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MIGRAINE COMPLICATED BY BRACHIALPLEXOPATHY AS DISPLAYED BY MRI ANDMRA: ABERRANT SUBCLAVIAN ARTERY

AND CERVICAL RIBSErnestina H. Saxton, MD, PhD, Theodore Q. Miller, MD, and James D. Collins, MD

Los Angeles, CA

This article describes migraine without aura since childhood in a patient with bilateralcervical ribs. In addition to usual migraine triggers, symptoms were triggered by neck exten-sion and by arm abduction and external rotation; paresthesias and pain preceded migrainetriggered by arm and neck movement. Suspected thoracic outlet syndrome was confirmed byhigh-resolution bilateral magnetic resonance imaging (MRI) and magnetic resonanceangiography (MRA) of the brachial plexus. An unsuspected aberrant right subclavian arterywas compressed within the scalene triangle. The aberrant subclavian artery splayed apartthe recurrent laryngeal and vagus nerves, displaced the esophagus anteriorly, and effacedthe right stellate ganglia and the C8-T1 nerve roots. Scarring and fibrosis of the left scalenetriangle resulted in acute angulation of the neurovascular bundle and diminished blood flowin the subclavian artery and vein. A branch of the left sympathetic ganglia was displaced asit joined the C8-T1 nerve roots. Left scalenectomy and rib resection confirmed the MRI andMRA findings; the scalene triangle contents were decompressed, and migraine symptomssubsequently resolved. (J Natl Mecd Assoc. 1999;91 :333-341.)

Key words: * aberrant subclavian artery* brachial plexus * migraine * MRA * MRI* nerve imaging * thoracic outlet syndrome

Migraine is a primary headache condition associatedwith blood flow changes in intracranial and extracere-bral blood vessels. A typical attack of migraine without

From the Departments of Neurology and Radiological Sciences,UCLA School of Medicine, Los Angeles, CA. Presented at theAnnual Convention and Scientific Assembly of the National MedicalAssociation, August 2-7, 1997, Honolulu, HI, and the AnnualMeeting of the Federation of American Societies for ExperimentalBiology, April 22, 1998, San Francisco, CA. Requests for reprintsshould be addressed to Dr James D. Collins, Dept of RadiologicalSciences, UCLA Medical Ctr, Ctr for the Health Sciences, Box951721, Los Angeles, CA 90095-1721.

aura as defined by the International Headache Societyconsists of unilateral moderate to severe throbbingheadache pain, with associated photophobia, phonopho-bia, nausea, and vomiting lasting from 4 to 72 hours.1Neck pain or stiffness often accompanies migraine evenin mild attacks.25 Patients report that neck pain as wellas certain positions of the neck can trigger a migraineattack. Headache is reported to be one of the commoncomplaints of thoracic outlet syndrome and may be apresenting symptom in some patients.6

Thoracic outlet syndrome is a disorder of the cervi-cothoracic spine caused by compression of the nerves andblood vessels supplying the upper limb.7'12 Thoracic out-let disorders may involve dysfunction at the cervicotho-racic level of the vertebral column, the first rib, the clavi-cle, the vascular supply, or adjacent soft tissues.'2Symptoms often consist of upper extremity pain associat-

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ed with numbness and tingling, radiating into the hands.Autonomic symptoms such as temperature and colorchanges may occur. Clinical diagnosis of thoracic outletsyndrome depends on general examination that mayinclude such provocative tests as Adson's and hyperab-duction maneuvers. Diagnostic noninvasive laboratorystudies are indirect and involve conventional radiographyand computerized tomography (CT). Computerizedtomography may incorporate special software programsto display vascular anatomy. However, these CT vasculardisplays do not adequately demonstrate soft tissues. Inaddition, CT of the thorax is routinely performed withpatient's arms overhead. In this position, the clavicle andthe subclavius muscle compress the subclavian vein onthe first rib (costoclavicular compression). Intrathoracic,intra-abdominal, and intracranial pressure increase underthese conditions. When contrast is injected, collateralblood flow is develops at the site of venous compression.This should be considered in the interpretation of theresults.

