Ultrasound Imaging of the Brachial Plexus Thoracic Outlet Syndrome and the Pectoral Bowing Ratio

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Ultrasound Imaging of the Brachial Plexus Thoracic Outlet Syndrome and The Pectoral Bowing Ratio

BENJAMIN M. SUCHER, D.O., FAOCPMR-D, FAAPMR

ETIOLOGY OF TOS

Myofascial v. Ribs/Bands Between Anterior and Middle Scalenes Under Pectoralis Minor (against Rib 1,2) Costoclavicular (between Clavicle and 1st Rib) Fibrous Bands -off rudimentary Rib/Transverse Process- Roots/Plexus “tethered”

Trauma-Episodic

Insidious-CTD, Postural

ETIOLOGY OF TOS Myofascial Pectoralis Minor (compressed or ‘tethered’) Cooper’s ligaments - traction Insidious- Postural

Average weight: 2-4lbs each

Suspensory Ligaments Often referred to as Cooper's Ligaments , these are the fibrous connections between the inner side of the breast skin and the pectoral muscles . Working in conjunction with the fatty tissues and the more fibrous lobular tissues, they are largely responsible for maintaining the shape and configuration of the breast. They bear a major portion of the task of preventing breast ptosis (sagging).

1 PATHOLOGY / TYPES OF TOS NEUROGENIC -True -Disputed -Nonspecific -Postural?

VASCULAR -Venous -Arterial -Mixed

COMBINED

INCIDENCE OF NEUROGENIC TOS

One per Million

Only 250 Surgical Candidates in U.S.

Cherington, et.al., Muscle Nerve, 1988

INCIDENCE OF TOS

23% (2000 PATIENTS) OF SOFT TISSUE C-SPINE INJURIES

72% DIAGNOSED INCORRECTLY 98% “missed” during initial ED eval

Woods, Modern Medicine, 1978 Schukla and Carlton, Southern Med J, 1996

2 THE BRACHIAL PLEXUS

DIFFERENTIAL DIAGNOSIS

RADICULOPATHY PLEXOPATHY (TOS)

Multiple Other Sites of Compression RADIAL Spiral groove Tunnel Consider:

Ligament of Struthers Peripheral Neuropathy CNS pathology Vascular pathology Pronator Syndrome Tendonitis Anterior Interosseous nerve syndrome DJD/OA Rheumatoid Disease Guyon’s Canal Ganglion, Tumor Infection

DIFFERENTIAL DIAGNOSIS OF TOS

1. Carpal Tunnel Syndrome

2. Ulnar Neuropathy-(Cubital Tunnel, Guyon’s Canal)

3. Cervical Radiculopathy

4. Cervical Myelopathy

5. Pancoast Tumor

3 DIAGNOSTIC STRESS TESTS FOR TOS

SCALENE PECTORALIS

Focal Regional Focal Regional

DIAGNOSIS OF TOS – STRESS TESTS Abnormal Results in Healthy Subjects

Maneuver Altered Pulse Pain Paresthesia

Adson’s 11% 0% 11%

CostoClavic 11% 0% 15%

EAST 62% 21% 36%

Supraclav Press 21% 2% 15%

Plewa and Delinger, Acad Emerg Med, 1998

DIAGNOSTIC TESTS FOR TOS

1. X-RAY

2. CT / MRI

3. Doppler / PPG

4. Angiography / Venography

5. EDX- EMG / NCS

6. Autonomic Assessment

7. Ultrasound

4 DIAGNOSTIC TESTS FOR TOS

Anatomic v. Physiologic Vascular v. Neurologic X-Ray Autonomic Autonomic Autonomic Assessment Assessment Assessment

MRI Scan MRI Scan MRI Scan

Doppler/Photo- Doppler/Photo- plethysmography plethysmography

CT Scan EDX EDX

Angiography/ Angiography/ Venography Venography

Ultrasound Ultrasound Ultrasound Ultrasound

ELECTRODIAGNOSIS OF TOS

1. Low amplitude median motor response 2. Low amplitude ulnar sensory response 3. Normal median sensory amplitude …..…………………………………………….Wilbourn4. Neurogenic MUP C8-T1 5. Abnormal MAC-low amplitude 6. Prolonged F-wave/Axillary F-Loop 7. Abnormal C8 Root Stim (amp / latency) 8. Abnormal Ulnar SEP: N9, N9 -13

