Nath RK, Laing P. Surg Neurol. 1998 Aug;50(2):110-20; discussion 120-1. ..................98

Spinal cord stimulation revisited. Segal R, Stacey BR, Rudy TE, Baser S, Markham J. Neurol Res. 1998 Jul;20(5):391-6. ..........................99

Dual channel electrostimulation in pain. Devulder J, De Laat M, Rolly G. Acta Neurol Belg. 1998 Jun;98(2):195-8. ...............................................100

Pain management from the viewpoint of the anesthetist. [Article in German] Ingold O. Praxis (Bern 1994). 1998 Feb 11;87(7):232-7. ...........................................................................100

Psychological variables associated with outcome of spinal cord stimulation trials. Olson KA, Bedder MD, Anderson VC, Burchiel KJ, Villanueva MR. Neuromodulation. 1998 Jan;1(1):6-13. doi: 10.1111/j.1525-1403.1998.tb00025.x. .................................................................................................100

Spinal cord stimulation: a valuable treatment for chronic failed back surgery patients. Devulder J, De Laat M, Van Bastelaere M, Rolly G. J Pain Symptom Manage. 1997 May;13(5):296-301. ....................................................................................................................................................................101

Cost-effectiveness analysis of spinal cord stimulation in treatment of failed back surgery syndrome. Bell GK, Kidd D, North RB. J Pain Symptom Manage. 1997 May;13(5):286-95. .......................................101

Stimulation of the central and peripheral nervous system for the control of pain. Stanton-Hicks M, Salamon J. J Clin Neurophysiol. 1997 Jan;14(1):46-62. ...............................................102

Epidural spinal cord stimulation does not improve microvascular blood flow in neuropathic pain. Devulder J, Duprez D, De Laat M, Rolly G. Angiology. 1996 Dec;47(12):1145-9. ....................................102

Prospective, multicenter study of spinal cord stimulation for relief of chronic back and extremity pain.

Burchiel KJ, Anderson VC, Brown FD, Fessler RG, Friedman WA, Pelofsky S, Weiner RL, Oakley J, Shatin D. Spine (Phila Pa 1976). 1996 Dec 1;21(23):2786-94. .................................................................103

Infra-red thermographic evaluation of spinal cord electrostimulation in patients with chronic pain after failed back surgery.

Devulder J, Dumoulin K, De Laat M, Rolly G. Br J Neurosurg. 1996 Aug;10(4):379-83. ...........................103

Prognostic value of psychological testing in patients undergoing spinal cord stimulation: a prospective study.

North RB, Kidd DH, Wimberly RL, Edwin D. Neurosurgery. 1996 Aug;39(2):301-10; discussion 310-1. ..104

Short test-period spinal cord stimulation for failed back surgery syndrome. Rainov NG, Heidecke V, Burkert W. Minim Invasive Neurosurg. 1996 Jun;39(2):41-4. ............................104

Prospective outcome evaluation of spinal cord stimulation in patients with intractable leg pain. Ohnmeiss DD, Rashbaum RF, Bogdanffy GM. Spine (Phila Pa 1976). 1996 Jun 1;21(11):1344-50; discussion 1351. .........................................................................................................................................105

A psychoanalytic investigation to improve the success rate of spinal cord stimulation as a treatment for chronic failed back surgery syndrome.

Dumoulin K, Devulder J, Castille F, De Laat M, Van Bastelaere M, Rolly G. Clin J Pain. 1996 Mar;12(1):43-9. ...........................................................................................................................................105

Spinal cord stimulation for chronic low back pain: a systematic literature synthesis. Turner JA, Loeser JD, Bell KG. Neurosurgery. 1995 Dec;37(6):1088-95; discussion 1095-6. ..................106

Prognostic factors of spinal cord stimulation for chronic back and leg pain. Burchiel KJ, Anderson VC, Wilson BJ, Denison DB, Olson KA, Shatin D. Neurosurgery. 1995 Jun;36(6):1101-10; discussion 1110-1. ......................................................................................................106

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Significance of the spinal cord position in spinal cord stimulation. Holsheimer J, Barolat G, Struijk JJ, He J. Acta Neurochir Suppl. 1995;64:119-24. ...................................107

Treatment of the failed back surgery syndrome due to lumbo-sacral epidural fibrosis. Fiume D, Sherkat S, Callovini GM, Parziale G, Gazzeri G. Acta Neurochir Suppl. 1995;64:116-8. ..........107

Spinal cord stimulation versus spinal infusion for low back and leg pain. Hassenbusch SJ, Stanton-Hicks M, Covington EC. Acta Neurochir Suppl. 1995;64:109-15. ...................108

Spinal cord stimulation versus reoperation for failed back surgery syndrome: a prospective, randomized study design.

North RB, Kidd DH, Piantadosi S. Acta Neurochir Suppl. 1995;64:106-8. ................................................108

Treatment of chronic lumbago and radicular pain by spinal cord stimulation. Long-term results. [Article in French]

Hieu PD, Person H, Houidi K, Rodriguez V, Vallee B, Besson G. Rev Rhum Ed Fr. 1994 Apr;61(4):271-7. ....................................................................................................................................................................108

Long-term pain relief during spinal cord stimulation. The effect of patient selection. Van de Kelft E, De La Porte C. Qual Life Res. 1994 Feb;3(1):21-7. ..........................................................109

Italian multicentric study on pain treatment with epidural spinal cord stimulation. Broggi G, Servello D, Dones I, Carbone G. Stereotact Funct Neurosurg. 1994;62(1-4):273-8. ................109

A prospective, randomized study of spinal cord stimulation versus reoperation for failed back surgery syndrome: initial results.

North RB, Kidd DH, Lee MS, Piantodosi S. Stereotact Funct Neurosurg. 1994;62(1-4):267-72. ..............109

Spinal cord stimulation in low back and leg pain. Meglio M, Cioni B, Visocchi M, Tancredi A, Pentimalli L. Stereotact Funct Neurosurg. 1994;62(1-4):263-6. ....................................................................................................................................................................110

Spinal cord stimulation for the failed back syndrome. LeDoux MS, Langford KH. Spine (Phila Pa 1976). 1993 Feb;18(2):191-4. ...............................................110

Spinal cord stimulation in failed back surgery syndrome. De La Porte C, Van de Kelft E. Pain. 1993 Jan;52(1):55-61. .....................................................................110

Clinical and technical results from spinal stimulation for chronic pain of diverse pathophysiologies. Law JD. Stereotact Funct Neurosurg. 1992;59(1-4):21-4. .........................................................................111

Spinal neurostimulation for the treatment of chronic pain: changes in indications and patient selection after 19 years' experience. [Article in German]

Winkelmüller W. Schmerz. 1991 Dec;5(4):243-6. ......................................................................................111

Treatment of chronic pain by epidural spinal cord stimulation: a 10-year experience. Kumar K, Nath R, Wyant GM. J Neurosurg. 1991 Sep;75(3):402-7. .........................................................111

Failed back surgery syndrome: 5-year follow-up after spinal cord stimulator implantation. North RB, Ewend MG, Lawton MT, Kidd DH, Piantadosi S. Neurosurgery. 1991 May;28(5):692-9. .........112

Spinal cord stimulation in 60 cases of intractable pain. Simpson BA. J Neurol Neurosurg Psychiatry. 1991 Mar;54(3):196-9. .......................................................113

Spinal cord stimulation in chronic pain: evaluation of results, complications,and technical considerations in sixty-nine patients.

Devulder J, Vermeulen H, De Colvenaer L, Rolly G, Calliauw L, Caemaert J. Clin J Pain. 1991 Mar;7(1):21-8. .............................................................................................................................................113

Spinal cord stimulation for chronic, intractable pain: superiority of "multi-channel" devices. North RB, Ewend MG, Lawton MT, Piantadosi S. Pain. 1991 Feb;44(2):119-30. .....................................113

Dorsal column stimulation (DCS): cost to benefit analysis. Bel S, Bauer BL. Acta Neurochir Suppl (Wien). 1991;52:121-3. ................................................................114

Spinal cord stimulation for intractable pain: long-term follow-up. North RB. J Spinal Disord. 1990 Dec;3(4):356-61. ....................................................................................114

Spinal cord stimulation in 112 patients with epi-/intradural fibrosis following operation for lumbar disc herniation.

Probst C. Acta Neurochir (Wien). 1990;107(3-4):147-51. ..........................................................................114

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Spinal cord stimulation and surgical cordotomy for nerve root scars following herniated lumbar disk intervention. [Article in Italian]

Probst C. Clin Ter. 1989 Nov 15;131(3):145-7. ..........................................................................................114

Outcome of implanted spinal cord stimulation in the treatment of chronic pain: arachnoiditis versus single nerve root injury and mononeuropathy. Brief clinical note.

Meilman PW, Leibrock LG, Leong FT. Clin J Pain. 1989 Jun;5(2):189-93. ...............................................114

Spinal cord stimulation in management of chronic pain. A 9-year experience. Meglio M, Cioni B, Rossi GF. J Neurosurg. 1989 Apr;70(4):519-24. .........................................................115

Posterior spinal cord neurostimulation in lumbar radiculitis pain. Apropos of 14 cases. [Article in French]

Batier C, Frerebeau P, Kong A Siou D, Privat JM, Roquefeuil B, Seignarbieux F, Sergent P. Agressologie. 1989 Mar;30(3):137-8. ................................................................................................................................115

Spinal cord stimulation in chronic pain therapy. Devulder J, De Colvenaer L, Rolly G, Caemaert J, Calliauw L, Martens F. Clin J Pain. 1990 Mar;6(1):51-6. ....................................................................................................................................................................115

Dorsal column stimulation: its application in pain therapy. Devulder J. Acta Anaesthesiol Belg. 1989;40(2):121-2. ............................................................................116

Chronic medullary neuro-stimulation in lumbosacral spinal arachnoiditis. [Article in French] Fassio B, Sportes J, Romain M, Vallespir R. Rev Chir Orthop Reparatrice Appar Mot. 1988;74(5):473-9. ....................................................................................................................................................................116

Dorsal column stimulation (DCS) in chronic pain: report of 31 cases. Mittal B, Thomas DG, Walton P, Calder I. Ann R Coll Surg Engl. 1987 May;69(3):104-9. ........................116

Dorsal column stimulation in pain treatment. Wester K. Acta Neurol Scand. 1987 Feb;75(2):151-5. ...............................................................................116

Targeting a spinal stimulator to treat the 'failed back surgery syndrome'. Law JD. Appl Neurophysiol. 1987;50(1-6):437-8. ......................................................................................116

Totally implantable spinal cord stimulation for chronic pain: design and efficacy. Shatin D, Mullett K, Hults G. Pacing Clin Electrophysiol. 1986 Jul;9(4):577-83. .......................................117

Spinal cord stimulation in the treatment of chronic back and lower extremity pain syndromes. Leibrock LG, Meilman P, Cuka D, Green C. Nebr Med J. 1984 Jun;69(6):180-3. .....................................117

Lumbosacral spinal fibrosis (spinal arachnoiditis). Its diagnosis and treatment by spinal cord stimulation.

de la Porte C, Siegfried J. Spine (Phila Pa 1976). 1983 Sep;8(6):593-603. ..............................................117

Epidural nerve stimulation of the lower spinal cord and cauda equina for the relief of intractable pain in failed low back surgery.

Blume H, Richardson R, Rojas C. Appl Neurophysiol. 1982;45(4-5):456-60. ............................................117

Epidural dorsal column stimulation for relief of intractable pain. Kaufmann GE. J Med Assoc Ga. 1978 Nov;67(11):902-3. ........................................................................117

Safety and clinical efficacy. Burton CV. Neurosurgery. 1977 Sep-Oct;1(2):214-5. ................................................................................118

Safety and clinical efficacy of implanted neuroaugmentive spinal devices for the relief of pain. Burton CV. Appl Neurophysiol. 1977-1978;40(2-4):175-83. ......................................................................118

Delayed intraspinal hemorrhage after dorsal column stimulation for pain. Grillo PJ, Yu HC, Patterson RH Jr. Arch Neurol. 1974 Jan;30(1):105-6. ...................................................118

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Spinal Cord Stimulation Spinal cord stimulation for cancer-related low back pain.

Yakovlev AE, Resch BE. Am J Hosp Palliat Care. 2012 Mar;29(2):93-7. Epub 2011 Jun 13. Comprehensive Pain Management of the Fox Valley, SC, Appleton, WI, USA. aeyakovlev@yahoo.com

OBJECTIVE: At least one third of patients with cancer have pain at the time of their diagnosis. In an attempt to provide increased pain relief for patients with intractable cancer pain, unconventional agents and interventional procedures including spinal cord stimulation (SCS) have received considerable attention. METHODS: Patients with cancer-related low back pain underwent an uneventful SCS trial with percutaneous placement of 2 temporary 8-electrode leads placed at the level of T8-T9-T10. RESULTS: After experiencing excellent pain relief during the 2-day trial, patients were subsequently implanted with permanent leads and generator with sustained pain relief at 12 months postoperation. CONCLUSION: Spinal cord stimulation provides an effective, alternative treatment option for select patients with cancer-related pain who have failed conservative treatment. ______________________________________________________________________________ Triangular stimulation method utilizing combination spinal cord

stimulation with peripheral subcutaneous field stimulation for

chronic pain patients: a retrospective study.

Navarro RM, Vercimak DC. Neuromodulation. 2012 Mar;15(2):124-31. doi: 10.1111/j.1525-1403.2011.00422.x. Epub 2012 Feb 13. Memorial Hospital of South Bend, Pain Control Center, South Bend, Indiana, USA.

Objectives: This retrospective data collection study aims to evaluate the responses of patients who have been implanted with a neuromodulation system using a combination of spinal cord stimulation (SCS) and peripheral subcutaneous field stimulation (PSFS) leads for chronic intractable pain. Materials and Methods: Forty patients with chronic, intractable pain implanted with both SCS and PSFS leads were enrolled in a retrospective data collection study. Pre-implant data (demographics, pain levels, pain location, and medication use) and post-implant data (pain levels, medication use, and device programming reports) were compared to measure short- and long-term improvements in pain for a period of approximately six months. Device system use and parameter data were collected. Results: The majority of patients experienced immediate and short-term pain relief and reduction in oral pain medications as a result of combination SCS/PSFS therapy. The improvements were maintained for some, but not all patients by six months. Patients cycled through multiple programs over follow-up; the use of triangular stimulation was consistent over time, and by six months, patients preferred this program over others. Limitations of the retrospective chart review included missing data and variable follow-up times, and may have made determinations of long-term efficacy difficult. Conclusions: This study demonstrates that combination SCS and PSFS therapy is potentially a beneficial treatment option for reducing pain levels and oral pain medication compared with baseline in previously resistive chronic pain patients. There is a need for further study of this therapy in a greater number of subjects and in a prospective, controlled setting. In the author's general experience, triangular stimulation is very effective for treating isolated low back pain, because it covers larger topographic areas of the lower back than flow or field stimulation. An investigational device exemption study will be necessary for subcutaneous field stimulation indicated for focal isolated pain to be adequately investigated and utilized by physicians in the future. ______________________________________________________________________________ Spinal cord stimulation with hybrid lead relieves pain in low back

and legs.

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de Vos CC, Dijkstra C, Lenders MW, Holsheimer J. Neuromodulation. 2012 Mar;15(2):118-23. doi: 10.1111/j.1525-1403.2011.00404.x. Epub 2011 Nov 10. Department of Neurosurgery, Medisch Spectrum Twente Hospital, Enschede, The Netherlands; MIRA-Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands; Stichting the Neurobionics Foundation, Enschede, The Netherlands.

Objective: The failed back surgery syndrome (FBSS) is the most common chronic pain syndrome. Whereas it is relatively easy to achieve pain relief in the lower limbs of FBSS patients with spinal cord stimulation (SCS), it is difficult to manage low back pain with SCS. The performance of a paddle-shaped SCS lead that can be inserted surgically as well as percutaneously (a hybrid lead) was evaluated in a prospective study on the relief of low back pain and leg pain in patients with FBSS. Materials and Methods: Patients with FBSS being eligible for SCS were enrolled in the study, and a hybrid lead was placed surgically. Outcome measures included pain scores for low back and leg pain assessed by visual analog scale (VAS), pain medication, and patient satisfaction. These scores were assessed before and at regular intervals after implantation. Results: It was shown that a single hybrid lead, generally positioned over the physiological midline of the spinal cord, is capable of alleviating both low back and leg pain in patients with FBSS. Forty-five subjects were eligible for SCS and received trial stimulation. Forty-two of them had a successful trial period and were converted to a permanent system. Their average VAS score at baseline was 8.0 for lower limb pain and 7.5 for low back pain. After six months of SCS, these average VAS scores were reduced to 3.2 and 3.5, respectively, and also pain medication was reduced significantly. Conclusion: SCS with a hybrid lead in subjects with FBSS is safe, and causes significant pain relief in both the low back and the lower limbs. ______________________________________________________________________________ Subcutaneous Stimulation as an Additional Therapy to Spinal Cord

Stimulation for the Treatment of Lower Limb Pain and/or Back Pain:

A Feasibility Study.

Hamm-Faber TE, Aukes HA, de Loos F, Gültuna I. Neuromodulation. 2012 Mar;15(2):108-17. doi: 10.1111/j.1525-1403.2011.00393.x. Epub 2011 Sep 21. Albert Schweitzer Hospital, Pain Treatment Center, Dordrecht, The Netherlands; and Optimal Care Pain Clinic, Rotterdam, The Netherlands.

Objective: The objective of this study was to demonstrate the efficacy of subcutaneous stimulation (SubQ) as an additional therapy in patients with failed back surgery syndrome (FBSS) with chronic refractory pain, for whom spinal cord stimulation (SCS) was unsuccessful in treating low back pain. Study Design: Case series. Materials and Methods: FBSS patients with chronic limb and/or low back pain whose conventional therapies had failed received a combination of SCS (8-contact Octad lead) and/or SubQ (4-contact Quad Plus lead(s)). Initially leads were placed in the epidural space for SCS for a trial stimulation to assess response to suppression of limb and low back pain. Where SCS alone was insufficient in treating lower back pain, leads were placed superficially in the subcutaneous tissue of the lower back, directly in the middle of the pain area. A pulse generator was implanted if patients reported more than 50% pain relief during the trial period. Pain intensity for limb and lower back pain was scored separately, using visual analog scale (VAS). Pain and Quebec Back Pain Disability Scale (QBPDS) after 12-month treatment were compared with pain and QBPDS at baseline. Results: Eleven FBSS patients, five male and six female (age: 51 ± 8 years; mean ± SD), in whom SCS alone was insufficient in treating lower back pain, were included. In nine cases, SubQ was used in combination with SCS to treat chronic lower back and lower extremity pain. In two cases only SubQ was used to treat lower back pain. SCS significantly reduced limb pain after 12 months (VAS(bl) : 62 ± 14 vs. VAS(12m) : 20 ± 11; p= 0.001, N= 8). SubQ stimulation significantly reduced low back pain after 12 months (VAS(bl) : 62 ± 13.0 vs. VAS(12m) : 32 ± 16; p= 0.0002, N= 10). Overall pain medication was reduced by more than 70%. QBPDS improved from 61 ± 15 to 49 ± 12 (p= 0.046, N= 10). Furthermore, we observed that two patients returned to work. Conclusion: SubQ may be an effective additional treatment for chronic low back pain in patients with FBSS for whom SCS alone is insufficient in alleviating their pain symptoms. ______________________________________________________________________________

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Back pain: a real target for spinal cord stimulation?

Rigoard P, Delmotte A, D'Houtaud S, Misbert L, Diallo B, Roy-Moreau A, Durand S, Royoux S, Giot JP, Bataille B. Neurosurgery. 2012 Mar;70(3):574-84; discussion 584-5. Department of Neurosurgery, Poitiers University School of Medicine, Poitiers, France. p.rigoard@chu-poitiers.fr

BACKGROUND: Failed back surgery syndrome represents one of the most frequent etiologies of chronic back pain and is a major public health issue. Neurostimulation has currently not been validated in the treatment of back pain because of technological limitations in implantable spinal cord stimulation (SCS) systems. New-generation leads using several columns of stimulation can generate longitudinal and/or transverse stimulation fields into the spinal cord. OBJECTIVE: To investigate, through extensive stimulation testing, the capacity of multicolumn tripolar leads to achieve back territory paresthesia coverage in refractory failed back surgery syndrome patients. METHODS: Eleven patients implanted with a 16-contact spinal cord stimulation lead (Specify 5-6-5, Medtronic Inc) were assessed with a systematic exploration of 43 selected stimulation configurations to generate bilateral back paresthesia in addition to leg territory coverage. RESULTS: The tripolar lead successfully generated paresthesia in both bilateral back and leg territories in 9 patients (81.8%). Success rates of multicolumn stimulation patterns were significantly higher than for longitudinal configurations for lombodorsal paresthesia coverage. Six months after implantation, significant pain relief was obtained compared with preoperative evaluation for global pain (Visual Analog Scale, 2.25 vs 8.2 preoperatively; P < .05), leg pain (Visual Analog Scale, 0.5 vs 7.6 preoperatively; P < .05), and back pain (Visual Analog Scale, 1.5 vs 7.8 preoperatively; P < .05). CONCLUSION: These results suggest that multicolumn leads can reliably generate back pain coverage and favor pain relief outcomes. This may lead physicians to reconsider new indications for spinal cord stimulation. Expanding neurostimulation perspectives to intractable back pain syndromes could become realistic in the near future. ______________________________________________________________________________ Is spinal cord stimulation an effective treatment option for

discogenic pain?

Vallejo R, Zevallos LM, Lowe J, Benyamin R. Pain Pract. 2012 Mar;12(3):194-201. doi: 10.1111/j.1533-2500.2011.00489.x. Epub 2011 Jul 29. Pain Medicine Physician, Millennium Pain Center, Bloomington, Illinois 61701, USA. vallejo@millenniumpaincenter.com

INTRODUCTION: In a prospective observational study conducted in an urban pain management center, we evaluated whether spinal cord stimulation (SCS) is effective in relieving discogenic pain of IDD origin. METHODS: Thirteen patients with intractable discogenic low back pain were enrolled. Four patients never underwent permanent implantation due to insurance denial, medical reasons or failed trial and served as a control group. Nine patients underwent SCS implantation (treatment group). All patients were followed for 12 months and assessed at each interval for pain (NRS), disability (ODI), and opioid use. RESULTS: Nine patients completed the SCS trial with > 50% pain relief. The pretrial NRS score was 7.8 ± 0.5 mm in treated patients vs. 6.5 ± 1.7 mm in control patients. At 3, 6 and 12 months, the NRS was reduced to 2.9 ± 0.7 mm, 1.7 ± 0.5 mm, and 2.9 ± 0.5 mm, respectively in treated patients. NRS was unchanged in the control patients (6.5 ± 1.9 mm). The ODI score prior to the SCS trial in treated patients was 53.1 ± 3.4% vs. 54.0 ± 20.5 in control patients. At 3, 6 and 12 months the ODI scores were 39.0 ± 8.0%, 38.7 ± 4.6%, and 41.1 ± 3.9%, respectively in the treated patients, and 48.5 ± 29.5 at 12 months in control patients. In 6 patients receiving opioids prior to the SCS trial, average consumption was reduced by 69% (P = 0.036) over 12 months of therapy as compared with a 54% increase in the control patients. SCS usage was stable over the 12-month study. CONCLUSIONS: The current study indicates that SCS may provide effective pain relief, improve disability, and reduce opioid usage in patients with discogenic pain. ______________________________________________________________________________ Treatment of Multifocal Pain with Spinal Cord Stimulation.

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Yakovlev AE, Resch BE. Neuromodulation. 2012 Feb 29. doi: 10.1111/j.1525-1403.2012.00435.x. [Epub ahead of print] Comprehensive Pain Management of the Fox Valley, SC, Appleton, WI, USA.

Introduction: We report a retrospective case study of combined treatment of cancer-related pain and chronic low back and lower extremity pain related to postlaminectomy syndrome (PLS) with one spinal cord stimulation (SCS) system. Methods: The patient underwent an uneventful SCS trial with percutaneous placement of two temporary eight-electrode leads (Medtronic Inc., Minneapolis, MN) placed at the level of T8-T9-T10 and T5-T6-T7. Results: After successful trial, he was implanted with permanent leads and generator, reporting sustained pain relief at 12-month follow-up visit. Discussion: SCS is a trialable, reversible, and interactive therapy permitting patients to control the level of stimulation they feel based on their degree of pain. Conclusion: SCS provides an effective, alternative treatment for select patients with cancer-related chest wall pain and pain related to PLS who have failed conservative treatment. ______________________________________________________________________________ Spinal cord stimulation: a review.

Compton AK, Shah B, Hayek SM. Curr Pain Headache Rep. 2012 Feb;16(1):35-42. SMC Pain Center, Schneck Medical Center, 411 West Tipton Street, Seymour, IN 47274, USA.

Spinal cord stimulation (SCS) is a safe and effective treatment of a variety of chronic pain conditions. As our understanding of the mechanisms of action and potential uses of SCS has evolved, clinical and technological advancements have followed. This review provides an overview of potential mechanisms of action of SCS, evidence for its effectiveness, potential complications, and highlights of developing areas of interest. ______________________________________________________________________________ Managing chronic pain with spinal cord stimulation.

Epstein LJ, Palmieri M. Mt Sinai J Med. 2012 Jan-Feb;79(1):123-32. doi: 10.1002/msj.21289. Department of Anesthesiology, Mount Sinai School of Medicine, New York, NY, USA. lawrence.epstein@mountsinai.org

Since its introduction as a procedure of last resort in a terminally ill patient with intractable cancer-related pain, spinal cord stimulation has been used to effectively treat chronic pain of varied origins. Spinal cord stimulation is commonly used for control of pain secondary to failed back surgery syndrome and complex regional pain syndrome, as well as pain from angina pectoris, peripheral vascular disease, and other causes. By stimulating one or more electrodes implanted in the posterior epidural space, the patient feels paresthesias in their areas of pain, which reduces the level of pain. Pain is reduced without the side effects associated with analgesic medications. Patients have improved quality of life and improved function, with many returning to work. Spinal cord stimulation has been shown to be cost effective as compared with conservative management alone. There is strong evidence for efficacy and cost effectiveness of spinal cord stimulation in the treatment of pain associated with intractable angina, failed back surgery syndrome, and complex regional pain syndrome. In this article, we review the history and pathophysiology of spinal cord stimulation, and the evidence (or lack thereof) for efficacy in common clinical practice. ______________________________________________________________________________ A prospective, open-label, multicenter study to assess the

efficacy of spinal cord stimulation and identify patients who

would benefit.

Moriyama K, Murakawa K, Uno T, Oseto K, Kawanishi M, Saito Y, Taira T, Yamauchi M. Neuromodulation. 2012 Jan-Feb;15(1):7-11; discussion 12. doi:10.1111/j.1525-1403.2011.00411.x. Epub 2011 Dec 12. Department of Pain Medicine, Hyogo College of Medicine, Hyogo, Japan. pain-med@hyo-med.ac.jp

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OBJECTIVE: To identify patients likely to benefit from spinal cord stimulation (SCS). Materials and METHODS: This multicenter, prospective, open-label study included medical centers experienced in SCS therapy, carried out in 13 physicians in seven centers. We recruited 55 patients with complex regional pain syndrome, failed back surgery syndrome, or peripheral vascular disease. Neurostimulators were implanted in 34 patients found to respond to SCS in a preliminary test, who were then followed for six months. Thirty-four patients scored their pain on a visual analog scale (VAS) and completed the EuroQol-5D questionnaire before and after test stimulation and after one and six months. RESULTS: During test stimulation, the mean VAS and quality of life (QOL) scores improved from 74.0 to 23.4 and from 0.430 to 0.664, respectively, in the 34 patients. At six months, the mean VAS score was 29.7 in 29 patients and the mean QOL score was 0.661 in 31 patients. CONCLUSION: SCS may improve pain management and QOL. ______________________________________________________________________________ Cephalad lead migration following spinal cord stimulation

implantation.

McGreevy K, Williams KA, Christo PJ. Pain Physician. 2012 Jan-Feb;15(1):E79-87. The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.

Lead migration (LM) is the most common complication after spinal cord stimulation (SCS). Although multiple reports of caudad LM have been described, cephalad LM has not been reported. Here we describe a case in which a stimulator lead migrates in the cephalad direction. A 60-year-old male with failed back surgery syndrome underwent SCS lead implantation via a dual lead approach to the top of vertebral body (VB) T9. A standard strain relief loop was used for each lead in the paramedian pocket. Postoperative testing revealed 100% paresthesia coverage of the painful areas. For the first 4 days, the patient continued to have excellent coverage; however, by the seventh day, the paresthesias ascended to above the nipple line. At the 2-week follow-up, cephalad migration of the left lead to the top of VB T1 was confirmed on fluoroscopy. The patient underwent successful lead revision in which a single paramedian incision technique was used to place extra sutures and a "figure-of-eight" strain relief loop. We provide the first case report of significant cephalad LM following SCS lead implantation. This migration can occur despite the use of current standard anchoring techniques. Additional investigation into the mechanism of such LM and lead-securing techniques is warranted. ______________________________________________________________________________ The impact of spinal cord stimulation on physical function and

sleep quality in individuals with failed back surgery syndrome: A

systematic review.

Kelly GA, Blake C, Power CK, O'Keeffe D, Fullen BM. Eur J Pain. 2011 Dec 21. doi: 10.1002/j.1532-2149.2011.00092.x. [Epub ahead of print] UCD School of Public Health, Physiotherapy and Population Science, Health Sciences Centre, University College Dublin, Ireland.

The aim of this review was to determine the impact of spinal cord stimulation (SCS) on physical function and sleep quality in individuals with failed back surgery syndrome (FBSS). This review comprised three phases: an electronic database search (PubMed, Cinahl Plus, EMBASE, PsychInfo, Pedro, Cochrane Library) identified potential papers; these were screened for inclusion criteria, with extraction of data from accepted papers and rating of internal validity by two independent reviewers using the Effective Public Health Practice Project quality assessment tool, a tool designed to assess non-RCTs (randomized controlled trials) as well as RCTs. Strength of the evidence was rated using the Agency for Health Care Policy and Research guidelines. The search generated 13 quantitative papers that fulfilled the inclusion criteria; all 13 studies investigated the impact of SCS on physical function, and nine studies investigated the impact of SCS on sleep quality. Consistent evidence (level C) found that SCS positively affected physical function, with improvements in participation in activities of daily living, leisure, social and work-related activities. Similarly, consistent evidence (level C) found improvements in sleep quality following SCS. Improvements in sleep quantity, a reduction in awakenings and a decrease in sleep

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medication use were also noted (level D). The impact of SCS on cognitive function, i.e., memory and concentration, was also assessed using the same search strategy, no papers fulfilled the inclusion criteria for this study. Spinal cord stimulation effectively addressed many physical function and sleep problems associated with FBSS; however, there is a need for further high-quality objective investigations to support this. ______________________________________________________________________________ Costs and cost-effectiveness of spinal cord stimulation (SCS) for

failed back surgery syndrome: an observational study in a workers'

compensation population.

Hollingworth W, Turner JA, Welton NJ, Comstock BA, Deyo RA. Spine (Phila Pa 1976). 2011 Nov 15;36(24):2076-83. Department of Social Medicine, University of Bristol, Bristol, England. william.hollingworth@bristol.ac.uk

STUDY DESIGN: Prospective cohort study. OBJECTIVE: We estimated the cost-effectiveness of spinal cord stimulation (SCS) among workers' compensation recipients with failed back surgery syndrome (FBSS). SUMMARY OF BACKGROUND DATA: Randomized controlled trial (RCT) evidence suggests that SCS is more effective at 6 months than medical management for patients with FBSS. However, procedure costs are high and workers' compensation claimants often have worse outcomes than other patients. METHODS: We enrolled 158 FBSS patients receiving workers' compensation into three treatment groups: trial SCS with or without permanent device implant (n = 51), pain clinic (PC) evaluation with or without treatment (n = 39), and usual care (UC; n = 68). The primary outcome was a composite measure of pain, disability and opioid medication use. As reported previously, 5% of SCS patients, 3% of PC patients and 10% of UC patients achieved the primary outcome at 24 months. Using cost data from administrative databases, we calculated the cost-effectiveness of SCS, adjusting for baseline covariates. RESULTS: Mean medical cost per SCS patient over 24 months was $52,091. This was $17,291 (95% confidence intervals [CI], $4100-30,490) higher than in the PC group and $28,128 ($17,620-38,630) higher than in the UC group. Adjusting for baseline covariates, the mean total medical and productivity loss costs per patient of the SCS group were $20,074 ($3840-35,990) higher than those of the PC group and $29,358 ($16,070-43,790) higher than those of the UC group. SCS was very unlikely (<5% probability) to be the most cost-effective intervention. CONCLUSION: In this sample of workers' compensation recipients, the high procedure cost of SCS was not counterbalanced by lower costs of subsequent care, and SCS was not cost-effective. The benefits and potential cost savings reported in RCTs may not be replicated in workers' compensation patients treated in community settings. ______________________________________________________________________________ A Unique Approach to Neurostimulation in Patients With Previous

Two-Segment Spine Surgery and Obstruction of Epidural Access for

Spinal Cord Stimulation: A Case Series.

Mironer YE, Hodge PJ, Parrott JT, Lal S, Latourette PC. Neuromodulation. 2011 Oct 25. doi: 10.1111/j.1525-1403.2011.00397.x. [Epub ahead of print] Carolinas Center for Advanced Management of Pain, NC-SC, Spartanburg, SC, USA Southeastern Neurosurgical & Spine Institute, Greenville, SC, USA Orthopedic & Spine Surgeons of SC, Columbia, SC, USA Carolina Neurosurgery, Greenwood, SC, USA.

Introduction: Patients with extensive surgery in the lumbar and thoracic spine are often not considered for neurostimulation due to the inability to perform a conventional spinal cord stimulation (SCS) trial. We are presenting six such patients in which spinal-peripheral neurostimulation (SPN) was used via a caudal approach. Methods: Six patients with intractable low back and leg pain following extensive lumbar and thoracic surgeries, up to at least the T10 level, underwent a stimulation trial with one caudal lead and one subcutaneous lead in order to achieve SPN. Results: In five cases, the trial was successful with coverage of the pain area and at least satisfactory pain relief. All six patients were implanted with a paddle lead(s) and a subcutaneous lead using SPN with good pain control. Conclusion: SPN with a caudal lead

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appears to be a viable option for SCS trial in patients with no possibilities for conventional trial lead placement. ______________________________________________________________________________ Invasive brain stimulation for the treatment of neuropathic pain.

Nguyen JP, Nizard J, Keravel Y, Lefaucheur JP. Nat Rev Neurol. 2011 Sep 20;7(12):699-709. doi: 10.1038/nrneurol.2011.138.

Service de Neurochirurgie, Center Hospitalo-Universitaire de Nantes, Hôpital Nord Laënnec, Boulevard Jacques Monod, Saint-Herblain, 44093 Nantes Cedex 1, France. jeanpaul.nguyen@chu-nantes.fr

Neurostimulation therapy is indicated for neuropathic pain that is refractory to medical treatment, and includes stimulation of the dorsal spinal cord, deep brain structures, and the precentral motor cortex. Spinal cord stimulation is validated in the treatment of selected types of chronic pain syndromes, such as failed back surgery syndrome. Deep brain stimulation (DBS) has shown promise as a treatment for peripheral neuropathic pain and phantom limb pain. Compared with DBS, motor cortex stimulation (MCS) is currently more frequently used, mainly because it is more easily performed, and has a wider range of indications (including central poststroke pain). Controlled trials have demonstrated the efficacy of MCS in the treatment of various types of neuropathic pain, although these trials included a limited number of patients and need to be confirmed by large, controlled, multicenter studies. Despite technical progress in neurosurgical navigation, results from studies of MCS are variable, and validated criteria for selecting good candidates for implantation are lacking. However, the evidence in favor of MCS is sufficient to include it in the range of therapeutic options for refractory neuropathic pain. In this Review, the respective efficacies and mechanisms of action of DBS and MCS are discussed. ______________________________________________________________________________ Results of neuromodulation for the management of chronic pain.

Sokal P, Harat M, Paczkowski D, Rudaś M, Birski M, Litwinowicz A. Neurol Neurochir Pol. 2011 Sep-Oct;45(5):445-51. Department of Neurosurgery, 10th Militray Clinical Hospital, Bydgoszcz, Poland. psokal@wp.pl

Background and purpose: Neuromodulative treatment of chronic pain syndromes is a modern mode of treatment of neuropathic and ischaemic pain. Its effectiveness is well documented in the literature. The objective of this work is to present the results of treatment of chronic pain syndromes on the basis of eight-year experience in our department. Material and methods : Since 2002, we have conducted 9 operations of motor cortex stimulation (MCS), 2 of deep brain stimulation (DBS), 45 of spinal cord stimulation (SCS) and 5 of sacral root stimulation (SRS) in the treatment of chronic pain. Results : We obtained good long-term results of neuromodulation in the form of clinical improvement (> 50%) in 4 of 9 patients with MCS (44%), in 13 diagnosed with failed back surgery syndrome (FBSS), 8 with other neuropathic pain, and 11 with angina pectoris from a group of 45 treated with SCS. Sacral root stimulation has been successful in 3 of 5 patients with perianal pain. The best treatment results in SCS, although not statistically significant, were observed in patients treated due to FBSS (13 out of 15) and angina pectoris (11 out of 15) (p = 0.12). In patients with neuropathic pain, peripheral and central, improvement was obtained in 8 out of 15 patients. Conclusions : A good indication for spinal cord stimulation is FBSS and angina pectoris. Motor cortex stimulation is helpful in the treatment of chronic central neuropathic pain. Further observations and a larger group of patients are necessary for a reliable assessment of the effectiveness of neuromodulative treatment of chronic pain in our clinic. ______________________________________________________________________________ Technique for steering spinal cord stimulator electrode.

MacDonald JD, Fisher KJ. Neurosurgery. 2011 Sep;69(1 Suppl Operative):ons83-6; discussion ons86-7. Department of Neurosurgery, University of Utah, Salt Lake City, Utah 84107, USA. neuropub@hsc.utah.edu

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BACKGROUND: Spinal cord stimulation is an established technology for management of chronic low back and leg pain when other surgical options have failed or are not feasible. Precise placement of the paddle-style electrode relative to the patient's distribution of pain can be difficult because of anatomic variation and the inherent limitations of electrode design. OBJECTIVE: To describe a surgical technique for adjustment of spinal cord stimulator epidural electrode location during placement or revision to optimize stimulation coverage. METHODS: We devised a method using a malleable disposable suture retrieval snare to precisely position an epidural electrode in either a midline or paramedian position during initial placement or revision. The snare is deployed and used to grasp a suture knot tied at the end of the electrode. The retriever is then used to position the electrode in the epidural space. Once satisfactory stimulation coverage is achieved, the snare is deployed to release the suture knot and the retriever is gently removed. RESULTS: We have used this method in 15 patients thus far to achieve optimal stimulation coverage. The total time required for electrode placement and repositioning, including the stimulation trial, has been substantially reduced. The patient-reported discomfort has also been significantly reduced. No adverse consequences of the technique have occurred. CONCLUSION: We believe that this technique is a novel and effective method for accurately steering an epidural electrode for dorsal column stimulation for management of chronic pain. ______________________________________________________________________________ Automatic adaptation of neurostimulation therapy in response to

changes in patient position: results of the Posture Responsive

Spinal Cord Stimulation (PRS) Research Study.

Schade CM, Schultz DM, Tamayo N, Iyer S, Panken E. Pain Physician. 2011 Sep-Oct;14(5):407-17. Center for Pain Control, Garland, TX 75042, USA. CMSchade@cpctx.com

BACKGROUND: Variation in the intensity of neurostimulation with body position is a practical problem for many patients implanted with a spinal cord stimulation system because positional changes may result in overstimulation or understimulation. These posture-related changes in patients' perception of paresthesia can affect therapeutic outcomes of spinal cord stimulation therapy. An accelerometer-based algorithm that automatically adjusts spinal cord stimulation based on sensed body position or activity represents a potential solution to the problem of position-mediated variations in paresthesia perception. OBJECTIVE: The objective of this study was to compare patient satisfaction ratings for manual versus automatic adjustment of spinal cord stimulation amplitude in response to positional changes. STUDY DESIGN: Prospective, multicenter, open-label, randomized trial SETTING: 2 pain centers in the US. METHOD: Twenty patients at 2 centers in the U.S. who had been implanted with a spinal cord stimulation system for low back and/or leg pain were enrolled in the study. During a 3-day run-in phase, patient position and activity changes were monitored with an ambulatory data recorder and with a research patient programmer which recorded all stimulation parameter changes. Patients who made >/= 2 amplitude adjustments per 24-hour period were invited to participate in an in-clinic phase. During the in-clinic phase, patients' preferred stimulation amplitude and therapy impedance measured at the preferred stimulation amplitude were determined as they performed a series of 8 physical tasks. Satisfaction ratings were determined during position transitions between the physical tasks using both manual and automatic adjustments. RESULTS: Among the 15 patients who completed the in-clinic test protocol, overall satisfaction ratings were significantly higher for automatic adjustment of stimulation amplitudes versus manual adjustments. Patients reported statistically significant improvements with automatic versus manual adjustment for the standing to supine transition and for supine to standing transition. Approximately 74% of participants rated the paresthesia intensity of the automatic adjustment algorithm as "just right" for the physical tasks that were completed. LIMITATIONS: Small study size. CONCLUSION: Patients preferred automatic versus manual adjustment of stimulation amplitude in response to changes in paresthesia consequent to positional changes during in-clinic testing. ______________________________________________________________________________ Epidural spinal cord stimulation for therapy of chronic pain.

Summary of the S3 guidelines. [Article in German]

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Tronnier V, Baron R, Birklein F, Eckert S, Harke H, Horstkotte D, Hügler P, Hüppe M, Kniesel B, Maier C, Schütze G, Thoma R, Treede RD, Vadokas V; Arbeitsgruppe zur Erstellung der S3-Leitlinie. Schmerz. 2011 Sep;25(5):484-92. Neurochirurgische Klinik, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Deutschland. volker.tronnier@uk-sh.de

Epidural spinal cord stimulation (SCS) is a reversible but invasive procedure which should be used for neuropathic pain, e.g. complex regional pain syndrome I (CRPS) and for mostly chronic radiculopathy in connection with failed back surgery syndrome following unsuccessful conservative therapy. Epidural SCS can also successfully be used after exclusion of curative procedures and conservative therapy attempts for vascular-linked pain, such as in peripheral arterial occlusive disease stages II and III according to Fontaine and refractory angina pectoris. Clinical practice has shown which clinical symptoms cannot be successfully treated by epidural SCS, e.g. pain in complete paraplegia syndrome or atrophy/injury of the sensory pathways of the spinal cord or cancer pain. A decisive factor is a critical patient selection as well as the diagnosis. Epidural SCS should always be used within an interdisciplinary multimodal therapy concept. Implementation should only be carried out in experienced therapy centers which are in a position to deal with potential complications. ______________________________________________________________________________ Retrograde C0-C1 insertion of cervical plate electrode for chronic

intractable neck and arm pain.

Moens M, De Smedt A, Brouns R, Spapen H, Droogmans S, Duerinck J, D'Haese J, D'Haens J, Nuttin B. World Neurosurg. 2011 Sep-Oct;76(3-4):352-4; discussion 268-9. Department of Neurosurgery, UZ Brussel, Brussels, Belgium. mtmoens@gmail.com

OBJECTIVE: Spinal cord stimulation is an effective treatment for chronic neuropathic pain after spinal surgery. In addition to the most common placement of electrodes at the thoracic level for low back and leg pain, electrodes can also be placed on a cervical level in patients with chronic neck and upper limb pain. Surgical insertion of plate electrodes via an orthodromal direction requires a partial laminectomy. Therefore, the authors describe a surgical technique using retrograde insertion of a plate electrode to avoid laminectomy. METHODS: Six patients with uncontrolled neck and upper limb pain despite optimal analgesic medication were treated with a surgical electrode placed at the C1-C2 level via a retrograde placement technique without laminectomy. RESULTS: All patients received stimulation paresthesias at the desired regions and reported significant pain reduction in the neck and arm regions. CONCLUSION: This retrograde placement of plate electrodes enables cervical lordosis to be overcome and results in adequate stimulation of the upper cervical region, which is mandatory to reduce neck and shoulder pain without laminectomy. ______________________________________________________________________________ Long-term outcome of patients treated with spinal cord stimulation

for therapeutically refractory failed back surgery syndrome: a

retrospective study. [Article in French]

Abeloos L, De Witte O, Riquet R, Tuna T, Mathieu N. Neurochirurgie. 2011 Jul;57(3):114-9. Epub 2011 Sep 9. Service de neurochirurgie, hôpital Erasme, 808, route de Lennik, 1070 Bruxelles, Belgique. labeloos@ulb.ac.be

BACKGROUND AND PURPOSE: Long-term efficiency (>5 years) of spinal cord stimulation for failed back surgery syndrome is poorly described in literature. The aims of our study were to evaluate the long-term efficiency and the quality of life of our series of patients with spinal cord stimulation for failed back surgery syndrome. METHODS: The data of 55 patients implanted successively in our institution between 1995 and 2005 for failed back surgery syndrome were collected retrospectively. We contacted them for a telephone survey focused on efficiency, quality of life and treatment satisfaction. RESULTS: An internal pulse generator was placed in 42 patients. Thirty-two of them were contacted to answer our survey with a mean follow-up of 8.3 years. Seventy-five percent of our population reported a pain decrease of greater or equal to 50%. The

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efficiency of percutaneous leads was reported as 50% for the quadripolars and 83% for the octopolars. The surgical leads evaluations were positive in 70% for 4 × 1 as well as for 4 × 2 leads. We observed a default of low back pain relief in 84% of patients with an incomplete pain relief (59%). The ability to sit, get out of the bed, and climb stairs increased in 75%. The walk was better in 82%. Decrease in drug consumption of greater or equal to 50% was observed in 66%. CONCLUSIONS: Our retrospective study demonstrates a satisfaction of 75% of the patients after 8.3-years follow-up. Spinal cord stimulation is an effective treatment for refractory failed back surgery syndrome. ______________________________________________________________________________ Spinal cord stimulation versus re-operation in patients with

failed back surgery syndrome: an international multicenter

randomized controlled trial (EVIDENCE study).

North RB, Kumar K, Wallace MS, Henderson JM, Shipley J, Hernandez J, Mekel-Bobrov N, Jaax KN. Neuromodulation. 2011 Jul-Aug;14(4):330-5; discussion 335-6. doi:10.1111/j.1525-1403.2011.00371.x. Epub 2011 Jul 7. Berman Brain and Spine Institute and Johns Hopkins University School of Medicine (ret.), Baltimore, MD, USA. rnorth@lifebridgehealth.org

OBJECTIVE: This paper presents the protocol of the EVIDENCE study, a multicenter multinational randomized controlled trial to assess the effectiveness and cost-effectiveness of spinal cord stimulation (SCS) with rechargeable pulse generator versus re-operation through 36-month follow-up in patients with failed back surgery syndrome. STUDY DESIGN: Study subjects have neuropathic radicular leg pain exceeding or equaling any low back pain and meet specified entry criteria. One-to-one randomization is stratified by site and by one or more prior lumbosacral operations. The sample size of 132 subjects may be adjusted to between 100 and 200 subjects using a standard adaptive design statistical method with pre-defined rules. Crossover treatment is possible. Co-primary endpoints are proportion of subjects reporting ≥ 50% leg pain relief without crossover at 6 and at 24 months after SCS screening trial or re-operation. Insufficient pain relief constitutes failure of randomized treatment, as does crossover. Secondary endpoints include cost-effectiveness; relief of leg, back, and overall pain; change in disability and quality of life; and rate of crossover. We are collecting data on subject global impression of change, patient satisfaction with treatment, employment status, pain/paresthesia overlap, SCS programming, and adverse events. DISCUSSION: As the first multicenter randomized controlled trial of SCS versus re-operation and the first to use only rechargeable SCS pulse generators, the EVIDENCE study will provide up-to-date evidence on the treatment of failed back surgery syndrome. ______________________________________________________________________________ Percutaneously implanted plates in failed back surgery syndrome

(FBSS).

