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PassPMR - 04 Electrodiagnostic Medicine > 3 - Radiculopathy & Pelexopathy > Flashcards

3 - Radiculopathy & Pelexopathy Flashcards

1
Q
A
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2
Q

List 6 Muscles With Dual Innervation 🔑

A

Cuccurollo 4th Edition Chapter 5 EDX pg382

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3
Q

Describe the difference between the dorsal and ventral rami of the spinal cord.

A

Origin

Both (dorsal roots and ventral roots) exist from spinal cord

They join beyond the dorsal root ganglion.

Dorsal Rami

Innervate the paraspinal muscles

Carry sensory information from overlying skin

Ventral Rami

Innervate anterior horn motor neurons of muscles of the cervical, brachial, or lumbosacral plexus.

Contains axons originating from sensory and sympathetic ganglia

Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg95

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4
Q

At which level do the lumbar nerve roots exit? Which root is most likely to be injured in a disc herniation? for i.e. L5/S1 🔑🔑 EXAM 2021

A

Lateral L3-L4 disc → L3 nerve root affected

  • Pain and sensory changes in anterior thigh
  • Weakness in hip flexors/knee extensors
  • Decreased patellar tendon reflex

Central L5-S1 disc herniation → S1 nerve root affected

  • Pain and sensory changes to posterior thigh/leg
  • Weakness to plantar flexion, hamstrings
  • Decreased ankle jerk reflex

Cuccurollo 4th Edition Chapter 4 MSK pg289

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5
Q

What is the distinction between spondylosis, spondylolisthesis, and spondylolysis? 🔑🔑 EXAM

A

Spondylosis

Nonspecific degenerative process of the spine, often due to osteoarthritis with osteophyte formation

Spondylolisthesis

Anterior subluxation of one vertebral body on another

Spondylolysis

Defect in the pars interarticularis that allows the vertebra to slip upward

Neurology Secrets 6th Eiditon Chapter 7 Radiculopathy pg95

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6
Q

What is the difference between a disc bulge, protrusion, and herniation 🔑🔑

A

Cuccurollo 4th Edition Chapter 4 MSK pg288-289

Spinal Cord Abutment

Epidural extension without cord compression

https://radiopaedia.org/articles/epidural-spinal-cord-compression-escc-scale-2

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7
Q

What are the non-discogenic non-spondylitic causes of radiculopathy? 🔑🔑

A
  1. Tumors
  2. Abcess
  3. Hermorrhage
  4. Cysts
  5. Infection: TB, Syphilis, HIV infection
  6. Arachnoiditis

PMR Secrets 3rd Edition Chapter 17 pg142

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8
Q

List 8 causes of radiculogpthy.

What are the two most common?

A

💡 Non-traumatic Cervical Myelopathy 1) Spondylosis 2) Stenosis.

Causes of radiculogpthy:

  1. Herniated nucleus pulposus (HNP) < 50 years
  2. Spinal stenosis > 50 years old
  3. Mass in the spine: lipoma
  4. Abscess
  5. Hematoma
  6. Metastasis
  7. Inflammation Tuberculosis (TB)
  8. Infection Arachnoiditis
  9. Diabetes mellitus

Cuccurollo 4th Edition Chapter 5 EDX pg380

PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg142 Q2

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9
Q

What condition can mimic cervical radiculopathy? 🔑

A

💡 C5-C6 radicular pain from shoulder to thumb passing elbow.

1- Fibromyalgia

Pain all over, female predominance, sleep problems, tender to palpation in multiple areas

2- Regional myofascial pain

Trigger point reproducing localized or radiating pain syndrome

3- Polymyalgia rheumatica

Age >50 yr; pain and stiffness in neck, shoulders, and hips; high ESR, responde to steroid

4- Acromioclavicular joint arthropathy

Pain in anterior chest with shoulder movement, tender on palpation & crossed adduction

5- Sternoclavicular joint arthropathy

Pain in anterior chest, pain with shoulder movement, pain on direct palpation

6- Shoulder bursitis, impingement syndrome, bicipital tendonitis

Pain with palpation, positive impingement signs, pain in C5 distribution

7- Lateral epicondylitis, Tennis elbow

Pain in lateral forearm, pain with palpation and resisted wrist extension

8- de Quervain’s tenosynovitis

Lateral wrist and forearm pain, tender at APL & EPB tendons; positive Finkelstein test

9- Trigger finger, stenosing, tenosynovitis of finger flexor tendons

Intermittent pain and locking of digit in flexion

PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg145 Q7 Table 17-2

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10
Q

What condition can mimic lumbar radiculopathy? 🔑

A

💡 Think 3D from anterio-lateral-poaterior hip down to soles passing knees.