In patients with thoracic outlet syndrome, magneticresonance imaging (MRI) typically is performed on thecervical spine to exclude cord lesions and radiculopathy.Multiplanar MRI and MRA display soft-tissue fascialplanes. Bilateral brachial plexus MRI and vascular three-dimensional (3D) reconstruction imaging demonstratethe relationship of nerves and blood vessels to their sur-rounding landmark anatomy and delineate the sites ofcompromise without the need for contrast agent.910'12

In the past two years, more than 50 patients referredto our outpatient neurology clinic for evaluation ofintractable migraine were found to have thoracic outletcomplaints. In addition to headache symptoms, thesepatients reported paresthesias, temperature and colorchanges (especially in the hands), and pain in the neck,shoulder, and upper extremity. Clinical examination witharm abduction and external rotation resulted in loss ofradial and brachial pulse with patients noting paresthe-sias, burning, arm pain or heaviness, and temperaturechanges. These maneuvers also triggered patients' typicalmigraine or headache symptoms.

The patient described in this article was one of thefirst cases evaluated by the authors. Her thoracic outletsyndrome symptoms and typical migraine attacks weretriggered by driving, neck extension, and abduction andexternal rotation of the upper extremities.'3",4 This articledemonstrates the sites of brachial plexus compression ina migraine patient with aberrant right subclavian artery,cervical ribs, and scarring and fibrosis of the left scalenetriangle. Plain chest radiograph, selected sequential MRI,and 2D time-of-flight (TOF) MRA are displayed. Images

that represent the landmark anatomy were selected;entire sequences for each plane could not be included inthis article. The images selected were chosen becausethey complement each other as a group. Individualimages were cross-referenced to the other sequences.

MATERIALS AND METHODSMagnetic Resonance Imaging

Plain chest radiographs (PA and lateral) are obtainedand reviewed prior to the bilateral brachial plexus MRI.The chest radiograph is obtained to detect osseousabnormalities and to eliminate the possibility of unsus-pected metallic objects. Respiratory gating is appliedthroughout the procedure to minimize motion artifactand maximize the contrast of the soft-tissue signalintensities. The patient is positioned supine in the bodycoil with his or her arms down to the side.A body coil is used because it offers optimal full

field of view for bilateral imaging of the brachial plexusand provides uniform signal-to-noise ratio across theimaging field necessary for 3D reconstruction. Surfacecoils are limited to depth and field of view and are notadequate for bilateral imaging of the brachial plexus. Awater bag (500 mL normal saline) is placed on the rightand the left sides of the neck above the shoulder girdleto increase signal-to-noise ratio for higher resolutionimaging. A full field of view (40-48 cm) of the neck andthe thorax is used to image both supraclavicular fossae.A minimum of four imaging sequences is obtained:contiguous (4-5 mm) coronal, transverse (axial), trans-verse oblique, and sagittal TI-weighted images. If thereis clinical evidence of scarring, tumor, or lymphaticobstruction, T2-weighted images or FSE (fast spinecho) pulse sequences are obtained.

The coronal sequence is imaged first. The brachialplexus envelops the artery, forming a neurovascularbundle. The nerves are best imaged when the cursorsare aligned to the arterial blood supply. Because themargins of the axillary artery vary in each patient, thecursors must be adjusted individually for each bilateralMRI brachial plexus examination. The cursors are posi-tioned from the skin surface of the posterior chest wallto the skin surface of the anterior chest wall for sym-metry and 3D reconstruction as well as for detectingabnormalities that may mimic brachial plexopathies.The superior landmark is set at the base of the skull, andthe inferior landmark is set at the level of the kidneys.The image that best demonstrates the arterial bloodflow to the upper extremities is selected as the baselineimage for the remaining sequences.

The transverse sequence is set from the baseline

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coronal image at the superior aspect of the third cervi-cal vertebral body to the carina. The lateral margins ofthe shoulder girdle are imaged to insure bilateral, simul-taneous display of the brachial plexus.

The transverse oblique sequence is set by aligning thecursors to the arterial blood supply of each upper extrem-ity using the baseline coronal sequence. The cursors arecentered to the plane of the axillary artery, 2 cm belowthe inferior cord of the brachial plexus to the superiormargin of the coracoid process. This sequence is neces-sary to detect signal intensity, architecture, and efface-ment of the long axis of the nerves, arteries, and veins.