Vonhögen LH, Vancamp T, Vanneste S, Pollet W, Dirksen R, Bakker P, Mestrom I, van de Looij T, Plazier M, de Ridder D. Neuromodulation. 2011 Jul-Aug;14(4):319-24; discussion 324-5. doi:10.1111/j.1525-1403.2011.00368.x. Epub 2011 Jul 7. Department of Anesthesiology & Invasive Paintherapy, Sint Maartenskliniek Nijmegen, Nijmegen, The Netherlands. l.vonhogen@maartenskliniek.nl

OBJECTIVE: To evaluate the clinical efficacy of pain suppression in back area and lower extremities by recently developed plate electrodes for spinal cord stimulation through percutaneous access. METHODS: A retrospective analysis is performed: 20 consecutive patients with both lower extremity pain and low back pain, with low back counting for at least 30% of the overall pain were implanted with a small profile plate type lead, S-Series (SJM), via percutaneous approach. Patients were asked to rate their back and leg pain as well as their overall satisfaction and data on quality of life (QOL) on a (0-10 point) visual analog scale (VAS) before and after implantation. Medication use, functional pain (pain when bending forward, moving), and patient satisfaction scores also were collected. RESULTS: A significant reduction of 55% and 45.7% in, respectively, VAS legs and VAS back pain was found. One year postoperatively the reduction was still present,

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respectively, 43% and 27% for the legs and the back. In 17 patients (85%) a clinically relevant reduction (defined as reduction of 2 points or 30% in VAS) in back pain was seen, with a mean decrease of 4.3 points (2.0-10.0) or 52% (22-100). Only three patients had no reduction in back pain, although they had reduction of their pain in the lower extremities. A significant and clinically relevant improvement of 66% and 70% was seen, respectively, for general satisfaction and QOL, respectively. One year postoperatively this improvement was still present, respectively, 69% and 75% for the satisfaction and QOL. Importantly functional pain also decreased by 51%. No infections occurred. Mean duration of post-op wound pain was 13.5 hours. CONCLUSION: Percutaneous implantation of the S-Series plate electrodes using a 10 gauge epidural needle combines the advantages of a minimal invasive technique with the possibility to cover the back area supplementing leg coverage in 85% of the failed back surgery syndrome patients. ______________________________________________________________________________ Long-term outcomes of spinal cord stimulation with paddle leads in

the treatment of complex regional pain syndrome and failed back

surgery syndrome.

Sears NC, Machado AG, Nagel SJ, Deogaonkar M, Stanton-Hicks M, Rezai AR, Henderson JM. Neuromodulation. 2011 Jul-Aug;14(4):312-8; discussion 318. doi: 10.1111/j.1525-1403.2011.00372.x. Epub 2011 Jul 7. Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA.

INTRODUCTION: Spinal cord stimulation (SCS) is frequently used to treat chronic, intractable back, and leg pain. Implantation can be accomplished with percutaneous leads or paddle leads. Although there is an extensive literature on SCS, the long-term efficacy, particularly with paddle leads, remains poorly defined. Outcome measure choice is important when defining therapeutic efficacy for chronic pain. Numerical rating scales such as the NRS-11 remain the most common outcome measure in the literature, although they may not accurately correlate with quality of life improvements and overall satisfaction. METHODS: We reviewed the medical records of patients with failed back surgery syndrome (FBSS) or complex regional pain syndrome (CRPS) implanted with SCS systems using paddle leads between 1997 and 2008 at the Cleveland Clinic with a minimum six-month follow-up. Patients were contacted to fill out a questionnaire evaluating outcomes with the NRS-11 as well as overall satisfaction. RESULTS: A total of 35 eligible patients chose to participate. More than 50% of the patients with CRPS reported greater than 50% pain relief at a mean follow-up of 4.4 years. Approximately 30% of the FBSS patients reported a 50% or greater improvement at a mean follow-up of 3.8 years. However, 77.8% of patients with CRPS and 70.6% of patients with FBSS indicated that they would undergo SCS surgery again for the same outcome. CONCLUSION: Patients with CRPS and FBSS have a high degree of satisfaction, indexed as willingness to undergo the same procedure again for the same outcome at a mean follow-up of approximately four years. The percentage of satisfaction with the SCS system is disproportionally greater than the percentage of patients reporting 50% pain relief, particularly among patients with FBSS. This suggests that the visual analog scale may not be the optimal measure to evaluate long-term outcomes in this patient population. ______________________________________________________________________________ Using the SAFE principles when evaluating electrical stimulation

therapies for the pain of failed back surgery syndrome.

Krames ES, Monis S, Poree L, Deer T, Levy R. Neuromodulation. 2011 Jul-Aug;14(4):299-311; discussion 311. doi: 10.1111/j.1525-1403.2011.00373.x. Epub 2011 Jul 7. Pacific Pain Treatment Centers, San Francisco, California, USA. krames118@gmail.com

Comment in Neuromodulation. 2011 Nov-Dec;14(6):489-91. OBJECTIVE: In this paper we review the literature on failed back surgery syndrome (FBSS) and use principles of Safety, Appropriateness, Fiscal Neutrality, and Effectiveness (SAFE) to determine the appropriate place for spinal cord stimulation (SCS) for the treatment of FBSS. METHODS AND RESULTS: We analyzed the most recent literature regarding treatments of pain due to FBSS and

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used the SAFE principles to reprioritize pain treatments, particularly electrical stimulation therapies, for FBSS in a more appropriate, relevant, and up to date continuum of care. CONCLUSIONS: Based on this review and analysis of the safety, appropriateness, cost-effectiveness, and efficacy of treatments for the pain of FBSS, relegating SCS to a last resort therapy is no longer justifiable. SCS should be considered before submitting a patient to either long-term systemic opioid therapy or repeat spinal surgery for chronic pain resulting from FBSS. ______________________________________________________________________________ Selected interventional methods for the treatment of chronic pain:

part 2: regional anesthetic techniques close to the spinal cord

and neuromodulative methods. [Article in German]

Böttger E, Diehlmann K. Anaesthesist. 2011 Jun;60(6):571-90. doi: 10.1007/s00101-011-1891-2.

Klinik für Anaesthesiologie, Operative Intensivmedizin und Schmerztherapie, Universitätsklinikum Gießen und Marburg, Standort Gießen, Deutschland, Eileen.Boettger@chiru.med.uni-giessen.de

Comment in Anaesthesist. 2011 Nov;60(11):1057-8; author reply 1058-62. Approximately 5-8 million people in Germany suffer from chronic pain and some patients can profit from specific interventional techniques. In detail these are regional anesthetic techniques close to the spinal cord, neuromodulation, blocks of the sympathetic chain and peripheral nerve blocks. Part 2 of the article presents regional anesthetic techniques close to the spinal cord and neuromodulative methods. Regional anesthetic techniques close to the spinal cord are of high importance for the treatment of chronic low back pain although the efficiency is highly disputed due to the lack of evidence. Neuromodulation includes amongst others intrathecal pharmacotherapy and spinal cord stimulation, which are used for highly selected patients and can lead to very good results for these patients. ______________________________________________________________________________ Failed back surgery syndrome.

Chan CW, Peng P. Pain Med. 2011 Apr;12(4):577-606. doi: 10.1111/j.1526-4637.2011.01089.x. Epub 2011 Apr 4. Wasser Pain Management Center, Mount Sinai Hospital, Toronto, Ontario, Canada.

BACKGROUND: Failed back surgery syndrome (FBSS) is a chronic pain condition that has considerable impact on the patient and health care system. Despite advances in surgical technology, the rates of failed back surgery have not declined. The factors contributing to the development of this entity may occur in the preoperative, intraoperative, and postoperative periods. Due to the severe pain and disability this syndrome may cause, more radical treatments have been utilized. Recent trials have been published that evaluate the efficacy and cost-effectiveness of therapeutic modalities such as spinal cord stimulation for the management of patients with failed back surgery. REVIEW SUMMARY: This article will describe the epidemiology and etiology of FBSS. The importance of prevention will be emphasized. In those patients with established FBSS, a guide to interdisciplinary evaluation and management will be outlined. Special attention will focus on recent trials that have studied the efficacy of more invasive procedures such as spinal cord stimulation. Finally, a suggested management pathway is presented. CONCLUSION: FBSS is a challenging clinical entity with significant impact on the individual and society. To better prevent and manage this condition, knowledge of the factors contributing to its development is necessary. While research on FBSS has increased in recent years, perhaps the best strategy to reduce incidence and morbidity is to focus on prevention. Patients diagnosed with FBSS should be managed in an interdisciplinary environment. More radical treatments for FBSS have now been extensively studied providing clinicians with much needed evidence on their efficacy. Incorporating these results into our current knowledge provides a basis on which to construct an evidence-based guide on how best to manage patients who suffer from FBSS. ______________________________________________________________________________

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Prospective, two-part study of the interaction between spinal cord

stimulation and peripheral nerve field stimulation in patients

with low back pain: development of a new spinal-peripheral

neurostimulation method.

Mironer YE, Hutcheson JK, Satterthwaite JR, LaTourette PC. Neuromodulation. 2011 Mar-Apr;14(2):151-4; discussion 155. doi: 10.1111/j.1525-1403.2010.00316.x. Epub 2010 Nov 2. Carolinas Center For Advanced Management of Pain, Greenville, SC 29615, USA.

OBJECTIVE: The goal of the study was to assess the efficacy of interaction between spinal cord stimulation (SCS) and peripheral nerve field stimulation (PNFS) and to evaluate a new spinal-peripheral neuromodulation method for low back pain. MATERIALS AND METHODS: The prospective two-part study included patients with low back pain due to failed back surgery syndrome and/or spinal stenosis. In the first part 20 patients were implanted with SCS and PNFS. They selected the best program out of three: SCS alone, PNFS alone, or both together. In the second part another 20 patients with the same implanted leads were selecting between three programs: SCS and PNFS separately, SCS as anode and PNFS as cathode, or in reverse. RESULTS: In the first part 79% of the patients selected simultaneous use of SCS and PNFS. The overall success of the trials was 85%. In the second part communication between SCS and PNFS provided wider coverage of axial pain. The overall success of the trials was 90%. CONCLUSION: Simultaneous use of SCS and PNFS increase efficacy of both methods for axial back pain. The new SPN method showed great potential in providing coverage for back pain. ______________________________________________________________________________ Spinal cord stimulation in a patient with spinal epidural

lipomatosis.

Zhang Y, Wood MJ, Gilligan C. Pain Med. 2011 Mar;12(3):377-81. doi: 10.1111/j.1526-4637.2011.01057.x. Epub 2011 Feb 18. Division of Pain Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.

BACKGROUND AND OBJECTIVE: Spinal cord stimulation is the most commonly used implantable neurostimulation modality for management of pain syndromes. For treatment of lower extremity pain, the spinal cord stimulator lead is typically placed in the thoracic epidural space, at the T10-T12 levels. Typically, satisfactory stimulation can be obtained relatively easily. Anatomical variability in the epidural space, such as epidural scarring, has been reported to prevent successful implantation of spinal cord stimulators. Spinal epidural lipomatosis describes an abnormal overgrowth of adipose tissue in the extradural space. Cases have documented spinal epidural lipomatosis complicating intrathecal baclofen pump implantation or causing repeated failure of epidural analgesia. However, so far, there is no published literature describing how spinal epidural lipomatosis affects spinal cord stimulation. CASE REPORT: We report a case of spinal cord stimulation in a patient with spinal epidural lipomatosis. Very high impedance was encountered during the trial spinal cord stimulator lead placement. Satisfactory stimulation was only obtained after repeated repositioning of the spinal cord stimulator trial lead. Post-procedure thoracic spine magnetic resonance imaging revealed marked thoracic epidural lipomatosis. At the level where satisfactory stimulation was obtained, the thickness of the epidural fat was within normal limits. The patient eventually underwent placement of a laminotomy lead with good coverage and pain relief. CONCLUSION: Spinal epidural lipomatosis significantly increases the impedance in the epidural space, making effective neurostimulation very difficult to obtain. Physicians should consider the possibility of spinal epidural lipomatosis when very high impedances are encountered during lead placement. ______________________________________________________________________________ Alternative approach to needle placement in cervical spinal cord

stimulator insertion.

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Zhu J, Falco FJ, Onyewu CO, Vesga R, Josephson Y, Husain A, Gutman G. Pain Physician. 2011 Mar-Apr;14(2):195-210. Mid Atlantic Spine & Pain Physicians, Newark, DE, USA. zzzzjim@gmail.com

BACKGROUND: Neuromodulation with spinal cord stimulation is a proven cost effective treatment for the management of common conditions such as chronic radicular leg pain from failed back surgery syndrome, complex regional pain syndrome, and other painful neuropathic pain syndromes. The traditionally instructed method for percutaneous spinal cord stimulator (SCS) lead placement promotes the use of a "loss of resistance" (LOR) technique under anteroposterior (AP) fluoroscopic guidance to assure midline lead placement and proper entry into the epidural space. OBJECTIVE: To describe the relevant anatomy and method for a precise needle placement approach for placement of percutaneous cervical spinal cord stimulation (SCS) leads without loss of resistance (LOR) using a syringe. An oblique fluoroscopic view is presented demonstrating successful placement of cervical SCS leads. DESIGN: Technical report. SETTING: Pain management clinic. METHODS: Discussion with accompanying fluoroscopic images. This technical report meets HIPAA compliance standards. RESULTS: Successful placement of percutaneous SCS leads without traditional loss of resistance using an oblique fluoroscopic approach. LIMITATIONS: Technical report only. The risks, potential complications, and benefit from this approach are beyond the scope of the article. CONCLUSIONS: This fluoroscopic technique provides an alternative means for placing percutaneous cervical SCS leads without the use of the traditional loss of resistance technique. ______________________________________________________________________________ Retrospective review of 707 cases of spinal cord stimulation:

indications and complications.

Mekhail NA, Mathews M, Nageeb F, Guirguis M, Mekhail MN, Cheng J. Pain Pract. 2011 Mar-Apr;11(2):148-53. doi: 10.1111/j.1533-2500.2010.00407.x. Epub 2010 Sep 8. Department of Pain Management, Cleveland Clinic, Cleveland, Ohio 44195, USA. mekhain@ccf.org

Appropriate patient selection and minimizing complications are critical for successful spinal cord stimulation (SCS) therapy in managing intractable pain. We thus reviewed electronic medical records of 707 consecutive cases of patients who received SCS therapy in the Cleveland Clinic from 2000 to 2005 with an emphasis on indications and complications. SCS was used to treat complex regional pain syndrome (CRPS) (345 cases), failed back surgery syndrome (235 cases), peripheral vascular disease (20 cases), visceral pain in the chest, abdomen, and pelvis (37 cases), and peripheral neuropathy (70 cases). CRPS and failed back surgery syndrome accounted for 82% of the cases. The implant-to-trial ratio was 75% on average, with the highest for CRPS type 2 (83%) and the lowest for peripheral vascular diseases (65%). The only documented complication associated with SCS trials was lead migration in 5 of 707 patients (0.7%). There were no permanent neurological deficits or deaths as a result of SCS implant or its complications. Hardware-related complications were common (38%) and included lead migration (22.6%), lead connection failure (9.5%), and lead breakage (6%). Revisions or replacements were required in these cases. Biologically related complications included pain at the generator site (12%) and clinical infection (4.5%; 2.5% with positive culture). The rates of infection varied among the different diagnoses with the highest in failed back surgery syndrome (6.3%). Patients with diabetes had an infection rate of 9%, over the 4% in non-diabetics. Infections were managed successfully with explantation and antibiotic therapy without permanent sequela. ______________________________________________________________________________ Combination therapy of radiofrequency lumbar facet joint

denervation and epidural spinal cord stimulation for failed back

surgery syndrome.

Terao T, Ishii T, Tani S, Abe T. Neurol Med Chir (Tokyo). 2011;51(11):805-9. Department of Neurosurgery, Atsugi City Hospital, Kanagawa. tohru@jg7.so-net.ne.jp

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An 81-year-old woman with failed back surgery syndrome (FBSS) was treated using a combination of percutaneous radiofrequency (RF) lumbar zygapophysial joint denervation and epidural spinal cord stimulation (SCS). She had undergone a staged laminectomy for narrowing of the spinal canal from L1 to S1 and degenerative spondylolisthesis at the L3-4 level. Postoperatively, in addition to low back pain (LBP) induced by dynamic motion, she began to experience intractable leg pain with a burning sensation, presumably caused by damage to the cauda equina. She initially underwent RF lumbar zygapophysial joint denervation for the LBP and subsequently underwent SCS via dual electrode leads for the leg pain. This combination therapy of RF denervation and SCS relieved the LBP almost entirely and relieved the leg pain by approximately 50%. The combination of these two minimally invasive interventions is particularly effective for severe leg pain and LBP in elderly patients or medically compromised cases with contraindications against general anesthesia, as well as in patients with FBSS. ______________________________________________________________________________ Alternative approach to needle placement in spinal cord stimulator

trial/implantation.

Zhu J, Falco F, Onyewu CO, Joesphson Y, Vesga R, Jari R. Pain Physician. 2011 Jan-Feb;14(1):45-53. Mid Atlantic Spine & Pain Physicians, Newark, NJ, USA. zzzzjim@gmail.com

Erratum in Pain Physician. 2011 Mar-Apr;14(2):217. Neuromodulation with spinal cord stimulation is a proven, cost effective treatment for the management of chronic radicular low back pain from failed low back surgery syndrome and other neuropathic pain conditions. The traditionally instructed method for percutaneous spinal cord stimulator lead placement promotes the use of a "loss of resistance" technique under anteroposterior fluoroscopic guidance to assure midline lead placement and proper entry into the epidural space. Loss of resistance is a reliable method to locate the epidural space in most clinical situations. However, in certain circumstances such as a congenital underdeveloped ligamentum flavum or defects of the ligamentum flavum, sometimes occurring after lumbar spine surgery, it might become difficult to use a loss of resistance technique to locate the epidural space. In this case, the level of resistance might not be clear. Further, a false loss of resistance might occur between changes in fascial planes that might lead to the uncertainty of needle depth. This paper introduces an alternative method for needle placement for spinal cord stimulator (SCS) trials and implantation without using the traditional loss of resistance technique. The technique allows for precise visual monitoring of the Tuohy needle tip under fluoroscopy to gauge needle depth as it enters into the tissue and the epidural space based on anatomic structural landmarks. This method allows for multiple lead placement or single lead insertion multiple times in the same interlaminar space. This is an alternative approach to the loss of resistance technique based on the fluoroscopic landmarks. Theoretically, this should be a safer approach for accessing the epidural space; however, further studies are needed to evaluate its safety. ______________________________________________________________________________ Counting the costs: case management implications of spinal cord

stimulation treatment for failed back surgery syndrome.

Mekhail N, Wentzel DL, Freeman R, Quadri H. Prof Case Manag. 2011 Jan-Feb;16(1):27-36. Department of Pain Management at Cleveland Clinic, USA.

PURPOSE/OBJECTIVES: The purpose of this article is to review clinical and health economic evidence supporting the use of spinal cord stimulation (SCS) for failed back surgery syndrome (FBSS) and to discuss implications for case managers' decision making. PRIMARY PRACTICE SETTINGS: Primary settings include hospital and home environments. FINDINGS/CONCLUSIONS: Patients with FBSS experience persistent or recurring pain in the lower back, legs, or both after one or more spinal surgeries. Surgical revision and nonsurgical FBSS therapies often result in minimal or no clinical improvement, and reoperations often result in more pain. The efficacy and safety of SCS have improved as a result of earlier intervention,

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technological advances, and increased awareness of SCS proper patient selection. A recent randomized controlled trial (RCT) demonstrated that at mean 3-year follow-up, SCS achieves significantly more pain relief and treatment satisfaction and lower opiate analgesic use than reoperation in patients with FBSS. Another RCT demonstrated that at 6-month follow-up, more patients with FBSS achieve pain relief, enhanced quality of life, improved functioning, and higher treatment satisfaction levels with SCS than with conventional medical management (CMM). Health-economic FBSS studies show that SCS is more cost-effective than CMM or reoperation. SCS is a well-established FBSS treatment option with demonstrated efficacy and cost-effectiveness in selected patients. IMPLICATIONS FOR CM PRACTICE: Case Managers should consider recommending SCS as one modality prior to reoperation in patients with FBSS who meet the clinical criteria for its appropriate use. ______________________________________________________________________________ 'Hybrid neurostimulator': simultaneous use of spinal cord and

peripheral nerve field stimulation to treat low back and leg pain.

Lipov EG. Prog Neurol Surg. 2011;24:147-55. Epub 2011 Mar 21. Advanced Pain Centers S.C., Hoffman Estates, Ill. 60169, USA. elipovmd@aol.com

Treatment of chronic back and leg pain in patients with failed back surgery syndrome (FBSS) remains problematic as none of the currently available approaches are universally successful in achieving lasting pain control. Spinal cord stimulation (SCS) is very effective for controlling radicular pain but rarely provides adequate control of pain in the lower back. Recently, a technique of peripheral nerve stimulation (PNS) was introduced to control pain in a group of patients for whom back pain dominated the clinical picture. Because PNS does not control neuropathic pain due to lumbosacral radiculopathy involving the lower extremities, we developed a hybrid technique of SCS and PNS that offers potential control of both axial pain in the lumbar area and radicular pain to the lower extremities. This chapter presents our results and the possible mechanisms of action. ______________________________________________________________________________ Simultaneous intrathecal opioid pump and spinal cord stimulation

for pain management: analysis of 11 patients with failed back

surgery syndrome.

Tomycz ND, Ortiz V, Moossy JJ. J Pain Palliat Care Pharmacother. 2010 Dec;24(4):374-83. Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15232, USA. tomycznd@upmc.edu

Dual-modality management of failed back surgery syndrome (FBSS) using a combination of an intrathecal opioid pump (IOP) and spinal cord stimulator (SCS) has not been investigated. The authors performed a retrospective review of 11 patients (8 men, 3 women) with FBSS who underwent nonsimultaneous surgical implantation of both an IOP and a thoracic SCS. Chart review and structured phone interviews were performed to obtain follow-up. Of the two modalities, 3 patients (27%) had an IOP placed first and 8 patients (73%) had a SCS implanted initially. Mean follow-up was 41.7 months (3-97 months). All 11 patients (100%) stated that the dual-modality treatment improved their quality of life and all continue to use both an IOP and SCS for pain control. Six patients (55%) felt that the IOP provided superior pain relief as compared to the SCS, 4 patients (36%) felt that IOP and SCS provided a similar degree of pain relief, and 1 patient (9%) said the SCS provided better pain relief than the IOP. Nine patients (82%) claimed that dual-modality treatment improved their activities of daily living. Nine patients (82%) reported that the combination of IOP and SCS treatment had allowed them to significantly decrease their oral pain medication requirements. Seven patients (64%) had hardware-related complications which required surgery; of this group, 2 patients (18%) needed more than one operation. Six patients (55%) had minor postoperative complications, which were managed nonoperatively. Overall, 10 patients (91%) were glad that they had implantation of both an IOP and SCS and would recommend this combined therapy to other patients. Dual neuroaugmentative treatment with an

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IOP and thoracic SCS can be safely performed and may provide satisfactory pain relief in appropriately selected patients with FBSS. ______________________________________________________________________________ Questions about Turner et al. Spinal cord stimulation for failed

back surgery syndrome: outcomes in a worker's compensation

setting.

North RB, Shipley J, Taylor RS, Eldabe S. Pain. 2010 Nov;151(2):550-1; author reply 551-2. Epub 2010 Sep 9.

Comment on Pain. 2004 Mar;108(1-2):137-47. ______________________________________________________________________________ Trial spinal cord stimulator reimplantation following lead

breakage after third birth.

Takeshima N, Okuda K, Takatanin J, Hagiwra S, Noguchi T. Pain Physician. 2010 Nov-Dec;13(6):523-6. Faculty of Medicine Yufu, Oita University, Oita, Japan. ntake@oita-u.ac.jp

BACKGROUND: Many studies have reported lead migration and breakage as complications of epidural spinal cord stimulation. In cases where rapid changes in physique such as those caused by pregnancy are expected, it is unclear whether extra consideration regarding possible adjustments and care to avoid complications such as lead breakage are required. OBJECTIVE: This article presents a case in which spinal cord stimulation was used to manage these complications in a woman during the perinatal period. DESIGN: Case report. SETTING: Pain management clinic. METHODS: The patient was a 36-year-old female, approximate weight of 100 pounds, and 5-foot 1 inch in height, whose chief complaint was lower back and bilateral leg pain. The pain could not be alleviated by conservative therapies such as nerve blockade, oral medications with non-steroidal anti-inflammatory drugs, antidepressants, anticonvulsants or physical therapy. A spinal cord stimulator was implanted at another facility, which relieved the pain. The patient subsequently had 2 vaginal births without any problems relating to the stimulation sites, and both infants were healthy. She experienced lead breakage after the third vaginal birth that led to the subsequent reimplantation procedure. RESULTS: The patient had 2 subsequent vaginal births following the initial implantation with no problems related to the stimulation sites, and both infants were healthy. At age 34, following her third vaginal birth, the stimulator became ineffective and was removed. The withdrawn lead wire was found to be broken in 2 places. LIMITATIONS: A case report. CONCLUSION: Pregnancy following implantation of a spinal cord stimulator might result in lead breakage as abdominal girth increases. The present case exemplifies how pregnancy following implantation of a spinal cord stimulator might cause lead breakage as abdominal girth increases. Extra care is required to prevent lead breakage when anchors are fixed. ______________________________________________________________________________ The use of spinal cord stimulation and intrathecal drug delivery

in the treatment of low back-related pain.

Bagnall D. Phys Med Rehabil Clin N Am. 2010 Nov;21(4):851-8. bagnall@rehabny.com

Spinal cord stimulation (SCS) and intrathecal drug delivery (IDD) are forms of neuromodulation, meaning that they are reversible and nondestructive. SCS is generally limited to conditions such as radiculopathy and pain of CNS origin. IDD is primarily effective for nociceptive or mixed pain, and its usage is generally limited to conditions within that realm. ______________________________________________________________________________

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Spontaneous resolution of nausea induced by spinal cord

stimulation for failed back surgery syndrome.

Vorenkamp KE, Baker NE. Neuromodulation. 2010 Oct;13(4):292-5. doi: 10.1111/j.1525-1403.2010.00291.x. University of Virginia Department of Anesthesia and Pain Medicine, Charlottesville, VA, USA.

Introduction: Spinal cord stimulation (SCS) is used for treatment of pain arising from a variety of pathologies. Reported side-effects related to SCS are most commonly technical complications including malfunction, lead migration, or severance. Up to date, only a few cases of gastrointestinal side-effects have been reported. Materials and Methods: A 54-year-old man with a 20-year history of low back pain developed persistent and refractory nausea following spinal cord stimulator implantation. Results: The nausea resolved spontaneously within eight weeks allowing continued use of the spinal cord stimulator. Conclusions: In this case report, we described the uncommon side-effect of nausea because of SCS that resolved over time allowing continued neurostimulation therapy in a patient with arachnoiditis and failed lumbar back surgery syndrome. We encourage other providers to report similar cases to help elucidate the mechanism of these seemingly underreported side-effects to allow continuation of the therapeutic effects of SCS. ______________________________________________________________________________ Spinal cord stimulation for the treatment of chronic pain in

patients with lumbar spinal stenosis.

Costantini A, Buchser E, Van Buyten JP. Neuromodulation. 2010 Oct;13(4):275-80. doi: 10.1111/j.1525-1403.2010.00289.x. Pain Clinic, Ospedale Clinicizzato S.S. Annunziata, Chieti, Italy; Pain Clinic, EHC-Hospital of Morges, Morges, Switzerland; and AZ Nikolaas-Campus SM, St. Niklaas, Belgium.

Objective: Chronic back and leg pain associated with lumbar spinal stenosis (LSS) is common in the elderly. Surgical decompression is usually performed when conservative treatments fail. We present an evaluation of the long-term outcome of patients suffering from symptomatic LSS treated with spinal cord stimulation (SCS). Materials and Methods: Data were collected prospectively in three independent registries in three European centers. Pooled data were analyzed retrospectively. Changes in pain intensity, functional status, and analgesic medication were compared at baseline and at the last available follow-up. Demographic data as well as details regarding the implantation procedure and any adverse events were systematically recorded. Results: Data were recorded in 69 patients with a mean follow-up period of 27 months. All patients showed clinically and statistically significant improvement in pain relief, the visual analog scale decreasing from 7.4 ± 2.3 to 2.8 ± 2.4 (p < 0.05). The use of analgesic medication decreased and the functional status improved. Conclusion: Spinal cord stimulation seems to be effective in the treatment of patients suffering from chronic pain associated with LSS. Being less invasive and reversible, SCS should be considered before surgical decompression, particularly in patients with increased risks associated with back surgery. ______________________________________________________________________________ Neurophysiological assessment of spinal cord stimulation in failed

back surgery syndrome.

de Andrade DC, Bendib B, Hattou M, Keravel Y, Nguyen JP, Lefaucheur JP. Pain. 2010 Sep;150(3):485-91. Epub 2010 Jun 29. Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, EA 4391, U-PEC, Créteil, France.

Despite good clinical results, the mechanisms of action of spinal cord stimulation (SCS) for the treatment of chronic refractory neuropathic pain have not yet been elucidated. In the present study, the effects of SCS were assessed on various neurophysiological parameters in a series of 20 patients, successfully treated by SCS for mostly unilateral, drug-resistant lower limb pain due to failed back surgery syndrome. Plantar sympathetic skin response (SSR), F-wave and somatosensory-evoked potentials (P40-SEP) to tibial nerve stimulation, H-reflex of soleus muscle,

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and nociceptive flexion (RIII) reflex to sural nerve stimulation were recorded at the painful lower limb. The study included two recording sets while SCS was switched 'ON' or 'OFF' for 1h. Significant changes in 'ON' condition were as follows: SSR amplitude, H-reflex threshold, and RIII-reflex threshold and latency were increased, whereas SSR latency, F-wave latency, H-reflex amplitude, P40-SEP amplitude, and RIII-reflex area were reduced. Analgesia induced by SCS mainly correlated with RIII attenuation, supporting a real analgesic efficacy of the procedure. This study showed that SCS is able to inhibit both nociceptive (RIII-reflex) and non-nociceptive (P40-SEP, H-reflex) myelinated sensory afferents at segmental spinal or supraspinal level, and to increase cholinergic sympathetic skin activities (SSR facilitation). Complex modulating effects can be produced by SCS on various neural circuits, including a broad inhibition of both noxious and innocuous sensory information processing. ______________________________________________________________________________ The cost-effectiveness of spinal cord stimulation in the treatment

of failed back surgery syndrome.

Taylor RS, Ryan J, O'Donnell R, Eldabe S, Kumar K, North RB. Clin J Pain. 2010 Jul-Aug;26(6):463-9. Peninsula Medical School, Universities of Exeter and Plymouth, UK.

OBJECTIVES: Healthcare policy makers and payers require cost-effectiveness evidence to inform their treatment funding decisions. Thus, in 2008, the United Kingdom's National Institute of Health and Clinical Excellence analyzed the cost effectiveness of spinal cord stimulation (SCS) compared with conventional medical management (CMM) and with reoperation and recommended approval of SCS in selected patients with failed back surgery syndrome (FBSS). We present previously unavailable details of the National Institute of Health and Clinical Excellence analysis and an analysis of the impact on SCS cost effectiveness of rechargeable implanted pulse generators (IPGs). METHODS: We used a decision analytic model to examine the cost effectiveness of SCS versus CMM and versus reoperation in patients with FBSS. We also modeled the impact of nonrechargeable versus rechargeable IPGs. RESULTS: The incremental cost-effectiveness of SCS compared with CMM was pound5624 per quality-adjusted life year, with 89% probability that SCS is cost effective at a willingness to pay threshold of pound20,000. Compared with reoperation, the incremental cost-effectiveness of SCS was pound6392 per quality-adjusted life year, with 82% probability of cost-effectiveness at the pound20,000 threshold. When the longevity of an IPG is 4 years or less, a rechargeable (and initially more expensive) IPG is more cost-effective than a nonrechargeable IPG. DISCUSSION: In selected patients with FBSS, SCS is cost effective both as an adjunct to CMM and as an alternative to reoperation. Despite their initial increased expense, rechargeable IPGs should be considered when IPG longevity is likely to be short. ______________________________________________________________________________ An analysis of the components of pain, function, and health-

related quality of life in patients with failed back surgery

syndrome treated with spinal cord stimulation or conventional

medical management.

Eldabe S, Kumar K, Buchser E, Taylor RS. Neuromodulation. 2010 Jul;13(3):201-9. doi: 10.1111/j.1525-1403.2009.00271.x. Epub 2010 Feb 22. Department of Pain & Anaesthesia, James Cook University Hospital, Middlesbrough, Cleveland, UK; Department of Neurosurgery, Regina General Hospital, Regina, Saskatchewan, Canada; Neuromodulation Centre EHC Hospital, Morges, & Anaesthesia Service, CHUV, Lausanne, Vaud, Switzerland; and Peninsula Medical School, Universities of Exeter and Plymouth, Devon, UK.

Objectives: Failed back surgery syndrome (FBSS) patients experience pain, functional disability, and reduced health-related quality of life (HRQoL) despite anatomically successful surgery. Examining sub-dimensions of health outcomes measures provides insight into patient well-being. Materials and Methods: The international multicenter PROCESS trial collected detailed HRQoL (EuroQol-5D; Short-Form 36) and function (Oswestry Disability Index) information on 100 FBSS patients. Results: At baseline, patients reported moderate-to-severe leg and back pain adversely affecting all dimensions of function and HRQoL. Compared with conventional medical management alone, patients also receiving spinal cord stimulation (SCS) reported superior pain

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relief, function, and HRQoL at six months on overall and most sub-component scores. The majority of these improvements with SCS were sustained at 24 months. Nonetheless, 36-40% of patients experienced ongoing marked disability (standing, lifting) and HRQoL problems (pain/discomfort). Conclusions: Longer-term patient management and research must focus on these refractory FBSS patients with persisting poor function and HRQoL outcomes. ______________________________________________________________________________ A critical review of the American Pain Society clinical practice

guidelines for interventional techniques: part 2. Therapeutic

interventions.

Manchikanti L, Datta S, Gupta S, Munglani R, Bryce DA, Ward SP, Benyamin RM, Sharma ML, Helm S 2nd, Fellows B, Hirsch JA. Pain Physician. 2010 Jul-Aug;13(4):E215-64. Pain Management Center of Paducah, Paducah, KY, USA. drlm@thepainmd.com

Comment in Pain Physician. 2011 Jan-Feb;14(1):E69-73; author reply E73-82. BACKGROUND: Clinical guidelines are a constructive response to the reality that practicing physicians require assistance in assimilating and applying the exponentially expanding, often contradictory, body of medical knowledge. They attempt to define practices that meet the needs of most patients under most circumstances. Ideally, specific clinical recommendations contained within practice guidelines are systematically developed by expert panels who have access to all the available evidence, have an understanding of the clinical problem, and have clinical experience with the procedure being assessed, as well as knowledge of relevant research methods. The recent development of American Pain Society (APS) guidelines has created substantial controversy because of their perceived lack of objective analysis and recommendations perceived to be biased due to conflicts of interest. OBJECTIVES: To formally and carefully assess the APS guidelines' evidence synthesis for low back pain for therapeutic interventions using the same methodology utilized by the APS authors. The interventions examined were therapeutic interventions for managing low back pain, including epidural injections, adhesiolysis, facet joint interventions, and spinal cord stimulation. METHODS: A literature search by 2 authors was carried out utilizing appropriate databases from 1966 through July 2008. Articles in which conflicts arose were reviewed and mediated by a third author to arrive at a consensus. Selections of manuscripts and methodologic quality assessment was also performed by at least 2 authors utilizing the same criteria applied in the APS guidelines. The guideline reassessment process included the evaluation of individual studies and systematic reviews and their translation into practice recommendations. RESULTS: The conclusions of APS and our critical assessment based on grading of good, fair, and poor, agreed that there is fair evidence for spinal cord stimulation in post lumbar surgery syndrome, and poor evidence for lumbar intraarticular facet joint injections, lumbar interlaminar epidural injections, caudal epidural steroids for conditions other than disc herniation or radiculitis, sacroiliac joint injections, intradiscal electrothermal therapy, endoscopic adhesiolysis, and intrathecal therapy. However, our assessment of APS guidelines for other interventional techniques, utilizing their own criteria, showed fair evidence for therapeutic lumbar facet joint nerve blocks, caudal epidural injections in disc herniation or radiculitis, percutaneous adhesiolysis in post lumbar surgery syndrome, radiofrequency neurotomy, and transforaminal epidural injections in radiculitis. Also it is illustrated that inclusion of latest literature will change the conclusions, with improved grading - caudal epidural, adhesiolysis, and lumbar facet joint nerve blocks from fair to good or poor to fair. The present critical assessment review illustrates that APS guidelines have utilized multiple studies inappropriately and have excluded appropriate studies. Our integrity assessment shows deep concerns that the APS guidelines illustrating significant methodologic failures which raise concerns about transparency, accountability, consistency, and independence. CONCLUSION: The current reassessment, using appropriate methodology, shows evidence similar to APS guidelines for several procedures, but differs extensively from published APS guidelines for multiple other procedures including caudal epidural injections, lumbar facet joint nerve blocks, lumbar radiofrequency neurotomy, and percutaneous adhesiolysis. ______________________________________________________________________________

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Pulse width programming in spinal cord stimulation: a clinical

study.

Yearwood TL, Hershey B, Bradley K, Lee D. Pain Physician. 2010 Jul-Aug;13(4):321-35. Comprehensive Pain and Rehabilitation, Pascagoula, MS 39581, USA. nopaindr@mac.com

BACKGROUND: With advances in spinal cord stimulation (SCS) technology, particularly rechargeable implantable, patients are now being offered a wider range of parameters to treat their pain. In particular, pulse width (PW) programming ranges of rechargeable implantable pulse generators now match that of radiofrequency systems (with programmability up to 1000 microseconds. The intent of the present study was to investigate the effects of varying PW in SCS. OBJECTIVE: To understand the effects of PW programming in spinal cord stimulation (SCS). DESIGN: Single-center, prospective, randomized, single-blind evaluation of the technical and clinical outcomes of PW programming. SETTING: Acute, outpatient follow-up. METHODS: Subjects using fully-implanted SCS for > 3 months to treat chronic intractable low back and/or leg pain. Programming of a wide range (50-1000 microseconds) of programmed PW settings using each patient's otherwise unchanged 'walk-in' program. OUTCOME MEASURES: Paresthesia thresholds (perception, maximum comfortable, discomfort), paresthesia coverage and patient choice of tested programs. RESULTS: We found strength-duration parameters of chronaxie and rheobase to be 295 (242 - 326) microseconds and 2.5 (1.3 - 3.3) mA, respectively. The median PW of all patients' 'walk-out' programs was 400 microseconds, approximately 48% higher than median chronaxie (p = 0.01), suggesting that chronaxie may not relate to patient-preferred stimulation settings. We found that 7/19 patients selected new PW programs, which significantly increased their paresthesia-pain overlap by 56% on average (p = 0.047). We estimated that 10/19 patients appeared to have greater paresthesia coverage, and 8/19 patients appeared to display a 'caudal shift' of paresthesia coverage with increased PW. LIMITATIONS: Small number of patients. CONCLUSIONS: Variable PW programming in SCS appears to have clinical value, demonstrated by some patients improving their paresthesia-pain overlap, as well as the ability to increase and even 'steer' paresthesia coverage. ______________________________________________________________________________ Lumbosacral radicular pain.

Van Boxem K, Cheng J, Patijn J, van Kleef M, Lataster A, Mekhail N, Van Zundert J. Pain Pract. 2010 Jul-Aug;10(4):339-58. Epub 2010 May 17. Department of Anesthesiology and Pain Management, Maastricht University Medical Centre, Maastricht, The Netherlands. koen.vb@telenet.be

Lumbosacral radicular pain is characterized by a radiating pain in one or more lumbar or sacral dermatomes; it may or may not be accompanied by other radicular irritation symptoms and/or symptoms of decreased function. The annual prevalence in the general population, described as low back pain with leg pain traveling below the knee, varied from 9.9% to 25%, which means that it is presumably the most commonly occurring form of neuropathic pain. The patient's history may give a suggestion of lumbosacral radicular pain. The best known clinical investigation is the straight-leg raising test. Final diagnosis is made based on a combination of clinical examination and potentially additional tests. Medical imaging studies are indicated to exclude possible serious pathologies and to confirm the affected level in patients suffering lumbosacral radicular pain for longer than 3 months. Magnetic resonance imaging is preferred. Selective diagnostic blocks help confirming the affected level. There is controversy concerning the effectiveness of conservative management (physical therapy, exercise) and pharmacological treatment. When conservative treatment fails, in subacute lumbosacral radicular pain under the level L3 as the result of a contained herniation, transforaminal corticosteroid administration is recommended (2 B+). In chronic lumbosacral radicular pain, (pulsed) radiofrequency treatment adjacent to the spinal ganglion (DRG) can be considered (2 C+). For refractory lumbosacral radicular pain, adhesiolysis and epiduroscopy can be considered (2 B+/-), preferentially study-related. In patients with a therapy-resistant radicular pain in the context of a Failed Back Surgery Syndrome, spinal cord stimulation is recommended (2 A+). This treatment should be performed in specialized centers. ______________________________________________________________________________

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Comparative effectiveness research and policy: experiences

conducting a coverage with evidence development study of a

therapeutic device.

Turner JA, Hollingworth W, Comstock B, Deyo RA. Med Care. 2010 Jun;48(6 Suppl):S129-36. Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA 98195-6560, USA. jturner@uw.edu

Comment in Med Care. 2011 Sep;49(9):e28. BACKGROUND AND OBJECTIVE: The Washington State workers' compensation agency funded a coverage with evidence development study to evaluate spinal cord stimulation (SCS) for chronic back and leg pain after spine surgery (failed back surgery syndrome). We previously published the study outcomes. We now report results from a second patient cohort; study costs; and industry, provider, and payer responses. RESEARCH DESIGN, SUBJECTS, AND MEASURES: This prospective cohort study compared patients with failed back surgery syndrome who received at least a trial of SCS (n = 51), Pain Clinic evaluation (n = 39), or Usual Care only (n = 68) on measures of pain, physical functioning, and opioid medication use at baseline and 6, 12, and 24 months. Between the end of subject enrollment and availability of final study results, a second SCS cohort (n = 30) was followed for 12 months. RESULTS: SCS was associated with no benefits beyond 6 months and entailed risks, including one life-threatening event. After reviewing the results, the workers' compensation program decided to maintain its SCS noncoverage policy. SCS manufacturers and providers criticized multiple aspects of the study to policy decision-makers at all stages of the study. Accumulated evidence will be reviewed by the Washington State Health Technology Assessment Program to make decisions regarding all Washington State agencies' coverage for SCS. CONCLUSIONS: Coverage with evidence development studies may yield important information not apparent from randomized clinical trials concerning long-term risks and benefits of a therapy in clinical practice for specific subpopulations, but are likely to be met with criticism from interested parties. ______________________________________________________________________________ Treatment of urinary voiding dysfunction syndromes with spinal

cord stimulation.

Yakovlev AE, Resch BE. Clin Med Res. 2010 Mar;8(1):22-4. Comprehensive Pain Management of the Fox Valley, SC 820 East Grant Street Suite 335 Appleton, Wisconsin 54911, USA. dryakovlev@foxvalleypainmd.com

This case report presents the use of spinal cord stimulation (SCS) in a patient with urinary incontinence who had previously undergone trial and implantation of InterStim therapy (Medtronic Neurological, Minneapolis, MN). The patient also experienced bilateral lower extremity pain and low back pain related to post-laminectomy syndrome. Having failed all conservative treatment, the patient underwent SCS trial and subsequent implantation. In the postoperative period using SCS therapy, the patient had excellent relief of urinary incontinence symptoms, along with relief of low back pain and bilateral lower extremity pain and was able to discontinue use of InterStim therapy. For this patient, SCS was effective in controlling the urinary voiding dysfunction symptoms, bilateral lower extremity pain and back pain. The use of SCS to treat urinary incontinence problems deserves further study to explore its therapeutic potentials. ______________________________________________________________________________ Ultrasound-guided transversus abdominis plane block for spinal

infusion and neurostimulation implantation in two patients with

chronic pain.

Asensio-Samper JM, De Andrés-Ibáñez J, Fabregat Cid G, Villanueva Pérez V, Alarcón L. Pain Pract. 2010 Mar;10(2):158-62. Epub 2010 Jan 8.

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Anesthesia, Critical Care and Multidisciplinary Unit for Pain Management, Valencia University General Hospital, 46014 Valencia, Spain. jmasensiosamper@hotmail.com.

OBJECTIVE: This case report describes an ultrasound approach to the transversus abdominis plane (TAP) local anesthetic block. This block induces sensory blockade in the lower half of the abdomen where the pulse generator or the infusion pump is to be housed in a subcutaneous pocket, and therefore provides an alternate to general anesthesia or administration of high-dose local anesthetics. CASE REPORT: We report two cases of neuromodulation procedures implantation of an internal morphine pump for severe somatic pain refractory to other therapies and placement of a double-stimulator generator for dorsal column stimulation in a patient diagnosed with postoperative failed-back syndrome. We successfully used ultrasound-guided TAP block to achieve ipsilateral sensory block of dermatomes T9-L1 in the context of a monitored anesthesia care multimodal approach. CONCLUSION: TAP block can be a potentially useful substitute to general anesthesia or local anesthesia for the pocket formation in neuromodulation techniques, and it provides adequate anesthesia of the abdominal wall. This block is potentially an important addition to the monitored anesthesia care protocol. ______________________________________________________________________________

Clinical applications of neurostimulation: forty years later.

Mekhail NA, Cheng J, Narouze S, Kapural L, Mekhail MN, Deer T. Pain Pract. 2010 Mar;10(2):103-12. Epub 2010 Jan 8. Department of Pain Management,Anesthesiology Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA. mekhain@ccf.org.

With the recent technological advances, neurostimulation has provided new hope for millions of patients with debilitating chronic pain conditions that respond poorly to other therapies. Outcome research demonstrated that patients with failed back surgery syndrome and complex regional pain syndromes benefit significantly from neurostimulation in pain reduction, functional capacity, and quality of life. Increasing clinical evidence supports the use of neurostimulation in post-herpetic neuralgia, peripheral neuropathy, occipital neuralgia, and other neuropathic pain conditions. Strong clinical evidences indicate that neurostimulation offers less invasive and more effective therapies for many patients with ischemic pain caused by cardiovascular and peripheral vascular diseases. A growing body of literature supports neurostimulation for visceral pain in general and interstitial cystitis in particular. As a basic principle, patient selection for the appropriate neurostimulation Seite 14 von 61 modalities is essential for safe, efficacious, and cost-effective applications of this therapy. Research with more vigorous designs is needed to establish evidence-based applications of neuromodulation therapy in emerging indications of pain management. ______________________________________________________________________________ Spinal cord stimulation as a treatment for refractory neuropathic

pain in tethered cord syndrome: a case report.