1- Fibromyalgia

Pain all over, female predominance, sleep problems, tender to palpation in multiple areas

2- Myofascial pain syndrome

Trigger point reproducing localized or radiating pain syndrome

3- Polymyalgia rheumatica

Age >50 yr; pain and stiffness in neck, shoulders, and hips; high ESR, response to steroid

4- Hip arthritis

Pain in groin, anterior thigh and weight-bearing, positive Patrick’s test

5- Trochanteric bursitis

Lateral hip pain, pain with palpation over lateral and posterior hip

6- Knee arthritis

7- Patellofemoral Pain

Anterior knee pain, worse with prolonged sitting, positive patellar compression test

8- Pes anserinus bursitis

Medial proximal tibia pain, tender to palpation

9- Hamstring tendinitis, chronic strain

Posterior knee and thigh pain, can mimic positive straight-leg raise, common in runners

10- Baker’s cyst

Posterior knee pain and swelling

11- Plantar fasciitis

Pain in sole of foot, worse with weight-bearing activities, tender to palpation

12- Gastrocnemius-soleus tendonitis, chronic strain

Calf pain, worse with sports activities, usually limited range of motion

PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg146 Q8 Table 17-3

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11
Q

Clinical Findings of Radiculopathies 3 marks 🔑🔑

A

LMN Syndrome:

  1. Sensory loss
  2. Radicular pain
  3. Muscle weakness
  4. Reduced reflexes
  5. Retention or Incontinence

PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg143 Q4

Cuccurollo 4th Edition Chapter 5 EDX pg380

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12
Q

60 yo man with neck pain, fasciculation on right deltoid and biceps. Mention the nerve root.

You evaluated a 60 year old man who has recurrent neck pain. On examination he has fasiculations of the right deltoid and biceps. What root represents the abnormalities seen in this man? (one mark)

A

C5 Motor root

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13
Q

MRI L4-L5 Disc, mention the root affected 🔑🔑

A
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14
Q

Motor Examination for Lumbar Radiculopathy (from L3 to S1) 🔑🔑

A

L3 Root

Power: hip adduction & knee extension weakness

L4 Root

Power: ankle dorsiflexion weakness (L4 > L5) test by having patient walk on heels

Reflex: decreased patellar reflex

L5 Root

Power: EHL weakness (L5), ankle inversion weakness

Trendelenburg gait & Abduction : gluteus medius weakness (L5)

Reflex: decreased Hamstring reflex

S1 Root

Ankle plantar flexion weakness (S1) have patient do 10 single leg toes stands

Reflex: decreased Achilles tendon reflex

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15
Q

What are the signs of an L4 radiculopathy?

A
  • Sensory: Pain and paresthesias radiating to the hip, anterior thigh, and medial aspects of the knee and calf. Sensation is impaired over the medial calf. (L4 dermatome)
  • Motor: Weakness occurs in the quadriceps and hip adductors.
  • Reflex: Knee jerk is diminished

Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg95

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16
Q

What are signs of an L5 radiculopathy? 🔑🔑

A

💡 It is most easily identified by weakness in the extensor hallucis longus (EHL)

  • Sensory: Pain radiating to the posterolateral buttock, lateral posterior thigh, and lateral leg.
  • Motor: Weakness in gluteus medius, tibialis anterior and posterior, peronei, and extensor hallucis longus. Result in difficulty in ankle dorsiflexion, eversion, inversion, and hip abduction.
  • Reflex: Ankle reflex is usually normal

Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg95

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17
Q

What are the signs of an S1 radiculopathy?

A
  • Sensory: Pain radiating to posterior buttock, posterior calf, and lateral foot (classic sciatica). Sensory loss in the third, fourth, and fifth toes.
  • Motor: Weakness may occur in the gluteus maximus (hip flexor) and plantar flexors.
  • Reflex: Ankle jerk is usually diminished

Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg95

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18
Q

What are the clinical features of lumbar stenosis?

A
  • Neurogenic intermittent claudication or pseudoclaudication
  • Pain is provoked by walking and standing, due increase in lordotic posture.

Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg96

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19
Q

List 4 Indications to refer LBP for surgical assessment. 🔑🔑

A
  1. Cauda Equina Syndrom
  2. Cervical Myelopathy (Compression)
  3. Progressive motor deficits
  4. Pain not responsive to treatment
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20
Q

Which categories of medication may be of help during acute phases of pain?