The sagittal sequence is obtained by aligning thecursors laterally to the coracoid process and medially toinclude the insertion of the anterior scalene muscle onthe first rib and the middle third of the first thoracic ver-tebral body. The sagittal plane is necessary to detecteffacement of the neurovascular bundle by the coracoidprocess, pectoralis minor muscle, clavicle and subclav-ius muscle, axillary masses, and abnormalities of thescalene triangle.

Coronal abduction and external rotation sequence dis-plays the posteroinferior rotation of the clavicles and sub-clavius muscles on the landmark anatomy of the neckand shoulder girdle. After completion of the 2D TOFMRA sequence, the patient is removed from the gantry,and without changing body position, the patient's armsare abducted and extended behind the head. The patientis then returned to the gantry. This sequence is imagedfrom the posterior level of the first thoracic nerve roots tothe anterior margin of the manubrium stemi and first ribsto display the rotation of the clavicles in relationship toanatomic landmarks. The sagittal abduction-externalrotation sequence is imaged from the lateral margin ofthe left coracoid process to the lateral margin of the rightcoracoid process. The images are then cross-referencedto the above imaging sequences. The clavicles and sub-clavius muscles rotate posterior inferiorly (18°-53°) andcompress the neurovascular bundles against the first ribs.The coronal and sagittal abduction-external rotationsequences capture images that demonstrate changes inthe relationship of the neurovascular bundles to the posi-tion of the clavicles.

When an image sequence is completed, it is trans-ferred to another screen at an independent workstationfor review and 3D-reformat display. The software for this3D reconstruction is already in a 1.5-Tesla GE SignaMRI unit (GE Medical Systems, Milwaukee, WI). Theimages are stored on CT and MRI (GE9800) format andon optical disks for 3D-color reconstruction on the ISGworkstation (ISG Technologies Inc, Mississauga,

Ontario, Canada). The entire study is monitored by theradiologist and requires 90 minutes. Selected Kodakcolor and black-and-white laser prints and transparenciesare obtained for lectures and poster presentations, andannotated images are preserved on VHS and archiveddigital optical disks.

EquipmentMagnetic resonance images are obtained on the 1.5-

Tesla GE Signa MR scanner. The 3D-reformattedimages are videotaped on a separate work console at themonitoring station, and computerized color is applied tothe images using an ISG console. A 512X256-matrixformat is used. The saline water bags are those suppliedfor intravenous use.

CASE REPORTA 36-year-old, right-handed woman presented for

evaluation of worsening migraine headache. She report-ed a history of headaches since childhood characteristicof migraine without aura. After menarche, hermigraines became more frequent and severe, with themost severe episodes occurring on the left side. Noassociation with the menstrual cycle occurred until shestarted oral contraceptive medication at age 18 years.The migraine attacks became more severe at the time ofmenses and were incapacitating during pregnancy. Theheadaches became less frequent and more manageableafter a total abdominal hysterectomy and bilateral salp-ingo-oopherectomy at age 22.

The patient reported that during the previous threeyears, since began training as a physical therapist, themigraines had increased in frequency and severity, andwere associated with neck pain and tightness. Themigraines were triggered more easily by alcohol, aro-matic scents such as perfumes and cologne, sunlightand heat, and lunchmeat. The frequent headaches werepreceded by "pins and needles" and a tingling sensationin both hands, mainly in the ring and little fingers, aswell as aching in the forearms. These arm symptomswere brought on by activities such as prolonged sittingor extending the neck when having her hair washed atthe hairdresser. Symptoms were the most severe afterarm abduction and external rotation, and the worstheadaches were left-sided, occurring 5-20 minutes afterprecipitation of arm symptoms by these maneuvers. Thesevere attacks also were associated with debilitatingnausea, vomiting, and photophobia.

Both of the patient's parents had a history ofmigraines. A physical examination revealed positivehyperextension and Adson's tests that were greater on the


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Figure 1.Coned down PA chest radiograph demonstrates bilateralcervical ribs. The small right cervical rib originates fr-om thetransverse process of C7 and overlies the posterior first rib.The larger left cervical rib crosses the high transverse processof the first thoracic vertebra, posterior first rib, and plura. Theright shoulder girdle is low. (5=fifth cervical vertebra; 6=sixthcervical vertebra; 7=seventh cervical vertebra; 1 T=first tho-racic vertebra; arrows=right cervical rib [3 arrows] and leftcervical rib [8 arrows]; open arrows=clavicles; A=aorta;TR=transverse process of C7.)

left than on the right side. These maneuvers producedobliteration of the radial pulse on the left and diminutionon the right, with sensory complaints in the hands andpain in the armns. Several minutes after these procedures,the patient reported headache and nausea. A neurologicexamination revealed mild weakness of finger abduction(digiti minimi), finger extension, and elbow extension inboth extremities, but greater on the left. Decreased vibra-tion sense was found on the left compared to the right,with deep tendon reflexes more forthcoming on the leftthan on the right. Chest radiographs demonstrated bilat-eral cervical ribs, with the left being larger than the right(Figure 1).