Moens M, De Smedt A, D'Haese J, Droogmans S, Chaskis C. J Med Case Reports. 2010 Feb 25;4:74. Department of Neurosurgery, UZ Brussel, Laarbeeklaan, Brussels, 1090, Belgium. mtmoens@gmail.com.

INTRODUCTION: The spinal cord is a target for many neurosurgical procedures used to treat chronic severe pain. Neuromodulation and neuroablation are surgical techniques based on well-known specific anatomical structures. However, anatomical and electrophysical changes related to the tethered spinal cord make it more difficult to use these procedures. CASE PRESENTATION: We report the case of a 37-year-old Caucasian woman who had several surgical interventions for tethered cord syndrome. These interventions resulted in severe neuropathic pain in her lower back and right leg. This pain was treated by spinal cord stimulation using intra-operative sensory mapping, which allowed the cord's optimal placement in a more caudal position. CONCLUSION: The low-voltage and more caudally placed electrodes are specific features of this treatment of tethered cord syndrome. ______________________________________________________________________________

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Modulation of neuronal activity after spinal cord stimulation for

neuropathic pain; H(2)15O PET study.

Kishima H, Saitoh Y, Oshino S, Hosomi K, Ali M, Maruo T, Hirata M, Goto T, Yanagisawa T, Sumitani M, Osaki Y, Hatazawa J, Yoshimine T. Neuroimage. 2010 Feb 1;49(3):2564-9. Epub 2009 Oct 27. Department of Neurosurgery, Osaka University, Graduated school of Medicine, Suita, Osaka, Japan.

Spinal cord stimulation (SCS) is an effective therapy for chronic neuropathic pain. However, the detailed mechanisms underlying its effects are not well understood. Positron emission tomography (PET) with H(2)(15)O was applied to clarify these mechanisms. Nine patients with intractable neuropathic pain in the lower limbs were included in the study. All patients underwent SCS therapy for intractable pain, which was due to failed back surgery syndrome in three patients, complex regional pain syndrome in two, cerebral hemorrhage in two, spinal infarction in one, and spinal cord injury in one. Regional cerebral blood flow (rCBF) was measured by H(2)(15)O PET before and after SCS. The images were analyzed with statistical parametric mapping software (SPM2). SCS reduced pain; visual analog scale values for pain decreased from 76.1+/-25.2 before SCS to 40.6+/-4.5 after SCS (mean+/-SE). Significant rCBF increases were identified after SCS in the thalamus contralateral to the painful limb and in the bilateral parietal association area. The anterior cingulate cortex (ACC) and prefrontal areas were also activated after SCS. These results suggest that SCS modulates supraspinal neuronal activities. The contralateral thalamus and parietal association area would regulate the pain threshold. The ACC and prefrontal areas would control the emotional aspects of intractable pain, resulting in the reduction of neuropathic pain after SCS. ______________________________________________________________________________ Spinal cord stimulation in a workers' compensation population: how

difficult it can be to interpret a clinical trial.

Wasan AD. Pain. 2010 Jan;148(1):3-4. Epub 2009 Nov 11. Brigham and Women's Hospital/Harvard Medical School, Anesthesiology, Perioperative and Pain Medicine, Pain Mangement Center 850 Boylston St., Boston, MA 02467, USA. awasan@partners.org

Comment in Pain. 2010 May;149(2):406-7. Comment on Pain. 2010 Jan;148(1):14-25. ______________________________________________________________________________ Spinal cord stimulation for failed back surgery syndrome: outcomes

in a workers' compensation setting.

Turner JA, Hollingworth W, Comstock BA, Deyo RA. Pain. 2010 Jan;148(1):14-25. Epub 2009 Oct 28. Department of Psychiatry & Behavioral Sciences and Department of Rehabilitation Medicine, University of Washington, 1959 NE Pacific St., Room BB1517a, Box 356560, Seattle, WA 98195-6560, USA. jturner@u.washington.edu

Comment in Pain. 2010 Jan;148(1):3-4. Med Care. 2011 Sep;49(9):e28. Questions remain concerning effectiveness and risks of spinal cord stimulation (SCS) for chronic back and leg pain after spine surgery ("failed back surgery syndrome" [FBSS]). This prospective, population-based controlled cohort study evaluated outcomes of workers' compensation recipients with FBSS who received at least a trial of SCS (SCS group, n=51) versus those who (1) were evaluated at a multidisciplinary pain clinic and did not receive SCS (Pain Clinic, n=39) or (2) received neither SCS nor pain clinic evaluation (Usual Care, n=68). Patients completed measures of pain, function, medication use, and work status at baseline and 6, 12, and 24 months later. We also examined work time loss compensation over 24 months. Few (<10%) patients in any group achieved success at any follow-up on the composite primary outcome encompassing less than daily opioid use and improvement in leg pain and function. At 6 months, the SCS group showed modestly greater improvement in leg pain and function, but with higher rates of daily opioid use.

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These differences disappeared by 12 months. Patients who received a permanent spinal cord stimulator did not differ from patients who received some pain clinic treatment on the primary outcome at any follow-up (<10% successful in each group at each follow-up) and 19% had them removed within 18 months. Both trial and permanent SCS were associated with adverse events. In sum, we found no evidence for greater effectiveness of SCS versus alternative treatments in this patient population after 6 months. ______________________________________________________________________________ Novel use of intraoperative dexmedetomidine infusion for sedation

during spinal cord stimulator lead placement via surgical

laminectomy.

Harned ME, Owen RD, Steyn PG, Hatton KW. Pain Physician. 2010 Jan;13(1):19-22 University of Kentucky, Lexington, KY 40536, USA. meharn2@email.uky.edu.

BACKGROUND: Spinal cord stimulators are most often placed through a percutaneous approach using minimal sedation and local anesthesia to facilitate intraoperative testing. However, when leads need to be placed using a laminectomy incision additional anesthesia is required which can complicate intraoperative testing. There is no consensus as to the best anesthetic choice when laminectomy-placed leads are required. OBJECTIVE: We present 2 cases where spinal cord stimulator leads were implanted through a surgical laminectomy under sedation using dexmedetomidine infusion and local anesthesia to provide a cooperative patient for intraoperative testing. CASE REPORT: Patient #1: A 40-year-old female with Complex Regional Pain Syndrome secondary to an automobile accident who had good pain control with a spinal cord stimulator until a lead fracture resulted in loss of stimulation. She required a laminectomy-placed lead which was implanted under dexmedetomidine infusion and local anesthesia. Patient #2: A 54-year-old female with Failed Back Syndrome who had good pain control until a lead fracture resulted in loss of stimulation. She underwent a laminectomy-placed lead, new battery pocket, and removal of the old system under a dexmedetomidine infusion and local anesthesia. LIMITATIONS: Report of only 2 cases. CONCLUSIONS: The anesthetic management from a laminectomy-placed spinal cord stimulator can present a difficult choice. A general anesthetic or even deep sedation can provide good operative conditions but limits intraoperative testing or in the case of deep sedation risks losing the airway in the prone position. On the other hand, minimal sedation, which facilitates intraoperative testing, can make the surgical procedure extremely uncomfortable or even unbearable. Dexmedetomidine infusion and local anesthesia provide sedation for the operative portions while rendering the patient alert and cooperative during intraoperative testing. ______________________________________________________________________________ Spinal cord stimulation for chronic pain.

Jeon Y, Huh BK. Ann Acad Med Singapore. 2009 Nov;38(11):998-1003. Department of Anesthesiology and Pain Medicine, Kyungpook National University Hospital, Republic of Korea.

Spinal cord stimulation (SCS) is one of the most effective modalities for management of refractory neuropathic pain unresponsive to conservative therapies. The SCS has been successful in providing analgesia, improving function, and enhancing quality of life for patients suffering from chronic pain conditions such as failed back surgery syndrome, complex regional pain syndrome, ischaemic and phantom limb pain, and coronary artery disease. This technique has proven to be cost effective in the long term despite its high initial cost. In this review article, we discuss the history of SCS development, mechanism of action, and indications for SCS. ______________________________________________________________________________ Spinal cord stimulation. [Article in Japanese]

Fukazawa K, Hosokawa T. Masui. 2009 Nov;58(11):1393-400. Department of Pain Treatment and Palliative Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566.

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Spinal cord stimulation (SCS) is an established treatment for intractable neuropathic pain. SCS is performed using an implantable pulse generator connected to leads with electrodes positioned in the dorsal epidural space, which are then used to stimulate the ascending and descending dorsal column fibres to achieve paresthesia covering the area of pain. It is based on the Gate Control Theory, introduced by Melzack and Wall in 1965, which suggests that stimulation of large afferent fibres can inhibit pain transmission at the level of the dorsal horns. More recent studies indicate that SCS releases substance P serotonin, noradrenaline and GABA in the dorsal horns; activation of the GABAB receptor may be linked to a decrease in the release of glutamate and other excitatory amino acids, resulting in a decrease of neuropathic pain. The clinical indications for SCS are mainly peripheral vascular diseases (PVD), refractory angina, failed back surgery syndrome (FBSS), complex regional pain syndrome (CRPS) type 1 and type 2, spinal cord stenosis and neuropathic pain. The new puncture trial method is less invasive and can reduce psychological resistance of the patient for SCS manipulation. ______________________________________________________________________________ Spinal cord stimulation: principles of past, present and future

practice: a review.

Kunnumpurath S, Srinivasagopalan R, Vadivelu N. J Clin Monit Comput. 2009 Oct;23(5):333-9. St George's School of Anaesthesia, Tooting, London, UK. dreeku@doctors.org.uk

Electric energy have been in use for the treatment of various ailments, including pain, since the time of Pharaohs. The theoretical basis of electrotherapy of pain was provided by the Gate Control Theory of Melzak and Wall. In 1965, Shealey et al. first introduced electrical stimulation of spinal cord for treating pain. At present spinal cord stimulation (SCS) is a well established form of treatment for failed back surgery syndrome, complex regional pain syndrome and refractory pain due to ischemia. The indications for SCS is growing and the technology involved in this is rapidly advancing, however, high level of scientific evidence is still lacking to support this form of therapy due to difficulties in blinding and comparing with control groups. Future developments in SCS could include, combined SCS-drug delivery system, bio feedback and closed loop systems. ______________________________________________________________________________ Generating evidence on spinal cord stimulation for failed back

surgery syndrome: not yet fully charged. Clin j pain. 2008;24:757-

758.

North RB, Shipley J, Taylor RS. Clin J Pain. 2009 Sep;25(7):650; author reply 651.

Comment on Clin J Pain. 2008 Nov-Dec;24(9):757-8. ______________________________________________________________________________ Spinal cord stimulation for control of low back pain after

multiple corrective surgeries for severe scoliosis: report of a

case.

Canlas BR, Yap AN, Fernando BY, Paiso JM. Pain Pract. 2009 Sep-Oct;9(5):404-5.

Kein Abstract vorhanden. ______________________________________________________________________________ Spinal cord and peripheral nerve stimulation techniques for

neuropathic pain.

de Leon-Casasola OA. J Pain Symptom Manage. 2009 Aug;38(2 Suppl):S28-38. Department of Anesthesiology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA. oscar.deleon@roswellpark.org

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When comprehensive medical pharmacological therapy titrated to maximum doses fails to provide an appropriate level of analgesia, or side effects associated with these therapies impair the ability to increase the doses to obtain appropriate therapeutic effects in patients with a variety of chronic neuropathic pain conditions, alternative methods, such as spinal cord stimulation and peripheral nerve stimulation, are effective alternative options. This article discusses important concepts to consider when implementing spinal cord and peripheral nerve stimulation therapy for the treatment of neuropathic pain conditions other than failed back surgery syndrome. The focus is primarily on post-surgical pain syndromes, which are frequently encountered in daily clinical practice. ______________________________________________________________________________ Spinal cord stimulation: a 20-year retrospective analysis in 260

patients.

Reig E, Abejón D. Neuromodulation. 2009 Jul;12(3):232-9. doi: 10.1111/j.1525-1403.2009.00220.x. Clínica del Dolor de Madrid, Madrid, Spain; and Pain Unit, Puerta de Hierro University Hospital, Madrid, Spain.

Introduction. Spinal cord stimulation (SCS) is used clinically by many pain physicians and neurosurgeons alike without regard to their own outcome data. Methods. We reviewed our 20-year experience retrospectively of patients receiving SCS implants and analyzed our data by pain type and group. Results. We present 260 patients, 140 men and 120 women. The most frequent type of pain in our series was neuropathic pain in 44.25% and the most frequent diagnosis was peripheral vascular disease (PVD) with 98 cases. The second was failed back surgery syndrome (FBSS) with 65 cases and the third was complex regional pain syndrome type I (CRPS I), with 40 cases. In CRPS group, the mean visual analog scale (VAS) of this group was 77.89 ± 13.38. In total, 5% had no pain relief, 40% had poor pain relief, 47.5% had good pain relief, and 7.5% had excellent pain relief. In FBSS group, the mean VAS was 79.62 ± 11.69 mm. A total of 13.80% had no pain relief at all, 35.39% had poor pain relief, 50.76% had good pain relief, and there were no patients in this group who had complete pain relief. A total of 98 patients, 78 men and 20 women, were diagnosed with PVD. The mean VAS of this group was 69.75 ± 14.36 mm. A total of 11.22% had poor pain relief, 87.75% had good pain relief. One patient had complete pain relief and all patients in this group perceived at least some improvement in their symptoms. The rate of complications was close to 28% in our overall sample. Conclusions. In conclusion, we demonstrated the utility over time of this type of treatment is comparable with other series of efficacy of SCS. The analgesic efficacy was close to 65% in the overall group. The therapy was not free of complications. The preponderance of our patients was patients with the diagnosis of PVD and our results in this group of patients were excellent. These excellent results of more than 90% improvement suggest to us that SCS be considered as a first-line approach to the clinical management of patients with pain and ulcer of PVD. ______________________________________________________________________________ Comprehensive evidence-based guidelines for interventional

techniques in the management of chronic spinal pain.

Manchikanti L, Boswell MV, Singh V, Benyamin RM, Fellows B, Abdi S, Buenaventura RM, Conn A, Datta S, Derby R, Falco FJ, Erhart S, Diwan S, Hayek SM, Helm S, Parr AT, Schultz DM, Smith HS, Wolfer LR, Hirsch JA; ASIPP-IPM. Pain Physician. 2009 Jul-Aug;12(4):699-802. Pain Management Center of Paducah, Paducah, KY, USA. drlm@thepainmd.com

BACKGROUND: Comprehensive, evidence-based guidelines for interventional techniques in the management of chronic spinal pain are described here to provide recommendations for clinicians. OBJECTIVE: To develop evidence-based clinical practice guidelines for interventional techniques in the diagnosis and treatment of chronic spinal pain. DESIGN: Systematic assessment of the literature. METHODS: Strength of evidence was assessed by the U.S. Preventive Services Task Force (USPSTF) criteria utilizing 5 levels of evidence ranging from Level I to III with 3 subcategories in Level II. OUTCOMES: Short-term pain relief was defined as relief lasting at least 6 months and long-term relief was defined as longer than 6 months, except for intradiscal therapies, mechanical disc decompression, spinal cord stimulation and intrathecal infusion systems, wherein up to one year relief was considered as short-term. RESULTS: The indicated

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evidence for accuracy of diagnostic facet joint nerve blocks is Level I or II-1 in the diagnosis of lumbar, thoracic, and cervical facet joint pain. The evidence for lumbar and cervical provocation discography and sacroiliac joint injections is Level II-2, whereas it is Level II-3 for thoracic provocation discography. The indicated evidence for therapeutic interventions is Level I for caudal epidural steroid injections in managing disc herniation or radiculitis, and discogenic pain without disc herniation or radiculitis. The evidence is Level I or II-1 for percutaneous adhesiolysis in management of pain secondary to post-lumbar surgery syndrome. The evidence is Level II-1 or II-2 for therapeutic cervical, thoracic, and lumbar facet joint nerve blocks; for caudal epidural injections in managing pain of post-lumbar surgery syndrome, and lumbar spinal stenosis, for cervical interlaminar epidural injections in managing cervical pain (Level II-1); for lumbar transforaminal epidural injections; and spinal cord stimulation for post-lumbar surgery syndrome. The indicated evidence for intradiscal electrothermal therapy (IDET), mechanical disc decompression with automated percutaneous lumbar discectomy (APLD), and percutaneous lumbar laser discectomy (PLDD) is Level II-2. LIMITATIONS: The limitations of these guidelines include a continued paucity of the literature, lack of updates, and conflicts in preparation of systematic reviews and guidelines by various organizations. CONCLUSION: The indicated evidence for diagnostic and therapeutic interventions is variable from Level I to III. These guidelines include the evaluation of evidence for diagnostic and therapeutic procedures in managing chronic spinal pain and recommendations for managing spinal pain. However, these guidelines do not constitute inflexible treatment recommendations. Further, these guidelines also do not represent "standard of care." ______________________________________________________________________________ Spinal cord stimulation as a novel approach to the treatment of

refractory neuropathic mediastinal pain.

Guttman OT, Hammer A, Korsharskyy B. Pain Pract. 2009 Jul-Aug;9(4):308-11. Epub 2009 May 15. Department of Anesthesiology, Pain Management Division, Mount Sinai School of Medicine, New York, New York 10029, USA. oren.guttman@mssm.edu

Spinal cord stimulation (SCS) offers new hope for patients with neuropathic pain. SCS "neuromodulates" the transmission and response to "painful" stimuli. The efficacy of SCS has been established in the treatment of a variety of neuropathic pain conditions and more recently in refractory angina pectoris, peripheral vascular disease, and failed back surgery syndrome. Recent publications suggest that visceral pain could be successfully treated with SCS. We report the first successful use of a spinal cord stimulator in the treatment of refractory neuropathic mediastinal, esophageal, and anterior neck pain following esophagogastrectomy. ______________________________________________________________________________ Pretreatment psychosocial variables as predictors of outcomes

following lumbar surgery and spinal cord stimulation: a systematic

review and literature synthesis.

Celestin J, Edwards RR, Jamison RN. Pain Med. 2009 May-Jun;10(4):639-53. Psychiatry Department, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.

BACKGROUND: In the multimodal treatment approach to chronic back pain, interventional back procedures are often reserved for those who do not improve after more conservative management. Psychological screening prior to lumbar surgery or spinal cord stimulation (SCS) has been widely recommended to help identify suitable candidates and to predict possible complications or poor outcome from treatment. However, it remains unclear which, if any, variables are most predictive of pain-related treatment outcomes. OBJECTIVE: The intent of this article is to perform a systematic review to examine the relationship between presurgical predictor variables and treatment outcomes, to review the existing evidence for the benefit of psychological screening prior to lumbar surgery or SCS, and to make treatment recommendations for the use of psychological screening. RESULTS: Out of 753 study titles, 25 studies were identified, of which none were randomized controlled trials and only four SCS studies met inclusion criteria. The methodological quality of the studies varied and some important shortcomings were identified. A positive relationship was found between one or more psychological factors and poor treatment outcome in

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92.0% of the studies reviewed. In particular, presurgical somatization, depression, anxiety, and poor coping were most useful in helping to predict poor response (i.e., less treatment-related benefit) to lumbar surgery and SCS. Older age and longer pain duration were also predictive of poorer outcome in some studies, while pretreatment physical findings, activity interference, and presurgical pain intensity were minimally predictive. CONCLUSIONS: At present, while there is insufficient empirical evidence that psychological screening before surgery or device implantation helps to improve treatment outcomes, the current literature suggests that psychological factors such as somatization, depression, anxiety, and poor coping, are important predictors of poor outcome. More research is needed to show if early identification and treatment of these factors through psychological screening will enhance treatment outcome. ______________________________________________________________________________ Demographic characteristics of patients with severe neuropathic

pain secondary to failed back surgery syndrome.

Thomson S, Jacques L. Pain Pract. 2009 May-Jun;9(3):206-15. Epub 2009 Mar 5. Pain Clinic, Basildon and Thurrock University Hospitals, Basildon, UK. simon.thomson@btuh.nhs.uk

BACKGROUND: Neuropathic pain commonly affects the back and legs and is associated with severe disability and psychological illness. It is unclear how patients with predominantly neuropathic pain due to failed back surgery syndrome (FBSS) compare with patients with other chronic pain conditions. AIMS: To present data on characteristics associated with FBSS patients compared with those with complex regional pain syndrome, rheumatoid and osteoarthritis, and fibromyalgia. METHODS: The PROCESS (Prospective Randomized Controlled Multicenter Trial of the Effectiveness of Spinal Cord Stimulation, ISRCTN 77527324) trial randomized 100 patients to spinal cord stimulation (n = 52) plus conventional medical management (CMM) or CMM alone (n = 48). Baseline patient parameters included age, sex, time since last surgery, employment status, pain location and severity (visual analogue scale), health-related quality of life (HRQoL), level of disability, medication, and nondrug therapies. Reference population data was drawn from the literature. RESULTS: At baseline, patients in the PROCESS study had a similar age and gender profile compared with other conditions. PROCESS patients suffered from greater leg pain and had lower HRQoL. PROCESS patients treatment cost was higher and they commonly took opioids, while antidepressants and nonsteroidal anti-inflammatory drugs were more often used for other conditions. Prior to baseline, 87% of patients had tried at least 4 different treatment modalities. CONCLUSIONS: Patients suffering from chronic pain of neuropathic origin following FBSS often fail to obtain adequate relief with conventional therapies (eg, medication, nondrug therapies) and suffer greater pain and lower HRQoL compared with patients with other chronic pain conditions. Neuropathic FBSS patients may require alternative and possibly more (cost-) effective treatments, which should be considered earlier in their therapeutic management. ______________________________________________________________________________ Nonsurgical interventional therapies for low back pain: a review

of the evidence for an American Pain Society clinical practice

guideline.

Chou R, Atlas SJ, Stanos SP, Rosenquist RW. Spine (Phila Pa 1976). 2009 May 1;34(10):1078-93. Department of Medicine, Oregon Evidence-Based Practice Center, Oregon Health and Science University, Portland, OR, USA. chour@ohsu.edu

Comment in Ann Intern Med. 2009 Oct 20;151(8):JC4-10, JC4-11. Evid Based Med. 2009 Dec;14(6):180-1. Spine (Phila Pa 1976). 2010 Apr 1;35(7):841; author reply 841-2. STUDY DESIGN: Systematic review. OBJECTIVE: To systematically assess benefits and harms of nonsurgical interventional therapies for low back and radicular pain. SUMMARY OF BACKGROUND DATA: Although use of certain interventional therapies is common or increasing, there is also uncertainty or controversy about their efficacy. METHODS: Electronic database

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searches on Ovid MEDLINE and the Cochrane databases were conducted through July 2008 to identify randomized controlled trials and systematic reviews of local injections, botulinum toxin injection, prolotherapy, epidural steroid injection, facet joint injection, therapeutic medial branch block, sacroiliac joint injection, intradiscal steroid injection, chemonucleolysis, radiofrequency denervation, intradiscal electrothermal therapy, percutaneous intradiscal radiofrequency thermocoagulation, Coblation nucleoplasty, and spinal cord stimulation. All relevant studies were methodologically assessed by 2 independent reviewers using criteria developed by the Cochrane Back Review Group (for trials) and by Oxman (for systematic reviews). A qualitative synthesis of results was performed using methods adapted from the US Preventive Services Task Force. RESULTS: For sciatica or prolapsed lumbar disc with radiculopathy, we found good evidence that chemonucleolysis is moderately superior to placebo injection but inferior to surgery, and fair evidence that epidural steroid injection is moderately effective for short-term (but not long-term) symptom relief. We found fair evidence that spinal cord stimulation is moderately effective for failed back surgery syndrome with persistent radiculopathy, though device-related complications are common. We found good or fair evidence that prolotherapy, facet joint injection, intradiscal steroid injection, and percutaneous intradiscal radiofrequency thermocoagulation are not effective. Insufficient evidence exists to reliably evaluate other interventional therapies. CONCLUSION: Few nonsurgical interventional therapies for low back pain have been shown to be effective in randomized, placebo-controlled trials. ______________________________________________________________________________ Rare Side-effects during Spinal Cord Stimulation: Gastrointestinal

Symptoms.

La Grua M. Neuromodulation. 2009 Apr;12(2):161-3. doi: 10.1111/j.1525-1403.2009.00202.x. Department of Anesthesiology and Critical Care, Pain Unit, "Misericordia e Dolce" Hospital, Prato, Italy.

In current medical literature, most reported complications during spinal cord stimulation (SCS) concern technical problems, such as malfunction, migration or breakage of the lead, or internal pulse generator dysfunction, while reports about side-effects caused by SCS are rare. In this clinical report, we describe uncommon and unexplained gastrointestinal (GI) side-effects of constipation, abdominal pain, and distension during SCS in a patient suffering for chronic neuropathic pain caused by failed back surgery syndrome. These GI symptoms disappeared after suspension of SCS and were reduced if the stimulation settings were reduced below paresthesia threshold. The symptoms experienced by our patient could be related to a functional and reversible block of parasympathetic outflow in the GI system since SCS may involve not only dorsal horn structures but also somatic and visceral sensory afferents to these structures in an unpredictable way. ______________________________________________________________________________ Modern potentialities of minimally invasive management of chronic

non-malignant pain. [Article in Russian]

Seeleger A. Zh Vopr Neirokhir Im N N Burdenko. 2009 Apr-Jun;(2):42-6; discussion 46-8.

In this retrospective investigation we demonstrated our results of treatment of chronic pain of nonmalignant etiology. The long-term effects of neuromodulation systems were examined in 215 patients with chronic nonmalignant pain syndromes. The mean follow-up period was 4 years. Most of the patients were satisfied with the therapy and have had good pain reduction throughout the follow-up period. In this study we analyzed the indications, selection of patients and the test phase for this kind of therapy. Neuromodulation included spinal cord stimulation (SCS) and intrathecal opioid therapy. We reported about the standards of implantation, the side effects and complications and failures of treatment. Our experience with the long-term administration of spinal opioid medications and SCS for nonmalignant pain encouraged us to use methods of neuromodulation for carefully selected patients. Good results with significant pain reduction demonstrated the consideration this kind of treatment about the conservative therapy. ______________________________________________________________________________

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Spinal cord stimulation for chronic pain of neuropathic or

ischaemic origin: systematic review and economic evaluation.

Simpson EL, Duenas A, Holmes MW, Papaioannou D, Chilcott J. Health Technol Assess. 2009 Mar;13(17):iii, ix-x, 1-154. School of Health and Related Research, The University of Sheffield, UK.

OBJECTIVES: This report addressed the question 'What is the clinical and cost-effectiveness of spinal cord stimulation (SCS) in the management of chronic neuropathic or ischaemic pain?' DATA SOURCES: Thirteen electronic databases [including MEDLINE (1950-2007), EMBASE (1980-2007) and the Cochrane Library (1991-2007)] were searched from inception; relevant journals were hand-searched; and appropriate websites for specific conditions causing chronic neuropathic/ischaemic pain were browsed. Literature searches were conducted from August 2007 to September 2007. REVIEW METHODS: A systematic review of the literature sought clinical and cost-effectiveness data for SCS in adults with chronic neuropathic or ischaemic pain with inadequate response to medical or surgical treatment other than SCS. Economic analyses were performed to model the cost-effectiveness and cost-utility of SCS in patients with neuropathic or ischaemic pain. RESULTS: From approximately 6000 citations identified, 11 randomised controlled trials (RCTs) were included in the clinical effectiveness review: three of neuropathic pain and eight of ischaemic pain. Trials were available for the neuropathic conditions failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS) type I, and they suggested that SCS was more effective than conventional medical management (CMM) or reoperation in reducing pain. The ischaemic pain trials had small sample sizes, meaning that most may not have been adequately powered to detect clinically meaningful differences. Trial evidence failed to demonstrate that pain relief in critical limb ischaemia (CLI) was better for SCS than for CMM; however, it suggested that SCS was effective in delaying refractory angina pain onset during exercise at short-term follow-up, although not more so than coronary artery bypass grafting (CABG) for those patients eligible for that surgery. The results for the neuropathic pain model suggested that the cost-effectiveness estimates for SCS in patients with FBSS who had inadequate responses to medical or surgical treatment were below 20,000 pounds per quality-adjusted life-year (QALY) gained. In patients with CRPS who had had an inadequate response to medical treatment the incremental cost-effectiveness ratio (ICER) was 25,095 pounds per QALY gained. When the SCS device costs varied from 5000 pounds to 15,000 pounds, the ICERs ranged from 2563 pounds per QALY to 22,356 pounds per QALY for FBSS when compared with CMM and from 2283 pounds per QALY to 19,624 pounds per QALY for FBSS compared with reoperation. For CRPS the ICERs ranged from 9374 pounds per QALY to 66,646 pounds per QALY. If device longevity (1 to 14 years) and device average price (5000 pounds to 15,000 pounds) were varied simultaneously, ICERs were below or very close to 30,000 pounds per QALY when device longevity was 3 years and below or very close to 20,000 pounds per QALY when device longevity was 4 years. Sensitivity analyses were performed varying the costs of CMM, device longevity and average device cost, showing that ICERs for CRPS were higher. In the ischaemic model, it was difficult to determine whether SCS represented value for money when there was insufficient evidence to demonstrate its comparative efficacy. The threshold analysis suggested that the most favourable economic profiles for treatment with SCS were when compared to CABG in patients eligible for percutaneous coronary intervention (PCI), and in patients eligible for CABG and PCI. In these two cases, SCS dominated (it cost less and accrued more survival benefits) over CABG. CONCLUSIONS: The evidence suggested that SCS was effective in reducing the chronic neuropathic pain of FBSS and CRPS type I. For ischaemic pain, there may need to be selection criteria developed for CLI, and SCS may have clinical benefit for refractory angina short-term. Further trials of other types of neuropathic pain or subgroups of ischaemic pain, may be useful. ______________________________________________________________________________ Spinal cord stimulation for patients with failed back surgery

syndrome: a systematic review.

Frey ME, Manchikanti L, Benyamin RM, Schultz DM, Smith HS, Cohen SP. Pain Physician. 2009 Mar-Apr;12(2):379-97. Advanced Pain Management and Spine Specialists, Fort Myers, FL 33919, USA. mfreymd@comcast.net

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BACKGROUND: Failed back surgery syndrome is common in the United States. Management of post lumbar surgery syndrome with multiple modalities includes interventional techniques, resulting in moderate improvement, leaving a proportion of patients in intractable pain. The systematic reviews of long-term benefits and risks of spinal cord stimulation (SCS) for patients with failed back surgery syndrome showed limited to moderate evidence and cost effectiveness. However, with the exponential increase in surgery in the United States, spinal cord implants are also increasing. Thus, the discussion continues with claims of lack of evidence on one hand and escalating increases in utilization on the other hand. STUDY DESIGN: A systematic review of SCS in patients with failed back surgery syndrome. OBJECTIVES: This systematic review is undertaken to examine the evidence from randomized controlled trials (RCTs) and observational studies to evaluate the effectiveness of SCS in post lumbar surgery syndrome and to demonstrate clinical and cost effectiveness. METHODS: Review of the literature was performed according to the Cochrane Musculoskeletal Review Group Criteria as utilized for interventional techniques for randomized trials and the Agency for Healthcare Research and Quality (AHRQ) criteria for observational studies. The 5 levels of evidence were classified as Level I, II, or III with 3 subcategories in Level II based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF). Data sources included relevant literature of the English language identified through searches of PubMed and EMBASE from 1966 to December 2008, and manual searches of bibliographies of known primary and review articles. OUTCOME MEASURES: The primary outcome measure was pain relief (short-term relief < or = one-year and long-term > one-year). Secondary outcome measures of improvement in functional status, psychological status, return to work, and reduction in opioid intake were utilized. RESULTS: The indicated evidence is Level II-1 or II-2 for long-term relief in managing patients with failed back surgery syndrome. LIMITATIONS: The limitations of this review included the paucity and heterogeneity of the literature. CONCLUSION: This systematic review evaluating the effectiveness of SCS in relieving chronic intractable pain of failed back surgery syndrome indicated the evidence to be Level II-1 or II-2 for clinical use on a long-term basis. ______________________________________________________________________________ Spinal cord stimulation: a basic approach.

Brook AL, Georgy BA, Olan WJ. Tech Vasc Interv Radiol. 2009 Mar;12(1):64-70. Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10467-2490, USA. abrook2214@aol.com

Chronic back pain and other refractory pain syndromes are a documented burden on our society. They also are a huge cost in quality of life and dollars spent on health care. Neuromodulation and specifically dorsal column stimulation of the spinal cord has been shown to decrease pain with minimal risk to the patient. We describe in this article the basic techniques and methods of both the stimulation trial and the permanent implantation of the leads and generator. With advanced imaging and the minimally invasive approach we further explain how to minimize any risk associated with this percutaneous procedure. ______________________________________________________________________________ Spinal cord stimulation compared with medical management for

failed back surgery syndrome.

Coleman SD, Mackey S. Curr Pain Headache Rep. 2009 Feb;13(1):1-2. Stanford University School of Medicine, 780 Welch Road, Palo Alto, CA 94304-1573, USA. coleman169@comcast.net

Kein Abstract vorhanden. ______________________________________________________________________________ Spinal cord stimulation for complex regional pain syndrome.

Shrivastav M, Musley S. Conf Proc IEEE Eng Med Biol Soc. 2009;2009:2033-6.

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Medtronic Neuromodulation, 7000 Central Ave NE, Minneapolis, Minnesota, 55432 USA. shaileshkumar.musley@medtronic.com

The therapy of spinal cord stimulation (SCS) is based on producing an electrical field on the dorsal surface of the spinal cord that blocks only neuropathic pain (ie, pain from damage to the nervous system). Most SCS devices deliver a biphasic pulse consisting of a pair of equal amplitude pulses with opposite polarity. SCS therapy is based on the gate control theory of pain and has been used for the treatment of diverse conditions of neuropathic pain, including complex regional pain syndromes (CRPS). In addition to CRPS, SCS is helpful in patients with failed back surgery syndrome, degenerative disk disease, and in patients with peripheral neuropathies. When used in the right patient, SCS provides significant pain relief in a majority of patients with CRPS. This review focuses on the effects of SCS on CRPS. In addition, an overview of the state of the art technologies used for implantable SCS medical devices is also provided. ______________________________________________________________________________ Generating evidence on spinal cord stimulation for failed back

surgery syndrome: not yet fully charged.

Chou R. Clin J Pain. 2008 Nov-Dec;24(9):757-8.

Comment in Clin J Pain. 2009 Sep;25(7):650; author reply 651. Comment on Clin J Pain. 2008 Nov-Dec;24(9):741-56. ______________________________________________________________________________ Systematic review of the (cost-)effectiveness of spinal cord

stimulation for people with failed back surgery syndrome.

Bala MM, Riemsma RP, Nixon J, Kleijnen J. Clin J Pain. 2008 Nov-Dec;24(9):741-56. II Department of Internal Medicine, Jagiellonian University Medical College, Krakow, Poland. gosiabala@mp.pl

Comment in Clin J Pain. 2008 Nov-Dec;24(9):757-8. OBJECTIVES: We conducted a systematic review to assess the (cost)effectiveness of spinal cord stimulation (SCS) in relieving certain kinds of pain for people with chronic pain owing to failed back surgery syndrome (FBSS). METHODS: We considered randomized trials, controlled observational studies of adult patients with chronic pain owing to FBSS, and case series with at least 50 patients permanently implanted, at least 60% FBSS patients and at least 1-year follow-up. SCS was additional to usual care and compared with usual care. The primary outcome was reduction of pain. Medline, Embase, Lilacs, Cinahl, and Cochrane Library databases were searched from inception until September 2006. An update search was carried out in January 2008. RESULTS: For the effectiveness analysis, 1 fully published randomized controlled trial, one randomized controlled trial with 6 month results (both of moderate quality), 1 retrospective cohort study, and 13 case series (all of low quality) were included. The mean period of follow-up was between 6 months and 8.8 years. These studies show that SCS is effective in the treatment of FBSS in terms of pain reduction. The effect was consistent in all analyzed studies. Improvements were also reported for other outcomes, such as quality of life and functional status. All the studies reported some complications, most of which were technical problems. In terms of cost-effectiveness, 3 studies met the inclusion criteria and offered the same conclusion that SCS is both more effective and less costly in the long-term, but there is an initial high cost associated with device implantation and maintenance. ______________________________________________________________________________ Quality of life, resource consumption and costs of spinal cord

stimulation versus conventional medical management in neuropathic

pain patients with failed back surgery syndrome (PROCESS trial).

Manca A, Kumar K, Taylor RS, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Buchser E, Fortini G, Richardson J, Taylor RJ, Goeree R, Sculpher MJ. Eur J Pain. 2008 Nov;12(8):1047-58. Epub 2008 Mar 21.

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Centre for Health Economics, Alcuin A Block, University of York, York YO10 5DD, United Kingdom. am126@york.ac.uk

Comment in Nat Clin Pract Neurol. 2008 Sep;4(9):472-3. BACKGROUND: Chronic back and leg pain conditions result in patients' loss of function, reduced quality of life and increased costs to the society. AIMS: To assess health-related quality of life (HRQoL) and cost implications of spinal cord stimulation plus non-surgical conventional medical management (SCS group) versus non-surgical conventional medical management alone (CMM group) in the management of neuropathic pain in patients with failed back surgery syndrome. METHODS: A total of 100 patients were randomised to either the SCS or CMM group. Healthcare resource consumption data relating to screening, the use of the implantable generator in SCS patients, hospital stay, and drug and non-drug pain-related treatment were collected prospectively. Resource consumption was costed using UK and Canadian 2005-2006 national figures. HRQoL was assessed using the EuroQol-5D (EQ-5D) questionnaire. Costs and outcomes were assessed for each patient over their first 6-months of the trial. RESULTS: The 6-month mean total healthcare cost in the SCS group (CAN$19,486; 12,653 euros) was significantly higher than in the CMM group (CAN$3994; 2594 euros), with a mean adjusted difference of CAN$15,395 (9997 euros) (p<0.001). However, the gain in HRQoL with SCS over the same period of time was markedly greater in the SCS group, with a mean EQ-5D score difference of 0.25 [p<0.001] and 0.21 [p<0.001], respectively at 3- and 6-months after adjusting for baseline variables. CONCLUSIONS: The addition of SCS to CMM in patients with neuropathic leg and back pain results in higher costs to health systems but also generates important improvements in patients' EQ-5D over the same period. ______________________________________________________________________________ Interventional pain therapy. [Article in Japanese]

Hosokawa T. Masui. 2008 Nov;57(11):1379-87. Pain Treatment & Palliative Care Unit, Univesity Hospital, Kyoto Prefectural University of Medicine, Kyoto.

Treatment of intractable chronic pain employs, nerve block, peripheral nerve stimulation, phototherapy, and drug therapy such as opioid and analgesia adjuvant. We also employ multi disciplinary approach with internal medicine, psychiatry and other related fields. In addition, in a portion of intractable chronic back pain, the pain relief is obtained by interventional approaches such as adhesionlysis and the neuroplasty with epiduroscopy as well as spinal cord stimulation therapy. ______________________________________________________________________________ Efficacy of a Single, Percutaneous, Across Midline, Octrode® Lead

Using a "Midline Anchoring" Technique in the Treatment of Chronic

Low Back and/or Lower Extremity Pain: A Retrospective Study.

Mironer YE, Satterthwaite JR, Lewis EM, Haasis JC, Latourette PC, Skoloff EM, Diaz RL. Neuromodulation. 2008 Oct;11(4):286-95. doi: 10.1111/j.1525-1403.2008.00178.x. Carolinas Center for Advanced Management of Pain, Asheville, NC-Hendersonville, NC-Greenville, SC-Greenwood, SC-Spartanburg, SC, USA; and Advanced Neuromodulation Systems Inc., Plano, TX, USA.

Introduction. Spinal cord stimulation is a widely used treatment modality for chronic pain, especially failed back surgery syndrome. However, migration of the lead or leads, coverage of axial pain, and the selection of an optimal system configuration continue to be subjects for serious debate. Materials and Methods. A retrospective study of the use of the method of "midline anchoring" of a single Octrode® lead, in 54 patients with low back and/or lower extremity pain, was done to assess the efficacy of this technique. Results. During the study period of 9.3 months, only a 4% revision rate was reported. Reduction in pain of more than 50% and individual patient satisfaction scores were very high (85% and 87%, respectively). Successful bilateral pain coverage was obtained with a single Octrode® lead. The lower extremities and buttocks area were captured in 89% of the patients. Axial pain coverage was achieved in the majority of the patients, with 71%

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reporting adequate coverage of the upper lumbar spine. A "guarded cathode" array was used in the vast majority of the cases, with a relatively low position of the lead. Conclusions. "Midline anchoring" of the spinal cord stimulation lead is an effective implantation technique, allowing the use of a single, percutaneous, Octrode® lead, while preventing lead migration and allowing capture of axial and lower extremity pain, unilateral as well as bilateral. This study revives the idea of a single lead as a possible optimal configuration. ______________________________________________________________________________ The effects of spinal cord stimulation in neuropathic pain are

sustained: a 24-month follow-up of the prospective randomized

controlled multicenter trial of the effectiveness of spinal cord

stimulation.

Kumar K, Taylor RS, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Buchser E, Fortini G, Richardson J, North RB. Neurosurgery. 2008 Oct;63(4):762-70; discussion 770. Department of Neurosurgery, Regina General Hospital, Regina, Canada.

OBJECTIVE: After randomizing 100 failed back surgery syndrome patients to receive spinal cord stimulation (SCS) plus conventional medical management (CMM) or CMM alone, the results of the 6-month Prospective Randomized Controlled Multicenter Trial of the Effectiveness of Spinal Cord Stimulation (i.e., PROCESS) showed that SCS offered superior pain relief, health-related quality of life, and functional capacity. Because the rate of crossover favoring SCS beyond 6 months would bias a long-term randomized group comparison, we present all outcomes in patients who continued SCS from randomization to 24 months and, for illustrative purposes, the primary outcome (>50% leg pain relief) per randomization and final treatment. METHODS: Patients provided data on pain, quality of life, function, pain medication use, treatment satisfaction, and employment status. Investigators documented adverse events. Data analysis included inferential comparisons and multivariate regression analyses. RESULTS: The 42 patients continuing SCS (of 52 randomized to SCS) reported significantly improved leg pain relief (P < 0.0001), quality of life (P <or= 0.01), and functional capacity (P = 0.0002); and 13 patients (31%) required a device-related surgical revision. At 24 months, of 46 of 52 patients randomized to SCS and 41 of 48 randomized to CMM who were available, the primary outcome was achieved by 17 (37%) randomized to SCS versus 1 (2%) to CMM (P = 0.003) and by 34 (47%) of 72 patients who received SCS as final treatment versus 1 (7%) of 15 for CMM (P = 0.02). CONCLUSION: At 24 months of SCS treatment, selected failed back surgery syndrome patients reported sustained pain relief, clinically important improvements in functional capacity and health-related quality of life, and satisfaction with treatment. ______________________________________________________________________________ Spinal cord stimulation for failed back surgery syndrome--does it

work and is it cost-effective?

Sciubba DM, Gokaslan ZL. Nat Clin Pract Neurol. 2008 Sep;4(9):472-3. Epub 2008 Jul 22. Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA. dsciubb1@jhmi.edu

Comment on Eur J Pain. 2008 Nov;12(8):1047-58. This Practice Point commentary discusses a study by Manca et al. that aimed to investigate the health-related quality-of-life and cost implications of spinal cord stimulation (SCS) plus nonsurgical conventional medical management (CMM) versus nonsurgical CMM alone. Manca et al. reported that the mean total 6-month health-care cost in the SCS group was significantly higher than that in the CMM alone group. However, the gain in health-related quality of life for patients undergoing SCS was significantly greater than that for patients undergoing CMM alone over this same period. In addition, patients in the SCS group used fewer analgesics and nondrug pain treatments (e.g. physical therapy), thus offsetting the upfront costs of SCS by 15%. The relevance of this study in

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providing an evaluation of health-care expenditures directed at treating low back pain relative to actual treatment outcomes is discussed. ______________________________________________________________________________ Spinal cord stimulation versus reoperation for failed back surgery

syndrome: a cost effectiveness and cost utility analysis based on

a randomized, controlled trial.

Wilkinson HA. Neurosurgery. 2008 Aug;63(2):E376; author reply E376.

Comment on Neurosurgery. 2007 Aug;61(2):361-8; discussion 368-9. ______________________________________________________________________________ Spinal Cord Stimulation Has Comparable Efficacy in Common Pain

Etiologies.

Krames ES, Oakley JC, Foster AM, Henderson J, Prager JP, Rashbaum RR, Stamatos J, Weiner RL. Neuromodulation. 2008 Jul;11(3):171-181. doi: 10.1111/j.1525-1403.2008.00163.x. Pacific Pain Treatment Center, San Francisco, CA, USA; Yellowstone Neurosurgical Associates, Billings, MT, USA; Boston Scientific Neuromodulation, Valencia, CA, USA; Stanford University Medical Center, Stanford, CA, USA; California Pain Medicine Centers, Los Angeles, CA, USA; Texas Back Institute, Plano, TX, USA; North Shore University Hospital, Syosset, NY, USA; and Dallas Neurosurgical Associates, Dallas, TX, USA.

Objectives. The probability of success with spinal cord stimulation (SCS) depends largely on appropriate patient selection. Here, we have assessed the predictive value of pain etiology as it relates to pain relief with SCS as part of a prospective multicenter clinical trial. Methods. Sixty-five subjects with chronic and intractable pain tested an epidural SCS system. Subjects reported pain ratings (visual analog scale) with stimulation off and stimulation on at scheduled follow-up visits for up to 18 months after activation of the system. Visual analog scale scores were averaged and stratified by dominant pain etiologies, comprising failed back surgery syndrome, complex regional pain syndrome, and a subgroup of subjects with miscellaneous other pain etiologies. Results. More than 70% of subjects in each subgroup had successful outcomes during the temporary trial period and similar percentages of subjects from each etiology subgroup subsequently went on to permanent implantation. After permanent implantation, all subgroups reported more than 50% pain relief, on average, at each follow-up time point. No predictive value of pain etiology was observed. Conclusions. Spinal cord stimulation is an effective therapy for neuropathic pain arising from a variety of causes. Failed back surgery syndrome, complex regional pain syndrome, and pain of other etiologies responded equally well to SCS. ______________________________________________________________________________ Use of spinal cord stimulator for treatment of lumbar

radiculopathy in a patient with severe kyphoscoliosis.

Atallah J, Armah FA, Wong D, Weis PA, Fahy BG. Pain Physician. 2008 Jul-Aug;11(4):555-9. Department of Anesthesiology and Orthopedic Surgery, University of Toledo Medical Center, Toledo, OH 43614, USA. jattallah99@yahoo.com

Spinal cord stimulation (SCS) has been a therapeutic option for chronic pain for over 40 years with a common indication being failed back surgery syndrome (FBSS). This case reports the successful implantation of a spinal cord stimulator in a patient with FBSS and kyphoscoliosis for treatment of radicular pain. Technical considerations and anatomical difficulties that may be encountered during placement with kyphoscoliosis will be discussed. This patient had failed other therapies including oral medications, epidural steroid injections, spinal surgeries, and physical and aquatic therapies. On physical examination the patient had a severely deformed lumbar spine. Careful review of the spine radiographs and CT scan revealed lead placement might be possible at the level of T12-L1 or L1-2. A Medline search did not reveal a case of kyphoscoliosis with radicular pain treated with SCS. After a successful percutaneous trial, a SCS was implanted. Fourteen weeks later, the patient reported being pain free with an increased physical activity level and opioid discontinuation.