A

1- NSAIDS

musculoskeletal inflammation or inflammation or nerve root swelling

2- Muscle relaxants

Muscle spasms and improve sleep

3- Antidepressant drugs (e.g., tricyclics) and antiepileptic drugs (e.g., gabapentin)

For neuropathic pain

Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg101

21
Q

EDX findings in radiculoapthy

List 4 conditions where EMG is normal in radiculopathy

A

Positive EDX Study for Radiculopathy

FIBs or PSWs should be found in two different muscles innervated by two different peripheral nerves originating from the same root

Normal EMG in Radiculopathy (Remember 1st two common causes)

  1. Acute Lesion: maybe decreased recruitment of MUAPs in weak muscles.
  2. Pure sensory: proximal to DRG
  3. Pure demyelinating: unless conduction block → weakness → low MUAP recruitment
  4. Spinal Stenosis
  5. Proximal Muscles

Cuccurollo 4th Edition Chapter 5 pg381

22
Q

Findings of EDX study in Radiculopathy? 🔑🔑

A

Abnormal

  • Only motor weakness with axonal lesion will show reduced CMAP

Normal

  1. Sensory symptoms
  2. Purely demyelinating
  3. Incomplete
  4. Chronic reinnervation

NCS

  • SNAP: Normal since lesion is located proximal to the DRG (pre-ganglionic)
  • CMAP: Normal or reduced amplitude if axonal degeneration occurs
  • H-reflex: Abnormal in an S1 radiculopathy (not pathognomonic)
  • F-waves: Muscles have more than one root innervation, which can result in a normal latency

EMG (mixed picture)

  • Large MUAP at reduced recruitment pattern.

Cuccurollo 4th Edition Chapter 5 EDX pg380

23
Q

Needle EMG criteria for diagnosing a radiculopathy? 🔑 What is the positive findings indicating present of radiculopathy in EMG study?

A

EMG criteria for Radiculopathy

  • FIBs or PSWs should be found in two different muscles innervated by same root but two different peripheral nerves
  • Six muscles (five peripheral muscles + paraspinals)

Normal in

  1. Demyelinating neuropathies
  2. Pure sensory nerve injuries
  3. Chronic nerve injuries
  4. Missed by random sampling

Cuccurollo 4th Edition Chapter 5 EDX pg381

Muscles for sampling

Upper Limb: deltoid, triceps, pronator teres, abductor pollicis brevis, extensor digitorum communis, and cervical paraspinal muscles. (pointing forward)

Lower Limb: vasts medialis, anterior tibialis, posterior tibialis, short head of biceps femoris, medial gastrocnemius, and lumbar paraspinal muscles.

PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg147 Q16

24
Q

Why is the EMG normal for many people with radiculopathy? 🔑

A

1- Sensory radiculopathy:

Affects sensory nerve roots and causes radicular pain and numbness will demonstrate a normal EMG.

2- Motor radiculopathy (motor neurapraxia)

Demyelination lesion will result in normal study

3- Chronic Radiculopathies

Slow axonal loss that is balanced with reinnervation may show polyphasic motor units or large motor units firing in a reduced recruitment pattern.

PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg147 Q15

4- Some muscles are dual innervated, resulting in normal study

25
Q

C6 Radiculopathy. What would you be the CMAP in the ulnar and median nerve? 🔑🔑 EXAM
Give 3 reasons for normal CMAP result even with clinical findings.

A

Reduced CMAP

  • Radiculopathy with severe axonal lesions (specially with clinical motor weakness)

Normal CMAP

  1. Purely demyelinating (Result in abnormal sensory study only, motor will be normal)
  2. Incomplete
  3. Reinnervation has occurred (chronic injury)

Cuccurollo 4th Edition Chapter 5 EDX pg380

https://now.aapmr.org/electrodiagnosis-of-radiculopathies-cervical-thoracic-and-lumbar/

26
Q

What is the most commonly affected level with cervical radiculopathy?🔑🔑

A

C7 (C6-C7 disc herniation)

27
Q

Draw the brachial plexus 🔑🔑 EXAM

A
28
Q

The only muscle of the arm that is a flexor and that is innervated by the posterior trunk of the plexus 🔑🔑

A

Brachioradialis, Radial nerve (C5-C6)

29
Q

List 5 sensory branches of upper trunk and 3 sensory branches of lower trunk. List the peripheral branches affected in upper vs lower trunk injury. 🔑🔑

A
30
Q

List 4 causes of plexopathy.

