1. Non-Traumatic Brachial Plexopathy All that radiates…..

2. Disclosure I have NO RELEVANT financial disclosures.

3. What’s on the menu today? Review common brachial plexopathies Discuss key history and physical examination issues which differentiate plexus from radiculopathy Discuss positives and pitfalls of major diagnostic studies

4. Brachial Plexopathy Brachial Plexus Neuropathy (Neuralgic amyotrophy ) (Parsonage-Turner) True neurogenic thoracic outlet syndrome Diabetic cervical radiculoplexus neuropathy Malignancy – Primary tumor – Malignant invasion – Radiation

5. Brachial plexopathy Traumatic plexopathy Perioperative plexopathy Stinger/burner Hematoma/ false aneurysm Perioperative – Stretch neck/ shoulder – Medial sternotomy – Regional anesthesia – Local shoulder surgery – Brachial plexus neuropathy

6. Neuralgic Amyotrophy: Parsonage and Turner Syndrome

7. History – Sudden onset of severe pain, often nocturnal, followed by weakness – Pain presents in cervical spine or shoulder blade and upper arm – Pain often diminishes or resolves after weakness develops – Often preceded by infection, trauma, vaccination, surgical intervention, stress

8. Neuralgic Amyotrophy: Parsonage and Turner Syndrome Physical examination – Patchy findings which are not dermatomal; may be a combination of radiculopathy, brachial plexopathy and peripheral nerve abnormalities – Presentation (in order of frequency) Upper and/or middle plexus – Frequently with long thoracic nerve involvement Pan plexus > middle plexus/ posterior cord Lower plexus Anterior interosseus nerve predominant Van Alfen, 2006

9. NA: Diagnostic studies EMG: patchy findings of root/ plexus/ nerve Confounding factors include comorbidites or asymptomatic electrical findings MRI brachial plexus and shoulder – Most common abnormalities supra/infraspinatus – Acute: increase in T2 signal (muscular edema) – Subacute: T2 changes persist, atrophy may develop – Subacute to chronic: increased T1 signal due to fat infiltration (Scalf, 2007)

10. Neuralgic Amyotrophy: Differential diagnosis Cervical radiculopathy Brachial Plexopathy Peripheral nerve

11. True Neurologic Thoracic Outlet Syndrome

12. True Neurologic TOS Most common cause: cervical rib/band – Elongated transverse process of C7, band arises from this C7 to upper first rib – Other etiologies include anterior scalene injury – T1 stretched >C8 Levin, 1998

13. True Neurologic TOS History – Gradual onset of wasting and weakness of hand – Paresthesias of ulnar forearm and small finger – May have achiness in forearm Physical – Thenar weakness/ atrophy> than hypothenar muscles – Flexor forearm muscles weak – Sensory loss varies, may not split ring finger

14. True Neurologic TOS: Studies MRI/ Xray of cervical spine MRI brachial plexus Electrodiagnostic studies – Most sensitive findings: mabc snap often absent, ulnar snap low amplitude, median cmap low amplitude mabc and median cmap share T1 innervation Few small fibs in thenar > hypothenar musculature Levin 1998

15. True Neurologic TOS: Differential diagnosis Cervical radiculopathy (C8 or T1) – T1 results in more thenar weakness/ dermatomal findings (more T1 in APB) – C8 results in more hypothenar weakness/dermatomal findings Peripheral nerve Spinal cord injury Other brachial plexopathies Syrinx Motor neuron disease

16. Diabetic cervical radiculoplexus neuropathy

17. Diabetic cervical radiculoplexus neuropathy (Massie, 2012) Median age: 62 years old(32-83) Pain initial symptom followed by subacute progression of weakness and numbness Weakness is most common presenting complaint Involves motor, sensory and autonomic fibres Upper, middle and lower plexus equally involved

18. Diabetic cervical radiculoplexus neuropathy May precede or present simultaneously with lower extremity symptoms – Greater than 50% of patients had at least one other body region affected (contralateral extremity, lumbosacral, thoracic) Often improves over 2-9 months May recur

19. Diabetic cervical radiculoplexus neuropathy: studies Electrodiagnosis – Axonal neuropathy, paraspinal denervation Snaps/cmaps decreased, ncv normal Fibs, polys and large amplitude potentials in distribution of clinical complaints – Abnormal sensory and autonomic testing frequent MRI reveals brachial plexus abnormality Plexus>peripheral nerve increased T2 signal Nerve hypertrophy>contrast enhancement Muscle increased T2(edema) subacutely increased T1 (fat) chronically

20. Diabetic cervical radiculoplexus neuropathy: studies CSF protein elevated Pathology: ischemic injury secondary to microvasculitis

21. Diabetic cervical radiculoplexus neuropathy: Differential Diagnosis Radiculopathy Neuralgic amyotrophy Peripheral nerve CIDP Myelopathy