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Technical considerations with kyphoscoliosis may discourage pain physicians from attempting SCS. This case illustrates that with careful selection, some of these patients may be candidates for SCS with good results. ______________________________________________________________________________ Reassessment of evidence synthesis of occupational medicine

practice guidelines for interventional pain management.

Manchikanti L, Singh V, Derby R, Schultz DM, Benyamin RM, Prager JP, Hirsch JA. Pain Physician. 2008 Jul-Aug;11(4):393-482. Pain Management Center of Paducah, Paducah, KY, USA. drlm@thepainmd.com

Comment in Pain Physician. 2008 Sep-Oct;11(5):700; author reply 705-6. Pain Physician. 2008 Sep-Oct;11(5):701-3; author reply 705-6. BACKGROUND: Appropriately developed practice guidelines present statements of best practice based on a thorough evaluation of the evidence from published studies on the outcomes of treatments, which include the application of multiple methods for collecting and evaluating evidence for a wide range of clinical interventions and disciplines. However, the guidelines are neither infallible, nor a substitute for clinical judgment. While the guideline development process is a complex phenomenon, conflict of interest in guideline development and inappropriate methodologies must be avoided. It has been alleged that the guidelines by the American College of Occupational and Environmental Medicine (ACOEM) prevent injured workers from receiving the majority of medically necessary and appropriate interventional pain management services. An independent critical appraisal of both chapters of the ACOEM guidelines showed startling findings with a conclusion that these guidelines may not be applied in patient care as they scored below 30% in the majority of evaluations utilizing multiple standardized criteria. OBJECTIVE: To reassess the evidence synthesis for the ACOEM guidelines for the low back pain and chronic pain chapters utilizing an expanded methodology, which includes the criteria included in the ACOEM guidelines with the addition of omitted literature and application of appropriate criteria. METHODS: For reassessment, randomized trials were utilized as it was in the preparation of the guidelines. In this process, quality of evidence was assessed and recommendations were made based on grading recommendations of Guyatt et al. The level of evidence was determined utilizing the quality of evidence criteria developed by the U.S. Preventive Services Task Force (USPSTF), as well as the outdated quality of evidence criteria utilized by ACOEM in the guideline preparation. Methodologic quality of each individual article was assessed utilizing the Agency for Healthcare Research and Quality (AHRQ) methodologic assessment criteria for diagnostic interventions and Cochrane methodologic quality assessment criteria for therapeutic interventions. RESULTS: The results of reassessment are vastly different from the conclusions derived by the ACOEM guidelines. The differences in strength of rating for the diagnosis of discogenic pain by provocation discography and facet joint pain by diagnostic facet joint nerve blocks is established with strong evidence. Therapeutic cervical and lumbar medial branch blocks and radiofrequency neurolysis, therapeutic thoracic medial branch blocks, cervical interlaminar epidural steroid injections, caudal epidural steroid injections, lumbar transforaminal epidural injections, percutaneous and endoscopic adhesiolysis, and spinal cord stimulation qualified for moderate to strong evidence. Additional insight is also provided for evidence rating for intradiscal electrothermal therapy (IDET), automated percutaneous disc decompression, and intrathecal implantables. CONCLUSION: The reassessment and reevaluation of the low back and chronic pain chapters of the ACOEM guidelines present results that are vastly different from the published and proposed guidelines. Contrary to ACOEM's conclusions of insufficient evidence for most interventional techniques, the results illustrate moderate to strong evidence for most diagnostic and therapeutic interventional techniques. ______________________________________________________________________________ Epidural abscess due to spinal cord stimulator trial.

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Rauchwerger JJ, Zoarski GH, Waghmarae R, Rabinowitz RP, Kent JL, Aldrich EF, Closson CW. Pain Pract. 2008 Jul-Aug;8(4):324-8. Epub 2008 May 23. Department of Anesthesiology/Division of Pain Management, University of Maryland Medical Center, Baltimore, Maryland, USA. jacobjeffrey74@hotmail.com

Spinal cord stimulation is increasingly utilized as a treatment to alleviate low back pain and lumbar radiculopathy, particularly in patients with failed back surgery syndrome. We present an illustrative case of early, rapidly progressive methicillin-resistant Staphylococcus aureus (MRSA) infection after a brief stimulator trial lead implantation. Operators should maintain a high level of suspicion for deep infection, including epidural abscess, even when only minor symptoms and signs are present. Because of the poor ability to clear infections in the presence of a retained foreign body, the device must be explanted immediately. Subsequent surgical intervention, however, may nevertheless still be needed. While a variety of bacteria may cause epidural abscess, methicillin sensitive Staphylococcus aureus, and increasingly, MRSA and community-associated MRSA, are the most likely etiologic organisms. ______________________________________________________________________________ A 50-year-old man with chronic low back pain.

Rathmell JP. JAMA. 2008 May 7;299(17):2066-77. Epub 2008 Apr 1. Center for Pain Medicine, Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. jrathmell@partners.org

Mr S, a 50-year-old man, has long-standing low back pain. His pain began more than 20 years earlier with a lumbar disk herniation and has persisted despite diskectomy. He has undergone numerous treatments, but he remains disabled with ongoing pain. His treatment course is used to frame the epidemiology and pathophysiology underlying acute and chronic lumbosacral and radicular pain. The roles of neuropathic pain medications, chronic opioid therapy, physical therapy, spinal manipulation, and multidisciplinary pain treatment programs are reviewed. The indications for and outcomes associated with interventional pain treatments, including epidural steroid injection, facet blocks and radiofrequency treatment for facet-related pain, intradiskal electrothermal therapy, spinal cord stimulation, and intrathecal drug delivery, are discussed. Clinicians are given an evidence-based approach to using available treatment options for low back pain. ______________________________________________________________________________ Efficacy of transverse tripolar spinal cord stimulator for the

relief of chronic low back pain from failed back surgery.

Buvanendran A, Lubenow TJ. Pain Physician. 2008 May-Jun;11(3):333-8. Department of Anesthesiology, Rush University Medical Center, Chicago, IL 60612, USA. asokumar@aol.com

BACKGROUND: Failed back surgery syndrome is a common clinical entity for which spinal cord stimulation has been found to be an effective mode of analgesia, but with variable success rates. OBJECTIVE: To determine if focal stimulation of the dorsal columns with a transverse tripolar lead might achieve deeper penetration of the electrical stimulus into the spinal cord and therefore provide greater analgesia to the back. DESIGN: Case report. METHODS: We describe a 42-year-old female with failed back surgery syndrome that had greater back pain than leg pain. The tripolar lead configuration was achieved by placing percutaneously an octapolar lead in the spinal midline followed by 2 adjacent quadripolar leads, advanced to the T7-T10 vertebral bodies. RESULTS: Tripolar stimulation pattern resulted in more than 70% pain relief in this patient during the screening trial, while stimulation of one or 2 electrodes only provided 20% pain relief. After implantation of a permanent tripolar electrode system with a single rechargeable battery, the pain relief was maintained for one year. CONCLUSION: This is case report describing a case of a patient with chronic low back pain with a diagnosis of failed back surgery syndrome in which transverse tripolar stimulation using an octapolar and 2 quadripolar leads appeared to be beneficial. The transverse tripolar system consists of a central cathode surrounded by anodes,

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using 3 leads. This arrangement may contribute to maximum dorsal column stimulation with minimal dorsal root stimulation and provide analgesia to the lower back. ______________________________________________________________________________ Spinal cord stimulation in conjunction with peripheral nerve field

stimulation for the treatment of low back and leg pain: a case

series.

Bernstein CA, Paicius RM, Barkow SH, Lempert-Cohen C. Neuromodulation. 2008 Apr;11(2):116-23. doi: 10.1111/j.1525-1403.2008.00152.x. Coast Pain Management, Newport Beach, CA, USA; Newport Beach Headache and Pain Institute, Newport Beach, CA, USA; Anesthesiology and Pain Medicine, University of California, Irvine, 101 The City Drive South Orange, CA, USA.

Background. The treatment of chronic low back and leg pain remains a difficult medical challenge, particularly for patients with postlaminectomy syndrome. While spinal cord stimulation (SCS) has been a significant addition to the available options, it is often inadequate in relieving both the back and leg pain components. We hypothesized that for some patients the combination of SCS with peripheral nerve field stimulation (PNFS) would be a safe, effective alternative that would be more effective than either modality alone. Objective. Our objective was to demonstrate the efficacy of PNFS used in combination with SCS for the treatment of chronic pain syndromes involving the lower back and legs. Study Design. Case series. Methods. A total of 20 patients with chronic low back and leg pain syndromes who had failed conventional therapies underwent implantation of a combination of traditional SCS and PNFS. Leads were placed in the epidural space, as well as superficially in the subcutaneous tissues of the lower back, directly in the region of maximum pain. Patients initially underwent a trial of stimulation to assess response, and a permanent system was implanted if patients reported greater than 50% pain relief during the trial. For some patients, a combination was used at the time of the initial trial. In other cases, the decision to proceed with the combination was made later, either at the time of permanent implant, or later on, after SCS alone failed to adequately control pain. Results. In each case, PNFS was used in combination with traditional SCS for patients with chronic lower back and lower extremity pain. While not all of these patients ultimately proceeded with the combination of SCS and PNFS to control their pain, the majority of patients found the combination better in controlling their overall pain than either modality alone. In addition, using a combined approach at the time of trial provided a noninvasive and effective method of comparing the efficacy of each method, allowing patients to identify the best form of neuromodulation for their particular pain. Conclusions. Due to the availability of 16 contact capacity generators, neurostimulation with multiple leads in various combinations-including both epidural and peripheral nerve field stimulation simultaneously-can be applied safely and effectively. The availability of this combined approach for a trial of stimulation prior to implant allows patients to compare SCS to PNFS and to indicate a preference for one over the other or for the combination. We conclude that PNFS may be used in combination with SCS as a safe and effective alternative treatment for patients with chronic low back and leg pain, and further suggest that the combined approach should be considered as a treatment option for this population. ______________________________________________________________________________ Rechargeable spinal cord stimulation versus non-rechargeable

system for patients with failed back surgery syndrome: a cost-

consequences analysis.

Hornberger J, Kumar K, Verhulst E, Clark MA, Hernandez J. Clin J Pain. 2008 Mar-Apr;24(3):244-52. Cedar Associates LLC, Menlo Park, CA 94025, USA. jhornberger@cedarecon.com

OBJECTIVES: Spinal cord stimulation (SCS) has been used for almost 40 years to treat refractory neuropathic pain after failed back surgery. Fully implantable non-rechargeable pulse generators have a battery life of between 2 and 5 years. A new SCS system with a rechargeable power source may last 10 to 25 years, or longer. The potential economic implications of longer battery life with a new SCS system has yet to be assessed. The study objective is to estimate the average difference in lifetime costs between rechargeable and non-rechargeable pulse generators used in treatment with SCS for failed back surgery syndrome. METHODS: A generalized state-transition probability

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framework was used to model costs. Input parameters for the base case analysis were obtained from several data sources including published literature, Medicare fee schedules, Medicare claims data, and expert opinion. RESULTS: A rechargeable SCS system is projected to require from 2.6 to 4.2 fewer battery generator replacements for battery depletion than a non-rechargeable SCS system. The total lifetime savings of a rechargeable system range from $104,000 to $168,833. In all of the one-way sensitivity analyses conducted, a rechargeable system saves money. Among all of the assumptions underlying the analysis, the annual cost after device removal contributes the most uncertainty. CONCLUSIONS: A rechargeable SCS system is projected to save up to $100,000 over a patient's lifetime. Fewer pulse generator replacements will also decrease patient discomfort and morbidity from procedural complications. ______________________________________________________________________________ Neurophysiological evidence of antidromic activation of large

myelinated fibres in lower limbs during spinal cord stimulation.

Buonocore M, Bonezzi C, Barolat G. Spine (Phila Pa 1976). 2008 Feb 15;33(4):E90-3. Unit of Clinical Neurophysiology, Fondazione Salvatore Maugeri, Scientific Institute of Pavia, Italy. michelangelo.buonocore@fsm.it

STUDY DESIGN: This study was designed to verify the hypothesis of a constant, antidromic activation of fibers traveling along peripheral sensory nerves during spinal cord stimulation (SCS). OBJECTIVE: To investigate the neurophysiological characteristics (latency, amplitude, waveform) of potentials recorded in peripheral sensory nerves during the SCS. SUMMARY OF BACKGROUND DATA: SCS is widely used for the relief of chronic benign pain resistant to conservative therapies, but its antalgic mechanism is poorly understood. Antidromic activation of peripheral nerve fibers is one of the hypothesized antalgic mechanisms, but very few neurophysiological studies have been conducted on this subject. METHODS: Sixteen patients undergoing a percutaneous test trial of SCS for chronic pain in the lower limb (4 males, 12 females, mean age of 54.2, and age range 41-77 years) were enrolled. Diagnoses included: failed back surgery syndrome, complex regional pain syndrome type I, painful lumbosacral radiculopathy, and painful peripheral neuropathy. All patients had a lead percutaneously implanted in the epidural space at a vertebral level ranging from T9-T12. Nerve action potentials were generally recorded in nonpainful leg but, when the pain was outside the investigated nerve territory, a bilateral recording was performed. Twenty-one different studies were carried out on 16 patients. RESULTS: The results confirmed the hypothesis that cutaneous afferents were regularly activated by SCS. CONCLUSION: The authors hypothesize that this antidromic activation could represent a possible antalgic mechanism of SCS in patients with peripheral neuropathic pain, but further neurophysiological studies will be needed to elucidate this hypothesis. ______________________________________________________________________________ Functional magnetic resonance imaging of cerebral activation

during spinal cord stimulation in failed back surgery syndrome

patients.

Stancák A, Kozák J, Vrba I, Tintera J, Vrána J, Polácek H, Stancák M. Eur J Pain. 2008 Feb;12(2):137-48. Epub 2007 Oct 30. Charles University Prague, Department of Normal, Pathological and Clinical Physiology, Third Faculty of Medicine, Ke Karlovu 4, 12000 Prague 2, Czech Republic. stancak@lf3.cuni.cz

Spinal cord stimulation (SCS) consisting of electrical stimulation of the dorsal spinal cord using epidural electrodes has been shown to relieve chronic neuropathic pain. To analyze the cerebral activation patterns related to SCS, and to evaluate the effects of SCS on the processing of acute experimental pain, we performed functional magnetic resonance imaging (fMRI) on eight patients suffering from failed back surgery syndrome who were also being treated with SCS for severe pain in their legs and lower back. Three types of stimulation were used, each lasting 36s: (i) SCS, (ii) heat pain (HP) applied to the leg affected by neuropathic pain, and (iii) simultaneous HP and SCS. During SCS, we found increased activation of the medial primary sensorimotor cortex somatotopically corresponding to the foot and/or perineal region, contralateral posterior insula, and the ipsilateral secondary somatosensory cortex (S2). Decreased activation was seen in the

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bilateral primary motor cortices and the ipsilateral primary somatosensory cortex corresponding to the shoulder, elbow and hand. Compared to separately presented HP and SCS, simultaneous HP and SCS showed statistically significant activation of the bilateral inferior temporal cortex and the ipsilateral cerebellar cortex. The activation of the primary motor cortex, insula and S2 during SCS may directly interfere with the processing of neuropathic pain. When SCS is associated with heat pain, the paralimbic association cortex and cerebellum show activation exceeding the sum of activations resulting from separate SCS and heat pain stimulation. The explanation of this could possibly rest with the continuous comparisons of simultaneous pain and somatosensory sensations occurring in a single dermatome. ______________________________________________________________________________ Lumbar post-laminectomy syndrome: II. Pain management using neuro-

modulation techniques. [Article in Spanish]

Robaina Padrón FJ. Neurocirugia (Astur). 2008 Feb;19(1):35-44. Unidad del Dolor Crónico y Neurocirugía Funcional, Hospital Universitario de Gran Canaria Dr. Negrín. Las Palmas de Gran Canaria.

The application of neuro-modulation techniques in general is currently gaining acceptance in various aspects of medicine. Neuro-modulation is defined as: "Therapeutical interventions using implantable devices to modify the functioning of central, peripheral and autonomic nervous systems". Following lumbar disc surgery, or lumbar spine surgery in general, several chronic pain syndromes can result, either in the lumbar region and/or in the lower limbs. The current status is for the application of surgery to the degenerative spine (degenerative disc disease and lumbar stenosis) for the relief of chronic pain. A review of the methodology of evidence based medicine, show that the instrumented and fusion techniques are not the answered despite 20 years of the use of these techniques following failure of surgery for the relief of back pain syndrome. Neuro-modulation techniques represent a step in the right direction for the management of these chronic pain syndromes. Frequently they enable the resolution of chronic pain following spine surgery without having to resort to repeat surgery. We describe here the different neuro-modulation techniques (spinal cord stimulation, spinal drug infusions) which can be used in the case of back surgery failure, and we describe technical aspects and "tricks of the trade" for the correct implantation of the devices used in techniques. Neuro-modulation techniques are applied to the management of chronic pain following disc surgery and represent a valid alternative to repeat surgery and/or arthrodesis (instrumented or not). Neurosurgeons are again called to play active roles in the field of neuro-modulation for the treatment. ______________________________________________________________________________ Using image-guided techniques for chronic low back pain.

Boyajian SS. J Am Osteopath Assoc. 2007 Nov;107(10 Suppl 6):ES3-9. Advanced Pain Consultants, PA, 805 Cooper Rd, Suite 2, Voorhees, NJ 08043-3814, USA. sboyajian@comcast.net

Image-guided spine intervention is used primarily for its precise diagnostic capabilities. This article reviews basic principles of the more common image-guided diagnostic techniques specifically as they relate to patients with low back pain. It also includes discussion of advanced modes of therapy, including spinal cord stimulation and intrathecal therapy, providing primary care physicians with an understanding of the primary indications for these therapeutic modalities. Two illustrative case presentations have been added to "refresh" this article, which was originally published in a supplement to the September 2005 issue of the JAOA and to further enhance primary care physicians' understanding of spinal intervention. ______________________________________________________________________________ Spinal cord stimulation versus conventional medical management for

neuropathic pain: a multicentre randomised controlled trial in

patients with failed back surgery syndrome.

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Kumar K, Taylor RS, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Buchser E, Fortini G, Richardson J, North RB. Pain. 2007 Nov;132(1-2):179-88. Epub 2007 Sep 12. Department of Neurosurgery, Regina General Hospital, 1440 14th Avenue, Regina, Sask., Canada. krishna.kumar@rqhealth.ca

Comment in Pain. 2007 Nov;132(1-2):10-1. Patients with neuropathic pain secondary to failed back surgery syndrome (FBSS) typically experience persistent pain, disability, and reduced quality of life. We hypothesised that spinal cord stimulation (SCS) is an effective therapy in addition to conventional medical management (CMM) in this patient population. We randomised 100 FBSS patients with predominant leg pain of neuropathic radicular origin to receive spinal cord stimulation plus conventional medical management (SCS group) or conventional medical management alone (CMM group) for at least 6 months. The primary outcome was the proportion of patients achieving 50% or more pain relief in the legs. Secondary outcomes were improvement in back and leg pain, health-related quality of life, functional capacity, use of pain medication and non-drug pain treatment, level of patient satisfaction, and incidence of complications and adverse effects. Crossover after the 6-months visit was permitted, and all patients were followed up to 1 year. In the intention-to-treat analysis at 6 months, 24 SCS patients (48%) and 4 CMM patients (9%) (p<0.001) achieved the primary outcome. Compared with the CMM group, the SCS group experienced improved leg and back pain relief, quality of life, and functional capacity, as well as greater treatment satisfaction (p<or=0.05 for all comparisons). Between 6 and 12 months, 5 SCS patients crossed to CMM, and 32 CMM patients crossed to SCS. At 12 months, 27 SCS patients (32%) had experienced device-related complications. In selected patients with FBSS, SCS provides better pain relief and improves health-related quality of life and functional capacity compared with CMM alone. ______________________________________________________________________________ Spinal cord stimulation: stimulating questions.

Turner JA, Deyo RA, Loeser JD. Pain. 2007 Nov;132(1-2):10-1. Epub 2007 Sep 12.

Comment in Pain. 2008 Mar;135(1-2):209-10; author reply 210-11. Comment on Pain. 2007 Nov;132(1-2):179-88. ______________________________________________________________________________ Squamous cell carcinoma occurring within incision of recently

implanted spinal cord stimulator.

Atallah J, Wainscott J, Sloan D, Moore K, Fahy BG. Pain Physician. 2007 Nov;10(6):771-4. Department of Anesthesiology, University of Kentucky Chandler Medical Center, Lexington, KY, USA. jatallah99@yahoo.com

Spinal Cord Stimulation (SCS) is a treatment option for chronic pain patients. Spinal cord stimulation has been employed in the treatment of chronic pain for more than 30 years. The most common indication for SCS is the failed back syndrome with leg pain. Its indications have expanded beyond back and lower extremities pain to include axial low back pain, CRPS, mesenteric ischemia, peripheral neuropathy, limb ischemia, and refractory angina pectoris. The SCS has become a more versatile form of analgesia. The number of wound complications will surely rise in conjunction with the increasing number of devices being implanted. We describe a case of a well-differentiated squamous cell carcinoma occurring within the incision site of a recently implanted spinal cord stimulator early in the postoperative period. The patient developed a rapidly growing mass within the leads incision. The mass was confirmed to be squamous cell carcinoma by biopsy. The mass was excised under local anesthesia with appropriate margins. It was determined that the carcinoma did not extend below the dermis, and that there was no involvement of the underlying fascia. The device was tested for proper functioning, and the leads were thus left in place. While the development of skin malignancies in surgical wounds has been described in the literature, to our knowledge there have been no reports of a cutaneous neoplasm developing early in the postoperative period after spinal cord stimulator implantation. ______________________________________________________________________________

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Spinal cord stimulation with interleaved pulses: a randomized,

controlled trial.

North RB, Kidd DH, Olin J, Sieracki JM, Boulay M. Neuromodulation. 2007 Oct;10(4):349-57. doi: 10.1111/j.1525-1403.2007.00123.x. Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD; and Department of Population and Family Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA.

Objectives. The development of multicontact electrodes and programmable, implanted pulse generators has increased the therapeutic success of spinal cord stimulation (SCS) by enhancing the ability to capture and maintain pain/paresthesia overlap. This study sought to determine if interleaved stimulation and/or frequency doubling improves pain/paresthesia overlap in patients with failed back surgery syndrome. Methods. Using a patient-interactive computer system that quantifies SCS performance and presents stimulation settings in randomized, double-blind fashion, we compared the effect on pain/paresthesia overlap of interleaved stimulation (rapidly interleaved pulse trains using two different contact combinations) vs. standard treatment with a single contact combination, controlling for frequency doubling. Stimulation amplitude (charge per phase, as determined by varying pulse voltage or width) was adjusted to a subjectively comfortable intensity (usage amplitude), which was maintained for all trials in each patient. The number of percutaneous spinal electrodes used (one or two) and the phase angle between interleaved pulses were additional study variables. Results. Multivariate analysis of 266 test results from 15 patients revealed a statistically significant (p ≤ 0.05) association between increased computer-calculated pain/paresthesia overlap and 1) high- and low-frequency interleaved stimulation using two combinations of contacts and 2) frequency doubling using one combination. We found no significant effect for electrode configuration (single or dual), pulse width matching, or phase angle. Conclusions. The statistically significant advantages we observed for SCS with interleaved stimulation are explained, at least in part, by the effects of frequency doubling. These findings have important implications for the design and adjustment of pulse generators. ______________________________________________________________________________ EFNS guidelines on neurostimulation therapy for neuropathic pain.

Cruccu G, Aziz TZ, Garcia-Larrea L, Hansson P, Jensen TS, Lefaucheur JP, Simpson BA, Taylor RS. Eur J Neurol. 2007 Sep;14(9):952-70. EFNS Panel on Neuropathic Pain, Vienna, Austria. cruccu@uniroma1.it

Pharmacological relief of neuropathic pain is often insufficient. Electrical neurostimulation is efficacious in chronic neuropathic pain and other neurological diseases. European Federation of Neurological Societies (EFNS) launched a Task Force to evaluate the evidence for these techniques and to produce relevant recommendations. We searched the literature from 1968 to 2006, looking for neurostimulation in neuropathic pain conditions, and classified the trials according to the EFNS scheme of evidence for therapeutic interventions. Spinal cord stimulation (SCS) is efficacious in failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS) type I (level B recommendation). High-frequency transcutaneous electrical nerve stimulation (TENS) may be better than placebo (level C) although worse than electro-acupuncture (level B). One kind of repetitive transcranial magnetic stimulation (rTMS) has transient efficacy in central and peripheral neuropathic pains (level B). Motor cortex stimulation (MCS) is efficacious in central post-stroke and facial pain (level C). Deep brain stimulation (DBS) should only be performed in experienced centres. Evidence for implanted peripheral stimulations is inadequate. TENS and r-TMS are non-invasive and suitable as preliminary or add-on therapies. Further controlled trials are warranted for SCS in conditions other than failed back surgery syndrome and CRPS and for MCS and DBS in general. These chronically implanted techniques provide satisfactory pain relief in many patients, including those resistant to medication or other means. ______________________________________________________________________________ Appetite suppression and weight loss incidental to spinal cord

stimulation for pain relief.

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Pereira E, Foster A. Obes Surg. 2007 Sep;17(9):1272-4. Belleville Memorial Hospital, Belleville, IL, USA.

Spinal cord stimulation (SCS) uses electrical stimulation of the dorsal columns of the spinal cord to prevent the perception of intractable neuropathic pain signals, but its mechanisms and consequences of use are poorly understood. Two overweight female patients who were implanted with SCS systems (Precision; Advanced Bionics/Boston Scientific, Valencia, CA) reported better than 50% relief of their chronic back and leg pain. Unexpectedly, SCS stimulation was also associated with a tingling sensation in the viscera and a reduction in appetite. Both patients were thus able to reduce food intake at mealtimes and had lost about 9 kg in the first 4 months of SCS use, despite denying changes in exercise habits. The mechanism by which SCS can reduce the desire for food is unknown, but this and similar neuromodulation techniques may hold promise for weight loss in patients who fail other treatments or are not healthy enough for surgery. ______________________________________________________________________________ Spinal cord stimulation versus reoperation for failed back surgery

syndrome: a cost effectiveness and cost utility analysis based on

a randomized, controlled trial.

North RB, Kidd D, Shipley J, Taylor RS. Neurosurgery. 2007 Aug;61(2):361-8; discussion 368-9. Department of Neurosurgery, The Johns Hopkins University, Baltimore, Maryland 21287, USA. RNorth@jhmi.edu

Erratum in Neurosurgery. 2009 Apr;64(4):601. Comment in Neurosurgery. 2008 Aug;63(2):E376; author reply E376. OBJECTIVE: We analyzed the cost-effectiveness and cost-utility of treating failed back-surgery syndrome using spinal cord stimulation (SCS) versus reoperation. MATERIALS AND METHODS: A disinterested third party collected charge data for the first 42 patients in a randomized controlled crossover trial. We computed the difference in cost with regard to success (cost-effectiveness) and mean quality-adjusted life years (cost-utility). We analyzed the patient-charge data with respect to intention to treat (costs and outcomes as a randomized group), treated as intended (costs as randomized; crossover failure assigned to a randomized group), and final treatment costs and outcomes. RESULTS: By mean 3.1-year follow-up, 13 of 21 patients (62%) crossed from reoperation versus 5 of 19 patients (26%) who crossed from SCS (P < 0.025) [corrected]. The mean cost per success was US $117,901 for crossovers to SCS. No crossovers to reoperation achieved success despite a mean per-patient expenditure of US $260,584. The mean per-patient costs were US $31,530 for SCS versus US $38,160 for reoperation (intention to treat), US $48,357 for SCS versus US $105,928 for reoperation (treated as intended), and US $34,371 for SCS versus US $36,341 for reoperation (final treatment). SCS was dominant (more effective and less expensive) in the incremental cost-effectiveness ratios and incremental cost-utility ratios. A bootstrapped simulation for incremental costs and quality-adjusted life years confirmed SCS's dominance, with approximately 72% of the cost results occurring below US policymakers' "maximum willingness to pay" threshold. CONCLUSION: SCS was less expensive and more effective than reoperation in selected failed back-surgery syndrome patients, and should be the initial therapy of choice. SCS is most cost-effective when patients forego repeat operation. Should SCS fail, reoperation is unlikely to succeed. ______________________________________________________________________________ Effects of spinal cord stimulation on the cortical somatosensory

evoked potentials in failed back surgery syndrome patients.

Polácek H, Kozák J, Vrba I, Vrána J, Stancák A. Clin Neurophysiol. 2007 Jun;118(6):1291-302. Epub 2007 Apr 23. Charles University Prague, Department of Normal, Pathological and Clinical Physiology, Third Faculty of Medicine, Ke Karlovu 4, Prague 2, Czech Republic.h.polacek@seznam.cz

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OBJECTIVE: To evaluate the functional activation of the somatosensory cortical regions in neuropathic pain patients during therapeutic spinal cord stimulation (SCS). METHODS: In nine failed back surgery syndrome patients, the left tibial and the left sural nerves were stimulated in two sessions with intensities at motor and pain thresholds, respectively. The cortical somatosensory evoked potentials were analyzed using source dipole analysis based on 111 EEG signals. RESULTS: The short-latency components of the source located in the right primary somatosensory cortex (SI: 43, 54 and 65ms) after tibial nerve stimulation, the mid-latency SI component (87ms) after sural nerve stimulation, and the mid-latency components in the right (approximately 161ms) and left (approximately 168ms) secondary somatosensory cortices (SII) were smaller in the presence of SCS than in absence of SCS. The long-latency source component arising from the mid-cingulate cortex (approximately 313ms) was smaller for tibial and larger for sural nerve stimuli during SCS periods compared to periods without SCS. CONCLUSIONS: SCS attenuates the somatosensory processing in the SI and SII. In the mid-cingulate cortex, the effect of SCS depends on the type of stimulation and nerve fibers involved. SIGNIFICANCE: Results suggest that the effects of SCS on cortical somatosensory processing may contribute to a reduction of allodynia during SCS. ______________________________________________________________________________ Spinal cord stimulation with a dual quadripolar surgical lead

placed in general anesthesia is effective in treating intractable

low back and leg pain.

Duyvendak W. Neuromodulation. 2007 Apr;10(2):113-9. doi: 10.1111/j.1525-1403.2007.00099.x. Department of Neurosurgery, Virga Jesse Hospital, Hasselt, Belgium.

Objectives. Spinal cord stimulation has been used extensively for failed back surgery syndrome, although dominant axial low back pain is difficult to treat effectively with this modality. The use of a surgically placed, double, quadripolar lead may result in better paresthesia of the low back, therefore enhancing outcomes in this difficult to treat population. Materials and Methods. Accordingly, this prospective study was designed to assess the effectiveness of placing such a lead at the T8-T10 level under general anesthesia without intraoperative testing for concordancy of paresthesia distribution. Results. The study showed that 70% of patients had "good" or "complete" long-term pain relief after placement of a surgically placed dual quadripolar lead under general anesthesia and analgesic consumption decreased significantly. The ability to lead a more active and social life was increased and 85% of patients said they would undergo spinal cord stimulation again. Placing the lead higher in the spinal canal (T8) resulted in a tendency for better paresthesia coverage of the low back when compared to lower lead placements. Conclusions. Placing a double quadripolar paddle lead under general anesthesia resulted in good clinical outcome similar to other implant techniques. ______________________________________________________________________________ Neurostimulation technology for the treatment of chronic pain: a

focus on spinal cord stimulation.

Foletti A, Durrer A, Buchser E. Expert Rev Med Devices. 2007 Mar;4(2):201-14. University Hospital, Anesthesia and Pain Department, CHUV, 1000 Lausanne, Switzerland. antonio.foletti@chuv.ch

Over the past 40 years we have seen how electrical stimulation for the relief of pain has progressed from an experimental treatment based upon a clinical theory to being on the threshold of becoming a standard of medical practice. While tens of thousands of devices are implanted every year, the mechanism of action still evades complete understanding. Nevertheless, technological improvements have been considerable and the current neuromodulation devices are both extremely sophisticated and reliable. Unlike most conventional treatments, neurostimulation cannot be restricted to one speciality as its clinical applications ignore the boundaries of medical specialities. Conditions such as neuropathic pain in the back and the leg, complex regional pain syndrome, ischemic pain due to peripheral vascular disease and coronary artery disease are likely to respond to spinal cord stimulation. Even though the evidence for efficacy remains unsatisfactory,

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the stimulation of the dorsal column has been remarkably successful in relieving pain and improving function in patients who have failed conventional management. The development, the technicalities and the most important clinical applications of spinal cord stimulation are reviewed here. ______________________________________________________________________________ Interventional approaches to pain management.

Markman JD, Philip A. Med Clin North Am. 2007 Mar;91(2):271-86. Department of Anesthesiology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA. john_markman@urmc.rochester.edu

This article reviews the evidence for several common interventional techniques for the treatment of chronic pain, including: intraspinal delivery of analgesics, reversible blockade with local anesthetics, augmentation with spinal cord stimulation, and ablation with radiofrequency energy or neurolytic agents. The role of these techniques is defined within the framework of a multidisciplinary approach to the neurobehavioral syndrome of chronic pain. Challenges to the study of the analgesic efficacy of procedural interventions are explored, as are the practical issues raised by their clinical implementation, with the aim of helping nonspecialist physicians identify the patients most likely to benefit from these approaches. ______________________________________________________________________________ Neuromodulation of the cervical spinal cord in the treatment of

chronic intractable neck and upper extremity pain: a case series

and review of the literature.

Vallejo R, Kramer J, Benyamin R. Pain Physician. 2007 Mar;10(2):305-11. Millennium Pain Center, Bloomington, IL 61701, USA. vallejo@millenniumpaincenter.com

Comment in Pain Physician. 2007 May;10(3):515-6; author reply 516-7. Electrical spinal neuromodulation in the form of spinal cord stimulation is currently used for treating chronic painful conditions such as complex regional pain syndrome, diabetic neuropathy, postherpetic neuralgia, peripheral ischemia, low back pain, and other conditions refractory to more conservative treatments. To date, there are very few published reports documenting the use of spinal cord stimulation in the treatment of head/neck and upper limb pain. This paper reports a case series of 5 consecutive patients outlining the use of spinal cord stimulation to treat upper extremity pain. All subjects had previously undergone cervical fusion surgery to treat chronic neck and upper limb pain. Patients were referred following failure of the surgery to manage their painful conditions. Spinal cord stimulators were placed in the cervical epidural space through a thoracic needle placement. Stimulation parameters were adjusted to capture as much of the painful area(s) as possible. In total, 4 out of 5 patients moved to implantation. In all cases, patients reported significant (70-90%) reductions in pain, including axial neck pain and upper extremity pain. Interestingly, 2 patients with associated headache and lower extremity pain obtained relief after paresthesia-steering reportedly covered those areas. Moreover, 2 patients reported that cervical spinal cord stimulation significantly improved axial low back pain. Patients continue to report excellent pain relief up to 9 months following implantation. This case series documents the successful treatment of neck and upper extremity pain following unsuccessful cervical spine fusion surgery. Given this initial success, prospective, controlled studies are warranted to more adequately assess the long term utility and cost effectiveness of electrical neuromodulation treatment of chronic neck and upper extremity pain. ______________________________________________________________________________ Dual electrode spinal cord stimulation in chronic leg and back

pain.

Rainov NG, Demmel W, Heidecke V. Acta Neurochir Suppl. 2007;97(Pt 1):85-9.

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Department of Neurosurgery, Central Clinic Augsburg, Augsburg, Germany. nikolai.rainov@medizin.uni-halle.de

Patients with chronic back and leg pain (CBLP) suffer from a disabling spinal condition of multifactorial origin and are often resistant to medical therapy. Spinal cord stimulation (SCS) is a minimally invasive option for treatment of chronic pain in these patients, which involves placement of epidural electrodes close to the midline of the spinal cord. SCS was originally introduced and used for decades with a single electrode. The development of fully implantable dual channel pulse generators connected to dual multicontact electrodes has given pain clinicians a more versatile tool to treat axial low back pain accompanied by radicular neuropathic pain with irregular and asymmetric distribution, a feature which is found in most CBLP patients. It has been hypothesized that using dual electrodes may improve long term outcome for CBLP patients compared with single electrodes. Current evidence however does not lend strong support to this assumption. Given the high cost of treatments for CBLP and of SCS itself, there is an urgent need for high-quality evidence for the effectiveness of dual electrode SCS in relieving pain and/or improving function in patients with CBLP. ______________________________________________________________________________ Spinal cord stimulation for failed back surgery syndrome and other

disorders.

Nicholson CL, Korfias S, Jenkins A. Acta Neurochir Suppl. 2007;97(Pt 1):71-7. Department of Neurosurgery, Newcastle General Hospital, Regional Neurosciences Centre, Newcastle-Upon-Tyne, UK.

Chronic pain is a complex condition that requires a multi-disciplinary approach to management. Spinal cord stimulation (SCS) has evolved into a relatively easily implemented, reversible technique with low morbidity for the management of chronic, intractable pain in selected patients. Percutaneous placement of electrode arrays, under local anaesthesia. supported by programmable, implanted electronics has been a major technical advance. Multicenter prospective studies were conducted and demonstrated that SCS. as a neuromodulation procedure, is indeed a superior method for treatment of chronic pain if the patients are selected with caution and a proper strategy. Future development of innovative electrodes and pulse generation systems will continue to improve this therapy. ______________________________________________________________________________ Management of chronic severe pain: spinal neuromodulatory and

neuroablative approaches.

Raslan AM, McCartney S, Burchiel KJ. Acta Neurochir Suppl. 2007;97(Pt 1):33-41. Department of Neurological Surgery, Oregon Health & Science University, Portland 97239, USA. raslana@ohsu.edu.

The spinal cord is the target of many neurosurgical procedures used to treat pain. Compactness and well-defined tract separation in addition to well understood dermatomal cord organization make the spinal cord an ideal target for pain procedures. Moreover, the presence of opioid and other receptors involved in pain modulation at the level of the dorsal horn increases the suitability of the spinal cord. Neuromodulative approaches of the spinal cord are either electrical or pharmacological. Electrical spinal cord modulation is used on a large scale for various pain syndromes including; failed back surgery syndrome (FBSS), complex regional pain syndrome (CRPS), neuropathic pain, angina, and ischemic limb pain. Intraspinal delivery of medications e.g. opioids is used to treat nociceptive and neuropathic pains due to malignant and cancer pain etiologies. Neuroablation of the spinal cord pain pathway is mainly used to treat cancer pain. Targets involved include; the spinothalamic tract, the midline dorsal column visceral pain pathway and the trigeminal tract in the upper spinal cord. Spinal neuroablation can also involve cellular elements such as with trigeminal nucleotomy and the dorsal root entry zone (DREZ) operation. The DREZ operation is indicated for phantom type pain and root avulsion injuries. Due to its reversible nature spinal neuromodulation prevails, and spinal neuroablation is performed in a few select cases. ______________________________________________________________________________

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An introduction to operative neuromodulation and functional

neuroprosthetics, the new frontiers of clinical neuroscience and

biotechnology.

Sakas DE, Panourias IG, Simpson BA, Krames ES. Acta Neurochir Suppl. 2007;97(Pt 1):3-10. P. S. Kokkalis Hellenic Center for Neurosurgical Research, Athens, Greece. sakasde@med.uoa.gr.

Operative neuromodulation is the field of altering electrically or chemically the signal transmission in the nervous system by implanted devices in order to excite, inhibit or tune the activities of neurons or neural networks and produce therapeutic effects. It is a rapidly evolving biomedical and high-technology field on the cutting-edge of developments across a wide range of scientific disciplines. The authors review relevant literature on the neuromodulation procedures that are performed in the spinal cord or peripheral nerves in order to treat a considerable number of conditions such as (a) chronic pain (craniofacial, somatic, pelvic, limb, or due to failed back surgery), (b) spasticity (due to spinal trauma, multiple sclerosis, upper motor neuron disease, dystonia, cerebral palsy, cerebrovascular disease or head trauma), (c) respiratory disorders, (d) cardiovascular ischemia, (e) neuropathic bladder, and (f) bowel dysfunction of neural cause. Functional neuroprosthetics, a field of operative neuromodulation, encompasses the design, construction and implantation of artificial devices capable of generating electrical stimuli, thereby, replacing the function of damaged parts of the nervous system. The present article also reviews important literature on functional neuroprostheses, functional electrical stimulation (FES), and various emerging applications based on microsystems devices, neural engineering, neuroaugmentation, neurostimulation, and assistive technologies. The authors highlight promising lines of research such as endoneural prostheses for peripheral nerve stimulation, closed-loop systems for responsive neurostimulation or implanted microwires for microstimulation of the spinal cord to enable movements of paralyzed limbs. The above growing scientific fields, in combination with biological regenerative methods, are certainly going to enhance the practice of neuromodulation. The range of neuromodulatory procedures in the spine and peripheral nerves and the dynamics of the biomedical and technological domains which are reviewed in this article indicate that new breakthroughs are likely to improve substantially the quality of life of patients who are severely disabled by neurological disorders. ______________________________________________________________________________ Interventional techniques: evidence-based practice guidelines in

the management of chronic spinal pain.

Boswell MV, Trescot AM, Datta S, Schultz DM, Hansen HC, Abdi S, Sehgal N, Shah RV, Singh V, Benyamin RM, Patel VB, Buenaventura RM, Colson JD, Cordner HJ, Epter RS, Jasper JF, Dunbar EE, Atluri SL, Bowman RC, Deer TR, Swicegood JR, Staats PS, Smith HS, Burton AW, Kloth DS, Giordano J, Manchikanti L; American Society of Interventional Pain Physicians. Pain Physician. 2007 Jan;10(1):7-111. American Society of Interventional Pain Physicians, Paducah, KY 42001, USA. mark.boswell@ttuhsc.edu

Comment in Pain Physician. 2007 Mar;10(2):381; author reply 381. BACKGROUND: The evidence-based practice guidelines for the management of chronic spinal pain with interventional techniques were developed to provide recommendations to clinicians in the United States. OBJECTIVE: To develop evidence-based clinical practice guidelines for interventional techniques in the diagnosis and treatment of chronic spinal pain, utilizing all types of evidence and to apply an evidence-based approach, with broad representation by specialists from academic and clinical practices. DESIGN: Study design consisted of formulation of essentials of guidelines and a series of potential evidence linkages representing conclusions and statements about relationships between clinical interventions and outcomes. METHODS: The elements of the guideline preparation process included literature searches, literature synthesis, systematic review, consensus evaluation, open forum presentation, and blinded peer review. Methodologic quality evaluation criteria utilized included the Agency for Healthcare Research and Quality (AHRQ) criteria, Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria, and Cochrane review criteria. The designation of levels of evidence was from Level I (conclusive), Level II (strong), Level III (moderate), Level IV (limited), to Level V (indeterminate). RESULTS: Among the

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diagnostic interventions, the accuracy of facet joint nerve blocks is strong in the diagnosis of lumbar and cervical facet joint pain, whereas, it is moderate in the diagnosis of thoracic facet joint pain. The evidence is strong for lumbar discography, whereas, the evidence is limited for cervical and thoracic discography. The evidence for transforaminal epidural injections or selective nerve root blocks in the preoperative evaluation of patients with negative or inconclusive imaging studies is moderate. The evidence for diagnostic sacroiliac joint injections is moderate. The evidence for therapeutic lumbar intraarticular facet injections is moderate for short-term and long-term improvement, whereas, it is limited for cervical facet joint injections. The evidence for lumbar and cervical medial branch blocks is moderate. The evidence for medial branch neurotomy is moderate. The evidence for caudal epidural steroid injections is strong for short-term relief and moderate for long-term relief in managing chronic low back and radicular pain, and limited in managing pain of postlumbar laminectomy syndrome. The evidence for interlaminar epidural steroid injections is strong for short-term relief and limited for long-term relief in managing lumbar radiculopathy, whereas, for cervical radiculopathy the evidence is moderate. The evidence for transforaminal epidural steroid injections is strong for short-term and moderate for long-term improvement in managing lumbar nerve root pain, whereas, it is moderate for cervical nerve root pain and limited in managing pain secondary to lumbar post laminectomy syndrome and spinal stenosis. The evidence for percutaneous epidural adhesiolysis is strong. For spinal endoscopic adhesiolysis, the evidence is strong for short-term relief and moderate for long-term relief. For sacroiliac intraarticular injections, the evidence is moderate for short-term relief and limited for long-term relief. The evidence for radiofrequency neurotomy for sacroiliac joint pain is limited. The evidence for intradiscal electrothermal therapy is moderate in managing chronic discogenic low back pain, whereas for annuloplasty the evidence is limited. Among the various techniques utilized for percutaneous disc decompression, the evidence is moderate for short-term and limited for long-term relief for automated percutaneous lumbar discectomy, and percutaneous laser discectomy, whereas it is limited for nucleoplasty and for DeKompressor technology. For vertebral augmentation procedures, the evidence is moderate for both vertebroplasty and kyphoplasty. The evidence for spinal cord stimulation in failed back surgery syndrome and complex regional pain syndrome is strong for short-term relief and moderate for long-term relief. The evidence for implantable intrathecal infusion systems is strong for short-term relief and moderate for long-term relief. CONCLUSION: These guidelines include the evaluation of evidence for diagnostic and therapeutic procedures in managing chronic spinal pain and recommendations for managing spinal pain. However, these guidelines do not constitute inflexible treatment recommendations. These guidelines also do not represent a "standard of care." ______________________________________________________________________________ Survey of the practice of spinal cord stimulators and intrathecal

analgesic delivery implants for management of pain in Canada.

Peng PW, Fedoroff I, Jacques L, Kumar K. Pain Res Manag. 2007 Winter;12(4):281-5. Department of Anesthesiology and Pain Management, Toronto Western Division, University Health Network, University of Toronto, Toronto, Ontario, Canada. philip.peng@uhn.on.ca.