Bilateral MRI and MRA of the brachial plexus wererequested to demonstrate the site of brachial plexus com-promise. The large left cervical rib crossed the highertransverse process of the first thioracic vertebral body. Anaberrant right subclavian artery was discovered on the

coronalMR eqec (Fg re) hrter rgiae

Figure 2.Coronal sequences demonstrating the aberrant subclavianartery originating from the left descending aorta andascending posterior to the esophagus and trachea and effac-ing the right stellate ganglia. The right and left commoncarotid arteries originate from the aorta. (A=aorta;AC=acromion; C=clavicle; C6-C7=nerve root; D=deltoid;H=humerus; SA=subclavian artery; SCG=superior cervicalganglion; SG=stellate ganglion; SPC=spinal cord;SUP=supraspinatus muscle; SY=sympathetic nerve; T=tra-chea; V=vagus nerve; 6=sixth cervical vertebra; 7=seventhcervical vertebra; LM=lateral mass [pillar] of vertebral body.)

from the left descending aorta and ascended obliquelyposterior to the esophagus and trachea, anterior to thefirst thoracic and seventh cervical vertebral bodies overthe posterior apex of the pleura. The artery effaced thestellate ganglia over the posterior aspect of the pleura andwas compressed in the scalene triangle by the large rightanterior scalene muscle. The right C7 cervical nerve rootwas displaced anteriorly by the cervical rib. The left sub-clavian artery entered the scalene triangle over the lowfirst rib. The large left middle scalene muscle displacedthe C5, C6, and C7 cervical nerve roots anteriorly as theycoursed over the cervical rib into the supraclavicularfossa. These nerve roots were straightened and their sig-nal intensity diminished.

Transverse sequence confirmed the aberrant rightsubclavian artery originating from the aortic arch. Theartery narrowed within the scalene triangle as it archedacutely over the first rib. There was acute angulationand compression of the left neurovascular bundle poste-rior to the anterior scalene muscle. The left C8-TI nerveroots were crimped by the dilated subclavian artery. Theleft transverse oblique sequence confirmed the acute


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Figure 3.Sequential right sagittal image demonstrating ascent of theaberrant sublavian artery as it courses posterior to theesophagus and trachea, passing the first and second tho-racic vertebral bodies. The artery is in the retroesophagealspace, impinging the vagus nerve. (6=sixAt cervical vertebra;7=seventh cervical vertebra; 1 T=first thoracic vertebra;2T=second thoracic vertebra; CC=common carotid artery;E=esophagus; T=trachea; SA=subclavian artery; SPC=spinalcord; RCL=recurrent laryngeal nerve; and V=vagus nerve.)

angulation of the left neurovascular bundle. The leftcervical rib was identified anterior and lateral to thetransverse process of C7 as it coursed anteriorly overthe intercostal nerve of the first thoracic vertebral body.A branch of the sympathetic ganglia was displaced bythe lung anterior-medially as it joined the C8-TI nerveroots. The right transverse oblique sequence confirmedthe dilatation of the aberrant subclavian artery and theeffacement of the TI nerve root as it coursed anteriorly.The C8-T1 nerve roots crossed the pleura binding to thedilated subclavian artery. The artery was compressed asit passed between the anterior and middle scalene mus-cles and narrowed lateral to the anterior scalene.

The right sagittal sequence demonstrated the retroe-sophageal position of the narrowed aberrant subclavianartery (Figures 3 and 4). The artery bisected the vagusand right recurrent laryngeal nerves (Figure 4), descend-ed into the scalene triangle, and effaced the stellate gan-glia (Figures 5 and 6). The artery invaginated the lungand displaced the C8-TI nerve roots superiorly.

