intro to neurostimulation asent feb 28 2013

Neurostimulation: An Overview

Thursday Feb 28th

Shaun Comfort, MD, MBA

Adaptix Clinical Solutions, LLC

American Society for Experimental NeuroTherapeutics | 15th Annual Meeting

Disclosure(s)

Consulting relationships with multiple Pharma, Bio, and Medical Device Companies

Equity: J&J


Other:

I will discuss some currently unapproved Rx/Research technologies

Learning Objectives

• Outline the context & history of Neurostimulation

• Identify several current Neurostim therapies

The Brave New World of Neurostimulation


Basic Definitions

• Fundamental Quantity: Charge = Coulomb

• Negative Charges: Electrons = 1.6 x 10-19 C

• Moving Charges: Current = Amp {C/sec}

• Charge Source (eg Battery): Voltage = Potential Energy/Ch = Volt {Joules/C}

• Useful Relation: Ohm’s Law V = iR

• Other Useful Terms:

• Frequency = Cycles/sec {Hertz}


Basic Definitions, cont


Neurostimulation?

• Neurostimulation? • The modulation of nervous system activity by

electrically activating individual or groups of neurons in the body, to achieve a clinical goal.

• Can be achieved using:

• Surface electrodes

• Implantable electrodes

• Indirect: Vector Force Fields (TMS)


Early Neurostimulation?

• First application of neurostimulation:

• Scribonius Largus, 65 AD

• Torpedo fish (electric ray)

• for relieving pain (Early TENS?)

• Empirical findings that electricity applied to skin had interesting effects such as pain reduction


Coincidental Physics


Faradization for Pain Relief


The Good Old Days?

• Early Faradization primitive and overly broad claims: • “Electreat” device – Willie Kent 1st

person prosecuted under FD&C (1938) for Unsubstantiated Claims

• Claims later limited to pain

• However, this approach evolved into Transcutaneous Electrical Stimulation (TENS) used today for pain (eg, Shealy MD & Medtronics, 1970s)


Beyond Peripheral Faradization

• Early 20th century - co-incident advances in electronics and medicine produced new tools for electrophysiology: ECG (1911), EEG (Berger, 1924) and therapy: ECT (Cerletti & Bini, 1938)


http://en.wikipedia.org/wiki/File:Bergonic_chair.jpg

http://en.wikipedia.org/wiki/File:Willem_Einthoven_ECG.jpg

http://en.wikipedia.org/wiki/File:HansBerger_Univ_Jena.jpeg

If That Is the Past, Where Are We Today?

• We are riding the 20th Century wave of Neuroscience + Moore’s Law

• The results are: • Implantable micro-electronics

• Open (VNS, DBS) - and Closed-loop (?) therapies

• Wireless monitoring (eg, Implanted EEG)

• Smart diagnostics (eg, ECG/EEG Interpretation)

• Rapid advances in Neurosurgery, fMRI, etc


Moore’s Law

To 1st approximation, doubling of transistor density & computing efficiency every 18 months


SCS, TENS, tDCS, etc


TENS, TMS, DBS, VNS, etc



NS Classification Grid

External Implanted

Peripheral NS • TENS - Pn

• CI – Aud • GES - GI • SNS - GU

Central NS

• ECT – Dep • TMS – Dep • TNS – HA • tDCS

• SCS – Pn • OI –Vis • VNS-Ep

• DBS-PD, Et, Ep

• CtS - Ep

Aud = Auditory; CI = Cochlear Implant; CtS = Cortical Stimulation; Dep = Depression; Ep = Epilepsy; Et = Essential Tremor; GI = Gastrointestinal; GNS = GastricElectric Stimulation; GU = Genitorurological; HA = Headache; OI = Occipital Implant;PD =

Parkinson’s Dz; Pn = Pain/Analgesia; SCS = Spinal Cord Stimulation; SNS = Sacral Nerve Stimulation; TNS = Trigeminal Nerve Stmulation; Vis = Vision

Current NS Treatment Modalities

What Are the Challenges?

• Clinical Trials: Demonstrating efficacy under placebo conditions difficult due to blinding & operator characteristics

• Long-term Stable Power Sources: Bigger batteries vs. recharging for implantables

• Closed Loop vs. Open Loop Methodologies

• Support: Implantable Neurostim looking much like pharma/biologic development: Time and $$$

Impact on Clinical Care and Practice • NS has a long history of use in medicine • NS is a useful adjunctive tool in the treatment of Neurologic conditions • Several therapies have proven efficacy and safety for various disease conditions (eg, ET, Epilepsy) • Much interest in new approaches:

• Implantable cortical and Deep Brain Stim for Epilepsy + other conditions • Non-invasive surface Trigeminal & Vagal Stimulation

• Clinical trials, development timelines can be challenging • NS is still maturing

Thank You!

Contact Information:

[email protected]

References/Data/Graphic Sources

• tp://en.wikipedia.org/wiki/Electric_current • antenna-theory.com; Physlink.com, various Google Images • tp://www.burtonreport.com/infspine/NSHistNeurostimPar

tI.htm • thefullwiki.org;

http://en.wikipedia.org/wiki/Electroconvulsive_therapy and ../Electroencephalography

• http://www.economist.com/blogs/dailychart/2011/10/computing-power & letshavetheconversation.blogspot.com

• Osteoarthritis.about.com; Scientific American.com; http://www.burtonreport.com/infspine/NSHistNeurostimPartI.htm

• Osteoarthritis.about.com; Medtronic.com; Cyberonics.com

http://www.burtonreport.com/infspine/NSHistNeurostimPartI.htm

http://www.burtonreport.com/infspine/NSHistNeurostimPartI.htm

intro to neurostimulation asent feb 28 2013

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