BACKGROUND: In 2006, the Canadian Neuromodulation Society was formed. The present survey characterizes the practice of spinal cord stimulator (SCS) and intrathecal analgesic delivery pump (IADP) implantation for pain management in different centres across Canada. METHOD: A structured questionnaire was designed to examine the funding source, infrastructure and patient screening process in different centres implanting SCSs and IADPs. Centres that performed more than 10 implants per year were surveyed. The survey was centre-based, ie, each centre received one questionnaire regardless of the number of staff involved in neuromodulation practice. RESULTS: Fourteen centres were identified and 13 responded. Implantation of SCS and IADP was performed in 12 and 10 centres, respectively. In most centres, failed back surgery syndrome was the most frequent indication for SCS and IADP implantation. For SCS, all centres always performed a trial; the majority used percutaneous electrode (83%) before the SCS implantation. Routine psychological screening was performed in 25% of centres before any SCS trial procedure. For IADP, all centres performed a trial injection or infusion before implantation. Five centres (50%) performed psychological screening in almost all patients. Continuous infusion techniques were the most popular (50%) used for the trial. CONCLUSION: The present survey provides a 'snapshot' of

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the practice of SCS and IADP implantation in Canada. A review of SCS and IADP trials indicated that Canadian practices are mostly, but not always, consistent with those elsewhere. ______________________________________________________________________________

Patient satisfaction with spinal cord stimulation for failed back

surgery syndrome. [Article in Spanish]

De Andrés J, Quiroz C, Villanueva V, Valía JC, López Alarcón D, Moliner S, Monsalve V. Rev Esp Anestesiol Reanim. 2007 Jan;54(1):17-22. Servicio de Anestesiología, Reanimación y Unidad Multidisciplinar para el Tratamiento del Dolor, Consorcio Hospital General Universitario, Valencia. deandres_jos@gva.es

INTRODUCTION: The incidence of failed back surgery syndrome is about 40%. We studied the efficacy of and patient satisfaction with use of a spinal cord stimulator to treat this syndrome. MATERIAL AND METHODS: A period of 72 months of experience with implanted spinal cord stimulators was analyzed in this observational, descriptive study of patients who were included retrospectively. Patients met criteria for failed back surgery syndrome according to the taxonomy of the International Association for the Study of Pain. A chi2 test was used to compare qualitative variables. Results for quantitative variables were compared by analysis of variance. Statistical significance was set at P < 0.05. RESULTS: Thirty-four patients were studied. Both lumbar back and radicular pain assessed on a visual analog scale (VAS) decreased significantly from the mean overall score of 6. As time passed, fewer patients felt the system met their expectations. More patients said the system met their expectations in the first months after implantation (73.5%) than at a later interview (55.9%). Seventeen complications were reported, the most common being mechanical difficulties with the implanted stimulator. None of the complications were serious. Use of additional medication to control pain decreased in 38.2% of the cases. A total of 73.5% of the patients considered the implanted stimulator to be beneficial and 67.6% would have a spinal cord stimulator implanted again. CONCLUSIONS: Spinal cord stimulation improves lumbar back pain in patients with failed back surgery syndrome and reduces the amount of additional medication taken to control pain. It is important for patients to adjust their expectations about the implanted stimulator. ______________________________________________________________________________ Neurostimulation in patients with chronic neuropathic pain in the

so-called failed back surgery syndrome (world and the author's

experience). [Article in Russian]

Zeeliger A, Bersnev VP. Zh Vopr Neirokhir Im N N Burdenko. 2007 Jan-Mar;(1):53-7; discussion 57-9.

The failed back surgery syndrome (FBSS) is defined as protracted or recurrent pain, mainly in the lower back and/or legs, even after previous anatomically successful spinal surgery. Treatment of such patients commonly involves difficulties since neither medical therapy nor repeated back surgery does not result in adequate pain relief. Spinal cord stimulation (SCS) is a minimally invasive procedure that allows physicians and patients to define the effect of therapy just before permanent implantation. Both trial stimulation and permanent implantation are fully reversible. Early treatment with SCS has been shown to be very effective in correctly selected FBSS patients and therefore this procedure should be preferred over back resurgery. Clinical studies have demonstrated that CSC provides a sustained, long-term, 50% or more pain relief in over 60% of the patients and makes it possible to reduce the use of analgesics and to improve quality of life and functional status, thus permit many patients to resume work. Many patients told about fair therapeutic effects and the occurrence of mild side effects. Thus, SCS is an accessible alternative to traditional therapy. It is the treatment of choice in drug-resistant FBSS patients where recurrent neuropathic pin persists after surgery and analgesics are no longer effective. ______________________________________________________________________________ Spinal nerve root stimulation.

Haque R, Winfree CJ. Neurosurg Focus. 2006 Dec 15;21(6):E4.

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Department of Neurological Surgery, Columbia University Medical Center, New York, New York 10032, USA.

Spinal nerve root stimulation is a recently developed form of neuromodulation used for the treatment of chronic pain conditions. Unlike spinal cord stimulation, in which electrical impulses are directed at the dorsal columns, spinal nerve root stimulation guides electrical current directly to one or more nerve roots. There are a variety of techniques by which this can be accomplished, yet no consistent terminology to describe these variations exists. In this review, the authors group the various techniques according to anatomical approach, define each category, describe and illustrate each of the techniques, review the available reports on their uses, and discuss the advantages and disadvantages of each one. ______________________________________________________________________________ Spinal cord stimulation: indications and outcomes.

Lee AW, Pilitsis JG. Neurosurg Focus. 2006 Dec 15;21(6):E3. Department of Neurosurgery, Wayne State University, Detroit, Michigan, USA.

Spinal cord stimulation (SCS) is the most commonly used implantable neurostimulation modality for management of pain syndromes. In this paper the authors describe the current indications for SCS and its efficacy in the treatment of those diseases. Specifically, the literature on patient selection and outcomes after SCS for failed-back surgery syndrome (FBSS), refractory angina pectoris, peripheral vascular disease, and complex regional pain syndrome (CRPS) Type I was reviewed. Effective pain relief was obtained in 60 to 80% of patients with FBSS and CRPS Type I. Furthermore, these patients had significant improvements in quality of life (QOL) and a significantly greater chance of returning to work than patients who did not undergo SCS. The use of SCS in patients with inoperable angina (that is, refractory angina pectoris) resulted in significant decreases in chest pain and hospital admissions as well as increased exercise duration, with less morbidity than with open procedures that were performed for pain control only. Patients with inoperable PVD also demonstrated significant improvements in pain relief, QOL, and limb mobility. Reported complications were mostly related to hardware and were relatively minor. Review of randomized controlled studies supports the use of SCS as an effective treatment modality for pain associated with FBSS, refractory angina pectoris, peripheral vascular disease, and CRPS Type I. ______________________________________________________________________________ Psychological factors in spinal cord stimulation therapy: brief

review and discussion.

Doleys DM. Neurosurg Focus. 2006 Dec 15;21(6):E1. Pain and Rehabilitation Institute, Birmingham, Alabama 35213, USA. dmdpri@aol.com

Since its introduction in 1967 by Shealy and colleagues, spinal cord stimulation (SCS) therapy has become an accepted approach to the treatment of certain types of chronic pain. Significant advances have been made in surgical technique, hardware technology, and the variety of disorders for which SCS has proven to be potentially beneficial. Despite these advancements, 25 to 50% of patients in whom a preimplantation trial screening yields successful results report loss of analgesia within 12 to 24 months of implantation, even in the presence of a functioning device. Psychological factors may play an important role in understanding this observation and improving the outcomes. In this article the author briefly reviews some of the data on psychological factors potentially involved in SCS. Research on patients with low-back and extremity pain was more heavily relied on because this is the population for which the most data exist. The discussion is divided into four sections: 1) role of psychological factors; 2) psychological screening and assessment; 3) patient selection and psychological screening; and 4) psychological variables and outcomes. To date, the data remain speculative. Although few definitive conclusions can be drawn, the cumulative existing experience does lend itself to some reasonable recommendations. As with all therapies for chronic pain, invasive or noninvasive, the criteria for success and an acceptable level of failure need to be established, but remain elusive. The emphasis herein is to try to take what works and make it work better.

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______________________________________________________________________________ Lumbar spinal cord stimulation can improve muscle strength and

gait independently of the analgesic effect: a case report.

Buonocore M, Demartini L, Bonezzi C. Neuromodulation. 2006 Oct;9(4):309-13. doi: 10.1111/j.1525-1403.2006.00072.x. Unit of Clinical Neurophysiology, Unit of Pain Medicine and Fondazione Salvatore Maugeri, Scientific Institute of Pavia, Pavia, Italy.

Spinal cord stimulation (SCS) is widely used for pain relief in patients with failed back surgery syndrome (FBSS), and muscle weakness is a common finding in patients with chronic pain. We present here a single case report of a 47-year-old woman, who, after SCS for FBSS, had continuous improvement in lower leg muscle strength and gait, but only transient and minimal pain relief. To the authors' knowledge, this is only the second published case report of significant improvement in "motor" function, independent of the analgesic effect following SCS in FBSS. If SCS, in fact, does improve muscle strength, new strategies for the management of patients with chronic pain might be opened up. Further studies are needed to verify this hypothesis. ______________________________________________________________________________ Failure modes of spinal cord stimulation hardware.

Rosenow JM, Stanton-Hicks M, Rezai AR, Henderson JM. J Neurosurg Spine. 2006 Sep;5(3):183-90. Department of Neurosurgery, Feinberg School of Medicine of Northwestern University, Chicago, Illinois 60611, USA. jrosenow@nmff.org

OBJECT: Epidural spinal cord stimulation (SCS) is effective at treating refractory pain. The failure modes of the implanted hardware, however, have not been well studied. A better understanding of this could aid in improving the current procedure or designing future devices. METHODS: The authors reviewed electronic charts and operative reports of 289 patients who had undergone SCS implantation between 1998 and 2002 at the Cleveland Clinic Foundation. Data were collected on demographics, type of hardware, date of implantation procedure, indication for treatment, time to failure, and failure mode. Data were then analyzed to identify significant differences. A total of 577 procedures were performed, 43.5% of which involved revision or removal of SCS hardware. The most common indication was complex regional pain syndrome 1, and this was followed by failed-back surgery syndrome. The median number of procedures per patient was two. Approximately 80% of all leads were the percutaneous type. The majority (62%) of leads were placed in the thoracic region, and 33.5% of all leads required revision. Poor pain relief coverage was the most common indication for revision. Surgically implanted leads broke twice as often as percutaneous leads. In 46% of the patients, hardware revision was required, and multiple revisions were necessary in 22.5%. Three-way ANOVA revealed significant differences in failure mode rates according to location (cervical compared with thoracic, p = 0.037) and failure modes (p = 0.019). Laminotomy leads tended to break and migrate sooner than percutaneous leads. Thoracic leads became infected sooner than cervical leads. CONCLUSIONS: The results of this analysis of SCS hardware failures may be used as a basis for refining surgical technique and designing the next generation of SCS hardware. ______________________________________________________________________________ Quantitative sensory testing for spinal cord stimulation in

patients with chronic neuropathic pain.

Eisenberg E, Backonja MM, Fillingim RB, Pud D, Hord DE, King GW, Stojanovic MP. Pain Pract. 2006 Sep;6(3):161-5. Pain Relief Unit, Rambam Medical Center, Haifa Pain Research Group, Technion-Israel Institute of Technology, Haifa, Israel. e_eisenberg@rambam.health.gov.il

OBJECTIVE: A prospective pilot study was conducted, attempting to identify objective tests that would help clinicians to assess the efficacy of spinal cord stimulation (SCS) trial preceding permanent device implantation. Setting: Four university hospitals in the United States and Israel.

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Participants: Thirteen patients with radicular leg pain due to failed back surgery syndrome (FBSS) or leg pain due to complex regional pain syndrome (CRPS) who were candidates for SCS. METHODS: Participants underwent a series of quantitative sensory tests prior to, and seven days after the initiation of SCS trial. These tests included: vibration threshold (conducted using the VSA 3000; Medoc Inc., Ramat Ishay, Israel), cold threshold, warm threshold, heat pain threshold, phasic heat pain threshold, tonic heat pain threshold (conducted using the TSA 2001; Medoc Inc.), and electrical pain tolerance at 5, 250 and 2000 Hz (administered using the NerveScan 2000; Neurotron, Inc., Baltimore, MD, USA). RESULTS: Useful data were obtained from 12 patients. The results of the vibration threshold and the tolerance to electrical stimulation at 5 and 250 Hz changed with an SCS trial. These results also correlated with the decision regarding the permanent implantation, which was made independently of them. In contrast, the results of thermal thresholds and tolerance to electrical stimulation at 2000 Hz tests did not change with the SCS trial. CONCLUSIONS: Our findings, which agree with those of a few other studies, suggest that the vibration threshold and the tolerance to electrical stimulation at 5 and 250 Hz tests can assist the clinician to select the right patients for permanent stimulation. ______________________________________________________________________________ Peripheral nerve field stimulation in chronic abdominal pain.

Paicius RM, Bernstein CA, Lempert-Cohen C. Pain Physician. 2006 Jul;9(3):261-6. Newport Beach Headache and Pain Institute, 450 Newport Center Drive Suite 650, Newport Beach, CA 92660, USA. rpaicius@ocpain.com

INTRODUCTION: Spinal Cord Stimulation (SCS) has become an accepted therapeutic modality for the treatment of intractable pain syndromes, primarily used today in the settings of failed back surgery syndrome, neuropathic back and limb pain. The use of spinal cord stimulators for peripheral nerve field electrostimulation is becoming increasingly recognized as a safe, effective alternative for chronic pain conditions that are refractory to medical management and do not respond to traditional dorsal column stimulation. Advances in technology have allowed for minimally invasive percutaneous placement of multipolar leads with complex programmable systems to provide patient- controlled relief of pain in precisely targeted regions. With these improvements in hardware, the use of Peripheral Nerve Field Stimulation (PNFS) appears to have an untapped potential for providing patients with pain relief for a wider range of underlying conditions than was previously believed possible. We present three cases, each with a different etiology of chronic abdominal pain: one with inguinal neuralgia, one with chronic pancreatitis, and one with pain following liver transplant. Each patient was refractory to conventional medical approaches. For all three patients, PNFS provided significant relief from pain, enabling patients to decrease or discontinue their opioid medications and to enjoy significant improvement in their quality of life. We conclude that PNFS is a safe, effective and minimally invasive treatment that may be used successfully for a wide variety of indications including chronic abdominal pain. ______________________________________________________________________________ Prevention of percutaneous electrode migration in spinal cord

stimulation by a modification of the standard implantation

technique.

Renard VM, North RB. J Neurosurg Spine. 2006 Apr;4(4):300-3. Department of Neurosurgery, Johns Hopkins University, Baltimore, Maryland 21287-7713, USA.

OBJECT: Percutaneous spinal cord stimulation (SCS) electrodes are prone to migration even after scar tissue encapsulation. The authors devised a simple technique to eliminate longitudinal migration. METHODS: In 99 patients who received implanted percutaneous electrodes, less than 0.1 cm3 of silicone elastomer adhesive was injected between the anchoring sleeve and the electrode. As a result, no patient required revision surgery due to longitudinal electrode migration over a mean follow-up period of 20.2 +/- 12.3 months (range 1.8-39.7 months). Postimplant SCS-related surgical procedures were required in 15 patients (15%) for the following indications: infection in three patients, expanded area of pain in four patients, lateral migration after the sutures eroded through the supraspinous ligament in one patient, postural changes in stimulation in one

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patient, receiver-site pain in two patients, technical failure in three patients, and inadequate pain relief in one patient. CONCLUSIONS: With modification of the standard technique for implantation of percutaneous SCS electrodes, no longitudinal migration of electrodes was noted in this series of 99 patients. ______________________________________________________________________________ Neurostimulation for chronic neuropathic back pain in failed back

surgery syndrome.

Van Buyten JP. J Pain Symptom Manage. 2006 Apr;31(4 Suppl):S25-9. AZ Maria Middelares Pain Clinic, Sint Niklaas, Belgium. vanbuyten@skynet.be

Failed back surgery syndrome (FBSS) is defined as persistent or recurrent pain, mainly in the lower back and/or legs, even after previous anatomically successful spinal surgery. Treatment of such patients is difficult, with conservative therapy and repeated back surgery often proving unsuccessful at providing adequate pain relief. Spinal cord stimulation (SCS) is a minimally invasive procedure that allows physicians and patients to inexpensively evaluate the response to therapy before permanent implantation. Both trial stimulation and permanent implantation are fully reversible. Early treatment with SCS has been shown to be very effective in well-selected FBSS patients and should be considered instead of reoperation. Clinical studies have demonstrated that SCS provides a sustained, long-term, 50% or more reduction in pain in over 60% of patients and allows concomitant pain medication to be reduced. The substantial improvements in quality of life and functional status permit many patients to return to work. Patients express great satisfaction with SCS and minimal side effects are observed. Moreover, SCS has been shown to be a cost-effective alternative to conventional therapies. Thus, SCS is the treatment of choice in medically refractory FBSS patients where recurrent neuropathic pain persists after surgery and analgesics are no longer effective or accompanied by intolerable side effects. ______________________________________________________________________________ Spinal cord stimulation in complex regional pain syndrome and

refractory neuropathic back and leg pain/failed back surgery

syndrome: results of a systematic review and meta-analysis.

Taylor RS. J Pain Symptom Manage. 2006 Apr;31(4 Suppl):S13-9. Department of Public Health & Epidemiology, University of Birmingham, Birmingham, UK. r.s.taylor@bham.ac.uk

The drive for good quality evidence has highlighted the importance of well-conducted systematic reviews and meta-analyses that critically evaluate and grade studies for new or existing therapies. A systematic review and meta-analysis was performed to review the efficacy, safety, and cost effectiveness of spinal cord stimulation (SCS) in complex regional pain syndrome (CRPS) and refractory neuropathic back and leg pain/failed back surgery syndrome (FBSS). The results support the use of SCS in patients with refractory neuropathic back and leg pain/FBSS (Grade B evidence) and CRPS type I (Grade A evidence)/type II (Grade D evidence). SCS not only reduces pain, improves quality of life, reduces analgesic consumption, and allows some patients to return to work, with minimal significant adverse events, but may also result in significant cost savings over time. ______________________________________________________________________________ Spinal cord stimulation in treatment of chronic benign pain:

challenges in treatment planning and present status, a 22-year

experience.

Kumar K, Hunter G, Demeria D. Neurosurgery. 2006 Mar;58(3):481-96; discussion 481-96. Section of Neurosurgery, Department of Surgery, University of Saskatchewan, Regina General Hospital, Regina, Canada. krishna.kumar@rqhealth.ca

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OBJECTIVE: To present an in-depth analysis of clinical predictors of outcome including age, sex, etiology of pain, type of electrodes used, duration of pain, duration of treatment, development of tolerance, employment status, activities of daily living, psychological status, and quality of life. Suggestions for treatment of low back pain with a predominant axial component are addressed. We analyzed the complications and proposed remedial measures to improve the effectiveness of this modality. METHODS: Study group consists of 410 patients (252 men, 58 women) with a mean age of 54 years and a mean follow-up period of 97.6 months. All patients were gated through a multidisciplinary pain clinic. The study was conducted over 22 years. RESULTS: The early success rate was 80% (328 patients), whereas the long-term success rate of internalized patients was 74.1% (243 patients) after the mean follow-up period of 97.6 months. Hardware-related complications included displaced or fractured electrodes, infection, and hardware malfunction. Etiologies demonstrating efficacy included failed back syndrome, peripheral vascular disease, angina pain, complex regional pain syndrome I and II, peripheral neuropathy, lower limb pain caused by multiple sclerosis. Age, sex, laterality of pain or number of surgeries before implant did not play a role in predicting outcome. The percentage of pain relief was inversely related to the time interval between pain onset and time of implantation. Radicular pain with axial component responded better to dual Pisces electrode or Specify-Lead implantation. CONCLUSION: Spinal cord stimulation can provide significant long-term pain relief with improved quality of life and employment. Results of this study will be effective in better defining prognostic factors and reducing complications leading to higher success rates with spinal cord stimulation. ______________________________________________________________________________ Neural modulation by stimulation.

De Andrés J, Van Buyten JP. Pain Pract. 2006 Mar;6(1):39-45. Valencia General University Hospital, Valencia, Spain. deandres_jos@gva.es

Spinal cord stimulation (SCS) for the treatment of neuropathic pain is supported by good-quality randomized controlled trials, prospective and retrospective case studies, and observational case series that confirm its efficacy and safety. SCS has been successfully used in various refractory neuropathic pain conditions, including failed back surgery syndrome (FBSS), neuropathic back and leg pain, and complex regional pain syndrome (CRPS) types I and II. According to the Harbour and Miller Scale (2001), the evidence for SCS in FBSS has been classified as grade B, while that for CRPS type I has been classified as grade A. Clinical evidence has shown that compared to conventional pain therapy, more than two-thirds of carefully selected patients treated with SCS achieved sustained pain relief of 50% or more, with minimal side effects. Many patients were able to reduce their analgesic consumption. Quality of life improved and the majority of patients were happy with their treatment; in some cases, patients were able to return to work. Trial stimulation, which is relatively inexpensive and completely reversible, provides predictive value for long-term efficacy and increases the cost-effectiveness of permanent implantation. Studies consistently report that over time, SCS is potentially cost saving to the healthcare system. At present, SCS is considered a "last resort" in the treatment of refractory neuropathic pain, yet evidence suggests that early intervention with SCS results in greater efficacy and, in the case of FBSS, should be considered before re-operation. ______________________________________________________________________________ Use of a tubular retractor system as a minimally invasive

technique for epidural plate electrode placement under local

anesthesia for spinal cord stimulation: technical note.

Beems T, van Dongen RT. Neurosurgery. 2006 Feb;58(1 Suppl):ONS-E177; discussion ONS-E177. Department of Neurosurgery, Radboud University, Nijmegen Medical Centre, The Netherlands. T.Beems@nch.umcn.nl

OBJECTIVE: To improve the technique of placement of large plate electrodes for spinal cord stimulation with a minimally invasive approach using the METRx tubular retractor system (Medtronic Sofamor Danek, Minneapolis, MN). This dilating system splits the paravertebral musculature, avoiding the need to strip these muscles from the spine. The technique described

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makes it possible to perform the procedure (currently, it is most frequently performed using general anesthesia) with local anesthesia and sedation, allowing test stimulation, and with little intraoperative or postoperative discomfort for the patient. METHODS: The tubular retractor system was used to approach the spine at the desired level using local anesthesia. A small laminectomy was performed through the working tube, and the plate electrodes were introduced by the same approach. Test stimulation could be performed to determine the correct electrode position because only local anesthesia was used. RESULTS: Seven patients were scheduled for placement of large plate electrodes for spinal cord stimulation. In six patients, with different indications for the placement of spinal cord stimulation, the electrode could be placed using the minimally invasive tubular retractor system approach with local anesthesia and slight sedation. A good test stimulation was obtained in all of the patients, resulting in good pain relief after definitive implantation. We were not able to perform the procedure in one patient because we could not reach the spinal canal at the level operated on previously. All patients experienced only acceptable postoperative back pain. CONCLUSION: Using a tubular retractor system, implantation of plate electrodes for spinal cord stimulation can be performed under local anesthesia with acceptable discomfort for the patient, making the approach of the spinal canal minimally invasive. This method allows test stimulation to assess the correct electrode position and results in less local postoperative discomfort because of the small-muscle splitting approach. ______________________________________________________________________________ Minimally invasive procedures for the treatment of failed back

surgery syndrome.

Mavrocordatos P, Cahana A. Adv Tech Stand Neurosurg. 2006;31:221-52. Department of Anesthesiology, Pharmacology and Intensive Care, Geneva, Switzerland.

Failed back surgery syndrome has become unfortunately a common clinical entity. FBSS does not have one specific treatment because it does not have one specific cause. Some features are shared with chronic low back pain (CLBP) and some pathological processes are specific. Both pathologies are leading causes of disability in the industrialized world and costly medical and surgical treatments are continuously used despite their limited efficacy. Nonetheless, evidence based practice guidelines are systematically developed. In this chapter we cautiously review the vast, complex and at times contradictory literature regarding the treatment of FBSS. Interventional Pain literature suggests that there is moderate evidence (small randomized or non randomized or single group or matched case controlled studies) for medial branch neurotomy and limited evidence (non experimental one or more center studies) for intra-discal treatments in mechanical low back pain. There is moderate evidence for the use of transforaminal epidural steroid injections, lumbar percutaneous adhesiolysis and spinal endoscopy for painful lumbar radiculopathy and spinal cord stimulation and intrathecal pumps mostly after spinal surgery. In reality there is no gold standard for the treatment of FBSS but, these results seem promising. ______________________________________________________________________________ Spinal cord stimulation for axial low back pain: a prospective

controlled trial comparing 16-contact insulated electrodes with 4-

contact percutaneous electrodes.

North RB, Kidd DH, Olin J, Sieracki JN, Petrucci L. Neuromodulation. 2006 Jan;9(1):56-67. doi: 10.1111/j.1525-1403.2006.00043.x. Department of Neurosurgery, School of Medicine, Johns Hopkins University, Baltimore, Md, USA.

Use of multicontact electrodes and programmable implanted pulse generators has increased the efficacy of spinal cord stimulation for pain. Some investigators find dual column electrodes advantageous for difficult-to-treat axial low back pain, but we have reported significantly improved measures with a single percutaneous midline electrode vs. dual percutaneous electrodes and even better results with an insulated, 1 × 4, midline electrode. In this study, 10 patients provided computerized, quantitative parameter measures for a temporary percutaneous 1 × 4 electrode and for a permanent insulated 2 × 8 electrode. Compared with the 2 × 8, the 1 × 4 resulted in

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marginally better patient-rated (109%, p = 0.06) and computer-calculated pain/paresthesia overlap (107%, p = 0.17); higher scaled amplitude to cover the low back (106%, NS); and significantly lower voltage (78%, p = 0.0004), increased extraneous coverage (141%, p = 0.0000), and improved symmetry (25%, p = 0.001). Thus, we observed no significant technical advantage for the insulated 2 × 8 in treating axial low back pain. ______________________________________________________________________________ Spinal cord stimulation electrode design: a prospective,

randomized, controlled trial comparing percutaneous with

laminectomy electrodes: part II-clinical outcomes.

North RB, Kidd DH, Petrucci L, Dorsi MJ. Neurosurgery. 2005 Nov;57(5):990-6; discussion 990-6. Department of Neurosurgery, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21287-7881, USA.

OBJECTIVE: Spinal cord stimulation, in use for more than 30 years, has evolved into an easily implemented technique involving percutaneous or laminectomy electrode placement. In a randomized comparison of four-contact percutaneous and four-contact insulated laminectomy electrodes placed at the same level in the dorsal, epidural midline, quantitative measures of stimulator performance revealed significant technical advantages for the laminectomy electrodes. Our prospective, randomized, controlled trial compares clinical results in these same patients. METHODS: Impartial third parties followed our series of 24 patients with failed back surgery syndrome to gather clinical outcome data. We defined "success" as at least 50% sustained relief of pain and patient satisfaction with the result of treatment. RESULTS: At a mean follow-up of 1.9 years, 10 of 12 patients receiving the laminectomy electrode and 5 of 12 patients receiving the percutaneous electrode reported a successful outcome (P < 0.05). Follow-up at a mean of 2.9 years showed that this result was maintained in 5 of 12 patients with the laminectomy electrode and 3 of 12 with the percutaneous electrode (not statistically significant). Many patients reported improvements in most activities of daily living, and loss of function was rare. In addition, 9 patients with laminectomy electrodes and 4 with percutaneous electrodes reducted or eliminated analgesic intake (P < 0.05), and 2 returned to work. No electrode migration was observed. CONCLUSION: Laminectomy electrode placement, although more invasive than percutaneous placement, yields significantly better clinical results in patients with failed back surgery syndrome at mean 1.9 years follow-up. In our small sample, however, the statistical significance of this advantage disappeared at mean 2.9 years follow-up. ______________________________________________________________________________ Spinal cord stimulation in Failed-Back-Surgery-Syndrome.

Preliminary study for the evaluation of therapy by functional

magnetic resonance imaging (fMRI). [Article in German]

Rasche D, Siebert S, Stippich C, Kress B, Nennig E, Sartor K, Tronnier VM. Schmerz. 2005 Nov;19(6):497-500, 502-5. Neurochirurgische Klinik, Universitätsklinikum Heidelberg. dirk.rasche@med.uni-heidelberg.de

BACKGROUND: Spinal cord stimulation (SCS) is an effective alternative treatment in patients with chronic neuropathic pain and mainly radicular distribution. The aim of this prospective study was to investigate changes in BOLD signal with fMRI during active SCS and to correlate the results with the clinical pain intensity, measured with a visual analogue scale (VAS). PATIENTS AND METHODS: Three patients with failed back surgery syndrome were tested during the clinical trial of SCS. A first fMRI was performed with marked pain and a high VAS score. Before the second fMRI a therapeutic stimulation phase with pain reduction was carried out. RESULTS: With high pain levels SCS activated the cingulate gyrus, thalamus, prefrontal cortex, supplementary motor area and postcentral gyrus. After pain reduction, SCS did not elicit these activations in the second fMRI, using the same stimulation parameters. CONCLUSIONS: In patients with chronic neuropathic pain and high VAS levels, SCS elicited BOLD activation in the cingulate gyrus, thalamus, prefrontal cortex, and primary and secondary somatosensory area. Pain reduction by SCS resulted in a reduction of functional activity in these areas as revealed by follow-up fMRI.

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______________________________________________________________________________ Evaluation of a dual quadripolar surgically implanted spinal cord

stimulation lead for failed back surgery patients with chronic low

back and leg pain.

De Mulder PA, Rijdt BT, Veeckmans G, Belmans L. Neuromodulation. 2005 Oct;8(4):219-24. doi: 10.1111/j.1525-1403.2005.00028.x. Departments of Pain Therapy and Neurosurgery, Heilig Hartziekenhuis, Lier, Belgium and Departments of Anesthesiology and Neurosurgery, St. Dimphna Ziekenhuis, Geel, Belgium.

Objectives. Recent publications on dual program spinal cord stimulation (SCS) system demonstrate more flexible electrode programming, which helps to steer paresthesias towards all of the affected areas including the low back area. Materials and Methods. The following data were retrospectively sought from 20 nonrandomized failed back surgery patients at two centers treated by a dual quadripolar surgically implanted SCS lead: pain and paresthesia, VAS ratings, medication use, sleep patterns, daily activities, hardware problems, and willingness to repeat the procedure. The data were analyzed by the Wilcoxon signed rank test (p value < 0.05). Results. The average paresthesia coverage was 76%. After SCS implantation, analgesic use was decreased in 59% of the patients, sleeping time augmented, and quality of sleep improved. The number of patients taking benzodiazepines decreased. Sixty percent reported increased participation in social activities. Conclusions. This dual program surgical SCS technique is simple, respects patients' autonomy, and provides adequate analgesia with an increase in quality of life. ______________________________________________________________________________ Spinal Cord Stimulation vs. Conventional Medical Management: A

Prospective, Randomized, Controlled, Multicenter Study of Patients

with Failed Back Surgery Syndrome (PROCESS Study).

Kumar K, North R, Taylor R, Sculpher M, Van den Abeele C, Gehring M, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Fortini G, Richardson J, Buchser E, Tracey S, Reny P, Brookes M, Sabene S, Cano P, Banks C, Pengelly L, Adler R, Leruth S, Kelly C, Jacobs M. Neuromodulation. 2005 Oct;8(4):213-218. doi: 10.1111/j.1525-1403.2005.00027.x. Department of Neurosurgery Regina General Hospital, Regina, Saskatchewan, Canada; Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Public Health and Epidemiology, University of Birmingham, Edgbaston, Birmingham, UK; Centre for Health Economics, University of York, York, UK; Medtronic Europe Sàrl, Route de Molliau, Tolochenaz, Switzerland; Department of Neurosurgery, Montreal Neurological Institute and Hospital, Montreal, Quebec, Canada; Department of Pain & Anaesthesia, James Cook University Hospital, Middlesbrough, Cleveland, UK; Institute of Neurosurgery, Catholic University of Rome, Rome, Italy; Department of Neurosurgery, Hospital de la Santa Creu I Sant Pau, Barcelona, Spain; Pain Management Clinic, Basildon and Thurrock University Hospitals, Basildon, Essex, UK; Pain Clinic, Axxon Pain Medicine, Brisbane, Queensland, Australia; Pain Relief Unit, Rambam Medical Center, Haifa, Israel; Department of Neurosurgery, Centre Hospitalier Régional de Namur (CHR Namur), Namur, Belgium; Pain Management Department, Varese Regional Hospital and Macchi Foundation, Varese, Italy; Department of Pain and Anesthesia, Bradford Hospitals, Bradford, UK; and Anesthesia and Pain Management Services, Center for Neuromodulation EHC, Hospital of Morges, Morges, Switzerland, [ISRCTN77527324].

Introduction. Since its first application in 1967, numerous case series indicate that spinal cord stimulation (SCS) is an effective treatment for the management of failed back surgery syndrome (FBSS). However, only one randomized controlled trial has demonstrated that SCS provides more effective pain relief than re-operation and conventional medical management. The PROCESS randomized, controlled, multicenter trial aims to assess the clinical effectiveness and cost-effectiveness of SCS when added to conventional medical management compared to conventional medical management alone in patients with FBSS. Methods/Design. A total of 100 FBSS patients with predominantly neuropathic leg pain will be recruited from 12 centers and randomized to receive either conventional medical management alone or in combination with SCS for a period of 24 months. Patients will be evaluated at 1, 3, 6, 9, 12, 18, and 24 months. At the 6-month visit, patients will be classified as successful (≥ 50% pain relief in the legs) or unsuccessful (< 50% pain relief in the legs). If the results of the randomized treatment are unsuccessful, patients can cross over to the alternative treatment arm. Discussion. This paper highlights the rationale, design, methods, and challenges of an ongoing prospective, randomized, controlled, multicenter

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clinical trial that has been undertaken to obtain conclusive evidence of the clinical efficacy and cost-effectiveness of an SCS system in patients with FBSS. ______________________________________________________________________________ Interventional pain management: an overview for primary care

physicians.

Boyajian SS. J Am Osteopath Assoc. 2005 Sep;105(9 Suppl 4):S1-6. Advanced Pain Consultants, PA, 805 Cooper Rd, Suite 2, Voorhees, NJ 08043-3814, USA. sboyajian@comcast.com

Image-guided spine intervention is used primarily for its precise diagnostic capabilities. This article reviews basic principles of the more common image-guided diagnostic techniques specifically as they relate to patients with low back pain. It also includes discussion of advanced modes of therapy, including spinal cord stimulation and intrathecal therapy, providing primary care physicians with an understanding of the primary indications for these therapeutic modalities. ______________________________________________________________________________ Spinal cord stimulation for failed back surgery syndrome: a

decision-analytic model and cost-effectiveness analysis.

Taylor RJ, Taylor RS. Int J Technol Assess Health Care. 2005 Summer;21(3):351-8. University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. r.j.taylor@bham.ac.uk

OBJECTIVES: The aim of this study was to develop a decision-analytic model to assess the cost-effectiveness of spinal cord stimulation (SCS), relative to nonsurgical conventional medical management (CMM), for patients with failed back surgery syndrome (FBSS). METHODS: A decision tree and Markov model were developed to synthesize evidence on both health-care costs and outcomes for patients with FBSS. Outcome data of SCS and CMM were sourced from 2-year follow-up data of two randomized controlled trials (RCTs). Treatment effects were measured as levels of pain relief. Short- and long-term health-care costs were obtained from a detailed Canadian costing study in FBSS patients. Results are presented as incremental cost per quality adjusted life year (QALY) and expressed in 2003 Euros. Costs were discounted at 6 percent and outcomes at 1.5 percent. RESULTS: Over the lifetime of the patient, SCS was dominant (i.e., SCS is cost-saving and gives more health gain relative to CMM); a finding that was robust across sensitivity analyses. At a 2-year time horizon, SCS gave more health gain but at an increased cost relative to CMM. Given the uncertainty in effectiveness and cost parameters, the 2-year cost-effectiveness of SCS ranged from 30,370 Euros in the base case to 63,511 Euros in the worst-case scenario. CONCLUSIONS: SCS was found to be both more effective and less costly than CMM, over the lifetime of a patient. In the short-term, although SCS is potentially cost-effective, the model results are highly sensitive to the choice of input parameters. Further empirical data are required to improve the precision in the estimation of short-term cost-effectiveness. ______________________________________________________________________________ Association between methodological characteristics and outcome in

health technology assessments which included case series.

Stein K, Dalziel K, Garside R, Castelnuovo E, Round A. Int J Technol Assess Health Care. 2005 Summer;21(3):277-87. Peninsula Medical School, Exeter, Devon EX1 1PQ, UK. Ken.Stein@exeter.ac.uk

OBJECTIVES: Case series constitute a weak form of evidence for effectiveness of health technologies. However, for a variety of reasons, such studies may be included in health technology assessments. There are no clear criteria for assessing the quality of case series. We carried out an empirical investigation of the association between outcome frequency and methodological characteristics in a sample of health technology assessments. METHODS: Systematic reviews of functional endoscopic sinus surgery for nasal polyps, spinal cord stimulation for chronic back pain, and percutaneous transluminal coronary angioplasty and coronary artery bypass grafting for

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chronic stable angina were identified as containing more than forty case series. Data were extracted by one reviewer and checked by a second on population characteristics, outcomes, and the following methodological features: sample size, prospective/retrospective approach, consecutive recruitment, multi- or single-center organization, length of follow-up, independence of outcome measurement, and date of publication. Association between methodological features and outcome were explored in univariate and multivariate analyses using parametric and nonparametric tests and robust regression or analysis of variance/analysis of covariance, as appropriate. RESULTS: Included reviews contained between forty-two and seventy-six case series studies, involving 5 to 172,283 participants. Reporting of methodological features was poor and limited the analyses. In general, we found little evidence of any association between methodological characteristics and outcome. Sample size is used as an inclusion criterion in many reviews of'case series but was consistently shown to have no relationship to outcome in all analyses. A prospective approach was not associated with outcome. Insufficient data were available to explore consecutive recruitment. Mixed results were shown for length of follow-up, independence of outcome measurement, and publication date. CONCLUSIONS: We found little evidence to support the use of many of the factors included in tools used for quality assessment of case series. Importantly, we found no relationship between study size and outcome across the four examples studied. Isolated examples of a potentially important relationship between other methodological factors and outcome were shown, for example, blinding of outcome measurement, but these examples were not shown consistently across the small number of examples studied. Further research into the determinants of quality in case series studies is required to support health technology assessment. ______________________________________________________________________________ Spinal cord stimulation.

Costantini A. Minerva Anestesiol. 2005 Jul-Aug;71(7-8):471-4. Unit of Physiopathology and Therapy of Pain, SS. Annunziata Hospital, and Department of Anesthesia and Resuscitation, G. D'Annunzio University, Chieti, Italy. amedeocostantini@tiscalinet.it

Spinal cord stimulation (SCS) is a neuromodulation technique using electricity, proposed for the first time by Shealy in 1967, as an alternative to neuroablation. Technological improvements in the last 20 years (percutaneous electrodes, single and dual leads, octopolar electrodes, high energy internal pulse generators) have allowed to obtain good results with SCS in various clinical situations of chronic pain. The main clinical indications to SCS are: vascular pain--refractory angina and peripheral vascular diseases (PVD); rachidian pain--failed back surgery syndrome (FBSS), degenerative low back leg pain (LBLP), nerve root lesions, incomplete spine lesions, spinal stenosis; neuropathic pain; chronic regional pain syndrome (CRPS) type 1 and type 2; perineal pain and urological diseases (urge-incontinence, interstitial cystitis). There are important differences between Europe and USA in the SCS use in various indications, especially about PVD. Really, in Europe this technique has been widely used and, finally, there are prospective studies establishing the utility of SCS in: limb survival; pain control; regression to Fontaine stage II; improvement of free interval of claudication. All of this is going to change the attitude towards SCS in USA, where the amputation incidence for critical ischaemia is considerably higher than in Europe. An indication to SCS not very mentioned in literature and that seems to have good results is LBLP due to acquired or mixed (constitutional-acquired) spinal stenosis. In this situation SCS seems to improve notably pain control and quality of life index of patients. ______________________________________________________________________________ Spinal cord stimulation for axial low back pain: a prospective,

controlled trial comparing dual with single percutaneous

electrodes.

North RB, Kidd DH, Olin J, Sieracki JM, Farrokhi F, Petrucci L, Cutchis PN. Spine (Phila Pa 1976). 2005 Jun 15;30(12):1412-8. Department of Neurosurgery, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21287-7881, USA. RNorth@jhmi.edu

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STUDY DESIGN: A prospective, controlled, clinical trial comparing single and dual percutaneous electrodes in the treatment of axial low back pain from failed back surgery syndrome. OBJECTIVES: To clarify technical requirements and test the hypothesis that placing two linear arrays in parallel, thereby doubling the number of contacts, improves outcome. SUMMARY OF BACKGROUND DATA: Technical improvements have enhanced outcomes of spinal cord stimulation for chronic axial low back pain. Dual, parallel electrodes reportedly improve these outcomes. METHODS: Acting as their own controls, 20 patients who passed screening with single, 4-contact electrodes received permanent dual, 4-contact electrodes with 7- or 10-mm intercontact distances at the same vertebral level(s). We quantified and compared the technical and clinical results of the single and dual electrodes, adjusting stimulation parameters to specific psychophysical thresholds. RESULTS: Single electrodes provided significant (P < 0.01) advantages in patient- and computer-calculated ratings of pain coverage by paresthesias and in the scaled amplitude necessary to cover the low back, compared with dual 7-mm electrodes. Slight advantages without statistical significance were observed for the single over the dual 10-mm electrodes. Amplitude requirements were significantly lower for the single electrode than for either dual electrode. At long-term follow-up, 53% of patients met the criteria for clinical success. CONCLUSIONS: While we observed disadvantages for dual electrodes in treating axial low back pain, we achieved technical success with single or dual electrodes in most patients and maintained this success clinically with dual electrodes in 53%. ______________________________________________________________________________ Dual spinal cord stimulation for complex pain: preliminary study.

Abejón D, Reig E, Del Pozo C, Contreras R, Insausti J. Neuromodulation. 2005 Apr;8(2):105-11. doi: 10.1111/j.1525-1403.2005.00226.x. Department of Anesthesia and Critical Care Fundación Hospital Alcorcón. Madrid, Spain Clínica del Dolor de Madrid, Spain; Clínica del Dolor de Madrid, Spain; Clínica Unidad de Dolor, Clínica Puerta de Hierro, Madrid, Spain Unidad de Dolor, Hospital Severo Ochoa, Leganés, Madrid, Spain.

Objectives To retrospectively analyze by indices of success, patients with chronic complex pain, including, axial low back pain, receiving dual spinal cord stimulation (SCS) systems. Methods Eighteen patients with dual spinal cord stimulators have been retrospectively and nonrandomly analyzed. The preponderance of patients in our study group had failed back surgery syndrome (FBSS). Parameters of success of our therapy included reduction of medication, if any, complications, if any, and satisfaction with therapy and improvement in the quality of life, measured by a visual analogical scale (VAS) from 0 to 10. Patients were asked to rate their overall experience with their SCS systems and were divided into four separate groupings according to their overall rating of their therapy. These four groupings included therapy ratings of excellent (70-100%), good (> 50%), fair (< 50%), and poor (< 30%). Satisfaction with therapy and improvement in quality of life were evaluated on a five-point scale. Patients were asked to rate changes in their quality of life after therapy using the following normative scale: much better, better, no change, worse, and much worse. All the patients in our study were asked if they would repeat their therapy with dual spinal cord stimulation. Results Paresthesia coverage, overlapping the reported painful region, was obtained in 80% of the patients in our study. The VAS decreased an average of 5.6 (range 2-10) after 6 months and 4.9 (range 2-8) at the end of the study. Six patients (37.5%) reported excellent results; four patients (25%) reported good; three (18.7%), fair and poor. Seventy percent of the patients were satisfied with the treatment and reported an increase in their quality of life. Medications were reduced in 75% of the patients. Thirteen (81%) patients with dual lead SCS therapy were willing to repeat the SCS implant procedure. Complications occurred in 43.7%. Conclusions Dual spinal cord stimulation is appropriate and efficacious for treating complex pathology and complex pain that including pain of the low, axial back. ______________________________________________________________________________ Do the findings of case series studies vary significantly

according to methodological characteristics?

Dalziel K, Round A, Stein K, Garside R, Castelnuovo E, Payne L. Health Technol Assess. 2005 Jan;9(2):iii-iv, 1-146.

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Peninsula Technology Assessment Group, Peninsula Medical School, Universities of Exeter and Plymouth, Exeter, UK.

OBJECTIVES: To review the use of case series in National Institute for Clinical Excellence (NICE) Health Technology Assessment (HTA) reports, to review systematically the methodological literature for papers relating to the validity of aspects of case series design, and to investigate characteristics and findings of case series using examples from the UK's Health Technology Assessment programme. DATA SOURCES: Electronic databases. NICE website. Reports produced as part of the UK's HTA programme. REVIEW METHODS: NICE HTAs that used information from case series studies were obtained from the NICE website and a range of quality criteria applied. Searches of electronic databases, handsearched journals and the bibliographies of papers were made in order to find studies that assessed aspects of case series design, analysis or quality in relation to study validity. Hypotheses relating to the design of case series studies were developed and empirically investigated using four case examples from existing reports produced as part of the UK's HTA programme (functional endoscopic sinus surgery for nasal polyps, spinal cord stimulation for chronic back pain, percutaneous transluminal coronary angioplasty and coronary artery bypass grafting for chronic angina). Analysis was undertaken comparing studies within each review. RESULTS: There was no consensus on which case series to include in HTAs, how to use them or how to assess their quality, despite them being used in 30% of NICE HTAs. No previous studies empirically investigating methodological characteristics of case series were found. However, it is possible that the search strategy failed to find relevant studies. Poor reporting of case series characteristics severely constrained analysis and there were insufficient data to investigate all the hypotheses. Findings were not consistent across the different topics and were subject to considerable uncertainty. All the examples in our analysis were surgical interventions, which are prone to additional confounding factors due to difficulties of standardisation compared with drug treatment. Our findings may not be generalisable outside the interventions studied. The case series reports included generally exhibited poor reporting of methodological characteristics. This constrained our analysis. The use of several methods of analysis has led to apparently discrepant results. Given the number of analysis performed, the usual level of significance (p = 0.05) should be viewed with caution. The most important limitation of this study is the small number of cases on which the findings are based. The results are therefore tentative and should be viewed with caution. CONCLUSIONS: Case series are incorporated in a significant proportion of health technology assessments. Quality criteria have been used to appraise the quality of case series and decide on their inclusion in reviews of studies using this design. In this small series of case studies drawn from HTAs carried out for the NHS HTA programme, little evidence was found to support the use of many of the factors included in quality assessment tools. Importantly, no relationship was found between study size and outcome across the four examples studied. Isolated examples of a potentially important relationship between other methodological factors and outcome were shown, such as blinding of outcome measurement, but these were not shown consistently across the small number of examples studied. This study is based on a very small sample of studies and should therefore be considered as exploratory. Further investigation of the relationship between methodological features and outcome is justified given the frequency of use of case series in health technology assessments. Further research into the methodological features of case series and their outcome is justified in a wider sample of technologies and larger sets of case series. Value of information analyses including case series could be explored. Further exploration of the differences between case series and randomised controlled trial results, preferably using registry or comprehensive case series data, would be valuable. ______________________________________________________________________________ Spinal cord stimulation versus repeated lumbosacral spine surgery

for chronic pain: a randomized, controlled trial.