22. Brachial Plexus and tumors

23. Brachial plexus and Malignancy Malignancy (78%) – Primary tumor – Malignant invasion Radiation (22%) Kori, 1981

24. Brachial plexus and tumors Primary tumors (rarely malignant) – Primarily benign: peripheral nerve sheath tumors – Neurofibroma: Upper trunk, lateral cord Present with pain, supraclavicular mass Occasionally mild neurologic deficit – Schwannoma Often arise in spinal nerves Rare neurologic deficit – Intraneural perineurioma (rare) Slow progressive neurologic deficit

25. Brachial Plexopathy: malignant invasion Breast and lung (70%), followed by lymphoma Multiple others metastasize to upper lung before spreading to plexus (sarcoma, larynx, melanoma, bladder, etc) (Kori et al) Initial pain in shoulder to medial forearm/ulnar 2 fingers, can be severe in metastatic disease Weakness generally follows pain Sensory deficit in C7,C8 and T1 /medial cord distribution

26. Brachial plexopathy: Malignant invasion Primary tumors from head and neck may invade superior plexus Metastasis to lymph nodes may result in patchy involvement of plexus, but frequently involve lower trunk due to proximity of lateral axillary lymph nodes Significant number of patients have epidural extension of disease (Jaeckle, 2010)

27. Pancoast syndrome Superior pulmonary sulcus tumor – Tumor at apex of lung invades lower trunk/ medial cord – Pain along medial arm – Horner’s syndrome (2/3 of patients) Paravertebral tumor near T1, involves the sympathetic trunk or ganglia

28. Brachial Plexopathy post radiation treatment Most commonly delayed after radiation; risk is for the patient’s entire lifetime (3months – 26 years) Risk factors include – Technique – Total dose (>6000 rads, 50-74 Gy) – Dose/fraction – Radiation volume – Time from radiation – Radiation type – Concomitant use of chemotherapy – (Kori et al, 1981)(Stewart, 2010)(Jaeckle, 2010), (Stubblefield, MD, 2015)

29. Brachial Plexopathy post radiation treatment Rare complication: radiation-induced nerve sheath tumor of the brachial plexus (can be delayed for many years) Radiation-induced arteritis can result in ischemia in arm and hand (Kori et al, 1981)(Stewart, 2010)(Jaeckle, 2010)

30. Brachial plexopathy post radiation Most patients have sensory and motor abnormalities Edema in arm possible, but also seen with metastasis Presents with pain less commonly(18%) but can be severe and can develop later (65%) (Kori, 1981) Distribution is most commonly in upper trunk and less common “pan plexus” Horner’s syndrome less common than in direct metastatic spread – 14% with radiation vs 56% with metastasis (Kori, 1981) Can be progressive

31. Case One

32. Studies Radiation plexopathy: – Emg reveals fasciculations, myokymia, axonal damage – MRI/ CT scan chest and brachial plexus may need to repeated in 4-6 weeks if mass not seen – MRI cervical and thoracic spine if epidural spread a consideration – PET scan

33. Case 1 53 year old female 1-2 years of numbness in right arm 6 weeks ago patient wakes up with severe pain in the right upper extremity – Like a blood pressure cuff in upper arm radiating to the shoulder blade, no change in numbness

34. Case 1 3 days later patient receives cervical epidural. 3 days later patient notes weakness in right hand 1 week later patient has pronator teres injection and pain improves although no change in weakness or numbness

35. Case 1 At time of evaluation (6 weeks after onset of symptoms), no pain in cervical spine or upper extremity Arm is stiff from elbow to hand No change in numbness in right hand

36. Physical examination Cervical and shoulder mobility full 4/5 shoulder abductors, external rotators 4/5 abductor pollicis brevis 0/5 flexor digitorum profundus (median distribution) flexor pollicis longus DTR biceps 1/ 4 bilaterally Sensation decreased over distal volar thumb

37. Studies Cervical MRI: small noncompressive central disc herniation at C56 Ultrasound : pronator teres entrapment and median nerve entrapment at wrist

38. EMG/NCV 6 weeks post flare EMG – Median FDP and FPL spontaneous activity – FDP repetitive fire – FPL no voluntary potentials – APB normal, as is rest of screen NCV – Decreased amplitude right LAC (borderline) – Right Median mixed motor sensory prolonged

39. Differential Diagnosis Cervical Radiculopathy Brachial Plexopathy: Neuralgic amyotrophy Peripheral nerve lesion: anterior interrosseus syndrome, carpal tunnel, pronator syndrome

40. Actual treatment 1 month later: – Median nerve decompression at wrist – Median and anterior interosseus neurolysis – 5 months later “good” recovery of FDP, FPL What do you think now?

41. Controversy at the Rothman Institute! Disputed – Surgeon: pronator syndrome/anterior interrosseus syndrome Median nerve released at the pronator teres and carpal tunnel and patient ultimately recovered strength – Freedman: Neuralgic Amyotrophy Patient would have improved with or without surgery Acute, proximal pain, followed by weakness Patchy exam LAC involvement in addition to anterior interosseus

42. Conclusions History and physical is critical MRI/EDX may help to confirm diagnosis or be a trap Diagnosis can not be made in isolation of the history and physical