A
  1. Trauma: Traction, transection, obstetrical injuries, compression.
  2. Cancer (Pancoast tumor)
  3. Radiation therapy
  4. Idiopathic (neuralgic amyotrophy)

Cuccurollo 4th Edition Chapter 5 EDX pg383

31
Q

List 4 muscles innervated by C5-C6

A

💡 Axillary, MSK & Supinator

  1. Deltoid (Axillary n.)
  2. Teres Major (Axillary n.)
  3. Biceps (MSK n.)
  4. Brachialis (MSK n.)
  5. Supinator (Radial n.)
32
Q

What is the difference between C7-C8 vs C8-T1 in relation to hand function? 🔑

A

C7-C8 → wrist and finger drop

Radial

  1. Abd. poll. longus
  2. Ext. poll. brevis
  3. ECR brevis
  4. Ext. poll. longus
  5. EIP
  6. Ext. dig
  7. EDM
  8. ECU

C8-T1 → weak wrist, thumb & fingers flexion and grip functional.

Median:

Finger Flexors

  1. FDS—4 muscles

AIN “OK Sign”

  1. FDP—2 muscles
  2. Pronator quad
  3. FPL

LOAF

  1. Lumbricals—2 muscles
  2. Opponens pollicis
  3. Abductor pollicis brevis
  4. Flex poll. brevis 1/2

Ulner:

  1. FDP—2 muscles
  2. Dorsal interossei—4 muscles
  3. Palmar interossei—3 muscles
  4. Lumbricals—2 muscles
  5. Add poll.—1 muscle
  6. Flex poll. brevis 1/2
  7. Hypothenar muscles – Oppon. dig. min. – Abd. dig. min. – Flex. dig. min.
  8. Palmaris brevis
33
Q

What muscle and nerves if cut cant do shoulder external rotation, flexion & abduction?🔑🔑

A

Deltoid, Axillary nerve

34
Q

Rule of EDX study in plexopathy? what is the most important finding?

A

Benefits of EDX in plexopathy

  1. Localization of the lesion in relation to DRG
  2. Determining axonal or demyelination lesion or both
  3. Determining severity of lesion (axonal > demyelination)
  4. Rule out radiculopathy

Sensory Study

  • Decreased SNAP = axon loss distal to DRG
  • Normal SNAP = injury is proximal to DRG

Motor Study

  • Distal CMAP amplitude is the main prognostic factor in a plexopathy
  • It represents AXONAL LOSS

Late responses

  • F-waves may be delayed or absent in plexopathies
  • H-reflex to evaluate the S1 pathway but not pathognomonic
  • Nonspecific, as they cannot localize a focal lesion.

EMG in plexopathy

  • To rule out radiculopathy, and rule in plexopathy
    1. Abnormal peripheral muscles
    2. Normal paraspinal muscles

Cuccurollo 4th Edition Chapter 5 EDX pg383

35
Q

How to differentiate plexopathy and root avulsion in EDX?

A

Plexus lesion is post-ganglionic

Sensory nerve potentials are reduced

Root avulsion is pre-ganglionic

Sensory nerve potentials are normal

36
Q

List 3 Reasons for normal SNAP with +ve physical examination

A
  1. Lesion is hyperacute (less than 2 weeks), wallerian degeneration hasn’t occur
  2. Lesion is proximal to the dorsal root ganglion (DRG)
  3. Lesion is demyelination, possibly conduction block, leaving the axon relatively intact.
37
Q

EDX Nerve Root Avulsion 🔑

A

NCS

  • Normal SNAPs (even with clinical sensory loss, Injury proximal to DRG, pre-ganglionic)
  • Absent CMAPs

Needle EMG

  • Absent recruitment including the paraspinals.
38
Q

1) Affected root in Erb’s Palsy or Stinger. 🔑
2) Common causes
3) Erbs’ Palsy – list 8 muscles affected 🔑🔑

What nerves & muscles are affected in an Erb’s Palsy? 🔑🔑

4) EDX findings
5) Treatment

A

💡 Nerve traction C5–C6 nerve roots of the upper trunk

Causes:

Pediatrics: shoulder dystocia, forceps delivery

Adult: blow to the head, neck, or shoulder, sports related stinger or burner

Presentation

  1. Adducted arm (deltoid and supraspinatus [SS] weakness)
  2. Internally rotated (teres minor and infraspinatus [IS] weakness)
  3. Extended (bicep and brachioradialis [BR] weakness)
  4. Pronated (Supinator and BR weakness)
  5. Wrist flexed (extensor carpi radialis longus [ECR-L] and brevis weakness)

EDX

  • Stimulate at Erb’s point
  • Abnormal lateral cutanous n. of arm and forearm.