North RB, Kidd DH, Farrokhi F, Piantadosi SA. Neurosurgery. 2005;56(1):98-106; discussion 106-7. Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-7881, USA. RNorth@jhmi.edu

OBJECTIVE: Persistent or recurrent radicular pain after lumbosacral spine surgery is often associated with nerve root compression and is treated by repeated operation or, as a last resort, by spinal cord stimulation (SCS). We conducted a prospective, randomized, controlled trial to test our hypothesis that SCS is more likely than reoperation to result in a successful outcome by standard

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measures of pain relief and treatment outcome, including subsequent use of health care resources. METHODS: For an average of 3 years postoperatively, disinterested third-party interviewers followed 50 patients selected for reoperation by standard criteria and randomized to SCS or reoperation. If the results of the randomized treatment were unsatisfactory, patients could cross over to the alternative. Success was based on self-reported pain relief and patient satisfaction. Crossover to the alternative procedure was an outcome measure. Use of analgesics, activities of daily living, and work status were self-reported. RESULTS: Among 45 patients (90%) available for follow-up, SCS was more successful than reoperation (9 of 19 patients versus 3 of 26 patients, P <0.01). Patients initially randomized to SCS were significantly less likely to cross over than were those randomized to reoperation (5 of 24 patients versus 14 of 26 patients, P=0.02). Patients randomized to reoperation required increased opiate analgesics significantly more often than those randomized to SCS (P <0.025). Other measures of activities of daily living and work status did not differ significantly. CONCLUSION: SCS is more effective than reoperation as a treatment for persistent radicular pain after lumbosacral spine surgery, and in the great majority of patients, it obviates the need for reoperation. ______________________________________________________________________________ Interventional techniques in the management of chronic spinal

pain: evidence-based practice guidelines.

Boswell MV, Shah RV, Everett CR, Sehgal N, McKenzie Brown AM, Abdi S, Bowman RC 2nd, Deer TR, Datta S, Colson JD, Spillane WF, Smith HS, Lucas LF, Burton AW, Chopra P, Staats PS, Wasserman RA, Manchikanti L. Pain Physician. 2005 Jan;8(1):1-47. Department of Anesthesiology, University Hospitals of Cleveland Case School of Medicine, Cleveland, Ohio 44106, USA. boswellmv@earthlink.net

BACKGROUND: The lifetime prevalence of spinal pain has been reported as 54% to 80%, with as many as 60% of patients continuing to have chronic pain five years or longer after the initial episode. Spinal pain is associated with significant economic, societal, and health impact. Available evidence documents a wide degree of variance in the definition and the practice of interventional pain management. OBJECTIVE: To develop evidence-based clinical practice guidelines for interventional techniques in the management of chronic spinal pain, with utilization of all types of evidence, applying an evidence-based approach, with broad representation of specialists from academic and clinical practices. DESIGN: A systematic review of diagnostic and therapeutic interventions applied in managing chronic spinal pain by a policy committee. Design consisted of formulation of essentials of guidelines and a series of potential evidence linkages representing conclusions, and statements about relationships between clinical interventions and outcomes. METHODS: The elements of the guideline preparation process included literature searches, literature synthesis, systematic review, consensus evaluation, open forum presentation, formal endorsement by the Board of Directors of the American Society of Interventional Pain Physicians (ASIPP), and blinded peer review. Methodologic quality evaluation criteria utilized included AHRQ criteria, QUADAS criteria, and Cochrane review criteria. The designation of levels of evidence was from Level I (conclusive), Level II (strong), Level III (moderate), Level IV (limited), to Level V (indeterminate). RESULTS: The accuracy of facet joint nerve blocks was strong in the diagnosis of lumbar and cervical facet joint pain, whereas, it was moderate in the diagnosis of thoracic facet joint pain. The evidence was strong for lumbar discography, whereas, the evidence was limited for cervical and thoracic discography. The evidence was moderate for transforaminal epidural injections or selective nerve root blocks in the preoperative evaluation of patients with negative or inconclusive imaging studies. The evidence was moderate for sacroiliac joint injections in the diagnosis of sacroiliac joint pain. The evidence for therapeutic lumbar intraarticular facet injections of local anesthetics and steroids was moderate for short-term improvement and limited for long-term improvement, whereas, it was negative for cervical facet joint injections. The evidence for lumbar and cervical medial branch blocks was moderate. The evidence for medial branch neurotomy was moderate to strong for relief of chronic low back and neck pain. The evidence for caudal epidural steroid injections was strong for short-term relief and moderate for long-term relief in managing chronic low back and radicular pain, and limited in managing pain of postlumbar laminectomy syndrome. The evidence for interlaminar epidural steroid injections was strong for short-term relief and limited for long-term relief in managing lumbar radiculopathy, whereas, for

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cervical radiculopathy the evidence was moderate. The evidence for transforaminal epidural steroid injections was strong for short-term and moderate for long-term improvement in managing lumbar nerve root pain, whereas, it was moderate for cervical nerve root pain and limited for lumbar post laminectomy syndrome and spinal stenosis. The evidence for percutaneous epidural adhesiolysis was strong. For spinal endoscopic adhesiolysis, the evidence was strong for short-term relief and moderate for long-term relief. For sacroiliac intraarticular injections, the evidence was moderate for short-term relief and limited for long-term relief. The evidence for radiofrequency neurotomy for sacroiliac joint pain was indeterminate. The evidence for intradiscal electrothermal therapy was strong for short-term relief and moderate for long-term relief in managing chronic discogenic low back pain, whereas, for nucleoplasty, the evidence was limited. The evidence for spinal cord stimulation in failed back surgery syndrome and complex regional pain syndrome was strong for short-term relief and moderate for long-term relief. The evidence for implantable intrathecal infusion systems was moderate to strong. CONCLUSION: These guidelines included the evaluation of evidence for diagnostic and therapeutic procedures in managing chronic spinal pain and recommendations for managing spinal pain. However, these guidelines do not constitute inflexible treatment recommendations. These guidelines do not represent "a standard of care". ______________________________________________________________________________ Spinal cord stimulation for chronic back and leg pain and failed

back surgery syndrome: a systematic review and analysis of

prognostic factors.

Taylor RS, Van Buyten JP, Buchser E. Spine (Phila Pa 1976). 2005 Jan 1;30(1):152-60. University of Birmingham, Birmingham, United Kingdom. r.s.taylor@bham.ac.uk

STUDY DESIGN: Systematic review. OBJECTIVES: To assess efficacy and safety of spinal cord stimulation in patients with chronic leg and back pain and failed back surgery syndrome and to examine prognostic factors that predict spinal cord stimulation outcome. SUMMARY OF BACKGROUND DATA: A previous systematic review of spinal cord stimulation in patients with chronic back and leg pain and failed back surgery syndrome by Turner et al in 1995 identified 39 case studies and no controlled studies. METHODS: A number of electronic databases were searched through January 2002. Citation searching of included papers was undertaken, and gray literature was sought through contact with clinical experts. No language restrictions were applied. All controlled and noncontrolled study designs were included. Study selection was carried out independently by two reviewers. Prognostic factors (age, sex, duration of pain, time post surgery, follow-up duration, publication year, data collection year, indication, data collection country, study setting, and quality score) responsible for pain relief outcome across case series were examined using univariate and multivariate metaregression. RESULTS: One randomized controlled trial, one cohort study, and 72 case studies were included. The randomized controlled trial reported a significant benefit (P = 0.047) in the proportion of patients with failed back surgery syndrome reporting 50% or more pain relief with spinal cord stimulation (37.5%) compared with patients undergoing back reoperation (11.5%). There was evidence of substantial statistical heterogeneity (P < 0.0001) in the level of pain relief following spinal cord stimulation reported across case series studies. The four principal prognostic factors found to be predictive of increased level of pain relief with spinal cord stimulation were poor study quality score, short follow-up duration, multicenter (versus single center) studies, and the inclusion of patients with failed back surgery syndrome (versus chronic back and leg pain). Overall, 43% of patients with chronic back and leg pain/failed back surgery syndrome experienced one or more complications following a spinal cord stimulation implant, although no major adverse events were reported. CONCLUSIONS: Despite an increase in the number of studies over the last 10 years, the level of evidence for the efficacy of spinal cord stimulation in chronic back and leg pain/failed back surgery syndrome remains "moderate." Prognostic factors found to be predictive of the level of pain relief following spinal cord stimulation were study quality, follow-up duration, study setting, and patient indication. ______________________________________________________________________________ Improvement of muscle strenght independently of analgesic effect

following spinal cord stimulation. A case report.

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Buonocore M, Demartini L, Bonezzi C. Eura Medicophys. 2004 Dec;40(4):273-5. Unit of Clinical Neurophysiology, Salvatore Maugeri Foundation, Scientific Institute of Pavia, Pavia, Italy. mbuonocore@fsm.it

Spinal cord stimulation (SCS) is frequently used for relief of chronic benign pain resistant to conservative therapies. Clinical practice suggests, at least in patients with failed back surgery syndrome (FBSS), the possibility that SCS significantly improves motor performances. We present here the case of a 41-years-old female patient with FBSS, who showed a clear improvement in muscle strength after SCS, persisting at 6-months follow-up. We speculate that the electrical stimulation of posterior columns could potentiate the caudal, segmental spinal reflexes resulting in a facilitation of motoneurons activation. ______________________________________________________________________________ Multiple lead spinal cord stimulation for chronic mechanical low

back pain: a comparative study with intrathecal opioid drug

delivery.

Raphael JH, Southall JL, Gnanadurai TV, Treharne GJ, Kitas GD. Neuromodulation. 2004 Oct;7(4):260-6. doi: 10.1111/j.1094-7159.2004.04211.x.

The objective of this paper is to assess the outcome of implanted multiple thoracolumbar lead spinal cord stimulation (SCS) in mechanical back pain without prior spinal surgery. These results are compared with intrathecal opioid drug delivery (ITDD). An anonymous third party patient questionnaire study of pain relief, function and psychosocial quality of life measures (recorded on 11-point numerical rating scales) for 12 patients with SCS and 13 with ITDD was used. Pain was significantly reduced with multiple lead SCS from a median of 9.0-6.5 (p < 0.01) and with ITDD from a median of 8.5-5.5 (p < 0.01). There was a trend towards greater reduction in pain in the ITDD group compared with the SCS group (pain differences 4.5 and 2.6, respectively) but this did not reach statistical significance. The majority of psychosocial quality of life measures were significantly more improved in the ITDD group compared with the SCS group (p < 0.05). We conclude that multiple-lead SCS improves mechanical back pain in patients unresponsive to more conservative measures. However, ITDD provides significantly more improved quality of life measures, with a trend towards greater pain reduction than SCS. ______________________________________________________________________________ Spinal cord stimulation for refractory angina pectoris: a shocking

experience.

Murphy PM, Macsullivan R. Neuromodulation. 2004 Oct;7(4):246-8. doi: 10.1111/j.1094-7159.2004.04209.x. Department of Pain Medicine, Division of Anesthesia and Pain medicine, Mater Misericordiae Hospital, Dublin, Ireland.

Spinal cord stimulation has been extensively utilized in the treatment of conditions including complex regional pain syndrome, ischemic limb pain, failed back surgery syndrome, and angina pectoris. Recognized complications include infection, dural tap, and electrode movement. We report the case of a patient who experienced a sensation of extremely enhanced stimulation in the area covered by the spinal cord stimulator while in the vicinity of a high-tension electricity substation. Full resolution of symptoms occurred when the spinal cord stimulator was switched off, indicating that active stimulators may be susceptible to the effects of external electrical fields. ______________________________________________________________________________ Cost-benefit evaluation of spinal cord stimulation treatment for

failed-back surgery syndrome patients. [Article in French]

Blond S, Buisset N, Dam Hieu P, Nguyen JP, Lazorthes Y, Cantagrel N, Laugner B, Bellow F, Djian MC, Husson JL, Lapierre F, Blanc JL. Neurochirurgie. 2004 Sep;50(4):443-53. Service de Neurochirurgie, CHU Salengro, 2, avenue Oscar-Lambret, 59037 Lille. sblond@chru-lille.fr

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BACKGROUND AND PURPOSE: Spinal cord stimulation is a well-known treatment of rigorously selected failed-back surgery syndrome patients. Efficacy levels over 50% of pain relief have been reported in long-term studies. The objective of this multicenter prospective evaluation was to analyze the cost to benefit ratio of spinal cord stimulation treatment for failed back surgery syndrome patients. METHODS: Nine hospitals (pain evaluation and treatment centers) were involved in the study. Forty-three patients were selected and implanted between January 1999 and January 2000. For each patient, pre- and post-operative evaluations (6, 12 and 24 months after implantation) were performed to assess pain relief and economical impact on pain treatment costs. RESULTS: After 24 months, mean 60% pain relief was achieved as assessed with the neuropathic pain score using a Visual Analog Scale (success rate=70%), whereas low-back pain was moderately reduced (29%). The Oswestry Disability questionnaire score was improved by a mean 39%. Costs of pain treatment (medication, consultation, other) are reduced by a mean 64% (1705 Euro) per patient per year. CONCLUSIONS: This study confirms a clear analgesic effect on neuropathic sciatalgia, and moderate attenuation of low-back pain. One particular interest of this study is the medico-economic prospective evaluation showing that the initial cost of the implanted device is compensated by a significant, early, and stable reduction in the cost of associated pain therapies. ______________________________________________________________________________ Neuropathic limb pain and spinal cord stimulation: results of the

dutch prospective study.

Spincemaille GH, Beersen N, Dekkers MA, Theuvenet PJ. Neuromodulation. 2004 Jul;7(3):184-92. doi: 10.1111/j.1094-7159.2004.04198.x. Department of Neurosurgery, AZM, University Hospital Maastricht; Department of Health Policy and Management, Erasmus Hospital, Rotterdam; and Department of Anesthesiology. Alkmaar Medical Center, The Netherlands.

Baseline and 12-month follow-up data from a prospective controlled study on patients treated with SCS for neuropathic limb pain (NLP) are analyzed critically. The outcome on pain, use of medication, and quality of life are reported and compared with the literature. Patients enrolled from April 1999 to December 2001 were part of a quality system study by the Dutch Working Group on Neuromodulation. In two years, more than 400 patients were admitted for several indications of chronic neuropathic pain. Failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS) were the largest cohorts. FBSS was defined as persistent limb pain with/or without concomitant minor back pain after prior surgery for a slipped lumbar disc or spinal instability. SCS was a last resort therapy. Two criteria were used for eligibility: a SCL-90 score below 225 and a mean visual analog score (VAS) of four days according to Jensen of ≥ 5. One hundred sixty nine patients were registered for FBSS. Thirty four did not fulfill the eligibility criteria, and 135 received several questionnaires for baseline evaluation. Thirty patients did not have successful trial stimulation (< 50% pain relief), leaving 105 patients for implantation. The mean scores of the baseline evaluation were: SCL 137 (SD 28.3) and VAS 7.3 (SD 1.2), McGill pain questionnaire (MPQ) total PRI: 22.4 (9.4), Sickness Impact Profile (SIP) total score: 19.4 (SD10.1), ROLAND disability (RD) 16.9 (SD 3.5) and EUROQOL (EQ-5D) 55.2 (SD 14.5) (simple linear index). Medication quantification scale at intake was 11.5 (SD 7.9). 56.2% of the patients used one or more narcotic drugs at intake. 82% of the patients did not have a paid job at the time of inclusion. 61% of the patients lost their job due to their medical problems. Scores at 12-m follow-up were VAS 3.0 (SD 2.4), MPQ 10.8 (SD 8), SIP 11.7 (SD 9.4), EQ-5D 38.2 (SD 19.2) and RD 12.4 (SD 4.8). The difference between baseline and 12-m follow-up is statistically significant for all measures. We conclude that the outcome measures indicate that SCS significantly reduces pain and enhances quality of life in patients having NLP not responding to other adjuvant therapy. Recommendations are proposed to make studies more comparable. ______________________________________________________________________________ Do minimally invasive procedures have a place in the treatment of

chronic low back pain?

Cahana A, Mavrocordatos P, Geurts JW, Groen GJ. Expert Rev Neurother. 2004 May;4(3):479-90.

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Department of Anesthesiology, Pharmacology and Surgical Intensive Care, Geneva University Hospital, Geneva, Switzerland. alex.cahana@hcuge.ch

Chronic low back pain is the leading cause of disability in the industrialized world. Medical and surgical treatments remain costly despite limited efficacy. The field of 'interventional pain' has grown enormously and evidence-based practice guidelines are systematically developed. In this article, the vast, complex and contradictory literature regarding the treatment of chronic low back pain is reviewed. Interventional pain literature suggests that there is moderate evidence (small randomized, nonrandomized, single group or matched-case controlled studies) for medial branch neurotomy and limited evidence (nonexperimental one or more center studies) for intradiscal treatments in mechanical low back pain. There is moderate evidence for the use of transforaminal epidural steroid injections, lumbar percutaneous adhesiolysis and spinal endoscopy for painful lumbar radiculopathy, and spinal cord stimulation and intrathecal pumps mostly after spinal surgery. In reality, there is no gold standard for the treatment of chronic low back pain, but these results appear promising. ______________________________________________________________________________ Safety and efficacy of spinal cord stimulation for the treatment

of chronic pain: a 20-year literature review.

Cameron T. J Neurosurg. 2004 Mar;100(3 Suppl Spine):254-67. Department of Biomedical Engineering, University of Texas Southwestern Medical School, Dallas, Texas, USA. t.cameron@ans-medical.com

OBJECT: The purpose of this report was to examine the available literature to determine the safety and efficacy of spinal cord stimulation (SCS) for the treatment of chronic pain of the trunk and limbs. METHODS: The author identified 68 studies that fulfilled the efficacy inclusion/exclusion criteria, grouped on the basis of pain indication, with an overall population of 3679 patients. Fifty-one studies fulfilled all safety inclusion/exclusion criteria. Based on the literature review, the author found that SCS had a positive, symptomatic, long-term effect in cases of refractory angina pain, severe ischemic limb pain secondary to peripheral vascular disease, peripheral neuropathic pain, and chronic low-back pain, and that, in general, SCS was a safe and effective treatment for a variety of chronic neuropathic conditions. CONCLUSIONS: Despite the positive findings, there is an urgent need for randomized, controlled, long-term studies on the efficacy of SCS involving larger patient sample sizes. ______________________________________________________________________________ Prospective study of the success and efficacy of spinal cord

stimulation.

Allegri M, Arachi G, Barbieri M, Paulin L, Bettaglio R, Bonetti G, Demartini L, Violini A, Braschi A, Bonezzi C. Minerva Anestesiol. 2004 Mar;70(3):117-24. Anesthesia and Resuscitation Service I, S. Matteo Polyclinic, IRCCS, Pavia, Italy.

AIM: To explore success, the percentage of patients who received definitive implants compared to all patients screened, and efficacy, the percentage of patients that had improved in at least 3 of the 5 parameters after 1 year. In addition, we determined if there was a statistically significant reduction in pain and functional limiting. Finally, we wanted to investigate if the different paresthesia coverage has a different outcome after 1 year of SCS treatment. METHODS: We studied 170 patients with neuropathic pain syndrome, failed back surgery syndrome and vascular disease, who received spinal cord stimulation (SCS) in the last 4 years. We evaluated, at the beginning and after 1 year, the patients with a questionnaire that assessed pain, what kind of function, drug consumption, patient's satisfaction and the improvement in the quality of life. RESULTS: This study showed a success of more than 50% and an efficacy of more than 69.9%, with no significant differences in 3 different chronic pain conditions. Pain and functional limiting presented a statistically significant reduction. Finally, we confirmed that there were no statistically significant differences between patients with different paresthesia coverage. CONCLUSION: This prospective study confirmed that SCS had good success and efficacy in the treatment of several

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types of chronic pain. Finally, our study showed the importance of obtaining paresthesia in the affected area but it is not essential to cover the entire painful area. ______________________________________________________________________________ Spinal cord stimulation for patients with failed back surgery

syndrome or complex regional pain syndrome: a systematic review of

effectiveness and complications.

Turner JA, Loeser JD, Deyo RA, Sanders SB. Pain. 2004 Mar;108(1-2):137-47. Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA. jturner@u.washington.edu

Comment in Pain. 2010 Nov;151(2):550-1; author reply 551-2. We conducted a systematic review of the literature on the effectiveness of spinal cord stimulation (SCS) in relieving pain and improving functioning for patients with failed back surgery syndrome and complex regional pain syndrome (CRPS). We also reviewed SCS complications. Literature searches yielded 583 articles, of which seven met the inclusion criteria for the review of SCS effectiveness, and 15 others met the criteria only for the review of SCS complications. Two authors independently extracted data from each article, and then resolved discrepancies by discussion. We identified only one randomized trial, which found that physical therapy (PT) plus SCS, compared with PT alone, had a statistically significant but clinically modest effect at 6 and 12 months in relieving pain among patients with CRPS. Similarly, six other studies of much lower methodological quality suggest mild to moderate improvement in pain with SCS. Pain relief with SCS appears to decrease over time. The one randomized trial suggested no benefits of SCS in improving patient functioning. Although life-threatening complications with SCS are rare, other adverse events are frequent. On average, 34% of patients who received a stimulator had an adverse occurrence. We conclude with suggestions for methodologically stronger studies to provide more definitive data regarding the effectiveness of SCS in relieving pain and improving functioning, short- and long-term, among patients with chronic pain syndromes. ______________________________________________________________________________ Spinal cord stimulation in chronic pain: a review of the evidence.

Carter ML. Anaesth Intensive Care. 2004 Feb;32(1):11-21. Department of Anaesthesia, Bundaberg Base Hospital, PO Box 34, Bundaberg, Qld 4670.

This review looks at the evidence for the effectiveness of spinal cord stimulation in various chronic pain states. Spinal cord stimulation can only be effective when appropriate dorsal column fibres in the spinal cord are preserved and able to be stimulated. Spinal cord stimulation has been shown to have little to offer for patients with some diagnoses. Although 50 to 60% of patients with failed back surgery syndrome obtain significant pain relief with this technique, the strength of the evidence available is insufficient to clearly advocate its use in all patients with this condition. Though limited in quantity and quality, better evidence exists for its use in neuropathic pain, complex regional pain syndrome, angina pectoris and critical limb ischaemia. There is a lack of high quality evidence relating to spinal cord stimulation due to difficulties in conducting randomized controlled trials in this area. Serious methodological problems are encountered in blinding, recruitment and assessment in nearly all published trials of spinal cord stimulation. Suggestions regarding appropriate methodologies for trials which would produce better quality evidence are summarized. ______________________________________________________________________________ Spinal cord stimulation for chronic pain.

Mailis-Gagnon A, Furlan AD, Sandoval JA, Taylor R. Cochrane Database Syst Rev. 2004;(3):CD003783. Department of Medicine, Comprehensive Pain Program, 399 Bathurst Street, Fell Pavillion 4F811, Toronto, Ontario, Canada, M5T 2S8.

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BACKGROUND: Spinal cord stimulation (SCS) is a form of therapy used to treat certain types of chronic pain. It involves an electrical generator that delivers pulses to a targeted spinal cord area. The leads can be implanted by laminectomy or percutaneously and the source of power is supplied by an implanted battery or by an external radio-frequency transmitter. The exact mechanism of action of SCS is poorly understood. OBJECTIVES: To assess the efficacy and effectiveness of spinal cord stimulation in relieving certain kinds of pain, as well as the complications and adverse effects of this procedure. SEARCH STRATEGY: We searched MEDLINE and EMBASE to September 2003; the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 3, 2003); textbooks and reference lists in retrieved articles. We also contacted experts in the field of pain and the main manufacturer of the stimulators. SELECTION CRITERIA: We included trials with a control group, either randomized controlled trials (RCTs) or non-randomized controlled clinical trials (CCTs), that assessed spinal cord stimulation for chronic pain. DATA COLLECTION AND ANALYSIS: Two independent reviewers selected the studies, assessed study quality and extracted the data. One of the assessors of methodological quality was blinded to authors, dates and journals. The data were analysed using qualitative methods (best evidence synthesis). MAIN RESULTS: Two RCTs (81 patients in total) met our inclusion criteria. One was judged as being of high quality (score of 3 on Jadad scale) and the other of low quality (score of 1 on Jadad scale). One trial included patients with Complex Regional Pain Syndrome Type I (reflex sympathetic dystrophy) and the other patients with Failed Back Surgery Syndrome. The follow-up periods varied from 6 to 12 months. Both studies reported that SCS was effective, however, meta-analysis was not undertaken because of the small number of patients and the heterogeneity of the study population. REVIEWERS' CONCLUSIONS: Although there is limited evidence in favour of SCS for Failed Back Surgery Syndrome and Complex Regional Pain Syndrome Type I, more trials are needed to confirm whether SCS is an effective treatment for certain types of chronic pain. In addition, there needs to be a debate about trial designs that will provide the best evidence for assessing this type of intervention. ______________________________________________________________________________ Spinal cord stimulation does not change peripheral skin blood flow

in patients with neuropathic pain.

Ather M, Di Vadi P, Light D, Wedley JR, Hamann WC. Eur J Anaesthesiol. 2003 Sep;20(9):736-9. Guy's and St Thomas' Hospital, Pain Management Unit, London, UK.

BACKGROUND AND OBJECTIVE: Spinal cord stimulation has been used successfully for many years in the management of neuropathic pain. Nociceptive pathways are closely integrated into many autonomic reflexes. The aim was to test the hypothesis that pain relief caused by spinal cord stimulation is related to changes in peripheral skin blood flow. METHODS: Twelve patients with spinal cord stimulators implanted as a treatment for neuropathic pain were entered into the study. Laser Doppler perfusion scanning was used as a direct method for selective measurement of changes in skin (peripheral) blood flow. Measurements were taken before and after the onset of spinal cord stimulation over the site of its sensory projection. The degree of pain relief due to spinal cord stimulation and the skin temperature of each patient were also recorded. RESULTS: Apart from one patient, spinal cord stimulation did not change skin blood flow in a statistically significant manner. CONCLUSIONS: Pain relief due to spinal cord stimulation is not related to changes of skin blood flow. ______________________________________________________________________________ Management of chronic limb pain with spinal cord stimulation.

Fogel GR, Esses SI, Calvillo O. Pain Pract. 2003 Jun;3(2):144-51. Brodsky Chair of Spinal Surgery, Baylor College of Medcine, Houston, Texas 77030, USA.

BACKGROUND: Spinal Cord Stimulation (SCS) is a treatment option for chronic pain patients. The most common indication for SCS is the failed back syndrome with leg pain. In the last decade, advances in our understanding of appropriate stimulation programming, lead placement and the physiology of SCS, have led to changes in multi-site stimulation, and stimulation with differing

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programs. In the past, low back, axial neuropathic type pain was not responsive to SCS. With dual electrode arrays, and dual stimulation with alternating programs of stimulation, steering of stimulation paresthesia, and versatile programmable stimulation parameters, SCS has become a more versatile form of analgesia. PURPOSE: To describe the current treatment rational for SCS and the results of that treatment. RESULTS: The SCS is most efficient in patients with neuropathic pain of the extremities and less efficacious in patients with axial pain. CONCLUSION: SCS is the most effective treatment for limb pain not amenable to surgical decompression. The success of SCS in this chronic pain group is 80% successful in treatment of leg pain, and much less effective in treatment of axial pain. ______________________________________________________________________________ The performance and safety of an implantable spinal cord

stimulation system in patients with chronic pain: a 5-year study.

Buyten JP. Neuromodulation. 2003 Apr;6(2):79-87. doi: 10.1046/j.1525-1403.2003.03012.x.

Reliability and ease of use of the Itrel 3 System (Medtronic Inc., Minneapolis, MN) were prospectively assessed over 5 years in patients with a range of pain syndromes (mainly low back and/or leg pain, or ischemic pain due to peripheral vascular disease). The longevity of the implantable pulse generator (IPG) battery, the frequency with which system settings were changed, and the ease of use of the EZ patient programmer were assessed. Data on adverse events, pain relief, and patient satisfaction with therapy were also collected. Following a screening procedure, 85 systems were implanted in 84 patients. Twenty-four patients were withdrawn prematurely and, in an additional 32 cases, end of battery life was reached before the end of the study. The survival curve for the IPG batteries showed that approximately 50% are expected to last up to the sixth year. No device failures or unanticipated device-related adverse events were reported. At least 90% of patients considered the EZ patient programmer easy to use. System settings were stable over time. The intensity and duration of pain were reduced significantly and patient satisfaction with therapy was high. We conclude that the Itrel 3 System performed well over 5 years and was easy to use. Its safety and effectiveness for the relief of chronic intractable pain of the trunk or limbs were also confirmed. ______________________________________________________________________________ Spinal cord stimulation in chronic lumbar pain. [Article in

Italian]

Signorelli CD, Lavano A, Volpentesta G, Chirchiglia D, Signorelli F, Sibille M, Ferraro G, Veltri C, Aloisi M, Piragine G, Santangelo E, Pardatcher S, Pardatcher K. J Neurosurg Sci. 2003 Mar;47(1 Suppl 1):41-5. Cattedra di Neurochirurgia, Facoltà di Medicina e Chirurgia Università degli Studi Magna Graecia di Catanzaro, Via T. Campanella 115, 88100 Catanzaro, Italy.

Kein Abstract vorhanden. ______________________________________________________________________________ Spinal stimulation in failed back surgery syndrome [Article in

Italian]

Meglio M, Papacci F. J Neurosurg Sci. 2003 Mar;47(1 Suppl 1):32-6. Neurochirurgia Funzionale e Spinale, U.C.S.C. Policlinico Gemelli, L.go A. Gemelli 8, 00168 Roma, Italy. No abstract available. ______________________________________________________________________________ Acute vs. Prolonged Screening for Spinal Cord Stimulation in

Chronic Pain.

Weinand ME, Madhusudan H, Davis B, Melgar M. Neuromodulation. 2003 Jan;6(1):15-9. doi: 10.1046/j.1525-1403.2003.03002.x.

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Division of Neurosurgery, Department of Surgery, and Department of Anesthesiology, University of Arizona College of Medicine, Tucson, Arizona.

Spinal cord stimulation (SCS) was performed to test the hypothesis that pain relief data during acute (15 minute intraoperative) and prolonged (5 day) SCS screening have equivalent predictive value for long-term successful SCS control of chronic low back pain and/or lower extremity pain. A retrospective series of patients with chronic low back and/or lower extremity pain underwent either percutaneous or open (ie, laminectomy) SCS implantation during which acute intraoperative followed by prolonged screening trials for percentage pain relief (%PR) were performed. Data were analyzed for (a) correlation between positive predictive value (PPV) of acute and prolonged SCS screening for %PR and (b) PPV of acute vs. prolonged screening %PR for long-term SCS %PR. Fifty-four patients (male/female = 38/16; mean age ± SEM = 54.2 ± 2.0 years) underwent thoracic (T) (mean level = T9.1 ± 0.4) percutaneous (n = 33) and laminectomy (n = 21) implantation of SCS for acute (15 minute intraoperative) and prolonged (5.0 ± 0.3 days) SCS screening of pain relief. Correlation between successful (> 50%PR) pain relief during acute (n = 53/54, PPV = 98%) and prolonged (n = 47/52, PPV = 90%) screening was significant (Spearman Rank Correlation Coefficient, SRCC = 0.462, p < 0.01). After permanent SCS implantation, at mean follow-up = 9.4 ± 1.5 months, acute and prolonged SCS screening %PR PPV's were each statistically significant for predicting long-term SCS relief of chronic pain (n = 31/38, PPV = 82% and n = 31/36, PPV = 86%, SRCC = 0.462 and 0.433, respectively, p < 0.01). We conclude that successful pain relief during acute SCS screening is highly correlated with successful prolonged SCS screening of chronic low back and/or lower extremity pain relief. Acute and prolonged SCS screening appear to have equivalent predictive value for successful long-term SCS control of chronic low back and/or lower extremity pain. These preliminary results suggest potential justification for eliminating prolonged and retaining acute (intraoperative) SCS screening for selection of permanent SCS implantation candidates. ______________________________________________________________________________ Dorsal column stimulation for lumbar spinal stenosis.

Chandler GS 3rd, Nixon B, Stewart LT, Love J. Pain Physician. 2003 Jan;6(1):113-8. Medical Director, Department of Pain Management, Specialty Clinics of Georgia, 1240 Jesse Jewell Parkway, Suite #300, Gainesville, GA 30501, USA. sewell87@aol.com

Surgical decompression has been considered the gold standard for the symptomatic spinal stenotic patient. Thirty thousand decompressive procedures are performed annually and this number is expected to increase as the American population ages. Options are limited for the stenotic patient classified as a "poor surgical risk". Furthermore review of the literature indicates mixed results even in optimal populations. Nonsurgical approaches including epidural steroids and percutaneous adhesiolysis have not been completely evaluated. Spinal cord stimulation has a long safe efficacious history in the treatment of neuropathic extremity pain but has never been evaluated in the treatment of spinal stenosis. This retrospective cohort of 55 patients receiving spinal cord stimulation was selected from a total of 72 patients presenting with spinal stenosis over a 4 year period. Twenty-one underwent subsequent permanent implantation with success rate of 67% at 1.5 years. Twelve elected to not receive implant despite "successful trial". 22 had "failed trial". Verbal pain scores, narcotic intake, and function were monitored. Spinal cord stimulation is a promising nondestructive alternative in the treatment of symptomatic spinal stenosis. Mild-moderate stenosis, predominate leg pain, and "positive" exercise treadmill appear to be positive predictors. Prospective trials with rigorous statistical designs are needed. ______________________________________________________________________________ Spinal cord stimulation for chronic pain of spinal origin: a

valuable long-term solution.

North RB, Wetzel FT. Spine (Phila Pa 1976). 2002 Nov 15;27(22):2584-91; discussion 2592. Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA. rnorth@jhmi.edu

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STUDY DESIGN: A literature review was conducted. OBJECTIVE: To review the indications and efficacy of spinal cord stimulation, particularly in reference to chronic pain of spinal origin. SUMMARY OF BACKGROUND DATA: The first spinal cord stimulation was implanted by Shealy in 1967 via a subarachnoid route. Early systems were plagued with a high rate of complications and technical problems. With the evolving technology, especially the advent of multichannel programmable systems and more precise epidural placement, the ability of spinal cord stimulation to treat various pain syndromes improved. This article reviews the literature on spinal cord stimulation from 1967 to the present. METHODS: The literature is reviewed, with a particular focus on recent studies investigating the efficacy of spinal cord stimulation for low back pain. RESULTS: Most studies are limited by the same flaws, namely, retrospective study design. At this writing, the few published randomized prospective studies have suggested that spinal cord stimulation may be superior to repeat surgery. Complication rates have declined to approximately 8%, and reoperation is necessary in approximately 4% of patients. When current percutaneous techniques are used, a lead migration rate lower than 3% may be achieved. For certain topographies, laminotomy leads may be superior, particularly with regard to low back pain. CONCLUSIONS: The ultimate efficacy of spinal cord stimulation remains to be determined, primarily because of limitations associated with the published literature. However, on the basis of the current evidence, it may represent a valuable treatment option, particularly for patients with chronic pain of predominantly neuropathic origin and topographical distribution involving the extremities. The potential treatment of other pain topographies and etiologies by spinal cord stimulation continues to be studied. ______________________________________________________________________________ Spinal cord stimulation: mechanisms of action.

Oakley JC, Prager JP. Spine (Phila Pa 1976). 2002 Nov 15;27(22):2574-83. Northern Rockies Pain and Palliative Treatment Center, Billings, Montana 59101, USA. joshir@aol.com

STUDY DESIGN: A literature review and synthesis were performed. OBJECTIVE: To present the current understanding of the mechanisms of spinal cord stimulation in relation to the physiology of pain. SUMMARY OF BACKGROUND DATA: Spinal cord stimulation has been used for more than 30 years in the armamentarium of the interventional pain specialist to treat a variety of pain syndromes. Traditionally used for persisting leg pain after lumbar spinal surgery, it has been applied successfully in the treatment of angina pectoris, ischemic pain in the extremity, complex regional pain syndrome Types 1 and 2, and a variety of other pain states. This review presents the current status of what is known concerning how electrical stimulation of the spinal cord may achieve pain relief. METHODS: A literature review was conducted. RESULTS: The literature supports the theory that the mechanism of spinal cord stimulation cannot be completely explained by one model. It is likely that multiple mechanisms operate sequentially or simultaneously. CONCLUSION: Some clinical or experimental support can be found in the literature for 10 specific mechanisms or proposed mechanisms of spinal cord stimulation. ______________________________________________________________________________ Spinal cord stimulation (SCS) using an 8-pole electrode and

double-electrode system as minimally invasive therapy of the post-

discotomy and post-fusion syndrome--prospective study results in

34 patients. [Article in German]

Rütten S, Komp M, Godolias G. Z Orthop Ihre Grenzgeb. 2002 Nov-Dec;140(6):626-31. Klinik für Orthopädie am Lehrstuhl für Radiologie und Mikrotherapie, Universität Witten/Herdecke, Ressort Wirbelsäulenchirurgie und Schmerztherapie, St.-Anna-Hospital Herne, Deutschland, Germany. ruetten@orthopain.de

AIM: Therapy of a pronounced post-discotomy (PDS) and post-fusion syndrome (PFS) is often unsatisfactory because of the complexity and multifactorial pain genesis. If surgical interventions cannot promise relief and if the entire interdisciplinary spectrum of conservative treatment measures is inadequate, the area of neuromodulative procedures offers spinal cord stimulation (SCS). The objective of this study was to examine the therapeutic possibilities of SCS using an 8-pole electrode and double electrode system in PDS and PFS with extensive back-leg pain areas. METHOD: An appropriate SCS system was implanted in 34 patients with PDS and PFS. Follow-

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up examinations were made prospectively over a period of 24 months using general criteria and psychometric test measuring instruments validated for German-language use. RESULTS: An 8-pole double electrode system was implanted 23 times, a single electrode sufficed in 11 cases. The area of pain was covered in all patients. This required special technical capabilities of the SCS system. The results remained constant over 24 months. The morphine dose could be reduced by at least 50 %. All measuring instruments confirmed a clear reduction in pain and improvement in quality of life as a result of SCS implantation. CONCLUSION: The SCS is an minimally invasive surgical procedure which can enlarge the therapeutical possibilities of pronounced PDS and PFS resistant to other modes of treatment. Special technical possibilities of parameter setting are required to cover the pain areas. ______________________________________________________________________________ Spinal cord stimulation electrode design: prospective, randomized,

controlled trial comparing percutaneous and laminectomy

electrodes-part I: technical outcomes.

North RB, Kidd DH, Olin JC, Sieracki JM. Neurosurgery. 2002 Aug;51(2):381-9; discussion 389-90. Department of Neurosurgery, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21287-7713, USA. rnorth@jhmi.edu

OBJECTIVE: The clinical use of spinal cord stimulation for treatment of chronic intractable pain has been increasingly successful because of recent technical improvements, particularly the development of multiple-contact electrodes supported by programmable implanted pulse generators. Contemporary electrodes can be placed percutaneously in some cases and require a limited laminectomy in other cases. METHODS: We performed a prospective, randomized, controlled trial comparing two prototypical electrode designs, using a computerized system that allows direct patient interaction and quantitative measurements. A series of 24 patients with chronic lumbosacral pain syndromes first underwent testing with percutaneous four-contact electrodes and then underwent implantation, at the same spinal level, of one of two different electrode configurations; 12 patients received a new percutaneous four-contact electrode of the same design and 12 received an insulated four-contact array, which was implanted via laminectomy. RESULTS: The insulated array performed significantly (P = 0.0005-0.0047) better than the temporary percutaneous electrode for the same patients, according to all three measures tested (ratings of paresthesia coverage of pain, coverage calculated from patient drawings, and amplitudes), at the "usage" amplitude for the three standard bipoles examined. The insulated array also performed significantly (P = 0.0000-0.026) better than the permanent percutaneous electrode in terms of coverage ratings and amplitude requirements. Low back coverage ratings were significantly better for the insulated array than for the temporary percutaneous electrode, and scaled amplitudes necessary for low back coverage were significantly better for the permanent percutaneous electrode than for the temporary electrode. In comparison with the percutaneous temporary electrode, at subjectively identical stimulation intensities, the permanent insulated array required significantly lower amplitude. CONCLUSION: We can immediately infer from these technical data that the use of an insulated array, in comparison with a percutaneous electrode, would double battery life. Extended follow-up monitoring will be required to assess the extent to which the technical advantages we observed for the insulated array might be associated with improved clinical outcomes. ______________________________________________________________________________ Evolving patterns of spinal cord stimulation in patients implanted

for intractable low back and leg pain.

Sharan A, Cameron T, Barolat G. Neuromodulation. 2002 Jul;5(3):167-79. doi: 10.1046/j.1525-1403.2002.02027.x. Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania and Department of Bioengineering, University of Texas Southwestern Medical School, Dallas, Texas.

The objective of this study was to examine the programming strategies used in patients with intractable low-back pain treated with epidural spinal cord stimulation (SCS) utilizing paddle electrodes and a radio frequency (RF) stimulator. Programming strategies were examined in a

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group of patients implanted with a 16-contact paddle electrode and a dual channel RF receiver to treat chronic low-back pain. Baseline data included previous surgical history information, leg and low back pain severity and characteristics, and routine demographic information. Outcome measurements included the visual analog scale (VAS) (1), patient pain relief rating scale, and programming parameters. Patients rated their pain relief on a 5-point scale where 4 = excellent, 3 = good, 2 = fair, 1 = poor and 0 = none. Success was determined to be a pain relief score of "fair" or above. Data were collected during patient visits or by mail, at approximately 6, 12, and 24 months, postoperatively. Immediate postop data were available in 16 patients, 6-month data in 21 patients, 1-year data in 20 patients, and 2-year data in 10 patients, and analyzed for the purposes of examining programming strategies. The most common location for the tip of the electrode (lead) was found to be in the middle of the 8th thoracic vertebrae (N = 26). At the immediate postop assessment, the majority of cathodes were activated in the upper half of T9. By the 6-month follow-up, the majority of cathodes had shifted to the bottom of T9 and top of T10. Overall 88% of cathode locations were changed at one or more study visits. At 2 years, 86% of the programs used four or more active contacts. At 6 months, 83% of the patients reported that the therapy was a success, at 1 year, success was 94%, and by 2 years, success was 75%. Both SCS and chronic pain are dynamic processes. Complex pain patterns, such as the ones of patients who have pain in the low back and in one or both lower extremities, require a high degree of flexibility in the implanted SCS system. The system must provide the capability to redirect the current electronically over at least two segments of the spinal canal, to electronically steer the current in a medio-lateral direction, and to activate multiple electrical contacts simultaneously. The willingness and ability to provide extensive reprogramming in the long term follow-up is also of the utmost importance. Pain and its treatment with SCS is a dynamic process. ______________________________________________________________________________ Treatment of chronic pain with spinal cord stimulation versus

alternative therapies: cost-effectiveness analysis.

Kumar K, Malik S, Demeria D. Neurosurgery. 2002 Jul;51(1):106-15; discussion 115-6. Department of Surgery, Regina General Hospital, University of Saskatchewan, Canada. K.Kumar@sk.sympatico.ca

OBJECTIVE: There is limited available research measuring the cost-effectiveness of spinal cord stimulation (SCS), compared with best medical treatment/conventional pain therapy (CPT). The purpose of this study was to tabulate the actual costs (in Canadian dollars) for a consecutive series of patients treated with SCS in a constant health care delivery environment and to compare the costs with those for a control group treated in the same controlled environment. METHODS: We present a consecutive series of 104 patients with failed back syndrome. Within this group, 60 patients underwent SCS electrode implantation, whereas 44 patients were designated as control subjects. We monitored these patients for a 5-year period and tabulated the actual costs incurred in diagnostic imaging, professional fees paid to physicians, implantation (including the costs for hardware), nursing visits for maintenance of the stimulators, physiotherapy, chiropractic treatments, massage therapy, and hospitalization for treatment of breakthrough pain. From these data, the cumulative costs for each group were calculated for a 5-year period. An analysis of Oswestry questionnaire results was also performed, to evaluate the effects of treatment on the quality of life. RESULTS: The actual mean cumulative cost for SCS therapy for a 5-year period was $29,123/patient, compared with $38,029 for CPT. The cost of treatment for the SCS group was greater than that for the CPT group in the first 2.5 years. The costs of treating patients with SCS became less than those for CPT after that period and remained so during the rest of the follow-up period. In addition, 15% of SCS-treated patients were able to return to employment, because of superior pain control and lower drug intake. No patients in the control group were able to return to employment of any kind. CONCLUSION: SCS is cost-effective in the long term, despite the initial high costs of the implantable devices. ______________________________________________________________________________ Four Year Follow-up of Dual Electrode Spinal Cord Stimulation for

Chronic Pain.

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Aló KM, Redko V, Charnov J. Neuromodulation. 2002 Apr;5(2):79-88. doi: 10.1046/j.1525-1403.2002.02017.x. Pain and Health Management Center, P.A., Houston, Texas.

This paper reports on 80 patients using dual electrode, spinal cord stimulation (SCS) over a four-year period Implant status, stimulation mode, anode-cathode configuration (array), cathode position, paresthesia overlap, explantation rates, complications, Visual Analog Scores (VAS), and overall satisfaction were examined in patients implanted with dual 8 contact, staggered, percutaneous electrodes. All patients had undergone implantation for chronic axial and extremity pain [e.g., Failed Back Surgery Syndrome (FBSS), Complex Regional Pain Syndrome (CRPS)]. Outcomes were evaluated in view of our previous reports in this same group at 24 and 30 months (1,2). Data was collected by a disinterested third party. At 48 months, 18 of the original 80 patients were lost to follow-up. Of the 62 patients contacted, 33 remained implanted and 29 (47%) had been explanted. After an average evaluation of 85 arrays (PainDoc, Advanced Neuromodulation Systems, Plano, Texas), 88% of patients reported using one or two "best" arrays (bipolar or guarded tripolar) to maintain favorable paresthesia overlap (89%), VAS reduction (8.1 to 4.9), and overall patient satisfaction (63%). These arrays were most commonly positioned about the physiologic midline of the COL3-4 vertebral segments for upper extremity pain, and the T9-10 vertebral segments for low back and lower extremity pain. In contrast to our initial reports where essentially all patients preferred more than two arrays to maintain "best" paresthesia overlap and outcome, only 12% of these same patients maintained this trend in this long-term follow-up study. The arrays most commonly selected long-term as the "best" ones (88% of all electrodes) were narrow (adjacent contact) bipoles and guarded cathode tripoles (< 8 contacts). Thirty-five percent of patients with thoracic implants achieved paresthesia in the low back at 48 months. Explantation rates and overall patient satisfaction were significantly affected by painful radio frequency (RF) antenna coupling. This data supports the efficacy of dual electrodes in optimizing long-term SCS paresthesia overlap and complex pain outcomes. ______________________________________________________________________________ Spinal cord stimulation.

Stojanovic MP, Abdi S. Pain Physician. 2002 Apr;5(2):156-66. Interventional Pain Program, MGH Pain Center, Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Cambridge, MA 02135, USA.

Erratum in Pain Physician. 2002 Jul;5(3):341. Spinal cord stimulation is the most common mode of neuromodulation used in managing chronic low back pain. It is minimally invasive and reversible as opposed to nerve ablation. The basic scientific background of the initial spinal cord stimulation trials was based on the gate control theory of Melzack and Wall. It has been demonstrated in multiple studies that dorsal horn neuronal activity caused by peripheral noxious stimuli could be inhibited by concomitant stimulation of the dorsal columns. Various other mechanisms, which may play a significant role in the mechanism of action of spinal cord stimulation, include the suppressive effect of spinal cord stimulation on tactile allodynia, increased dorsal horn inhibitory action of gamma-aminobutyric acid (GABA), prevention or abolition of peripheral ischemia, and effects on human brain activity. Spinal cord stimulation is indicated in low back pain with radiculopathy, failed back surgery syndrome, complex regional pain syndrome, peripheral vascular disease, and ischemic heart disease. There is substantial scientific evidence on the efficacy of spinal cord stimulation for treatment of low back and lower extremity pain of neuropathic nature. Clinical studies revealed a success rate of from 50% to 70% with spinal cord stimulation, with decreased pain intensity scores, functional improvement and decreased medication usage. This review discusses multiple aspects of spinal cord stimulation, including pathophysiology and mechanism of action, rationale, indications, technique, clinical effectiveness, and controversial aspects. ______________________________________________________________________________ Current and future trends in spinal cord stimulation for chronic

pain.