Wilbourn Tetrad of EDX Abnormalities* with TOS 1. Low amplitude median CMAP < 50% contralateral

2. Low amplitude ulnar SAP < 50% contralateral

3. Normal median SAP

4. Neurogenic MUP C8-T1

5. Relatively low or normal ulnar CMAP

The combination of above findings is “almost distinct for this syndrome”

*In order of prevalence

5 Why Normal EDX in TOS???

“...in moderate compression…normal fascicles adjacent to abnormal fascicles…suggests the basis for the frequent paradox of the patient ..with marked symptomatology but normal electrodiagnostic findings.

The abnormal findings in the ‘worst’ fascicles account for the patient’s symptoms, whereas the normal large myelinated fibers in the ‘better’ fascicles account for the normal electrodiagnostic studies.”

Mackinnon, Hand Clinics, 1992

Ultrasound Imaging of the Brachial Plexus

PMaj

PMM L AA M AV P

POSTERIOR

L = Lateral Cord PMaj = Pectoralis Major M = Medial Cord PMM = Pectoralis Minor P = Posterior Cord AA = Axillary Artery AV = Axillary Vein

TOS Case #1 48 y/o female with left UE pain, numbness/tingling and weakness, for the past 2 months. Paresthesias involve the entire hand, especially medial, and medial forearm, worse at night and with driving or keyboard activity, especially with arms overhead. Treatment with wrist and elbow braces did not provide relief.

PE: Normal, except for positive Phalen and Tinel testing over the carpal and cubital tunnels. Posture revealed anterior head/shoulder position, and thoracic outlet stress was positive with abduction and focal pectoral stress.

EDX: Median DML 3.4ms / 13mV [ Ulnar 2.6 / 17mV; no slowing across elbow ] Median DSL D-1 2.8ms / 32mcv [ Radial 2.5 / 15mcv ] Median DSL D-2 3.4ms / 38mcv [Ulnar 3.1ms / 39mcv] Median F-wave 26.0ms Ulnar F-wave 26.2ms

6 TOS Ultrasound Medial cord plexus irritation During arm abduction Pectoralis minor

Axillary artery Pec major

Axillary vein

DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress - Normal Subject

Neutral – arm adducted at side Abduction stress – 140 degrees No symptoms No symptoms Note linear orientation of pec minor Note persistent linear orientation of pec (no indentation) Note position of plexus to pec minor (no compression; good clearance)

DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress Test

Neutral: Abduction stress: Arm adducted at side Progressive, up to 125 degrees No symptoms Symptoms exacerbated Linear orientation of pec minor Note indentation of pec minor by Neurovasc bundle from below (dorsal) EDX: Median DML 2.8ms / 16mV [ Ulnar 2.3 / 15mV; no slowing across elbow ] Median DSL D-2 3.2ms / 43mcv [ Ulnar D5 = 3.0ms / 32mcv ]

7 TOS Case #2

52 y/o female with right UE pain, numbness and tingling, for the past month. Most paresthesias involve the medial forearm and hand, worse with the hand raised overhead (i.e., grooming).

PE: Posture exam revealed anterior shoulder protraction (R>L), and positive thoracic outlet stress testing (with abduction and focal pectoral pressure).

EDX: Median DML 3.3ms / 10mV [ Ulnar 3.1 / 12mV; no slowing across elbow ] Median DSL D-1 2.6ms / 55mcv [ Radial 2.8 / 16mcv ] Medial Antebrachial Cutaneous amplitude = 8mcv R; 18mcv L Median F-wave 28.2ms [L side = 27.2] Ulnar F-wave 27.4ms [L side = 26.4]

DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress Test (case #2)

Neutral: Arm partially abducted Abduction stress: No symptoms Progressive, up to 130 degrees Linear orientation of pec minor Symptoms exacerbated Note indentation of pec minor by Neurovasc bundle from below (dorsal) Medial cord ‘tucked’ against underside of pec minor; lateral cord is clear

Pectoral Bowing Ratio - Normal

Normal Subject

D Pectoralis minor A C B

POSTERIOR A-B = 28mm C-D = 1mm C-D/A-B = .036 = 3.6% Pectoral Bowing Ratio

8 Pectoral Bowing Ratio - TOS TOS Case

D Pectoralis minor B A C

A-B = 21mm C-D = 5.5mm C-D/A-B = .262 = 26.2% Pectoral Bowing Ratio

TOS Case #3

41 y/o female with right UE pain, numbness/tingling and weakness, for the past year. Paresthesias involve the entire hand (all digits), worse at night or with activity (drawing, painting).