Treatment

  • Rehabilitation
  • Intermittent splinting
  • Activity restriction

Cuccurollo 4th Edition Chapter 5 EDX pg385

39
Q

Errbs’ Palsy

List 4 sensory nerves affected 🔑🔑

List 3 motor nerves affected

A

Sensory Nerves

  1. Upper lateral cutaneous nerve of the arm (Axillary n.)
  2. Lower lateral cutaneous nerve of the arm (Radial n.)
  3. Lateral cutaneous nerve of the forearm (MSK n.)
  4. Superficial branch of the radial nerve
  5. Median Nerve
    1. Palmar cutaneous branch of the median n.
    2. Digital cutaneous branch of the median n.

Motor Nerves

  1. Axillary nerve
  2. Suprascapular nerve
  3. Musculocutaneus nerve
40
Q

How to differentiate Erb’s palsy from C5-C6 root injury in EDX? 🔑🔑

A

💡 Go back to anatomy, we know that Erb’s palsy is UPPER TRUNK plexopathy, so it’s AFTER THE ROOT, which spares some of the muscles. Also it can be AFTER THE DRG.

NCS

  • C5-C6: Normal SNAPs (Proximal to DRG)
  • Erb’s: Abnormal SNAP

EMG, Muscle involvement in Root but not Erb’s Palsy:

  1. Rhomboid (Dorsal Scapular n.)
  2. Serratus Anterior (Long Thoracic n.)
  3. Paraspinals
41
Q

Neck traction injury, complains of

  • A burning or electric shock sensation
  • Arm numbness and weakness immediately following the injury
  • A warm sensation Give three differential diagnoses. 🔑🔑 EXAM
A
  1. Upper trunk brachial plexus injury
  2. Cervical spine injury or stenosis
  3. Cervical disc injury
42
Q

26-year-old gentleman who was involved in a wrestling incident 2 days ago. 🔑🔑 EXAM 🟦

He complained of a burning pain radiating down his right arm, which started at the incident. The pain was followed by numbness and weakness of the same arm. He had to hold his arm against his body to relief the discomfort. His symptoms were resolved within few minutes without any residual complaints. Physical examination showed no neurological deficit.

(a) What is the most likely diagnosis?
(b) What is the pathophysiology of this condition?

A

Diagnosis

Stinger or burner

Pathology

Sudden forceful stretch in the nerve roots and brachial plexus as they emerge from the cervical spine.

PMR Secrets pg321

43
Q

Football player complaining of ‘dead arm’. List 4 DDx. What are 4 ‘red flags’ that would lead to further investigation? 🔑🔑 EXAM

A

DDx

  1. Stinger Traction Injury
  2. SLAP tear
  3. Shoulder dislocation
  4. Neuralgic Amyotrophy
  5. Thoracic outlet syndrome ( axillary artery + medial cord of BP)

Red flags:

  • Recurrent stinger
  • Persistent neurological deficit

Not sure about Q&A.

44
Q

1) Affected root in Klumpke’s Palsy. 🔑 EXAM
2) Common causes
3) Presentation
4) EDX findings
5) Treatment

A

Causes:

  1. Forced adduction seen in an MVA, falls
  2. Shoulder dislocations
  3. Pancoast tumor
  4. Thoracic outlet syndrome (TOS).

Presentation

  • Shoulder girdle muscle function is preserved
  • Wasting of the small hand muscles
  • Claw hand deformity (lumbrical weakness)
  • Horner syndrome

💡 Normal SNAP for proximal lesion even with clinical sensory loss. Abnormal CMAP in case of axonal loss

EDX

  • Normal SNAP indicate a nerve root avulsion
  • Reduced Medial antebrachial cutaneous sensory response

Treatment

  • Rehabilitation with incomplete lesions
  • Surgical exploration with a nerve root avulsion

Cuccurollo 4th Edition Chapter 5 EDX pg385

45
Q

What is Adson’s test?🔑🔑

A

The examiner locates the radial pulse. The patient’s head is rotated to face the test shoulder. The patient then extends the head while the examiner laterally rotates and extends the patient’s shoulder. The patient is instructed to take a deep breath and hold it.