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Deer TR. Curr Pain Headache Rep. 2001 Dec;5(6):503-9. The Center for Pain Relief, 1201 Washington Street East, Suite 100, Charleston, WV 25301, USA. DocTDeer@aol.com

Spinal cord stimulation (SCS) is a reversible treatment for chronic pain that is gaining favor as a first-line therapy for many disease states. Because there are no addictive issues and no side effects systemically, the treatment is moving up the treatment continuum ladder. First used clinically in 1967, the procedure was used exclusively for failed back surgery syndrome. Over the past 30 years selection criteria, psychologic screening, and technology have improved. These advances have broadened the treatment options for many patients in pain. This review focuses on the selection, indications, techniques, new advances, complications, and outcomes involved with SCS. A review is provided for the treatment of radiculitis, failed back surgery syndrome, complex regional pain syndrome, peripheral neuropathies, pelvic pain, occipital neuralgia, angina, ischemic extremity pain, and spasticity. Technologic advances such as multi-lead and multi-electrode arrays are also discussed in regard to the impact these developments have on the clinical application of the therapy. ______________________________________________________________________________ Patient satisfaction with spinal cord stimulation for predominant

complaints of chronic, intractable low back pain.

Ohnmeiss DD, Rashbaum RF. Spine J. 2001 Sep-Oct;1(5):358-63. Texas Health Research Institute and the Texas Back Institute Research Foundation, 6300 West Parker Road, Suite 100, Plano, TX 75093, USA. donnaohnmeiss@texashealth.org

BACKGROUND CONTEXT: Results of subsequent surgical intervention in patients with intractable pain after lumbar spine surgery are typically worse than for initial surgery, particularly in those with predominant complaints of back pain rather than lower extremity pain. Spinal cord stimulation (SCS) has been found to yield good results in patients with primary complaints of intractable lower extremity pain. Technological advances have broadened the indications for this treatment. PURPOSE: The purpose of this study was to evaluate patient satisfaction after SCS in the treatment of patients with predominant complaints of chronic, intractable, low back pain. STUDY DESIGN/SETTING: Data were collected from retrospective chart review and patient follow-up questionnaire. Patients were treated at a spine specialty center. PATIENT SAMPLE: The study group consisted of the consecutive series of our first 41 patients who underwent SCS for predominant complaints of low back pain. The mean symptom duration was 82.9 months, and the mean age was 47.9 years (range, 28-83 years). All but three patients had previously undergone lumbar spine surgery (mean, 2.3 prior surgeries). OUTCOME MEASURES: At the time of follow-up (5.5-19 months after SCS implantation), patients completed questionnaires assessing their satisfaction with their outcome, if they would have the procedure again knowing what their outcome would be and if they would recommend SCS to someone with similar problems. In determining outcome, a negative response was assigned for patients who had the device removed. A worst-case analysis was also conducted in which a negative response was assigned for patients lost to follow-up or who failed to respond to a particular question. Data were also collected on complications and re-operations. METHODS: All trial stimulation procedures were performed under local anesthetic with the patient providing feedback concerning pain relief achieved with various lead placements and settings. If one lead did not provide acceptable relief in all the areas needed, placement of a second lead was pursued. If the patient failed to maintain acceptable pain relief (> or =50% pain relief) during a multiday trial period, the leads were removed. If adequate relief was maintained during the trial period, the receiver was implanted. RESULTS: Responses to the follow-up questionnaire indicated that 60% of patients considered themselves improved from their preoperative condition and the remaining 40% did not; 78.1% of patients would recommend SCS to someone with similar problems, 69.0% were satisfied, 75.0% would have the procedure performed again if they had known their outcome before implantation. Among the 36 patients in whom the system was implanted, it was later removed in 4 because of lack of sufficient pain relief. Other re-operations included repositioning of the leads to regain pain relief in the areas needed, replacement of a malfunctioning unit and revision of lead extension wires. CONCLUSIONS: In this retrospective study, the majority of patients were satisfied with the results of SCS and would have

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the procedure again knowing what their outcome would be. These results suggest that further investigation of SCS is warranted in this difficult to treat patient population presenting with predominant complaints of chronic, intractable, axial low back pain. ______________________________________________________________________________ Spinal cord stimulation for nonspecific limb pain versus

neuropathic pain and spontaneous versus evoked pain.

Kim SH, Tasker RR, Oh MY. Neurosurgery. 2001 May;48(5):1056-64; discussion 1064-5. Department of Neurosurgery, Yeungnam University, Taegu, Korea.

OBJECTIVE: To compare the outcome of spinal cord stimulation (SCS) in patients with nonspecific limb pain versus patients with neuropathic pain syndromes and in patients with spontaneous versus evoked pain. METHODS: A retrospective review of 122 patients accepted for treatment with SCS between January 1990 and December 1998 was conducted. All patients first underwent a trial of SCS with a monopolar epidural electrode. Seventy-four patients had a successful trial and underwent permanent implantation of the monopolar electrode used for the trial (19 patients), or a quadripolar electrode (53 patients), or a Resume quadripolar electrode via laminotomy (2 patients). RESULTS: Of the 74 patients, 60.7% underwent implantation of a permanent device and were followed for an average of 3.9 years (range, 0.3-9 yr). Early failure (within 1 yr) occurred in 20.3% of patients, and late failure (after 1 yr) occurred in 33.8% of patients. Overall, 45.9% of patients were still receiving SCS at latest follow-up. Successful SCS (>50% reduction in pain for 1 yr) occurred in 83.3% of patients with nonspecific leg pain, 89.5% of patients with limb pain associated with root injury, and 73.9% of patients with nerve neuropathic pain. SCS was less effective for the control of allodynia or hyperpathia than for spontaneous pain associated with neuropathic pain syndromes. Third-party involvement did not influence outcome. There was a lesser incidence of surgical revisions when quadripolar leads were used than with monopolar electrodes. CONCLUSION: SCS is as effective for treating nonspecific limb pain as it is for treating neuropathic pain, including limb pain associated with root damage. ______________________________________________________________________________ Epidural spinal cord stimulation with a multiple electrode paddle

lead is effective in treating intractable low back pain.

Barolat G, Oakley JC, Law JD, North RB, Ketcik B, Sharan A. Neuromodulation. 2001 Apr;4(2):59-66. doi: 10.1046/j.1525-1403.2001.00059.x. Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania; Yellowstone Neurosurgical Associates, Yellowstone Medical Center East, Billings, Montana; Rocky Mountain Neurosurgical Alliance, Aurora, Colorado; and Department of Neurosurgery, Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.

The objective of this paper is to examine the outcomes of patients with intractable low-back pain treated with epidural spinal cord stimulation (SCS) utilizing paddle electrodes and a radio frequency (RF) stimulator. A multicenter prospective study was performed to collect data from patients suffering from chronic low-back pain. The study was designed to collect data from 60 patients at four centers and examine their outcomes at, or up to two years post implantation. Patients' participation included written responses to a series of preoperative questionnaires that were designed to collect previous surgical history information, leg and low back pain characteristics, and routine demographic information. Outcome measurements included the visual analog scale (VAS), the Oswestry Disability Questionnaire, the Sickness Impact Profile (SIP), and a patient satisfaction rating scale. Data were collected at each site during patient visits or by mail, at approximately six months, 12 months, and 24 months. A total of 44 patients have been implanted with a SCS system at the time of this writing. Follow-up data were available for 41 patients. Preoperatively, all patients reported more than 50% of their pain in the low back. All patients had pain in both their backs and legs. All patients showed a reported mean decrease in their 10-point VAS scores compared to baseline. The majority of patients reported fair to excellent pain relief in both the low back and legs. At six months 91.6% of the patients reported fair to excellent relief in the legs and 82.7% of the patients reported fair to excellent relief in the low back. At one year 88.2% of the patients reported fair to excellent relief in the legs and 68.8% of the

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patients reported fair to excellent relief in the low back. Significant improvement in function and quality of life was found at both the six-month and one-year follow-ups using the Oswestry and SIP, respectively. The majority of patients reported that the procedure was worthwhile (92% at six months, 88% at one year). No patient indicated that the procedure was not worthwhile. We conclude that SCS proved beneficial at one year for the treatment of patients with chronic low back and leg pain. ______________________________________________________________________________ Outcomes of spinal cord stimulation: patient validation.

Anderson VC, Carlson C, Shatin D. Neuromodulation. 2001 Jan;4(1):11-7. doi: 10.1046/j.1525-1403.2001.00011.x. Department of Neurological Surgery, Oregon Health Sciences University, Portland, Oregon and Center for Health Care Policy and Evaluation, United Health Group, Minneapolis, Minnesota.

Objective. To identify aspects of daily life that have been most affected by chronic low back pain among spinal cord stimulation (SCS) patients and to determine the relative contribution that improvement in each would make to patients' quality of life (QOL). Materials and Methods. Telephone survey of 44 patients with chronic low back pain who were about to undergo or had been recently implanted with an SCS system. Patients were asked to define, by open-ended response and examiner-read list, those aspects of daily life that had been most affected by pain and to assess the relative importance that improvement in each would make to daily life. Results. Patients identified 13 areas of daily function that were most significantly impacted by chronic low back pain. Most frequently, activities of daily living, decreased ability to work, psychological changes, and limitations to social life and recreation were identified. Functional status change, decreased ability to walk, and ability to perform daily household activities were rated as the most important change from among items included in examiner-read list. Conclusions. Patients with chronic low back pain seek improvement in multiple dimensions of QOL after SCS, particularly increased physical activity, social relations, work status, and mood. It is likely that patients' assessment of SCS "success" correlates highly with functional improvement. As such, an understanding of SCS therapeutic benefit and satisfaction requires that QOL be carefully assessed in future outcome trials. ______________________________________________________________________________ Spinal cord stimulation for failed back surgery syndrome.

Leveque JC, Villavicencio AT, Bulsara KR, Rubin L, Gorecki JP. Neuromodulation. 2001 Jan;4(1):1-9. doi: 10.1046/j.1525-1403.2001.00001.x. Division of Neurosurgery, Duke University Medical Center, Durham, North Carolina.

Objective. The purpose of this study is to evaluate the effectiveness of modern spinal cord stimulation (SCS) for the treatment of failed back surgery syndrome (FBSS). Materials and Methods. Thirty patients were treated with SCS between December 1992 and January 1998 for low back and radicular pain after multiple failed back surgeries. Permanent systems were implanted if trial stimulation led to > 50% pain reduction. Median long-term follow-up was 34 months (range, 6-66 months). Severity of pain was determined postoperatively by a disinterested third party. Results. Overall, 12 of the 16 patients (75%) who received permanent implants continued to report at least 50% relief of pain at follow-up. All six patients who underwent placement of laminectomy-styled electrode for SCS in the thoracic region had > 50% pain relief at long-term follow-up. Visual analog scores decreased an average of 3.2 (from 8.6 preoperatively to 5.4 postoperatively). Patients undergoing SCS placement via laminectomy in the thoracic region experienced an average decrease of 4.9 in VAS, whereas those who underwent percutaneous placement of thoracic leads had an average decrease of 2.5. Conclusions. SCS is an effective treatment for chronic low back and lower extremity pain which is refractory to conservative therapy and which is not amenable to corrective anatomic surgery. Though our patient population is small, our results imply that the laminectomy-style electrodes in the thoracic region achieve better long-term effectiveness than percutaneous leads. ______________________________________________________________________________

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The efficacy of spinal cord stimulation for chronic pain.

Kavar B, Rosenfeld JV, Hutchinson A. J Clin Neurosci. 2000 Sep;7(5):409-13. Department of Neurosurgery, Neuroscience Centre, Royal Melbourne Hospital, Melbourne, Australia.

A prospective study was undertaken to evaluate the efficacy of spinal cord stimulation (SCS) in the management of chronic pain syndrome. The study included all patients who underwent this procedure at the Royal Melbourne Hospital and the Melbourne Private Hospital over a period of two years. A total of 29 patients were managed by the end of June 1996. These patients were carefully screened by a neurosurgeon (JVR) and a psychiatrist. Of these, 26 patients had a follow up evaluation at the end of August 1996. From the group of 29 patients, four patients failed to obtain any relief during the trial phase of the procedure and thus did not have the stimulator implanted permanently. From the 25 patients who proceeded to have the stimulator implanted, 11 patients had a variable beneficial response, three patients found it to be of marginal benefit, six had no benefit, three patients initially had a good response but subsequently gained no benefit whilst two patients were uncertain of its benefit. It thus appears that SCS was of benefit in 50% of our carefully selected patients with chronic pain syndromes. ______________________________________________________________________________ Treatment of Chronic Pain in Failed Back Surgery Patients with

Spinal Cord Stimulation: a Review of Current Literature and

Proposal for Future Investigation.

Wetzel FT, Hassenbusch S, Oakley JC, Willis KD, Simpson RK Jr, Ross EL. Neuromodulation. 2000 Apr;3(2):59-74. doi: 10.1046/j.1525-1403.2000.00059.x. Department of Surgery, Section of Orthopedic Surgery and Rehabilitation, and Anesthesia and Critical Care, The University of Chicago Spine Center, Section of Orthopedic Surgery, Louis A. Weiss Memorial Hospital, Chicago, Illinois; Department of Neurosurgery, M.D. Anderson Cancer Center, Houston, Texas; Neurosurgical Associates, Northwest Neuroscience Institute, Seattle, Washingon; Alabama Pain Center, Huntsville, Alabama; and Pain Management Center, Brigham & Women's Hospital, Boston, Massachusetts.

Objective. The authors attempted to design and conduct a randomized, prospective study to investigate the efficacy of spinal cord stimulation (SCS) for patients with chronic back and leg pain following at least one previous surgery. While the scientific advantages of the randomized, prospective trial are considerable, the authors encountered numerous practical and ethical difficulties with conducting these trials. These are reviewed and an alternative investigative technique proposed. Materials and Methods. The literature on interventional and minimally invasive treatments for this population group is reviewed, and the strengths and weaknesses of different methodologies for conducting clinical research in an interventional setting are examined. Results. The difficulties inherent in a randomized, prospective study for an intervention vs. a nonintervention group are addressed, and an alternative methodology is proposed-that of a randomized interventional design. In this design, patients are assigned to a given treatment group, with each treatment exclusively available at different centers. Conclusions. By utilizing a randomized interventional study design, problems of comparability of procedures, provider reluctance to participate in randomized clinical trials, provider bias, detection bias, and transfer bias are eliminated. It is suggested that future investigations, particularly those which are interventionally or device-based, conform to this particular model. ______________________________________________________________________________ Treatment of chronic pain by spinal cord stimulation.

Tseng SH. J Formos Med Assoc. 2000 Mar;99(3):267-71. Department of Surgery, National Taiwan University Hospital, Taipei.

Chronic pain after injury of the nervous system is difficult to treat. This report describes our experience in the treatment of chronic pain by spinal cord stimulation (SCS) in four patients (three men and one woman, with ages ranging from 61 to 73 yr). One patient had chronic intractable pain due to a spinal cord injury, one had post-herpetic neuralgia, one had failed back surgery

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syndrome, and one had brachial plexus and spinal cord injuries. A permanent spinal cord stimulator was implanted in the patient with spinal cord injuries. In the other three patients, a permanent spinal cord stimulator was implanted after a successful trial stimulation with temporarily implanted electrodes. After 19 to 25 months (mean, 21 mo) of follow-up, three patients had satisfactory improvement of pain and one patient had temporary pain relief, but pain recurred two months after implantation. One patient had recurrence of pain after migration of an electrode, and the pain-relieving effects of SCS returned after repositioning the electrode. According to this preliminary experience, SCS is effective for pain reduction in selected patients with chronic pain. Long-term follow-up is mandatory to evaluate the benefits and complications of SCS for relief of chronic pain. ______________________________________________________________________________ Laminectomy versus percutaneous electrode placement for spinal

cord stimulation.

Villavicencio AT, Leveque JC, Rubin L, Bulsara K, Gorecki JP. Neurosurgery. 2000 Feb;46(2):399-405; discussion 405-6. Division of Neurosurgery, Duke University Medical Center, Durham, North Carolina 27712, USA.

OBJECTIVE: The purpose of this study was to compare the long-term effectiveness of spinal cord stimulation using laminectomy-style electrodes versus that using percutaneously implanted electrodes. METHODS: Forty-one patients underwent an initial trial period of spinal cord stimulation with temporary electrodes at Duke Medical Center between December 1992 and January 1998. A permanent system was implanted if trial stimulation reduced the patient's pain by more than 50%. Median long-term follow-up after permanent electrode placement was 34 months (range, 6-66 mo). Severity of pain was determined postoperatively by a disinterested third party using a visual analog scale and a modified outcome scale. RESULTS: Twenty-seven (66%) of the 41 patients participating in the trial had permanent electrodes placed. Visual analog scores decreased an average of 4.6 among patients in whom electrodes were placed via laminectomy in the thoracic region (two-tailed t test, P < 0.0001). Patients who underwent percutaneous placement of thoracic electrodes had an average decrease of 3.1 in their visual analog scores (two-tailed t test, P < 0.001). Electrodes placed through laminectomy furnished significantly greater long-term pain relief than did those placed percutaneously, as measured by a four-tier outcome grading scale (P = 0.02). CONCLUSION: Spinal cord stimulation is an effective treatment for chronic pain in the lower back and lower extremities that is refractory to conservative therapy. Electrodes placed via laminectomy in the thoracic region appear to be associated with significantly better long-term effectiveness than are electrodes placed percutaneously. ______________________________________________________________________________ Hardware failures in spinal cord stimulation for failed back

surgery syndrome.

Heidecke V, Rainov NG, Burkert W. Neuromodulation. 2000 Jan;3(1):27-30. doi: 10.1046/j.1525-1403.2000.00027.x. Department of Neurosurgery, Faculty of Medicine, Martin-Luther-University Halle-Wittenberg, Halle, Germany.

Spinal cord stimulation (SCS) is an efficient means for treatment of the postsurgical lumbar spine condition known as failed back surgery syndrome (FBSS). Although the devices and the implantation techniques are well established and the technology is sophisticated, there are some complications caused by hardware failures. This study was aimed at identifying the most frequent types of hardware failures and their causes in FBSS patients treated with SCS. In a retrospective analysis, a group of 42 FBSS patients using single lead SCS for 6-74 months was evaluated. Only hardware failures were considered in the analysis, and parameters such as occurrence of failure after primary implantation of the device, frequency and site of failure, stimulation time to failure (TF), and overall time of SCS usage were recorded. In the patient group studied, 12 surgical corrections of the hardware were carried out in 10 patients. In eight patients there was a single corrective procedure, in two additional cases there were two surgically corrected hardware failures each. The most often encountered type of hardware failure was lead breakage or disruption of

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insulation (percutaneously placed Quad leads only) leading to short circuiting and dysfunction (n= 8). Second in frequency were receiver (model 3470) failures due to insulation leakage at the plug connection site (n= 2). In one case, extension cable breakage caused dysfunction of the system, and another dysfunction was caused by distal extension cable disconnection. In conclusion, SCS is a low-complication procedure for treatment of benign low-back pain, but seems to be prone to lead and insulation failures. ______________________________________________________________________________ Spinal cord stimulation for treatment of failed back surgery

syndrome--two case reports.

Vijayan R, Ahmad TS. Med J Malaysia. 1999 Dec;54(4):509-13. Department of Anaesthesiology, Faculty of Medicine, University of Malaya, Kuala Lumpur.

Severe, persistent back pain following back surgery is often referred to as Failed Back Surgery Syndrome (FBSS). Conservative measures such as physiotherapy, back strengthening exercises, transcutaneous electrical nerve stimulation and epidural steroids may be inadequate to alleviate pain. Spinal Cord Stimulators were implanted into two patients suffering from FBSS. Both patients responded successfully to spinal cord stimulation with reduction of pain and disability. ______________________________________________________________________________ Multiple Program Spinal Cord Stimulation in the Treatment of

Chronic Pain: Follow-Up of Multiple Program SCS.

Aló KM, Yland MJ, Charnov JH, Redko V. Neuromodulation. 1999 Nov;2(4):266-72. doi: 10.1046/j.1525-1403.1999.00266.x. Pain and Health Management Center, Houston, Texas and North Shore Pain Management, Huntington, New York.

Objective. Follow-up of 80 patients using multiple program spinal cord stimulation (SCS). Methods. For 30 months, we followed 80 chronic pain patients who had undergone SCS implantations at our center. Thirty-six patients had Failed Back Surgery Syndrome (FBSS). Patients were evaluated in patient-controlled stimulation mode (patients can select one of several specific programs in response to their activities and pain level). We collected visual analog pain scores, patient satisfaction scores, pain maps, and paresthesia maps. Results. We previously reported our preliminary findings (Neuromodulation 1998;1 :30-45). At 24 months all patients were using more than one program. At 30 months, 62 patients (76%) were using more than two programs as their preferred stimulation mode and three patients (4%) were satisfied with only one stimulation program. At 30 months all patients chose patient-controlled stimulation as their preferred mode of stimulation. A total of 18 patients (23%) were explanted. Mean pain scores declined from 8.2 at baseline to 4.8 (p < 0.05, n= 79). Paresthesia overlap was 91% (n= 79). Of the patients with FBSS, 81% reported that they were using their SCS daily. Conclusions. In spinal cord stimulation the use of multiple electrodes and multiple stimulation programs, together with advanced programmability, increases paresthesia overlap, reduces pain scores, and may improve patient satisfaction with SCS therapy. This study indicates a significant patient preference for multiple program SCS, if patients are given the option to choose between a single program SCS system or a multiple program SCS system. ______________________________________________________________________________ Treatment of failed back surgery syndrome patients with low back

and leg pain: a pilot study of a new dual lead spinal cord

stimulation system.

Van Buyten JP, Van Zundert J, Milbouw G. Neuromodulation. 1999 Nov;2(4):258-65. doi: 10.1046/j.1525-1403.1999.00258.x. Algemeen Ziekenhuis Maria Middelares, Sint-Niklaas and Center Hospitalier Regional, Namur, Belgium.

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Objective. Treatment of pain associated with failed back surgery syndrome was evaluated in a pilot clinical study of a new dual lead spinal cord stimulation (SCS) system. Methods. The following data was retrospectively sought from 20 non-randomized patients at 2 centers treated by the new SCS system, instead of an implantable drug pump: 1) prior back surgeries, 2) pain and paresthesia mapping, 3) VAS ratings, 4) medication use, 5) sleep patterns, 6) physical abilities, 7) hardware problems, and 8) willingness to repeat the procedure. Two-year follow-up was sought from all patients. Results. The new dual lead SCS system provided good low back and leg paresthesia coverage. Patients reported having less pain and using fewer analgesics and narcotics during follow-up, compared to their preimplant experience. These improvements were statistically significant. Patients also improved their sleep and physical abilities during follow-up. While external hardware problems occurred, 65% of dual lead SCS patients were willing to repeat the SCS implant procedure. Conclusions. Dual lead stimulation proved beneficial for patients with low back and leg pain associated with failed back surgery syndrome. ______________________________________________________________________________ Spinal Cord Stimulation for the Relief of Pain: Proceedings of a

Symposium during the 4th International Congress of the

International Neuromodulation Society, September 16-20, 1998,

Lucerne, Switzerland.

Oakley JC. Neuromodulation. 1999 Jul;2(3):184-7. doi: 10.1046/j.1525-1403.1999.00184.x. Northwest Neuroscience Institute, Seattle, Washington.

Spinal cord stimulation has become an accepted technique used in the management of chronic neuropathic pain syndromes. However, a number of problematic questions remain unanswered. This introduction states some of these problems and concentrates on the problem of whether low back pain can be relieved by stimulation. This paper introduces subsequent contributions to this symposium, which offer some interesting new techniques, and attempts to answer some of the problems presented. ______________________________________________________________________________ Spinal cord stimulation for failed back surgery syndrome:

technical advances, patient selection and outcome.

North RB, Guarino AH. Neuromodulation. 1999 Jul;2(3):171-8. doi: 10.1046/j.1525-1403.1999.00171.x.

Department of Neurosurgery, Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland and Department of Anesthesiology, Washington University, St. Louis, Missouri.

Kein Abstract vorhanden. ______________________________________________________________________________ Spinal Cord Stimulation: Indications, Mechanism of Action, and

Efficacy.

Krames E. Curr Rev Pain. 1999;3(6):419-426. Pacific Pain Treatment Centers, 2000 Van Ness Avenue, Suite 402, San Francisco, CA 94109, USA.

Unrelieved pain is costly to the economic fabric of our society; its direct costs to patients and their families is staggering. Spinal cord stimulation for the treatment of chronic pain is cost-effective when used in the context of a pain treatment continuum. Many theories on the mechanism of action of spinal cord stimulation have been suggested, including activation of gate control mechanisms, conductance blockade of the spinothalamic tracts, activation of supraspinal mechanisms, blockade of supraspinal sympathetic mechanisms, and activation or release of putative neuromodulators. Whatever theory or theories of mechanism are correct, spinal cord stimulation has efficacy in the treatment of failed back surgery syndrome, complex regional pain syndromes, intractable pain due to peripheral vascular disease, and intractable pain due to angina. ______________________________________________________________________________

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Lumbar and Sacral Nerve Root Stimulation (NRS) in the Treatment of

Chronic Pain: A Novel Anatomic Approach and Neuro Stimulation

Technique.

Alo KM, Yland MJ, Redko V, Feler C, Naumann C. Neuromodulation. 1999 Jan;2(1):23-31. doi: 10.1046/j.1525-1403.1999.00023.x. Pain and Health Management Center, Houston, Texas; North Shore Pain Management Center, Huntington, New York; Department of Neurosurgery, University of Tennessee, Memphis, Memphis, Tennessee; and Swiss Pain Center, Rheinfelden, Switzerland.

Objective. The conventional technique used to stimulate the lumbar dermatomes is by stimulation of the dorsal columns of the spinal cord. Until recently, stimulation of nerve roots had not been successfully accomplished. We had performed selective nerve root cannulations for the placement of temporary catheters at cervical, thoracic, lumbar, and sacral levels in chronic pain patients using a caudad rather than craniad approach. We hypothesized that by stimulating the nerve roots we could improve paresthesia coverage in areas which cannot be covered effectively by spinal cord stimulation (SCS). To test this hypothesis, we have performed trials of nerve root stimulation (NRS) in patients who had failed SCS, or who were not candidates for SCS because their pain was otherwise inaccessible to stimulation. Methods. Five patients who had been unresponsive to conservative treatment, surgery, or SCS underwent 7-day trials with NRS. The diagnoses included: ilioinguinal neuralgia, discogenic low back pain, failed back syndrome, vulvodynia, and interstitial cystitis. We collected paresthesia maps, pain maps, pain visual analog scale (VAS) scores, and patient satisfaction ratings. Results. Paresthesia coverage was above 75% in all patients. VAS scores declined from a mean of 9 ± 1.0 to 2.4 ± 2.1 (p < 0.05, n= 5), all 5 patients requested permanent implantation, and 4 have been implanted so far. Conclusions. Lumbar and sacral NRS trials resulted in adequate paresthesia coverage and effective pain relief in all 5 patients. Further clinical trials to evaluate long-term success rates and safety are indicated. Detailed mapping studies are needed to evaluate the relationship between electrode placement and paresthesia patterns as well as the optimal stimulation parameters. ______________________________________________________________________________ Efficacy of transverse tripolar stimulation for relief of chronic

low back pain: results of a single center.

Slavin KV, Burchiel KJ, Anderson VC, Cooke B. Stereotact Funct Neurosurg. 1999;73(1-4):126-30. Department of Neurological Surgery, Oregon Health Sciences University, Portland, OR 97201, USA.

The goal of this study was to evaluate the efficacy of the transverse tripolar spinal cord stimulation system (TTS) in providing relief of low back pain in patients with chronic non-malignant pain. Transverse tripolar electrodes were implanted in the lower thoracic region (T(8-9) to T(12)-L(1)) in 10 patients with chronic neuropathic pain, all of whom reported a significant component of low back pain in combination with unilateral or bilateral leg pain. One patient reported inadequate pain relief during the trial and was not implanted with a permanent generator. A visual analogue scale of low back pain showed a nonsignificant decrease from 64 +/- 19 to 47 +/- 30 (p = 0.25; paired t test) after 1 month of stimulation. Similarly, functional disability evaluated using Oswestry Low Back Pain Questionnaire was not improved (p = 0. 46; paired t test). We conclude that chronic low back pain is not particularly responsive to the transverse stimulation provided by the TTS system. ______________________________________________________________________________ Epidural spinal cord stimulation for treatment of chronic pain--

some predictors of success. A 15-year experience.

Kumar K, Toth C, Nath RK, Laing P. Surg Neurol. 1998 Aug;50(2):110-20; discussion 120-1. Department of Surgery, The Plains Health Centre, University of Saskatchewan, Regina, Canada.

BACKGROUND: We have used epidural spinal cord stimulation (SCS) for pain control for the past 15 years. An analysis of our series of 235 patients has clarified the value of specific prognostic

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parameters in the prediction of successful SCS. METHODS: Patients were followed up for periods ranging from 6 months to 15 years with a mean follow-up of 66 months. The mean age of the 150 men and 85 women in the study was 51.4 years. Indications for SCS included failed back syndrome (114 patients), peripheral vascular disease (39 patients), peripheral neuropathy (30 patients), multiple sclerosis (13 patients), reflex sympathetic dystrophy (13 patients), and other etiologies of chronic intractable pain (26 patients). RESULTS: One hundred and eighty-nine patients received permanent devices; 111 (59%) of these patients continue to receive satisfactory pain relief. Pain attributable to failed back syndrome, reflex sympathetic dystrophy, peripheral vascular disease of lower limbs, multiple sclerosis, and peripheral neuropathy responded favorably to spinal cord stimulation. In contrast, paraplegic pain, cauda equine syndrome, stump pain, phantom limb pain, and primary bone and joint disease pain did not respond as well. Cases of cauda equina injury had promising initial pain relief, but gradually declined after a few years. After long-term follow-up, 47 of the 111 successfully implanted patients were gainfully employed, compared with 22 patients before implantation. The successful patients reported improvements in daily living as well as a decrease in analgesic usage. Multipolar stimulation systems were significantly more reliable (p < 0.001) than unipolar systems. Complications included hardware malfunction, electrode displacement, infection, and tolerance. CONCLUSION: Aside from etiologies of pain syndromes as a prognostic factor, we have identified other parameters of success. In patients who have undergone previous surgical procedures, the shorter the duration of time to implantation, the greater the rate of success (p < 0.001). The diagnosis of failed back syndrome must be considered a confounding factor in our analysis. Those patients whose pain did not follow a surgical procedure had better responses to SCS than patients who had multiple surgical procedures prior to their first implant. The advent of multipolar systems has significantly improved clinical reliability over unipolar systems. Age, sex, and laterality of pain did not prove to be of significance. ______________________________________________________________________________ Spinal cord stimulation revisited.

Segal R, Stacey BR, Rudy TE, Baser S, Markham J. Neurol Res. 1998 Jul;20(5):391-6. Department of Neurological Surgery, University of Pittsburgh, PA, USA.

The proportion of patients with intractable pain successfully managed with spinal cord stimulation (SCS) remains disputed. We analyze 27 consecutive patients with intractable pain treated with SCS using identical hardware (Itrel II System; Medtronic Neurological, Inc Minneapolis, MN, USA) by a single satisfactory diagnosis 1992 through 1995. A rigid selection protocol was used: 1. A satisfactory diagnosis of the pathologic process resulting in pain was made. 2. A corrective surgical procedure was judged not feasible by surgeons experienced in the particular pathology, e.g., vascular peripheral nerve, spine. 3. Lack of satisfactory response to noninterventional pain management modalities by an interdisciplinary pain clinic. 4. Independent psychological evaluation, including a structured interview was performed by a psychologist specialized in chronic pain management. In the last eight cases, a battery of self-report tests designed to assess psychosocial and behavioral consequences of the chronic pain problem were administered as well. All cases were of nonmalignant pain, except for one patient. Thirteen cases were diagnosed with failed back surgery syndrome (FBSS), one older patient with lumbosacral radiculopathy who refused decompression, one cervical radiculopathy and Klippel-Feil syndrome, six with reflex sympathetic dystrophy (RSD), two with peripheral vascular ischemic disease, one with post-thoracotomy pain syndrome, one with leg pain following resection of angiolipoma, one with traumatic superficial peroneal neuropathy, and one with Pancoast's tumor. Fifteen patients were female and twelve were male. All were Caucasian. Their ages ranged from 27 to 84 years (mean:48). The average follow-up was 21 months (range: 48-6). All patients underwent a three day trial screening with Pisces-Quad/Resume epidural leads connected to a temporary external stimulator. An Itrel II System pulse-generator was internalized in each of the 24 patients who had successful trial (three cervical and twenty-one thoracic-lumbar). There was no morbidity. Pain reduction was sustained in 22 out of the 24 patients who continue to use the stimulator. The same number would choose to receive in an electrical stimulator again. Normalization or improvement in Quantitative Sudomotor Axon Reflex Test (Q-SART) and Thermography was documented in the patients with RSD. We conclude that rigid selection protocol can maximize the proportion of patients with intractable pain

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who are successfully treated with SCS. Strict neurosurgical technique eliminates infection risk. Hardware selection minimizes incidence of malfunction. ______________________________________________________________________________ Dual channel electrostimulation in pain.

Devulder J, De Laat M, Rolly G. Acta Neurol Belg. 1998 Jun;98(2):195-8. Department of Anesthesia, University Hospital Ghent, Belgium.

Spinal cord stimulation is an accepted treatment for neuropathic pain. Technical advances in electrode design and better patient selection have led to better and sustained pain control by these devices. Multilead electrical stimulation is the latest innovation in implantable electrostimulation (Mattrix, Medtronic Minneapolis, USA). Two combined multipolar leads connected to a radiofrequency--coupled system can deliver electrical pulses of various amplitudes and pulse widths at different dermatome levels. Single stimulation is applied with different electrode configurations using both electrodes with identical stimulation parameters. In dual stimulation, the amplitude and the pulse width can vary between the electrode configurations. Dual channel stimulation helps steering stimulation paresthesias. Three patients illustrate the technical advantages of dual channel electrostimulation in the pain relief at multiple sites. Two patients with failed back surgery syndrome obtained more easily stimulation-induced paresthesias in the back and the legs. Dual channel stimulation is cost saving in patients implanted with two electrodes. This is presented in a third patient with an electrode in the thalamus--as pain treatment for cervicobrachialgia and a second in the epidural space--as treatment for the failed back surgery syndrome. These electrodes were connected to the Mattrix stimulator. ______________________________________________________________________________ Pain management from the viewpoint of the anesthetist. [Article in

German]

Ingold O. Praxis (Bern 1994). 1998 Feb 11;87(7):232-7. Schulthess-Klinik, Zürich.

In a pain clinic team the anesthetist has the knowledge and experience concerning the peripheral and central neural blockades. The value of the diagnostic, prognostic and therapeutic blockades is today under discussion. Patients with a chronic regional pain syndrome (CRPS) can find some relief with a series of somatic and sympatholytic blockades, which allow an aggressive physiotherapy. Epidural steroid injections are helpful in radiculopathic pain. In other types of pain (neuropathic, postherpetic, failed back surgery syndrome, abdominal, cervico-cephalgic, phantom limb pain und tumor pain) the spinal cord stimulation (SCS) and the intrathecal morphine pump are approved methods for intactable pain. ______________________________________________________________________________ Psychological variables associated with outcome of spinal cord

stimulation trials.

Olson KA, Bedder MD, Anderson VC, Burchiel KJ, Villanueva MR. Neuromodulation. 1998 Jan;1(1):6-13. doi: 10.1111/j.1525-1403.1998.tb00025.x. Pain Management Center, Department of Anesthesiology, Oregon Health Sciences, University, Portland, Oregon 97201-3098 (USA)Advanced Pain Management, Group, St. Vincent Hospital and Medical Center, Portland, Oregon, 97225 (USA)Division of Neurosurgery, Department of Surgery, Oregon Health Sciences, University, Portland, Oregon, 97201-3098 (USA).

Study Design. This is a prospective study designed to identify psychological factors associated with response to spinal cord stimulation (SCS) trial. Summary of Background Data. In most centers, implantation of a permanent SCS system is preceded by a trial of a temporary stimulating electrode. Yet, even among those who report greater than 50% pain reduction during trial, a significant number of these patients fail to receive long-term pain relief from the permanent system. Because mood disorders can alter pain report, we hypothesized that refined definition of the psychological factors associated with SCS success could result in improved selection of

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candidates for SCS trial. Methods. The study sample consisted of 43 chronic pain patients (72% failed back surgery syndrome, 77% with radiating low back pain) who were referred for implantable pain management. Following psychological evaluation, patients were admitted for a three-day inpatient trial of SCS. Report of at least 50% pain relief during trial was considered a success and resulted in implantation of the permanent stimulator. Patients were retrospectively divided into two groups: those whose pretrial pain was relieved by at least 50% ("success") and those whose pain was relieved by less than 50% ("failure"). Results. Univariate t-test or chi-square analyzes of group means of an extensive psychological battery followed by a global, stepwise logistic regression model of trial outcome was used to analyze between group results of a psychological test battery. MMPI depression and mania subscores were found to be significantly elevated among the two outcome groups (p = 0.007 and 0.025, respectively). Conclusions. Patient mood state is an important predictor of trial outcome. Specific indicators of SCS trial outcome are the MMPI depression and mania subscale scores with successful trials being associated with individuals who are less depressed and have higher energy levels. ______________________________________________________________________________ Spinal cord stimulation: a valuable treatment for chronic failed

back surgery patients.

Devulder J, De Laat M, Van Bastelaere M, Rolly G. J Pain Symptom Manage. 1997 May;13(5):296-301. Department of Anesthesia-Section Pain Clinic, University Hospital of Gent, Belgium.

Spinal cord stimulation (SCS) has been used in the treatment of "chronic failed back surgery syndrome" for many years. To evaluate long-term results and cost effectiveness of SCS, we interviewed 69 patients treated during a period of 13 years. Twenty-six patients stopped using SCS; there was no clear explanation for this unsatisfactory result in 10. Forty-three patients continued with the therapy and obtained good pain relief. Electrode breakage either spontaneous or due to a procedure to obtain better stimulation paresthesias was more frequent in the radiofrequency-coupled system group than in the battery group (mean +/- SEM 2.81 +/- 2.0 versus 1.42 +/- 1.51, respectively; P = 0.0018). Ten patients obtained better pain relief than during the trial procedure. Some still need opioid analgesics, but 11 of the 16 who require these drugs obtained a synergistic effect when concomitantly using the stimulator. Eleven patients have returned to work. In our center, the application of SCS costs on average $3660 per patient per year. Although this seems expensive, it may be a cost-effective treatment if other therapies fail. ______________________________________________________________________________ Cost-effectiveness analysis of spinal cord stimulation in

treatment of failed back surgery syndrome.

Bell GK, Kidd D, North RB. J Pain Symptom Manage. 1997 May;13(5):286-95. Charles River Associates Incorporated, Boston, MA, USA.

This article presents an analysis of the medical costs of spinal cord stimulation (SCS) therapy in the treatment of patients with failed back surgery syndrome (FBSS). We compared the medical costs of SCS therapy with an alternative regimen of surgeries and other interventions. Externally powered (external) and fully internalized (internal) SCS systems were considered separately. Clinical management models of each of the therapy alternatives were derived from the clinical literature, retrospective data sets, expert opinion, and published diagnostic and therapy protocols. No value was placed on pain relief or improvements in the quality of life that successful SCS therapy can generate. We found that by reducing the demand for medical care by FBSS patients, SCS therapy can lower medical costs. On average, given current screening and efficacy rates, SCS therapy pays for itself within 5.5 years. For those patients for whom SCS therapy is clinically efficacious, the therapy pays for itself within 2.1 years. ______________________________________________________________________________ Stimulation of the central and peripheral nervous system for the

control of pain.

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Stanton-Hicks M, Salamon J. J Clin Neurophysiol. 1997 Jan;14(1):46-62. Anaesthesia Pain Management Center, Cleveland Clinic Foundation, OH 44195, USA.

After suffering some setbacks since its introduction in 1967, stimulation of the spinal and peripheral nervous systems has undergone rapid development in the last ten years. Based on principles enunciated in the Gate Control Hypothesis that was published in 1968, stimulation-produced analgesia [SPA] has been subjected to intensive laboratory and clinical investigation. Historically, most new clinical ideas in medicine have tended to follow a three-tiered course. Initial enthusiasm gives way to a reappraisal of the treatment or modality as side-effects or unanticipated problems arise. The last and third phase proceeds at a more measured pace as the treatment is refined by experience. This review is divided into three parts as it traces the progress of spinal cord stimulation [SCS] and peripheral nerve stimulation [PNS]. The review commences with a discussion of the theory of SCS and PNS, and is followed by early reports during which it became apparent that the modality is essentially only effective in the treatment of neuropathic pain. The last section describes the modern experience including efficacy in specific types of pain and concludes with recent accomplishments that dramatize the relief of pain which can be achieved in nonoperable peripheral vascular disease or myocardial ischemia. Over the years, a search for those transmitters that might be influenced by spinal cord stimulation focused on somatostatin, cholecystokinin (CCK), vasoactive intestinal polypeptide (VIP), neurotensin and other amines, although only substance "P" was implicated. More recently, in animal studies, evidence that GABA-ergic systems are affected may explain the frequent successful suppression of allodynia that follows spinal cord stimulation. During the past eight years, much attention has been directed to studies that use a chronic neuropathic pain model. While PNS held significant promise as a pain relieving modality, early electrode systems and their surgical implantation yielded variable results due to evolving technical and surgical skills. These results dramatically reduced the continued development of PNS, which then gave way to a preoccupation with SCS. Modern development of SCS with outcome studies, particularly in relation to failed back surgery syndrome [FBSS] and the outcome of peripheral nerve surgery for chronic regional pain syndromes, has earned both modalities a place in the ongoing management of patients with intractable neuropathic pain. The last section, dealing with pain of peripheral vascular and myocardial ischemia, is perhaps one of the more exciting developments in stimulation produced analgesia and as the papers discussed demonstrate, can provide a level of analgesia and efficacy that is unattainable by other treatment modalities. SCS and PNS has an important role to play in the management of conditions that are otherwise refractory to conservative or other conventional management. ______________________________________________________________________________ Epidural spinal cord stimulation does not improve microvascular

blood flow in neuropathic pain.

Devulder J, Duprez D, De Laat M, Rolly G. Angiology. 1996 Dec;47(12):1145-9. Department of Anesthesia, University Hospital of Gent, Belgium.

For many years, spinal cord stimulation (SCS) has been used successfully in various pain syndromes. SCS is also used to treat vascularly-impaired patients since it apparently improves the microcirculation. The exact physiological mechanisms involved are still unclear. There are even some anecdotal reports of a cooling of the legs during SCS. This study investigated the vascular effects of SCS in 15 patients with failed back surgery syndrome, using infrared thermography of the affected foot and capillaroscopy in the nailfold of the big toe. There were no statistically significant differences (Student's t test) in temperature (P = 0.923) or red blood cell velocity (P = 0.819 first day and P = 0.218 second day) in the affected foot with or without stimulation. A physiological difference in relation to neuropathic pain might explain the lack of improvement in skin microcirculation with SCS. ______________________________________________________________________________ Prospective, multicenter study of spinal cord stimulation for

relief of chronic back and extremity pain.

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Burchiel KJ, Anderson VC, Brown FD, Fessler RG, Friedman WA, Pelofsky S, Weiner RL, Oakley J, Shatin D. Spine (Phila Pa 1976). 1996 Dec 1;21(23):2786-94. Division of Neurosurgery, Oregon Health Sciences University, Portland.

STUDY DESIGN: This prospective, multicenter study was designed to investigate the efficacy and outcome of spinal cord stimulation using a variety of clinical and psychosocial outcome measures. Data were collected before implantation and at regular intervals after implantation. This report focuses on 70 patients who had undergone 1 year of follow-up treatment at the time of data analysis. OBJECTIVES: To provide a more generalizable assessment of long-term spinal cord stimulation outcome by comparing a variety of pain and functional/quality-of-life measures before and after management. This report details results after 1 year of stimulation. SUMMARY OF BACKGROUND DATA: The historically diverse methods, patient selection criteria, and outcome measures reported in the spinal cord stimulation literature have made interpretation and comparison of results difficult. Although short-term outcomes are generally consistent, long-term outcomes of spinal cord stimulation, as determined by prospective studies that assess multidimensional aspects of the pain complaint among a relatively homogeneous population, are not well established. METHODS: Two hundred nineteen patients were entered at six centers throughout the United States. All patients underwent a trial of stimulation before implant of the permanent system. Most were psychologically screened. One hundred eighty-two patients were implanted with a permanent stimulating system. At the time of this report, complete 1-year follow-up data were available on 70 patients, 88% of whom reported pain in the back or lower extremities. Patient evaluation of pain and functional levels was completed before implantation and 3, 6, 12, and 24 months after implantation. Complications, medication usage, and work status also were monitored. RESULTS: All pain and quality-of-life measures showed statistically significant improvement during the treatment year. These included the average pain visual analogue scale, the McGill Pain Questionnaire, the Oswestry Disability Questionnaire, the Sickness Impact Profile, and the Back Depression Inventory. Overall success of the therapy was defined as at least 50% pain relief and patient assessment of the procedure as fully or partially beneficial and worthwhile. Using this definition, spinal cord stimulation successfully managed pain in 55% of patients on whom 1-year follow-up is available. Complications requiring surgical intervention were reported by 17% (12 of 70) of patients. Medication usage and work status were not changed significantly. CONCLUSIONS: This prospective, multicenter study confirms that spinal cord stimulation can be an effective therapy for management of chronic low back and extremity pain. Significant improvements in many aspects of the pain condition were measured, and complications were minimal. ______________________________________________________________________________ Infra-red thermographic evaluation of spinal cord

electrostimulation in patients with chronic pain after failed back

surgery.

Devulder J, Dumoulin K, De Laat M, Rolly G. Br J Neurosurg. 1996 Aug;10(4):379-83. Department of Anaesthesia, University Hospital, Gent, Belgium.

This study sought to visualize spinal-cord stimulation activity by infra-red thermography in humans suffering from chronic lumbosciatic pain. All the patients had previously undergone neurosurgery for a herniated intervertebral disc. Temperature changes were evaluated in two defined body areas after starting, stopping, maintaining or not starting the stimulation. In one body area, corresponding to the pain location, the patient experienced stimulation paraesthesia, whereas in the non-painful (second) area no stimulation paraesthesia were present. The patients were studied on four consecutive days with a randomly chosen stimulation pattern. Temperature changes in identical and comparable skin areas were measured and statistically analysed. No statistically significant temperature variation was found between the painful and non-painful areas. These findings do not confirm the idea that spinal cord stimulation induces vasodilation in the affected pain area when stimulation is present. Infra-red thermography is not able to differentiate the stimulated from the non-stimulated areas. ______________________________________________________________________________

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Prognostic value of psychological testing in patients undergoing

spinal cord stimulation: a prospective study.