PE: Posture exam revealed moderate anterior head protrusion and shoulder protraction (R>L), and positive thoracic outlet stress testing (with hyperabduction).

EDX: Median DML 2.9ms / 19mV [ Ulnar 2.9 / 21mV; no slowing across elbow ] Median DSL D-1 2.7ms / 39mcv [ Radial 2.7 / 13mcv ] Median Mixed Nerve latency = 2.0ms [ulnar = 1.9ms]

DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress Test (case #3)

PBR = 13%

Neutral: Abduction stress: Arm slightly abducted Progressive, up to 120 degrees; Symptoms exacerbated No symptoms Note indentation of pec minor; Medial and lateral cords ‘tucked’ against underside of pec minor

Left side Asymptomatic

PBR < 1%

9 DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress Test

39 y/o female with 3mo hx R-UE pain, numbness/tingling, weakness primarily lateral arm and first 2-3 digits, worse with keyboard use

PE unremarkable: neg Spurling, Tinel, Phalen tests; but posture revealed anterior/protracted right shoulder, and positive TOS stress with hyperabduction and focal pectoral pressure.

EDX: Median DML = 2.8ms / 14mV [ulnar 2.6ms/15mV] Median DSL = 2.6ms / 44mcv [radial 2.4ms/15mcv] Median F-wave = 25.6ms [ulnar 26.0ms]

DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress Test (prior case)

Pectoral Bowing Ratio - TOS

Pectoralis minor c = coracoid

A-A = 15mm B-B = 3.5mm B-B/A-A = .233 = 23.3% Pectoral Bowing Ratio

28 y/o female with several mo hx R-UE pain, tingling and weakness; all digits, diffuse upper limb symptoms worse with typing, driving and arms elevated

PE unremarkable: neg Spurling, Tinel, Phalen tests; but posture anterior head protrusion and shoulder protraction, and positive TOS stress with hyperabduction.

EDX normal: Median DML = 2.8ms / 14mV [ulnar 2.4ms/18mV] Median; DSL = 2.3ms / 64mcv [radial 2.2ms/25mcv] Median F-wave = 24.2ms [ulnar 23.4ms]

10 DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress Test

DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress Test (prior case)

53 y/o female with 5mo hx R-UE numbness and tingling, primarily in the first 3-4 digits (and forearm), worse at night and with keyboard use

PE: neg Spurling test, pos Tinel and Phalen tests; posture revealed anterior/protracted right shoulder, and positive TOS stress w/hyperabduct.

EDX: Median DML = 4.0ms / 11mV [ulnar 2.8ms/16mV] Median D1 DSL = 2.9ms / 29mcv [radial 2.6ms/13mcv] Dif = .3ms Median D4 DSL = 3.5ms / 17mcv [ulnar 3.1ms/21mcv Dif = .4ms Median Mixed latency = 2.2ms [ulnar 1.9ms] Dif = .3ms CSI mildly elevated = 1.0ms

DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress Test

44 y/o female with 6 month hx diffuse R-UE pain, tingling and weakness, worse at night.

PE unremarkable: neg Spurling, Tinel, Phalen tests; but posture revealed moderate right shoulder protraction, and positive TOS stress with hyperabduction

EDX: Median DML = 3.3ms / 18mV [ulnar 2.7ms/14mV] Median DSL = 2.7ms / 32mcv [radial 2.7ms/13mcv] Median F-wave = 27.5ms [ulnar 27.2ms]

11 DIAGNOSTIC ULTRASOUND OF TOS – Abduction Stress Test

Neutral: Abduction stress: Arm adducted at side Progressive, up to 135 degrees No symptoms Symptoms exacerbated Linear orientation of pec minor Note indentation of pec minor by Neurovasc bundle from below (dorsal) [lateral cord + medial cord] 39 y/o male with 1yr hx diffuse R-UE tingling, worse with activity