Coronal bilateral abduction and external rotation of

59,

Figure 4.Sequential right sagittal image demonstrating continuedascent of the aberrant subclavian artery splaying the vagusand recurrent laryngeal nerves anterior to the first and sec-ond thoracic vertebral bodies. (C7=seventh cervical verte-bra; 1 T=first thoracic vertebra; 2T=second thoracic verte-bra; CC=common carotid artery; E=esophagus; T=trachea;SA=subclavian artery; RCL=recurrent laryngeal nerve;V=vagus nerve; SG=stellate ganglion; and STM=sternoclei-domastoid muscle.)

the upper extremities confirmed the origin of the aber-rant subclavian artery from the descending left aorta(Figure 7). The artery was dilated proximal to the sca-lene triangle and was compressed within the triangle.The low right clavicle and the subclavius muscle com-pressed the neurovascular bundle against the hemitho-rax. On the left, intermediate gray signal intensities(fibrosis and scarring) marginated the neurovascularbundle. Two-dimensional TOF-reconstructed MRAimages displayed the origin of the aberrant subclavianartery from the descending aorta (Figure 8). The imagesdemonstrated proximal dilatation of the left axillosub-clavian vein, partial compression of the right axillosub-clavian vein, and compression of the aberrant subcla-vian artery within the scalene triangle. An amorphoushigh-signal intensity was displayed over the region ofthe left scalene triangle consistent with collateral circu-lation.

With MRI anatomic correlation, the patient under-went left surgical decompression. This consisted oftransaxillary first dorsal rib resection and resection of the


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Figure 5.Sequential right sagittal image demonstrating the aberrantsubclavian artery beginning its course over the pleural ofthe right lung. The stellate ganglion is effaced and dis-placed superolaterally. (1 T=first thoracic vertebra; 2T=sec-ond thoracic vertebra; C8=C8 cervical nerve root;CC=common carotid artery; LC=longus colli muscle;RL=right lung; SA=subclavian artery; SG=stellate ganglion;and V=vagus.; Ti =first thoracic nerve root; 1 =measure-ment of diameter of subclavian artery [8 mm].)

left cervical rib, subtotal anterior and middle scalenecto-my, lysis of the left axillosubclavian artery and vein, andneurolysis of the inferior trunk and TI nerve root of thebrachial plexus. At surgery, extensive abnormalities ofthe left thoracic outlet were observed. There was com-plete intercostalization of the scalene muscles with alarge muscle mass filling the concavity of the first ribsuperiorly. The cervical rib arose from the C7 transverseprocess and ended at the junction of the TI nerve rootand inferior trunk of the brachial plexus, deviating thebrachial plexus anteriorly and causing a groove in thenerve components in that region. The cervical rib wasenveloped in the intercostal muscle with a large attach-ment to the middle scalene muscle. A fibrocartilaginousband was observed above the cervical rib that appeared toarise from the transverse process of the C6 body on theleft. This band was attached to the first rib at the termi-nation of the cervical rib and further deviated the brachialplexus. Crossing fibers constricted the axillosubclavian

veslht ars fro th inecsaiesaeemsl

Figure 6.Sequential right sagittal image demonstrating the aberrantartery compressed anterior to the first thoracic vertebrabody, coursing over and invaginating the pleura on theright and displacing the stellate ganglion superior laterally.(C8=C8 cervical nerve root; Rl =first rib; Tl =T1 nerve root;IP=invaginated pleura; LC=longus colli muscle; RL=rightlung; SA=subclavian artery; SG=stellate ganglion;SY=sympathetic nerve and trunk; and V=vagus nerve;1 =measurement of diameter of subclavian artery [7 mm].)

(Figure 7). The cervical rib indented the inferior trunk ofthe brachial plexus and had to be elevated from the trunkprior to resection.

The intercostalized scalene muscle also contributedconstricting bands across the axillosubclavian vessels,the inferior trunk, and the Ti nerve root, all of whichwere lysed after sectioning of the muscle. Surgicaldecompression resulted in resolution of the intractablemigraines.

