2019

Plexopathies: Complex & PerplexingRyan D. Jacobson MDAssistant Professor of NeurologyRush University Medical Center, Chicago IL

2019

Financial Disclosure• I have no relevant disclosures

2019

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Agenda

• Goal: to provide a case-based discussion of common and uncommon issues in the neuromuscular evaluation of brachial plexopathies with focus on key clinical pearls

• The approach will be more clinical and decision-making based rather than anatomic or electrodiagnostic.

Agenda

• Brachial Plexus Anatomy & Trauma

• Brachial Neuritis / Parsonage-Turner Syndrome– Pathophysiology & Anatomic Specifics– Imaging– Prognosis– Rare Causes & Associations

• Malignancy: Infiltration vs. Radiation

• We will not delve into MR vs. ultrasound evaluation of the plexus much.

• Part 1: Brachial Plexus Anatomy & Trauma

Case 1: Caught in the Crossfire• 27-year-old man presents for evaluation of right hand pain and

weakness• 4 months prior, he was caught in the crossfire at a gas station, and

shot in the right chest. Bullet exited right armpit.• Immediately thereafter, the right arm was “frozen.”

Case 1, continued

• Over the subsequent months, his right arm strength has improved markedly.

• However, he continues to experience severe weakness of the right hand.

• He has numbness over the right 4th and 5th digits, and medial hand.

• Referred for EMG to evaluate localization of lesion, for prognostication

Case 1, examination

• On focused examination, there is wasting of the right hand intrinsics and the anterior forearm.

• There is weakness of the deep finger flexors, interossei, abductor pollicis brevis, flexor pollicis longus, and wrist flexors.

• Proximally, the arm is strong, and pronation, wrist extension, and finger extension seem strong.

• Pinprick is diminished over the 5th digit and medial 4th digit.

Where would you localize this patient’s symptoms?

• C8 nerve root?

• Lower trunk of the brachial plexus?

• Medial cord of the brachial plexus?

• Lateral cord of the brachial plexus?

42 patients seen following World War 2 with penetrating brachial plexus injuries.

13 upper trunk injuries – all recovered antigravity strength

21 injuries of posterior cord – majority recovered antigravity strength

25 injuries of C8/ T1 / medial cord. – any recovery rare

• Part 2: Brachial Neuritis / Parsonage-Turner Syndrome

Inflammatory: Neuralgic Amyotrophy, Brachial Plexitis, Parsonage Turner Syndrome

• Tend to have unilateral pain, followed by weakness and wasting

• Tends to affect upper trunk, tends to be very patchy• Special predilection for long thoracic nerve, suprascapular

nerve, sometimes distal involvement (AIN)• Pathology microvasculitic• Prognosis for continued recovery good• Steroids: may help pain, little evidence for help in motor

recovery• MRI may be abnormal but mostly a clinical diagnosis

What’s in the literature?

Annual incidence of 1.64 per 100,000 population

Precipitating Causes

• Early case series:– Spillane 1946: 26 of 46 cases were already hospitalized at the time of

presentation– Parsonage and Turner: some precipitating factor or illness in 98 of 136.

66 were already hospitalized

Prognosis and Natural History

• Early reports from Parsonage and Turner (1957)

Treatment of Parsonage-Turner?

• Tsairis, 1972: 10 patients given oral prednisone, 5 given IM ACTH, 15 with cortisone injections into the shoulder. Some pain relief.

• Van Alfen 2006: 41 of 246 patients treated with corticosteroids (oral). 25% found it helpful, median time to decrease in pain was 5 days compared to 20 days.

• Van Eijk 2009: 50 patients treated with oral prednisone for a month and compared to historical controls. See next slide.

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Case 2: Inpatient with Shoulder Pain

• 69-year-old man with multiple myeloma presented for evaluation of right shoulder pain and weakness

• History of multiple myeloma 9 months prior when he presented with back pain and compression fracture. X-rays revealed numerous lucencies.

• SPEP/IFIX abnormal, and bone marrow biopsy consistent with myeloma

• Treated with Bortezomib, Lenalidumide, Dexamethasone

Case 2, continued

• Admitted 3/2017 for autologous stem cell transplant with melphalan conditioning “PBSCT”

Case 2, continued• 3/13, 3/14/17: Melphalan infusion• 3/15/17: PBSCT• 3/20/17: developed severe right shoulder

pain and received morphine• 3/21/17: notes difficulty in lifting arm above

his head• 3/24/17: neurology consultation, unable to

abduct shoulder• 3/27/17: discharged from hospital

EMG, 4/7/2016

Case 2, continued

• 4/18/17: follows up in neurology clinic.