North RB, Kidd DH, Wimberly RL, Edwin D. Neurosurgery. 1996 Aug;39(2):301-10; discussion 310-1. Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

Comment in Neurosurgery. 1997 Jun;40(6):1341. OBJECTIVE: Associations between psychological and physical states are understood to exist, and the development of standardized psychological tests has allowed quantitative evaluation of this relationship. We tested whether associations exist between psychological test instruments and patients selected for therapeutic trials of spinal cord stimulation (SCS) for chronic, intractable pain. METHODS: Fifty-eight patients selected for SCS were tested prospectively with a battery of standardized psychological tests: Minnesota Multiphasic Personality Inventory with Wiggins content scales, Symptom Check List-90, and Derogatis Affects Balance Scale. Associations between treatment outcomes and preoperative test scores and clinical variables were tested by univariate and multivariate statistical analyses, in which the dependent variables were as follows: 1) the outcome of a therapeutic trial of stimulation (whether the patient derived sufficient reported pain relief with a temporary electrode to proceed with a permanent implant), and 2) long-term outcome of treatment with the permanent implant, as determined by disinterested third-party interview. RESULTS: Significant associations (P < or = 0.01) were observed between the outcome of the therapeutic trial of stimulation and psychological test results; patients with low "anxiety" scores on the Derogatis Affects Balance Scale and with high "organic symptoms" scores on the Wiggins test were significantly more likely to proceed to permanent implants, as determined by multivariate statistical models. There was an elevation in the Minnesota Multiphasic Personality Inventory hypochondriasis scale in these patients by univariate (P = 0.02), but not by multivariate, models. The multivariate model also identified young age, reproduction of leg pain by straight leg raising, and bilateral leg pain as favorable prognostic factors. The only association with favorable long-term outcome of implantation of a permanent device, by univariate analysis, was an elevated "joy" score on the Derogatis Affects Balance Scale. Multivariate analysis revealed no statistically significant predictors of long-term outcome. CONCLUSION: Because our study population was selected on the basis of recognized prognostic factors and long clinical experience, it may not be possible to generalize our findings to the overall pain clinic referral population. In the subpopulation we have chosen for SCS trials, psychological testing is of modest value and explains little of the observed variance in outcome. We find little evidence for selecting patients for SCS on the basis of psychological testing. Because self-reported outcome measures may themselves reflect the patient's psychological state, these findings should be considered carefully, in overall clinical context. A prospective study with additional objective outcome measures is underway, which will address some of these issues. ______________________________________________________________________________ Short test-period spinal cord stimulation for failed back surgery

syndrome.

Rainov NG, Heidecke V, Burkert W. Minim Invasive Neurosurg. 1996 Jun;39(2):41-4. Department of Neurosurgery, Faculty of Medicine, Martin-Luther-University Halle-Wittenberg, Germany.

The aim of this study was to investigate the effects of spinal cord stimulation (SCS) on patients with chronic pain due to failed back surgery syndrome and to evaluate selection criteria for predicting SCS success. Thirty-two patients were enrolled in the present study. Prior to test implantation, all of them have been screened with various plan questionnaires and were selected for the SCS procedure according to stringent criteria. The single-electrode neurostimulators Itrel II and Xtrel were used with percutaneously inserted leads. The leads were placed under X-ray image intensifier control, and position was modified until optimum paresthetic coverage of pain areas was achieved. Twenty-nine of the 32 test stimulation patients reported on a pain reduction of at least 50% and up to 90% of preimplantation values. After a test period of 24 to 72 hours, internalization

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of the whole SCS system followed. In 3 cases the lead was explanted after 3 days of test stimulation because of insufficient analgesic effect. No major complications were seen in this highly preselected group. Follow-ups of 2 to 3.5 years after lead implantation proved stable analgesia and good outcome in 25 patients. Further 4 patients experienced a late failure of the system due to decreased analgesic effects of SCS. In conclusion, if the selection of SCS candidate patients is performed very carefully and according to well defined criteria, test stimulation periods can be kept relatively short, thus reducing therapeutic failures, risk of infection, and costs of therapy. ______________________________________________________________________________ Prospective outcome evaluation of spinal cord stimulation in

patients with intractable leg pain.

Ohnmeiss DD, Rashbaum RF, Bogdanffy GM. Spine (Phila Pa 1976). 1996 Jun 1;21(11):1344-50; discussion 1351. Institute for Spine and Biomedical Research, Plano, Texas, USA.

STUDY DESIGN: The results of spinal cord stimulation were prospectively evaluated using both subjective patient self-report measures and objective physical functional testing. OBJECTIVES: The purpose of this study was to evaluate prospectively the effects of spinal cord stimulation implantation, performed with the patient awake and providing feedback, in patients with primary reports of intractable leg pain. SUMMARY OF BACKGROUND DATA: Spinal cord stimulation has been used for treating chronic pain of many types. However, even among those with intractable lower extremity pain, the outcome results have shown great variability. METHODS: The surgical procedure was performed with the patient awake and providing feedback to ensure optimal pain relief from the lead placement. The study group comprised 40 patients, ranging in age from 28 to 86 years. The average symptom duration was 65.4 months, and the average number of prior lumbar spine surgeries was 2.3 (range, 1 to 8). The primary data collection periods were preoperative, 6 weeks after, and 12 and 24 months after surgery. RESULTS: Statistically significant improvement in isometric lower extremity function was demonstrated 6 weeks after the spinal cord stimulation implantation. In the more painful leg, the performance increased from 457.5 ft-lb-sec to 629.8 ft-lb-sec (P < 0.01). The performance remained significantly improved at the 12- and 24-month follow-ups. Significant improvement was demonstrated on the physical scale of the Sickness Impact Profile at 6 weeks. At 24 months, all three scales (physical, psychological, and other) as well as the total score were significantly improved. Statistically significant decreases in pain, assessed by changes in visual analog scale scores, were noted in the legs, when walking, and in overall lifestyle. The use of narcotic medication decreased at all follow-up periods. At least 66% of the patients who were taking narcotics before spinal cord stimulation were taking reduced amounts or no narcotics 2 years later. At the time of the 24-month follow-up, at least 70% of patients reported that the procedure helped them, and would recommend it to someone with similar symptoms. CONCLUSIONS: Spinal cord stimulation implantation can result in improved physical function and decreased pain in patients who are carefully screened and in whom the implantation is performed with the patient awake to help ensure optimal pain-relieving lead placement. ______________________________________________________________________________ A psychoanalytic investigation to improve the success rate of

spinal cord stimulation as a treatment for chronic failed back

surgery syndrome.

Dumoulin K, Devulder J, Castille F, De Laat M, Van Bastelaere M, Rolly G. Clin J Pain. 1996 Mar;12(1):43-9. Department of Anesthesia, University Hospital of Gent, Belgium.

OBJECTIVE: The analysis of patient data concerning psychological structure and functioning produced an instrument to determine whether a neurostimulator ought to be implanted or not. DESIGN: A questionnaire containing 24 items was developed by a psychologist and tested in 40 chronic failed back surgery patients for whom a spinal cord stimulation seemed to be the only therapeutic approach. This questionnaire was based upon some crucial psychological themes, on

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which the patient took a position. A predictive indication factor (I.F.; %) for implantation of the neurostimulator was obtained from the 24 items. Six months after the implantation of the neurostimulator, we correlated the evaluation factor (E.F.; %) with a six-point evaluation scale considering the pain reduction. The aim was to compare the I.F. and E.F. to verify the correlation between them. This comparison was intended to answer the question if psychological variables included in our scale improve the success rate of the therapy. SETTING: Data were collected by a psychologist at the Pain Clinic of the University Hospital of Gent, Belgium. RESULTS AND CONCLUSIONS: The correlation between the I.F. and the E.F. was calculated for the 40 patients by the Spearman correlation test. A coefficient value of 0.8083 (p = 0.000) was found, indicating the existence of a very close correlation between the predictive I.F. and the E.F. The indication scale appears to be a useful instrument for clinical psychologists to predict the success rate of a spinal cord stimulator in this group of patients. ______________________________________________________________________________ Spinal cord stimulation for chronic low back pain: a systematic

literature synthesis.

Turner JA, Loeser JD, Bell KG. Neurosurgery. 1995 Dec;37(6):1088-95; discussion 1095-6. Department of Psychiatry, School of Medicine, University of Washington, Seattle, USA.

A systematic literature synthesis was performed to analyze the long-term risks and benefits of spinal cord stimulation for patients with failed back surgery syndrome. Relevant articles were identified through a MEDLINE search (January 1966-June 1994), bibliography reviews, searches of personal files, and literature supplied by a stimulator manufacturer. Two investigators independently reviewed each article to determine whether it met the following study inclusion criteria: 1) original data on return to work, pain, medication use, reoperations, functional disability, or stimulator use after permanent implantation of spinal cord stimulators in patients with chronic low back or leg pain despite previous back surgery; and 2) follow-up > or = 30 days for all patients. Articles were excluded if data from patients with other diagnoses were mixed with (and could not be separated from) data from patients with chronic low back or leg pain, or if their data were redundant with those reported in an included article. Articles written in languages other than English or French were excluded. Thirty-nine studies, all case studies, were analyzed. At follow-up (mean, 16 mo; range, 1-45 mo), an average of 59% of patients had > or = 50% pain relief (range, 15-100% of patients). Complications occurred in 42% of patients but were generally minor. It seems that approximately 50 to 60% of patients with failed back surgery syndrome report > 50% pain relief with the use of spinal cord stimulation at follow-up; the lack of randomized trials precludes conclusions concerning the effectiveness of spinal cord stimulation relative to other treatments, placebo, or no treatment. ______________________________________________________________________________ Prognostic factors of spinal cord stimulation for chronic back and

leg pain.

Burchiel KJ, Anderson VC, Wilson BJ, Denison DB, Olson KA, Shatin D. Neurosurgery. 1995 Jun;36(6):1101-10; discussion 1110-1. Division of Neurosurgery, Oregon Health Sciences University, Portland, USA.

Spinal cord stimulation (SCS) has been used for more than 20 years in the treatment of diverse pain conditions. Although recent studies have identified more clearly those conditions for which SCS offers a favorable prognosis, the identification of a patient population in whom reasonably long-term success can be expected has been difficult. In an effort to improve patient selection and increase the overall success rate of treatment, we have examined various physical, demographic, and psychosocial variables as predictors of SCS outcome. The study population consisted of 40 patients with chronic low back and/or leg pain, 85% of whom were diagnosed with failed back surgery syndrome. Medical history and demographic data were collected as part of an initial assessment along with patient responses to the Minnesota Multiphasic Personality Inventory, the visual analogue pain rating scale (VAS), the McGill Pain Questionnaire, the Oswestry Disability

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Questionnaire, the Beck Depression Inventory, and the Sickness Impact Profile. Treatment outcomes were examined and found to improve significantly after 3 months of stimulation. Subsequent regression analysis revealed that patient age, the Minnesota Multiphasic Personality Inventory depression subscale D, and the evaluative subscale of the McGill Pain Questionnaire (MPQe) were important predictors of posttreatment pain status. Increased patient age and D subscale scores correlated negatively with pain status, as measured by the percentage of changes in pretreatment and posttreatment VAS scores, % delta VAS. In contrast, higher MPQe correlated with improved pain status. By the use of the following equation and the definition commonly associated with SCS success (at least 50% decrease in the VAS pain level), the success or failure of 3 months of SCS was correctly predicted in 88% of the study population. Our results suggest that patient age, Minnesota Multiphasic Personality Inventory depression, and MPQe may be clinically useful in the prediction of pain status after 3 months of SCS in patients with chronic low back and/or leg pain. % delta VAS = 112.57 - 1.98 (D)-1.68 (Age) + 35.54 (MPQe). ______________________________________________________________________________ Significance of the spinal cord position in spinal cord

stimulation.

Holsheimer J, Barolat G, Struijk JJ, He J. Acta Neurochir Suppl. 1995;64:119-24. Institute for Biomedical Technology, University of Twente, Enschede, The Netherlands.

The effects of the antero-posterior and medio-lateral positions of the spinal cord in the dural sac on the perception threshold and paresthesia coverage in spinal cord stimulation were analyzed. The distributions of the dorsal cerebrospinal fluid (CSF) layer thickness, measured from transverse MR scans of normal subjects at various spinal levels, were used to calculate the distributions of threshold voltages for the stimulation of spinal nerve fibers by a computer model. These theoretical threshold distributions were shown to fit well to the corresponding distributions of perception threshold measured in patients. It is concluded that the thickness of the dorsal csf layer is the main factor determining the perception threshold and paresthesia coverage in spinal cord stimulation: an increasing thickness raises the threshold and reduces the coverage, and vice versa. The effects of an asymmetrical electrode position with respect to the spinal cord midline were also analyzed by computer modeling. It is concluded that a lateral asymmetry of less than 1 mm gives a significant reduction of perception threshold and may result in unilateral paresthesiae. ______________________________________________________________________________ Treatment of the failed back surgery syndrome due to lumbo-sacral

epidural fibrosis.

Fiume D, Sherkat S, Callovini GM, Parziale G, Gazzeri G. Acta Neurochir Suppl. 1995;64:116-8. Divisione di Neurochirurgia, Ospedale S. Filippo, Rome, Italy.

The failed back surgery syndrome (FBSS) is a severe, long-lasting, disabling and relatively frequent (5-10%) complication of lumbosacral spine surgery. Wrong level of surgery, inadequate surgical techniques, vertebral instability, recurrent disc herniation, and lumbo-sacral fibrosis are the most frequent causes of FBSS. The results after repeated surgery on recurrent disc herniations are comparable to those after the first intervention, whereas repeated surgery for fibrosis gives only 30-35% success rate, and 15-20% of the patients report worsening of the symptoms. Computerized tomography (CT) with contrast medium and, in particular, Gd-DPTA enhanced MRI have recently allowed a differentiation between these two pathologies permitting us to adopt different therapies. In 1982-92 we applied spinal cord stimulation (SCS) as a first therapy of FBSS with proven lumbo-sacral fibrosis. Fifty-five patients underwent percutaneous trial SCS with a mono/multipolar electrode placed at the level of Th9-12. In the 36 patients who had a positive response to the trial stimulation, the electrode was connected to an implantable neurostimulator. On January '94 a third party, not involved in the treatment of the patients, controlled 34 of the 36 patients with a mean follow-up of 55 months. We classified the patients reporting at least 50% pain relief and satisfaction with result as successful, and 56% of the patients fell in that category. 10 out of 34 patients were able to resume their work. The success rate was significantly higher in

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females (73%) than in males, and in radicular rather than axial pain. Our data have led us to consider SCS as a first choice treatment in FBSS due to lumbo-sacral fibrosis. ______________________________________________________________________________ Spinal cord stimulation versus spinal infusion for low back and

leg pain.

Hassenbusch SJ, Stanton-Hicks M, Covington EC. Acta Neurochir Suppl. 1995;64:109-15. Department of Neurosurgery, M.D. Anderson Cancer Center Houston, Texas, USA.

The relative roles of spinal cord stimulation and the spinal infusion of opioids in the treatment of chronic, non-cancer lower body pain remains unclear. This report contains a retrospective analysis of patients with chronic lower body, neuropathic pain and treated over a 5 year period. Unilateral leg and/or buttock pain was treated initially with spinal stimulation and bilateral leg or mainly low back pain was treated initially with spinal infusions. 26 patients received spinal stimulation. Pain relief was > or = 50% in 16 (62%) with increased activity levels. Stimulator coverage was most difficult or failed in patients with buttock pain. 16 patients received long-term spinal infusions. Pain relief was > or = 50% in 2 (13%) but 25-49% in another 8 (50%) with stable infusion doses and was best in patients requiring low-dose (< 1 mg/h morphine intrathecal) infusions in the trial period. The review indicates that spinal infusions may be best for bilateral or axial pain that has not responded to spinal stimulation. Clonidine appears to be an alternative in high-dose morphine patients. New diamond-shaped electrode and dual quadripolar arrays appear to be very helpful for back, buttock, and/or bilateral leg pain patterns. ______________________________________________________________________________ Spinal cord stimulation versus reoperation for failed back surgery

syndrome: a prospective, randomized study design.

North RB, Kidd DH, Piantadosi S. Acta Neurochir Suppl. 1995;64:106-8. Department of Neurosurgery and Biostatistics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Retrospectively reported results of spinal cord stimulation compare favorably with those of neurosurgical treatment alternatives for the treatment of failed back surgery syndrome, including reoperation and ablative procedures. There has been no direct prospective comparison, however, between SCS and other techniques for pain management. Therefore, we have designed a prospective, randomized comparison of spinal cord stimulation and reoperation in patients with persistent radicular pain, with and without low back pain, after lumbosacral spine surgery. Patients selected for reoperation by standard criteria are randomly assigned to initial treatment by one or the other technique. The primary outcome measure is the frequency of crossover to the alternative procedure, if the results of the first have been unsatisfactory after 6 months. Results for the first 27 patients reaching the 6-month crossover point show a statistically significant (p = 0.018) advantage for spinal cord stimulation over reoperation. Many other potentially important outcome measures will now be followed long-term as a larger overall study population accumulates. ______________________________________________________________________________ Treatment of chronic lumbago and radicular pain by spinal cord

stimulation. Long-term results. [Article in French]

Hieu PD, Person H, Houidi K, Rodriguez V, Vallee B, Besson G. Rev Rhum Ed Fr. 1994 Apr;61(4):271-7. Service de Neuro-Chirurgie, Centre Hospitalier Régional et Universitaire A. Morvan, Brest.

Seventy-seven patients with chronic, refractory, low back and radicular pain underwent implantation of a spinal cord stimulator between 1984 and 1992. Most patients had failed back surgery syndrome. In every case, an epidural quadripolar "Resume" electrode was implanted surgically. Results were evaluated after three months then after six to 98 months (mean follow-up 42 months). Long-term efficacy was good in 63.6% of cases, fair in 22%, and poor in 6.5%; treatment failure occurred in 7.9% of cases. Adverse events included one case of meningitis, two

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cases of local infection, and one case each of cerebrospinal fluid fistula and necrosis of the skin overlying the stimulator. The main causes of treatment failure were complications, inappropriate patient selection, and the escape phenomenon. The results of this study demonstrate that spinal cord stimulation is effective for the treatment of chronic low back and radicular pain in carefully selected patients; scrupulous application of restrictive selection criteria is essential to the success of the method. ______________________________________________________________________________ Long-term pain relief during spinal cord stimulation. The effect

of patient selection.

Van de Kelft E, De La Porte C. Qual Life Res. 1994 Feb;3(1):21-7. Department of Neurosurgery, Universitair Ziekenhuis Antwerpen, Edegem, Belgium.

We reviewed our experience with spinal cord stimulation (SCS) in treating 116 patients with pain in one or both legs. All these patients were selected for an initial week of trial stimulation by the criteria: pain due to a known benign organic cause, failure of conventional pain control methods and absence of major personality disorders. Selected patients included 78 with the Failed Back Surgery Syndrome (FBSS), in whom proven correlation existed between the clinical picture and the neuroradiological and electromyogram abnormalities. Eighty-four out of 116 selected patients underwent definitive SCS implantation after 1 week of trial stimulation with excellent results (more than 75% pain relief). They were followed clinically every 3 months for a mean follow-up period of 47 months. Forty-five patients (54%) continued to experience at least 50% of pain relief at the latest follow up. Seventy-seven patients (91%) were able to reduce their medication intake and 50 patients (60%) reported an improvement in lifestyle. FBSS patients responded more positively to the trial stimulation than the other patients. However, the later outcome was not affected by patient selection as long-term benefit was similar in all definitive SCS patients irrespective of aetiology. ______________________________________________________________________________ Italian multicentric study on pain treatment with epidural spinal

cord stimulation.

Broggi G, Servello D, Dones I, Carbone G. Stereotact Funct Neurosurg. 1994;62(1-4):273-8. Istituto Nazionale Neurologico C. Besta, Milano, Italia.

A multicentric study on the treatment of nonmalignant chronic pain with epidural spinal cord stimulation (SCS) has been carried out in 32 Italian centers devoted to pain therapy. Neurosurgical and anesthesiology units participated in this retrospective study. 410 of the eligible patients were enrolled in the protocol: 48% were male, 52% female. All patients underwent a screening test period (average 21 days) and 74% underwent the definitive implant. The diagnosis was failed back surgery syndrome in 45%, reflex sympathetic dystrophy in 15%, phantom limb pain in 14%, postherpetic neuralgia in 8%, peripheral nerve injury in 5%, others 13%. 84% received noninvasive unsuccessful treatment (10 tensor acupuncture). All had previous pharmacological therapy which was not always discontinued when SCS took place. Pain assessment had been done with the visual analog scale and verbal scale both subjectively and by the physician and nurses. Neuropsychological profile with minimal mental test or MMPI was obtained in 68% of the patients. These results were favorable (i.e. excellent or good; more than 50% reduction of pain) in 87% of the patients at the 3-month follow-up, 75% at the 6-month follow-up, 69% at the 1-year follow-up, and 58% at the 2-year follow-up. Complication rate was: dislocation of the electrocatheter 4%, technical problems 3%, infections of the system 2%. The results will be discussed in correlation with the different etiologies of the nonmalignant chronic pain syndrome. ______________________________________________________________________________ A prospective, randomized study of spinal cord stimulation versus

reoperation for failed back surgery syndrome: initial results.

North RB, Kidd DH, Lee MS, Piantodosi S. Stereotact Funct Neurosurg. 1994;62(1-4):267-72.

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Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Md., USA.

Spinal cord stimulation (SCS) has been reported to be effective treatment for the failed back surgery syndrome in a number of retrospective case series. Its retrospectively reported results compare favorably with those of neurosurgical treatment alternatives, such as reoperation and ablative procedures. There has been no direct prospective comparison, however, between SCS and other techniques for pain management. We have undertaken a prospective, randomized comparison of SCS and reoperation in patients with persistent radicular pain, with and without low back pain, following lumboscral spine surgery. Patients selected for reoperation by standard criteria have been randomly assigned to initial treatment by one or the other technique. The primary outcome measure is the frequency of crossover to the alternative procedure, if the results of the first have been unsatisfactory after 6 months. Results for the first 27 patients reaching the 6-month crossover point show a statistically significant (p = 0.018) advantage for SCS over reoperation. This is one of many potentially important outcome measures, which are to be followed long-term as a larger overall study population accrues. ______________________________________________________________________________ Spinal cord stimulation in low back and leg pain.

Meglio M, Cioni B, Visocchi M, Tancredi A, Pentimalli L. Stereotact Funct Neurosurg. 1994;62(1-4):263-6. Istituto di Neurochirurgia, Università Cattolica, Roma, Italia.

We have reviewed our experience with spinal cord stimulation (SCS) in patients with low back and leg pain. 33 patients complaining of leg and low back pain underwent percutaneous tests of SCS. 28 patients had failed back surgery syndromes, 1 patient had pain related to an L1 vertebral body fracture, another from Tarlow cysts and the remaining 3 patients had lumbosacral spondyloarthrosis and osteoporosis without radiological signs of root compression. 28 patients showed mono- or pluriradicular deficits. At the end of the test period (5-65 days), 21 patients (63.6%) reported more than 50% of pain relief (mean analgesia 75%) and were submitted to chronic stimulation. The mean follow-up was 45.5 months. At maximum available follow-up, 40% of the patients (13 out of the 33 initial patients) were successfully using the stimulator (mean analgesia 66.6%). ______________________________________________________________________________ Spinal cord stimulation for the failed back syndrome.

LeDoux MS, Langford KH. Spine (Phila Pa 1976). 1993 Feb;18(2):191-4. Division of Neurosurgery, University of Alabama, School of Medicine, Birmingham.

Thirty-two patients with failed back syndrome received a trial of spinal cord stimulation. Stimulators were internalized in 26; long-term follow-up was available for 23 of these patients. Seventy-six percent of the 22 patients with stimulators still present at 1 year and 74% of the 19 patients with stimulators still present at 2 years were receiving 50% or better pain relief. Patients routinely underwent pain team evaluation and therapy, psychological testing and a transcutaneous electrical nerve stimulator trial prior to consideration of spinal cord stimulation. The most common complication was electrode migration. Spinal cord stimulation should be considered as an important therapeutic modality in carefully selected patients with failed back syndrome. ______________________________________________________________________________ Spinal cord stimulation in failed back surgery syndrome.

De La Porte C, Van de Kelft E. Pain. 1993 Jan;52(1):55-61. Department of Neurosurgery, Universitair Ziekenhuis Antwerpen, Edegem, Belgium.

We have reviewed our experience with spinal cord stimulation in treating patients with the failed back surgery syndrome and have assessed patient and patient-selection characteristics as predictors of the long-term outcome. Neuroradiological investigations eliminated the possibility of a

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surgically treatable lesion and electromyogram assessed the chronic radicular suffering in correlation with the complaints and the clinical examination of the patient. Excellent pain relief (75% or more) during 1 week of trial stimulation and no major psychiatric or psychological pathology were criteria of selection. Seventy-eight patients underwent trial stimulation. Fourteen (18%) failed to obtain excellent pain relief during 1 week of stimulation and their electrodes were removed. The remaining 64 underwent an internalization of the system and they were followed by a clinical observation every 3 months and this for a mean follow-up period of 4 years (range: 1-7 years). Thirty-five patients (55%) continued to experience at least 50% of pain relief at the latest follow-up. Fifty-eight patients (90%) were able to reduce their medication, 39 patients (61%) reported a change in lifestyle, in that their ability to perform daily activities had improved significantly. Fifty-three patients (83%) continued to use their device at the latest follow-up. ______________________________________________________________________________ Clinical and technical results from spinal stimulation for chronic

pain of diverse pathophysiologies.

Law JD. Stereotact Funct Neurosurg. 1992;59(1-4):21-4.

Spinal stimulation has been indicated for pain of peripheral deafferentation, but not for low-back pain. Technical and clinical records of 241 consecutive spinal stimulator recipients were reviewed, including: peripheral deafferentation pain (n = 44); predominant pain of low back, postlaminectomy (n = 96), and predominant pain of leg(s), postlaminectomy (n = 48). The groups were not statistically different with respect to important clinical features. For the postlaminectomy syndromes, only the technical results correlated significantly with outcome. Spinal stimulation actually yielded results as good for the 'failed back surgery syndrome' as for peripheral deafferentation pain, because newer technical methods were proven to stimulate the low back predictably. ______________________________________________________________________________ Spinal neurostimulation for the treatment of chronic pain: changes

in indications and patient selection after 19 years' experience.

[Article in German]

Winkelmüller W. Schmerz. 1991 Dec;5(4):243-6. Klinik und Gemeinschaftspraxis für Neurochirurgie Paracelsus-Klimik, Am Natruper Holz 69, W-4500, Osnabrück, Bundesrepublik Deutschland.

After the initial clinical reports of Shealy 1967 dorsal column stimulation (DCS) was first introduced in Germany by Krainick (Freiburg) and Winkelmüller (Hannover) in 1972. At first, the success rate in unselected patients was unsatisfactory. The results improved with careful patient selection and better technical equipment allowing preliminary testing procedures before definitive implantation. The authors' own results in 335 patients treated by intermittent spinal cord stimulation (SCS) with implanted devices between 1972 and 1989 show that long-term beneficial effects can be obtained in pain of neurogenic origin rather than in nociceptor pain. Guidelines for the use of SCS were proposed by the German Society of Neurosurgery in 1990. The best indications and target group are cases with radicular low-back pain after failed back surgery, stump and phantom pain, pain states following partial lesions of brachial/lumbar plexus and peripheral nerves, sympathetic dystrophy and rest pain in peripheral vascular disease (PVD). Possible indications for SCS are pain after incomplete lesions of spinal cord or cauda equina, postherpetic neuralgia, sclerodermia and PVD. Failures must be expected in pain states related to progressive malignant disease and complete deafferentation after spinal lesions or root avulsion. ______________________________________________________________________________ Treatment of chronic pain by epidural spinal cord stimulation: a

10-year experience.

Kumar K, Nath R, Wyant GM. J Neurosurg. 1991 Sep;75(3):402-7. Division of Neurosurgery, Plains Health Centre, University of Saskatchewan, Regina, Canada.

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Epidural spinal cord stimulation by means of chronically implanted electrodes was carried out on 121 patients with pain of varied benign organic etiology. In 116 patients, the pain was confined to the back and lower extremities and, of these, 56 exhibited the failed-back syndrome. Most patients were referred by a pain management service because of failure of conventional pain treatment modalities. Electrodes were implanted at varying sites, dictated by the location of pain. A total of 140 epidural implants were used: 76 unipolar, 46 Resume electrodes, 12 bipolar, and six quadripolar. Patients were followed for periods ranging from 6 months to 10 years, with a mean follow-up period of 40 months. Forty-eight patients (40%) were able to control their pain by neurostimulation alone. A further 14 patients (12%), in addition to following a regular stimulation program, needed occasional analgesic supplements to achieve 50% or more relief of the prestimulation pain. Pain secondary to arachnoiditis or perineural fibrosis following multiple intervertebral disc operations, when predominantly confined to one lower extremity, seemed to respond favorably to this treatment. Uniformly good results were also obtained in lower-extremity pain secondary to multiple sclerosis. Pain due to advanced peripheral vascular disease of the lower limbs was well controlled, and amputation below the knee was delayed for up to 2 years in some patients. Pain due to cauda equina injury, paraplegic pain, phantom-limb pain, pure midline back pain without radiculopathy, or pain due to primary bone or joint disease seemed to respond less well. Patients who responded to preliminary transcutaneous electrical nerve stimulation generally did well with electrode implants. Notable complications included wound infection, electrode displacement or fracturing, and fibrosis at the stimulating tip of the electrode. Three patients in this series died due to unrelated causes. Epidural spinal cord stimulation has proven to be an effective and safe means of controlling pain on a long-term basis in selected groups of patients. The mechanism of action of stimulation-produced analgesia remains unclear; further studies to elucidate it might allow spinal cord stimulation to be exploited more effectively in disorders that are currently refractory to this treatment modality. ______________________________________________________________________________ Failed back surgery syndrome: 5-year follow-up after spinal cord

stimulator implantation.

North RB, Ewend MG, Lawton MT, Kidd DH, Piantadosi S. Neurosurgery. 1991 May;28(5):692-9. Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.

Spinal cord stimulation, in use for more than 20 years, has evolved into an easily implemented technique, with percutaneous methods for electrode placement. We have reviewed our experience with this technique in treating "failed back surgery syndrome," and have assessed patient and treatment characteristics as predictors of long-term outcome. A series of 50 patients with failed back surgery syndrome (averaging 3.1 previous operations), who underwent spinal cord stimulator implantation, was interviewed by impartial third parties, at mean follow-up intervals of 2.2 years and 5.0 years. Successful outcome (at least 50% sustained relief of pain and patient satisfaction with the result) was recorded in 53% of patients at 2.2 years and in 47% of patients at 5.0 years postoperatively. Ten of 40 patients who were disabled preoperatively returned to work. Improvements in activities of daily living were recorded in most patients for most activities; loss of function was rare. Most patients reduced or eliminated analgesic intake. Statistical analysis (including univariate and multivariate logistic regression) of patient characteristics as prognostic factors showed significant advantages for female patients and for those with programmable multi-contact implanted devices. These results, in patients with postsurgical lumbar arachnoid and epidural fibrosis and without surgically remediable lesions, compare favorably with the results in two separate series of patients with failed back surgery syndrome, in whom 1) surgical lesions were diagnosed and repeated operation performed; and 2) monoradicular pain syndromes were diagnosed and dorsal root ganglionectomies performed at our institution. This suggests the need for further assessment of selection criteria, critical analysis of treatment outcome, and prospective study of spinal cord stimulation and alternative approaches to failed back surgery syndrome. ______________________________________________________________________________ Spinal cord stimulation in 60 cases of intractable pain.

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Simpson BA. J Neurol Neurosurg Psychiatry. 1991 Mar;54(3):196-9. Department of Neurosurgery, London Hospital, Whitechapel, UK.

Sixty patients with spinal cord stimulators implanted for intractable pain lasting up to 50 years were followed for up to nine years. Forty seven per cent derived significant benefit, 23% modest benefit, 20% experienced no effect and 6.7% were made worse. Two were made worse after initial benefit. Complications, indications and factors relevant to the mode of action are discussed. ______________________________________________________________________________ Spinal cord stimulation in chronic pain: evaluation of results,

complications,and technical considerations in sixty-nine patients.

Devulder J, Vermeulen H, De Colvenaer L, Rolly G, Calliauw L, Caemaert J. Clin J Pain. 1991 Mar;7(1):21-8. Department of Anesthesia, University Hospital, Gent, Belgium.

Comment in: Clin J Pain. 1991 Sep;7(3):253-4.

Sixty-nine patients undergoing spinal cord stimulation (SCS) were studied for a period of up to 8 years. Indications, implantation techniques, and stimulation systems are presented in this article. Pain-suppressor effects of SCS are reviewed, assessing the clinical efficacy over time as well as complications with the stimulation device. Immediately following implantation, inadequate pain relief was noted in 20% of the patients. Decrease of the efficacy of pain alleviation occurs during the first 3 years after implantation. Most failures are noted in patients presenting with failed back surgery. This study also demonstrates that SCS systems should offer the capability of both monopolar and bipolar stimulation modes by the use of multipolar electrodes. ______________________________________________________________________________ Spinal cord stimulation for chronic, intractable pain: superiority

of "multi-channel" devices.

North RB, Ewend MG, Lawton MT, Piantadosi S. Pain. 1991 Feb;44(2):119-30. Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD.

Comment in Pain. 1991 Aug;46(2):236-7. Spinal cord stimulation has evolved over the past 20 years into an easily implemented technique, with low morbidity, for the treatment of intractable, chronic pain in properly selected patients. We report our experience with a series of 62 patients implanted between 1983 and 1987, with percutaneous and laminectomy electrodes, and with single- and "multi-channel" (programmable, multi-contact) devices. Fifty had chronic, intractable low back and leg pain ("failed back surgery syndrome," lumbar arachnoid fibrosis), five had spinal cord injuries, and seven "peripheral" pathology or stump pain. Statistical analysis of these and other patient characteristics and technical factors was undertaken to identify predictors of outcome. All patients were interviewed by a disinterested third party at a mean of 2.14 years following implantation. A majority of patients reported at least 50% sustained relief of pain and indicated that they would go through the procedure again for the same result. There was corresponding improvement in ability to perform various everyday activities, and decrease in use of analgesics. Ten of 40 failed back patients who were disabled before the procedure returned to work postoperatively. Superposition of stimulation paresthesias upon a patient's topography of pain was found to be a statistically significant predictor of successful relief of pain, by linear regression methods. Univariate and multivariate analysis of patient characteristics and technical factors as predictors of outcome demonstrated significant advantages for female patients, and for patients implanted with "multi-channel" devices. With these devices, electrode geometries with central cathode(s) flanked by rostral and caudal anode(s) were favored disproportionately. Technical improvements in implanted spinal cord stimulation devices, in particular the development of multi-contact percutaneous electrode arrays and supporting programmable electronics, have significantly improved clinical results. ______________________________________________________________________________

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Dorsal column stimulation (DCS): cost to benefit analysis.

Bel S, Bauer BL. Acta Neurochir Suppl (Wien). 1991;52:121-3. Department of Neurosurgery, Philipps University of Marburg, Federal Republic of Germany.

In order to analyse the ratio of costs to clinical benefit of the implantation of a neurostimulator (type Medtronic SE-4) we examined a group of 14 patients who required treatment for chronic lumboischialgia after repeated surgery for herniated discs. Over a period of two years we evaluated the pre- and postimplantation costs. The implantation of a DC-Stimulator resulted in a striking decrease in drug requirements, in the total time of clinical treatment, and in the degree of disability. The DCS provides a satisfying method of treatment for chronic lumboischialgia after repeated surgery for herniated discs. Despite relatively high primary costs, treatment with a DCS results in a significant decrease in the accumulated expenses in comparison to other methods of medical treatment in similar cases. ______________________________________________________________________________ Spinal cord stimulation for intractable pain: long-term follow-up.

North RB. J Spinal Disord. 1990 Dec;3(4):356-61. Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205.

Kein Abstract vorhanden. ______________________________________________________________________________ Spinal cord stimulation in 112 patients with epi-/intradural

fibrosis following operation for lumbar disc herniation.

Probst C. Acta Neurochir (Wien). 1990;107(3-4):147-51. Neurosurgical Clinic, Kantonsspital, Aarau, Switzerland.

A total of 112 patients with epi-/intradural fibrosis following operation for lumbar disc herniation were treated by spinal cord stimulation. Lumbosacral spinal fibrosis is seen particularly often after extensive and repeated operations. Radicular pain responds better to stimulation than back pain. A favourable long-term effect on radicular pain has been observed in 67% of patients treated by epidural implantation, the corresponding average follow-up period being 4 1/2 years. 40% of these patients needed less analgesics after the operation, while 25% of them showed an improved fitness for work. Among about 5,000 patients who underwent surgical treatment for lumbar disc herniation, an indication for spinal cord stimulation was found in 1.5%. By comparison, the frequency of the "last resort" procedure of microsurgical cordotomy was 0.3%. We no longer use other ablative methods like extirpation of spinal ganglia. ______________________________________________________________________________ Spinal cord stimulation and surgical cordotomy for nerve root

scars following herniated lumbar disk intervention. [Article in

Italian]

Probst C. Clin Ter. 1989 Nov 15;131(3):145-7.

Kein Abstract vorhanden. ______________________________________________________________________________ Outcome of implanted spinal cord stimulation in the treatment of

chronic pain: arachnoiditis versus single nerve root injury and

mononeuropathy. Brief clinical note.

Meilman PW, Leibrock LG, Leong FT. Clin J Pain. 1989 Jun;5(2):189-93.

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Dartmouth College, Hanover, New Hampshire 03755.

Over a 3 1/2-year period, a series of 20 chronic pain patients with back pain and with documented organic difficulties were treated by means of implanted spinal cord stimulation. Short-term treatment outcome was found to be significantly related to diagnosis, with single nerve root injury and mononeuropathy patients having better treatment outcomes than arachnoiditis patients with multiply injured nerve roots. Outcome was not related to the psychological evaluation, or age, sex, number of previous pain surgeries, pain location, the Minnesota Multiphasic Personality Inventory, or the Pain Assessment Index. Implications for patient selection are discussed. ______________________________________________________________________________ Spinal cord stimulation in management of chronic pain. A 9-year

experience.

Meglio M, Cioni B, Rossi GF. J Neurosurg. 1989 Apr;70(4):519-24. Institute of Neurosurgery, Catholic University, Rome, Italy.

Between 1978 and 1986, 109 patients with chronic pain underwent spinal cord stimulation (SCS) at the authors' institute as part of their pain treatment program. The results of SCS in these patients at the end of the test period and at the latest follow-up examination are analyzed in relation to the etiology of their pain. In 40 patients pain was associated with an obstructive peripheral vasculopathy, in 10 with a previous herpes zoster infection, in 15 with an incomplete traumatic spinal cord lesion, in nine with root and/or nerve damage, in 11 with cancer, and in 19 with previous back surgery. The etiology of the pain in five patients was uncertain. This experience supports the conclusion that the best indications for SCS are vasculopathic pain and post-herpetic neuralgia. No clinical usefulness was found for SCS in cancer pain or in central deafferentation types of pain. ______________________________________________________________________________ Posterior spinal cord neurostimulation in lumbar radiculitis pain.

Apropos of 14 cases. [Article in French]

Batier C, Frerebeau P, Kong A Siou D, Privat JM, Roquefeuil B, Seignarbieux F, Sergent P. Agressologie. 1989 Mar;30(3):137-8.

In 14 patients, spinal cord stimulation in lumbar radiculopathy follow multiple exploration or iterative surgery. For 10 out of this 14 patients treatment was successful; pain relief lasted a mean time of 12.7 months in 9 out of them. ______________________________________________________________________________ Spinal cord stimulation in chronic pain therapy.

Devulder J, De Colvenaer L, Rolly G, Caemaert J, Calliauw L, Martens F. Clin J Pain. 1990 Mar;6(1):51-6. Department of Anesthesia, University of Ghent, Belgium.

Spinal cord stimulation was undertaken in 45 patients referred to the University Hospital in Ghent. Failed back surgery was the major indication for implantation. Raynaud's phenomenon, causalgia, polyneuropathy, phantom limb pain, and diverse causes were the other indications. Before neurosurgical implantation of the system, a percutaneous epidural trial procedure was performed. The efficacy of the implanted stimulation system was estimated by considering the use of medication and the patients' personal appreciation of the obtained pain relief. Thirty-five patients experienced very good pain relief. Only two patients needed further narcotic analgesics. Eight patients stopped using the stimulation system. To ensure good results, strict selection criteria and many surgical reinterventions seemed to be necessary. Although spinal cord stimulation is a nonablative technique, many complications may occur. ______________________________________________________________________________

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Dorsal column stimulation: its application in pain therapy.

Devulder J. Acta Anaesthesiol Belg. 1989;40(2):121-2. Dept. of Anesthesia, Univ. Hospital, Ghent, Belgium.

Clinical report about 45 patients treated with dorsal column stimulation. ______________________________________________________________________________ Chronic medullary neuro-stimulation in lumbosacral spinal

arachnoiditis. [Article in French]

Fassio B, Sportes J, Romain M, Vallespir R. Rev Chir Orthop Reparatrice Appar Mot. 1988;74(5):473-9. Clinique St. Jean, Montpellier.

Between 1983 and 1986, 20 patients were treated by chronic spinal cord stimulation for the relief of pain. These patients suffered from lumbar arachnoiditis or root fibrosis causing lumbar pain and sciatica following operations for disc herniation or repeated radiculography. In this short series, the results obtained were satisfactory, with 12 good results which were stable over a 2-year period, thanks to careful selection of the subjects within the framework of a multidisciplinary pain clinic. The treatment of the fibrosis and the mechanism of neurostimulation are reviewed. ______________________________________________________________________________ Dorsal column stimulation (DCS) in chronic pain: report of 31

cases.

Mittal B, Thomas DG, Walton P, Calder I. Ann R Coll Surg Engl. 1987 May;69(3):104-9.

Thirty-one patients of chronic pain treated with dorsal column stimulation (DCS) are reported. All of them had been treated previously with drugs and multiple procedures including injections and frequently several operations. After a trial of percutaneous DCS, permanent implantations were carried out. The patients have been followed for up to eight years. Overall, sixty per cent of patients had good to fair relief of pain with DCS. Some of them had a good response for five years and more. ______________________________________________________________________________ Dorsal column stimulation in pain treatment.

Wester K. Acta Neurol Scand. 1987 Feb;75(2):151-5.

Thirty-five patients with chronic pain were treated by electrical stimulation of the dorsal columns through implanted epidural electrodes. In 5, such stimulation had minimal pain-reducing effect during an immediate postoperative trial period, and the electrodes were removed. In the remaining 30, an electrode system for chronic stimulation was implanted. Four of these died of related or unrelated causes. The electrode system was removed in 2 patients due to infections, and in 1 due to mechanical discomfort. The remaining 23 patients answered a questionnaire concerning the pain reducing effect of stimulation (4-60 months postoperatively, median 15 months). The group as a whole estimated the pain reducing effect of stimulation as weak. Only 10 patients (43.5%) used the stimulator regularly. Even in these patients, the pain-reducing effect was limited. Chronic back pain after repeated back surgery responded relatively better to stimulation than did the other cases. Phantom limb pain was most resistant. The modest results suggest future restriction on the use of such stimulation. ______________________________________________________________________________ Targeting a spinal stimulator to treat the 'failed back surgery

syndrome'.

Law JD. Appl Neurophysiol. 1987;50(1-6):437-8.

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Kein Abstract vorhanden. ______________________________________________________________________________ Totally implantable spinal cord stimulation for chronic pain:

design and efficacy.

Shatin D, Mullett K, Hults G. Pacing Clin Electrophysiol. 1986 Jul;9(4):577-83.

Neurostimulators used to treat chronic, intractable pain have evolved from technical developments in pacemaker technology. A totally implantable spinal cord stimulation (SCS) system was designed based on elements of a widely used cardiac pacemaker. This paper reports on the transformation of pacemaker technology for neurostimulation applications and presents results of using this system for the treatment of 90 patients with chronic, intractable pain of the low back and/or legs. Significant reduction in pain levels resulted from use of a totally implantable spinal cord stimulation system. Seventy percent of the patients experienced good or excellent pain relief at an average of 14.5 months after implant. Patients who used an automatic ON/OFF cycling mode of stimulation reported greater pain relief than patients who were stimulated continuously. ______________________________________________________________________________ Spinal cord stimulation in the treatment of chronic back and lower

extremity pain syndromes.

Leibrock LG, Meilman P, Cuka D, Green C. Nebr Med J. 1984 Jun;69(6):180-3.

Kein Abstract vorhanden. ______________________________________________________________________________ Lumbosacral spinal fibrosis (spinal arachnoiditis). Its diagnosis

and treatment by spinal cord stimulation.

de la Porte C, Siegfried J. Spine (Phila Pa 1976). 1983 Sep;8(6):593-603.

From 1973 to 1981, 94 patients suffering from low-back pain, with or without spread into the lower extremities, were candidates for therapeutic spinal cord stimulation. The etiology of pain in all cases was lumbosacral spinal fibrosis due to multiple myelographies and surgical interventions on the lumbar spine. The long-term results, based on a four-year follow-up, reveal a 60% subjective improvement of pain, a 40% substantial reduction of medication, and a 26% increase in working capacity. The concept of spinal arachnoiditis is reviewed and the term lumbosacral spinal fibrosis proposed. The treatment of this chronic painful and disabling disease is discussed. ______________________________________________________________________________ Epidural nerve stimulation of the lower spinal cord and cauda

equina for the relief of intractable pain in failed low back

surgery.

Blume H, Richardson R, Rojas C. Appl Neurophysiol. 1982;45(4-5):456-60.

Kein Abstract vorhanden. ______________________________________________________________________________ Epidural dorsal column stimulation for relief of intractable pain.

Kaufmann GE. J Med Assoc Ga. 1978 Nov;67(11):902-3.

Kein Abstract vorhanden. ______________________________________________________________________________

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Safety and clinical efficacy.

Burton CV. Neurosurgery. 1977 Sep-Oct;1(2):214-5.

When applied under the circumstances of minimal patient risk documented in this paper, implanted neuroaugmentive spinal devices are a reasonable means of therapy for selected severe pain problems. With presently developed screening techniques, in 198 patients predominantly suffering from failed back surgery syndrome, a 50% good-to-excellent result was obtained. These figures represent a very significant improvement in the success of treatment for this group of patients when compared to other present modes of therapy. With continued optimization of the use of spinal neuroaugmentive devices, it is likely that clinical success can be further improved in the future. ______________________________________________________________________________ Safety and clinical efficacy of implanted neuroaugmentive spinal

devices for the relief of pain.

Burton CV. Appl Neurophysiol. 1977-1978;40(2-4):175-83.

When applied under the circumstances of minimal patient risk, as documented in this paper, implanted neuroaugmentive spinal devices are a reasonable means of therapy for selected severe pain problems. With presently developed screening techniques, a 50% good-to-excellent result was obtained in 198 patients predominently consisting of 'failed back surgery syndrome' (94%). These figures represent a very significant improvement in success of treatment for this group of patients when compared to other present modes of therapy. With continued optimization of the use of spinal neuroaugmentive devices, it is likely that future clinical success can be significantly improved. ______________________________________________________________________________ Delayed intraspinal hemorrhage after dorsal column stimulation for

pain.

Grillo PJ, Yu HC, Patterson RH Jr. Arch Neurol. 1974 Jan;30(1):105-6.

Kein Abstract vorhanden. .

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