DISCUSSIONThe patient described here had a history of headache

since childhood, which fulfilled the InternationalHeadache Society criteria for migraine without aura.'Of significance was the fact that in addition to usualtriggers, the patient's migraine symptoms were trig-gered by positions of the neck and arms that caused tho-racic outlet neurovascular compression. The migrainewas preceded by paresthesias in the hands and pain inthe arms that were greater on the left than the right. On


BRACHIAL PLEXOPATHY

Figur-e 7.Coronal abdluction and external rotation of the upper extrem-ities demonstrate the aberrant subclavian artery and the leftclavicle and subclavius muscle compressing the neurovascularbundle on the left. (A=aorta; ABSA=aberrant subclaviianartery; C=clavicle; CP=coracoid process; D=-deltoid muscle;H=humerus; LL=left lung; LT=long thoracic nerve; MS--middlescalene muscle; RL=right lung; SG--stellate ganglion; SK=skin;SM=subclavius muscle; SPC=spinal cord; STM=-stemnocleido-mastoid muscle; 5=fifth cervical vertebra; 6=sixt cervical ver-tebra; 7=seventh cervical vertebra; 1 T=first thoracic vertebra;C5-C6=junction of fifth and sixth cervical nerve roots;C6=sixth cervical nerve root; C7=seventh cervical nerve root;P=pulmonary artery; SA=subclavian artery; SN=suprascapu-lar nerve; SR=second rib; W=saline water bag; X=site offibrosis and scarring of the neurovascular bundle with inter-mediate gray signal intensifies.)

physical examination, provocative maneuvers includingabduction and external rotation of the upper extremitiestriggered a migraine attack.

The chest radiograph demonstrated bilateral cervicalribs (Figure 1). The MRI and MRA studies demonstrat-ed abnormalities of the thoracic outlet. These includedbilateral cervical ribs and compression of the neurovas-cular structures, especially on the left, by the large cervi-cal and first ribs as well as the middle scalene muscle.T'he MRI and MRA studies also displayed the presenceand course of an aberrant right subclavian artery. Theabeffant subclavian artery effaced the esophagus andsplayed apart the recurrent laryngeal and vagus nerves inthe retroesophageal space. It effaced the stelate gangliaand was compressed within the scalene triangle (Figures

Figure 8.Coronal reconstruction 2D TOF MRA demonstrates proximaldilatation of the left axillosubclavian vein, partial compres-sion of the right axillosubclavian vein, collateral flow on theleft side, and the aberrant subclavian artery as it narrowswithin the right scalene triangle. (A=aorta; ABSA=aberrantsubclavian artery; AX=axillosubclavian artery; AXV=axillo-subclavian vein; BRV=brachiocephalic vein; CC=commoncarotid artery; J=internal jugular vein; SA=subclavianartery; SV=subclavian vein; TCV=transverse cervical vein;VA=vertebral artery; XJ=external jugular vein; X=site of com-pression of aberrant subclavian artery; CV=cephalic vein;W=saline water bag.)

3-6). The pressure on the recurrent laryngeal nerve andesophagus with the impingement in the retroesophagealspace most likely accounted for the patient's reports ofepisodes of hoarseness and dysphagia.

The coronal abduction-external rotation sequencetriggered upper bilateral extremity pain and paresthe-sias that were greater on the left than the right. Amigraine followed the upper extremity symptoms whilethe patient was still in the gantry and worsened after sheexited the imaging unit. Abduction-external rotationMRI demonstrated compression of the neurovascularbundle bilaterally at the time of the triggered symptoms(Figure 7). The captured images provided the clinicianwith a record of the anatomic dysfunction that correlat-ed with the patient's presenting symptoms.

Surgical decompression confirned the neurovascularanomalies displayed on the MRI and MRA. Prior tosurgery, the patient underwent scalene block, which waspositive and consistent with thoracic outlet syndrome.However, in subsequent patients to be reported, MRIand MRA of the brachial plexus were used as the soleanatomic correlation to determine surgical decompres-sion, in the absence of electrophysiologic studies such asevoked potentials, electromyography, nerve conduction,


BRACHIAL PLEXOPATHY

or other invasive studies such as scalene block.The relationship of migraine to neurovascular com-

pression associated with structural abnormalities of thethoracic outlet was documented by MRI techniques. Thiswas achieved by the radiologist monitoring the entirebilateral MRI and MRA of the brachial plexus.Functional anatomic imaging also was possible byabduction and external rotation of the upper extremitiesin the MRI gantry, which duplicated the same symptomsthat occurred in the physician's office. Abduction-exter-nal rotation of the upper extremities caused the claviclesand subclavius muscles to rotate posteroinferiorly andcompress the subclavian vein and the soft tissues anteri-or to the scalene triangles (Figure 7). This pressure wastransmitted to the scalene triangle, triggering the patient'ssymptoms (costoclavicular compression).'2 Abduction-external rotation of the upper extremities increasesintrathoracic pressure, causes venous obstruction, andincreases interscalene triangle compression, which trig-ger paresthesias, pain, and migraine.12'13