• Examination: atrophy of right infraspinatus. Full strength other than:– R Deltoid 2/5 strength– R Infraspinatus 3/5 strength– No obvious scapular winging

Diagnosis?

Brachial Neuritis

Why?

• Several autoimmune complications, including neuromuscular complications, possible after allogeneic SCT

• Case 1: autologous SCT, melphalan. Bilateral upper extremity weakness and areflexia 14 days later.

• Case 2: autologous SCT, melphalan. Bilateral upper extremity weakness and wrist drop “within 14 days.”

• Case 3: autologous SCT, melphalan. Unilateral hand pain and C5/C6 myotome weakness 14 days later.

Case 3: Swim in the Ganges gone wrong

• 29-year-old man is referred for evaluation of left shoulder pain and weakness

• Recently admitted for acute liver failure• Traveling in India from mid-December through

mid-March 2017• In mid-March, he went swimming in the Ganges

River with his roommate to celebrate the end of the trip

Case 3, continued

• Late March 2017: developed fever, chills, nausea, and abdominal pain. Developed unusual “greasy” bowel movements

• 4/8/2017: transferred to academic center

Case 3, continued

• 4/9/2017: begins to note unusual, vague, dull left shoulder pain

• 4/10/17: noted to have numbness, paresthesias over left L deltoid muscle. PT notes difficulty with shoulder abduction and external rotation. X-ray normal.

Case 3, continued

• 4/21/2017: continues to note severe L shoulder pain and mild shoulder weakness.

5/8/17• Neurology visit: pain has improved to 4/10 severity, but still with severe

left shoulder pain

Hepatitis E

• ssRNA virus• Spread by fecal-oral route, blood. Often spread through drinking

water.• Most common cause of acute infectious hepatitis in the world.• Only 2-5% of infected patients are symptomatic.• Endemic in Asia, Africa

• About 30-40 cases in the literature• None in the US as far as I can tell • 26 of the 30 with bilateral involvement

Case 3, update

• Prescribed 50 mg prednisone

• Physical therapy

• Weakness gradually improved

Case 4: Complex Patient with a Floppy Thumb

• 49 year old man presents for evaluation of left thumb weakness• History of lupus nephritis, renal transplant• About 5 weeks ago, fell about 8 feet and bruised his ribs, spent

two days in bed• While in bed, noted worsening left shoulder, elbow, and hand pain

Case 4, continued

• While recovering, noted that his left thumb was weak and could not be bent correctly.

• Also developed unusually severe pain over the pad of the left thumb.

• Over time, the pain has gradually improved but severe thumb flexion weakness persists.

Case 4, examination

General: old fistula site in left volar mid forearm

Neurologic ExamMotor: full strength other than no movement of left thumb flexion. Thumb opposition, abduction strong. Pronation strong, finger flexion strong.Sensory: pinprick sensation normal throughout

Predilection for the AIN

• First seen by Parsonage & Turner, further defined by Kiloh and Nevin (1952)

• Reviewed 16 cases of AIN palsy• 4 traumatic, 12 spontaneous

ANTERIOR INTEROSSEOUS NERVE PALSYA review of 16 cases

M. K. SOOD and F. D. BURKE

From the Pulvertaft Hand Centre, Derbyshire Royal Infirmary, Derby, UK

• Part 3: Malignancy, Infiltration vs. Radiation

Case 5

• 63 year old woman presents for evaluation of right arm weakness and numbness• 2014: diagnosed with R breast cancer, treated with surgery, radiation, chemotherapy• 2016-2017: presented with recurrent disease affecting R chest skin, R chest wall. Treated

with chemotherapy• 2017: underwent right carpal tunnel release

Case 5

• She now presents to the neurology clinic for worsening R arm symptoms.

• Despite CTS surgery, she has worsening numbness of the lateral hand and lateral forearm

• Also notices mild weakness of the R arm

Case 5

• Exam:4-/5 weakness in R bicepsTrace weakness R deltoid, triceps, infraspinatus.Hyporeflexic throughout.Diminished pinprick sensation over lateral hand and forearm.

MR Brachial Plexus

Neoplastic Plexopathy

• Most common in lung/breast cancer• More likely to affect the lower trunk• More likely to be painful• EMG: dysfunction in distribution of injury• Imaging: may show enhancement, nodularity, presence of tumor

Radiation Plexopathy

• Most common following treatment of breast cancer• Tends to develop insidiously over months – mean of 10 months after radiation

completion• More likely to affect upper trunk• Less likely to be painful• EMG: dysfunction in distribution of injury, fasciculations and myokymia• Imaging: may show hyperintensity, enhancement of plexus

• THANK YOU

• Please see the printed handout for references.