PE unremarkable: neg Spurling, Tinel, Phalen tests; but posture revealed moderate anterior head protrusion and right shoulder protraction, and positive TOS stress with hyperabduction

EDX: Median DML = 3.6ms / 14mV [ulnar 3.0ms/17mV] Median DSL = 2.7ms / 41mcv [radial 2.7ms/10mcv] Median F-wave = 27.3ms [ulnar 27.0ms]

THE ELECTRODIAGNOSTIC REPORT

Report the abnormality (Interpretation): Most often: “No abnormalities noted”…..or: “....prolongation of the F-wave latencies on the left, consistent with proximal slowing (at the plexus level) due to focal demyelination….low amplitude of the left medial antebrachial cutaneous nerve response, consistent with partial axon loss….”

Diagnostic ultrasound imaging (high resolution, 4-15MHz linear transducer) of the left shoulder (infraclavicular region) reveals normal appearance of the neurovascular bundle and pectoralis minor muscle (transverse imaging). However, during progressive arm abduction, the medial and lateral cords of the brachial plexus (and axillary artery) contact and ‘indent’ the posterior edge of the pectoralis minor, as upper limb symptoms develop and increase. The pectoral bowing ratio is abnormally elevated at 120 degrees of abduction to 16.2% (normal <10%).

Summarize with ‘Impressions’ or ‘Conclusions’: 1. No electrical evidence of radiculopathy, plexopathy, nerve injury… 2. Left thoracic outlet syndrome (brachial plexopathy) - postural type; electrically negative (or….‘very mild, electrically’)

MANIPULATIVE TREATMENT of TOS

PECTORALIS MINOR

12 MANIPULATIVE TREATMENT of TOS

SCALENUS ANTERIOR & MEDIUS

PECTORALIS MINOR

Ultrasound-Guided Manipulation of TOS

Pre-manipulation abduction stress Post-manipulation abduction stress Symptoms; PBR = 13.6% No symptoms; PBR = 0

pmaj manip of pect minor

pmin

32 y/o female, 18mo hx of left UE pain, numbness, weakness. Numbness into all digits, especially #s 3-5 and medial forearm, worse with arm elevated. EDX completely normal. Posture - protracted shoulder. Positive hyperabduction stress test.

Ultrasound-Guided Manipulation of TOS

Local Twitch Response

13 Ultrasound-Guided Manipulation of TOS

pmaj

pmin

Pre-manipulation abduction stress Post-manipulation abduction stress Symptoms; PBR = 16.3% Minimimal symptoms; PBR = 5.9%

Notice change in lateral cord shape (from oval to ellipsoid)

48 y/o female, several year hx of Right upper limb pain, numbness, and weakness. Numbness into the lateral 3 digits, worse with arm elevated. EDX completely normal. Posture - protracted shoulder. Positive hyperabduction stress test and focal pectoral pressure.

Ultrasound-Guided Manipulation of TOS

Pre-manipulation abduction stress Post-manipulation abduction stress Symptoms; PBR = 11.4% No symptoms; PBR = 4%

manip of pect minor

42 y/o female, 3mo hx of left UE pain, numbness, tingling, weakness. Numbness into all digits, and the forearm. EDX completely normal. Posture - protracted left shoulder. Positive hyperabduction and focal pectoral stress test.