Intracranial and extracerebral blood flow changesare postulated to contribute to migraine pain.'5'16Compression of the blood vessels in the thoracic outletnot only produces local blood flow changes,'7"8 but alsomay contribute to impairment of cerebral vascular reac-tivity and blood flow, with resultant migraine pain andsymptoms. Additionally, autonomic changes also maycontribute to the vascular changes that accompanymigraine. Thoracic outlet patients often present clini-cally with autonomic changes, especially changes insympathetic tone, in the extremities, and MRI demon-strates compression of the brachial plexus.'8 In thepatient described here, in addition to neurovascularcompression, the stellate ganglia were compromisedand the sympathetic nerves displaced. Stellate ganglionblockade has been postulated to be associated withblood flow changes and precipitating migraine pain andsymptoms in certain patients.'9'20

Thus, abnormalities in sympathetic tone may havecontributed to changes in blood vessel reactivity and toblood flow changes that induced migraine pain. Surgicalfirst rib resection and scalenectomy to decompress theneurovascular structures resolved the autonomic symp-toms and brachial plexus complaints. In this patient, thesurgical procedure also resolved the intractable migrainesymptoms and resulted in less frequent attacks and betterresponse to migraine medications.

Definitive conclusions about the pathogenesis ofmigraine cannot be made from this clinical and MRIstudy. It is likely that both vascular and neurogenicmechanisms are involved in the complex disorder that is

migraine. Since the first presentation of this study in1997, we have evaluated more than 50 patients withintractable headache; patients' symptoms were directlyrelated to neurovascular and autonomic abnormalitiesof the thoracic outlet. In these patients, who were sub-jects of a subsequent study, maneuvers that produceneurovascular compromise triggered their migrainecomplaints.21 In these patients, bilateral abductionexternal rotation MRI sequence demonstrated changesconsistent with increased intraabdominal and intracere-bral pressures as well as increased intrathoracic pres-sure. Impaired venous flow was demonstrated asincreased signal intensities within the internal jugular,subclavian, brachiocephalic, and innominate veins, atthe same time that the patients complained of triggeredmigraine symptoms while in the MRI gantrly.2'22Venous obstruction and impaired venous drainage ofthe head and neck contributed to migraine symptoms inthese patients.

Knowledge of anatomy is important in understandingand interpreting MRI and MRA studies in patients.23 Animportant anatomic finding in this patient was the courseof the aberrant right subclavian artery from its originfrom the descending aorta to its retroesophageal position,with splaying apart of the vagus and recurrent laryngealnerves and effacement of the stellate ganglia not previ-ously reported.

CONCLUSIONNeurovascular compression in a migraine patient

with thoracic outlet abnormalities triggered migraineattacks. Surgical decompression resulted in resolutionof the intractable migraine. High-resolution multiplanarbilateral MRI and MRA of the brachial plexus provideddefinitive diagnostic anatomic modalities in surgicalmanagement of a TOS patient with migraine.21 The use-fulness of bilateral MRI and MRA in delineating com-pression abnormalities of the brachial plexus and in sur-gical management of this patient was evident (even inthe absence of conventional electrophysiologic studiesand invasive studies such as scalene block). Magneticresonance imaging displayed the anatomic finding notpreviously reported of an aberrant right subclavianartery splaying apart the vagus and recurrent laryngealnerves in the retroesophageal space and effacement ofthe stellate ganglia.

Literature Cited1. Headache Classification Committee of the International

Headache Society. Classification and diagnostic criteria forheadache disorders, cranial neuralgias and facial pain.Cephalalgia. 1988;8(suppl 7):10-73.


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2. Edmeads J. The cervical spine and headache. Neurology.1988;38: 1874-1878.

3. Vernon H, Steiman I, Hagino C. Cervicogenic dysfunc-tion in muscle contraction headache and migraine: a descriptivestudy. JManipulative Physiol Ther. 1992;15:418-429.