A disappearance of the pulse and reproduction of symptoms indicates a positive test.

Orthopedic Physical Assessment, 7th Edition (Magee)

46
Q

1) Common causes of Thoracic Outlet Syndrome (TOS) 🔑🔑
2) Presentations & Examination 🔑🔑
3) EDX findings 🔑🔑
4) Treatment

A

Compression Sites

  1. Between the medial and anterior scalene muscles over the first rib (hypertrophied scalene muscles)
  2. Between the first rib and the clavicle (cervical rib, fibrous bands)
  3. Beneath the insertion pectoralis muscle on coracoid process (postural factors)

Vasogenic

  • Subclavian artery, subclavian vein, or axillary vein
  • Artery: Ischemia, necrosis, vague pain, fatigue, with decreased color and temperature.
  • Vein: bluish, swollen, achy limb.
  • Positive Adson’s test (subclavian artery) - Allan test - Roos test

Neurogenic

  • Pain and numbness along the medial aspect of the forearm and hand
  • Worsen with overhead activity.
  • Hand muscle wasting may also be noted (median thenar > ulnar intrinsics).

C8-T1 Lower Trunk Plexopathy

  • Median & Ulnar n. injury
  • Sensory and motor affection

NCS

  • Decreased SNAP for medial cutaneous n. of forearm (Lower trunk)
  • Median SNAP is spared (Upper and Lower Trunk)
  • Decreased CMAP of median n. (Hand weakness)
  • Decreased CMAP & SNAP of ulnar n. (Branches from lower trunk only)

EMG

  • Abnormal spontaneous activity for median and ulnar hand muscles (lower trunk) EMG.

Treatment

  1. Rehabilitation with a focus on ROM exercises
  2. Stretching of tight muscles
  3. Strengthening of the scapular stabilizers
  4. Surgery can be indicated for a first rib or fibrous band resection
  5. Botulinum toxin injection to the scalene, subclavius, and/or pectoralis minor muscles
  6. Scalenectomy with or without first rib resection, is required.

Cuccurollo 4th Edition Chapter 5 EDX pg385-386

47
Q

1) Common causes of Neuralgic Amyotrophy (Acute Brachial Neuritis)
2) Presentation
3) List 5 Nerves for EDX study 🔑🔑 EXAM
4) Treatment

A

Causes

  • Idiopathic, inflammatory, immune-mediated process
  • After immunization, infection, surgery, or pregnancy

Presentation:

  • Pain in shoulder or periscapular region, exacerbated by abduction and rotation.
  • Weakness in a patchy patchy or multifocal involvement, asymmetrically bilateral.
  • Lasting 2-3 weeks then slowly improves
  • Fasciculations and atrophy may be seen (LMN)
  • Autonomic dysregulation
    • Trophic skin changes
    • Temperature dysregulation
    • Increased sweating
    • Altered nail/hair growth

EDX

  1. Spinal accessory nerve
  2. Suprascapular nerve
  3. Long thoracic nerve
  4. Axillary nerve
  5. Anterior interosseus nerve [AIN]

💡 Acute deinnervation with positive sharp waves and fibrillation potentials Reduced amplitude, preserved conduction velocity and distal latency

Treatment

  • Observation and pain control with recovery taking up to 3 years.
  • Operative nerve exploration, neurolysis, nerve transfer or tendon transfer be be indicated if there is no evidence of EMG recovery by 9-12 months.

Cuccurollo 4th ed - Chapter 5 EDX pg386

48
Q

How to differentiate between neoplastic and radiation plexopathy? 🔑🔑 EXAM 🟦

A

Cuccurollo 4th Edition Chapter 5 EDX pg387 Table 5-28

Braddom 6th Edition Chapter 41 Table 41.3

49
Q

Patient who is post-mastectomy and treated with chemotherapy and radiation.

Presented with thenar/hypothenar wasting.

What is the most likely diagnosis?

What are two likely causes of muscle wasting? 🔑🔑 EXAM

A

Diagnosis

  1. Breast tumor metastasis
  2. Secondary carcinoma from history of radiation
  3. Radiation induced plexopathy (less likely b/c involves upper trunks)

Causes of wasting

  1. Ulnar neuropathy (Hypothenar)
  2. Median neuropathy (Thena = LOAF)

Canada Q Bank

PassPMR - 04 Electrodiagnostic Medicine (8 decks)

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