Ultrasound of the Brachial Plexus - Supraclavicular

C6 roots

Bony tubercles

14 REFERENCES

1. Sucher BM: Thoracic outlet syndrome – A myofascial variant: Part 1. Pathology and diagnosis. JAOA 1990;90:686-704.2. 2. Sucher BM: Thoracic outlet syndrome. In: Plexopathy (section). Physical Medicine and Rehabilitation (textbook). eMedicine (www.eMedicine.com) April, 2001 (Updated and republished: Feb 25, 2015). 3. Mackinnon SE, Patterson GA, and Novak CB: Thoracic outlet syndrome: A current overview. Seminars in Thoracic and Cardiovascular Surgery 1996;8:176-182. 4. Mackinnon SE and Novak CB: Evaluation of the patient with thoracic outlet syndrome. Seminars in Thoracic and Cardiovascular Surgery 1996; 8:190-200. 5. Ferrante MA: Brachial plexopathies: Classifications, causes, and consequences. Muscle & Nerve 2004;30:547-568. 6. Wilbourn AJ: Case Report #7: True neurogenic thoracic outlet syndrome. American Association of Electromyography and Electrodiagnosis. 1982. 7. Cuetter, AC and Bartoszek DM: The thoracic outlet syndrome: Controversies, overdiagnosis, overtreatment, and recommendations for management. Muscle & Nerve 1989;12:410-419. 8. Stewart JD: Brachial plexus. In: Focal Peripheral Neuropathies. West Vancouver, JBJ Publishing. 2010, pp. 120-161. 9. Sucher BM: Palpatory diagnosis and manipulative management of carpal tunnel syndrome: Part 2. ‘Double crush ’ and thoracic outlet syndrome. JAOA 1995;95:471-479. 10. Hong C-Z and Simons DG: Response to treatment for pectoralis minor myofascial pain syndrome after whiplash. J Musculoskel Pain 1993;1:89-131. 11. Sucher BM and Glassman JH: Upper extremity syndromes. In: Stanton D and Mein E (eds): Manual Medicine. Physical Medicine and Rehabilitation Clinics of North America. Philadelphia, WB Saunders Co, 7:4:787-810, Nov, 1996. 12. Sucher BM: Thoracic outlet syndrome – Postural type: Ultrasound imaging of pectoralis minor and brachial Plexus abnormalities. PM&R 2012;4:65-72.

References (cont)

13. Simons DG, Travell JG, and Simons LS: Pectoralis minor muscle. In: Travell & Simons ’ Myofascial Pain and Dysfunction: The Trigger Point Manual. Volume 1. Upper Half of the Body (2nd Ed). Baltimore, Williams & Wilkins, pp. 844-856. 14. Ahuja AT, Antonio GE, Griffith JF, et al: Thoracic outlet, In: Diagnostic and Surgical Imaging Anatomy Ultrasound. Amirsys, Salt Lake City, 2007, pp. III: 10-19. 15. Kovacs P and Gruber H: Interventional techniques, In: Peer S and Bodner G (eds): High Resolution Sonography of the Peripheral Nervous System. Springer, 2008, pp. 169-185. 16. Caress JB and Walker FO: Ultrasound of peripheral nerves: An AANEM Workshop. In: Muscle Ultrasound and Ultrasound of Peripheral Nerves – 2006 AANEM Annual Scientific Meeting, American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM). 2006, pp. 1-4. 17. Martinoli C Bacigalupo LE, Damasio MB, et al: High-resolution sonographic imaging of the neuromuscular system. In: Emerging Concepts and Technologies in Neuromuscular Medicine - 2005 AANEM Plenary Session, American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM), 52nd Annual Scientific Meeting, Monterey, CA. 2005, pp 43-50. 18. Bodner G: Nerve compression syndromes, In: Peer S and Bodner G (eds): High Resolution Sonography of the Peripheral Nervous System. Springer, 2008, pp. 71-122. 19. Peer S: High resolution sonography of the peripheral nervous system: General considerations and technical concept, In: Peer S and Bodner G (eds): High Resolution Sonography of the Peripheral Nervous System. Springer, 2008, pp.1-13. 20. Totten PA and Hunter JM: Therapeutic techniques to enhance nerve gliding in thoracic outlet syndrome and carpal tunnel syndrome. Hand Clinics. 1991;7:505-520. 21. Sucher BM: Thoracic outlet syndrome – A myofascial variant: Part 2. Treatment. JAOA 1990;90:810-823. 22. Sucher BM and Heath DM: Thoracic outlet syndrome – A myofascial variant: Part 3. Structural and postural considerations. JAOA 1993;93: 334-345. 23. Tsujii M, Hirata H, Morita, and Uchida A: Palmar bowing of the flexor retinaculum on wrist MRI correlates with subjective Reports of pain in carpal tunnel syndrome. Journal of Magnetic Resonance Imaging. 2009;29:1102-1105. 24. Sucher BM: Ultrasonography-guided osteopathic manipulative treatment for a patient with thoracic outlet syndrome [case Report]. J Am Osteopath Assoc. 2011;111(9):543-547.