4. Kidd RF, Nelson R. Musculoskeletal dysfunction of theneck in migraine and tension headache. Headache. 1993;33:566-569.

5. Blau N, MacGregor MB. Migraine and the neck.Headache. 1994;34:88-90.

6. Raskin NH, Howard MW, Ehrenfeld WK. Headache asthe leading symptom of thoracic outlet syndrome. Headache.1985;25:208-210.

7. Sunderland S. Blood supply of the nerves to the upperlimb in man. Arch Neurol Psych 1945;53:91-115.

8. Lord JW, Rosati LM. Thoracic outlet syndromes. ClinSymp. 1971;23:1-32.

9. Collins JD, Shaver M, Disher AC, Miller TQCompromising abnormalities of the brachial plexus as displayedby magnetic resonance imaging. Clin Anat. 1995;8:1-16.

10. Collins JD, Disher AC, Miller TQ The anatomy of thebrachial plexus as displayed by magnetic resonance imaging:technique and applications.JNatlMedAssoc. 1995;87:489-498.

11. ThompsonJF,Jannsen F. Thoracic outlet syndromes. BrJSurg. 1996;83:435-436.

12. Collins JD, Shaver M, Disher A, Miller TQ The costo-clavicular syndrome as displayed by MRI and MRA: reformatand 3D graphic display. Clin Anat. 1997; 10:131.

13. Saxton EH, CollinsJD, Miller TQ Migraine complicat-ed by brachial plexopathy: Aberrant subclavian artery and cervi-cal ribs. Presented at: Annual Convention and ScientificAssembly of the National Medical Association; August 2-7, 1997;Honolulu, HI.

14. Saxton E, Collins JD, Disher A, Miller TQ Migrainecomplicated by brachial plexopathy as displayed by MRI andMRA. FASEBJ 1998;12:A11O.

15. Harer C, vonKummer R. Cerebrovascular C02 reactivi-ty in migraine: assessment by transcranial Doppler ultrasound. J

Neuroll 1991;238:23-26.16. Thomsen LL, Iversen HK, OlesenJ. Cerebral blood flow

velocities are reduced during attacks of unilateral migraine with-out aura. Cephalalgia. 1997;15:109-116.

17. CollinsJD, Shaver ML, Disher A, Miller TQ The vascu-lar supply of the brachial plexus as displayed by magnetic reso-nance imaging: magnetic resonance angiography (MRA).Presented at: 11th Annual Scientific Program of the AmericanAssociation of Clinical Anatomists;June 16, 1994; Galveston, TX.

18. Saxton EH, Collins JD, Disher A, Miller TQ Migrainecomplicated by brachial plexopathy as displayed by magneticresonance imaging (MRI) and magnetic resonance angiography(MRA). Presented at: Annual Convention and ScientificAssembly of the National Medical Association; August 1-6, 1998,New Orleans, LA.

19. Lehman LJ, Warfield CA, Bajwa ZH. Migraine headachefollowing stellate ganglion blockade for reflex sympathetic dys-trophy. Headache. 1995;36:335-337.

20. Uyemaya T, Kugimiya T, Ogawa T, Kandori Y, IshizukaA, Hanaoka K. Changes in cerebral blood flow estimated afterstellate ganglion block by single-photon emission computedtomography. JAuton Nerv Syst. 1995;50:339-346.

21. Saxton EH, Collins JD, Miller TQ Migraine complicat-ed by brachial plexopathy as displayed by MRI and MRA.Presented at: 15th Annual Scientific Program of the AmericanAssociation of Clinical Anatomists; June 9-13, 1998; Lexington,KY.

22. Saxton EH, Collins JD, Ahn S, Miller TQ Venousobstruction in brachial plexopathy as displayed by MRI, MRA,and 3D reconstruction in migraine patients with thoracic outletsyndrome. FASEBJ 1999;12:A676.

23. CollinsJD, Shaver ML, Disher AC, Miller TQ Bilateralmagnetic resonance imaging of the brachial plexus and peripher-al nerve imaging; technique and three-dimensional color. In:Omer GE, Spinner M, Van Beek AL. Management of PeripheralNerve Problems. 2nd ed. Philadelphia, PA: WB Saunders Co;1998:82-93.


migraine complicated by brachial as displayed by mri … · brachial plexopathy figure 1. coned...

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