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PassPMR - 04 Electrodiagnostic Medicine > 5- Lower Extremities Mononeuropathies > Flashcards

5- Lower Extremities Mononeuropathies Flashcards

1
Q

Draw Lumbarosacral Plexus

A
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2
Q

Lumbar Plexus ( Root - 5 Sensory Branches - 3 Muscle Groups - 1 Reflex) 🔑🔑

A

Root

  • L2-L4 (Following dermatomes)

Sensory

  1. Femoral branch of genito-femoral nerve
  2. Obturator nerve
  3. Lateral femoral cutaneous nerve of thigh
  4. Medial & Intermediate and medial cutaneous nerves of thigh (from femoral nerve)
  5. Saphenous nerve (from femoral nerve)

Motor

  1. Iliopsoas: Lumbar spinal nerves L1-3 (psoas) and parts of the femoral nerve (iliacus).
  2. Quadriceps (Femoral n.)
  3. Adductors (Obturator n.)

Reflexes

  1. Knee jerk
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3
Q

List 6 Etiologies of Lumbosacral Plexopathy

A

Structural

  1. Retroperitoneal hemorrhage
  2. Abdominal Tumor
  3. Aneurysm
  4. Endometriosis
  5. Trauma
  6. Hip dislocation

Non-Structural

  1. Diabetic amyotrophy
  2. Obstetric injuries (Post-partum foot drop)
  3. Radiation
  4. Inflammation
  5. Infarction

Ref: Shapiro

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4
Q

Adductor magnus innervation 🔑🔑

A

Posterior branch of obturator nerve (adductor) and sciatic nerve (hamstring)

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5
Q

Innervation for: Foot 1st & 5th DI, Gmax & Gmed

A

Gmax: Inferior glute n.

Gmed, Gmini & TFL: Superior glute n.

Tibial n. branch into

Foot 1st DI: Medial planter n.

Foot 5th DI: Lateral planter n.

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6
Q

Anteriolateral thigh pain and paresthesia. Spot diagnosis. 🔑🔑

A

Meralgia paresthetica → Lateral femoral cutaneous nerve

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7
Q

Anteromedial leg numbness after bypass. Dx? 🔑🔑

A

Saphenous neuropathy – blood supply to the nerve is interrupted during surgery and ischemic neuropathy

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8
Q

Draw femoral triangle

A
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9
Q

Root and Branches of femoral nerve. (7 muscles and 3 sensory) 🔑🔑

A

Root

  • L2-L4
  • Posterior division of lumbar plexus
  • Obturator n. → anterior division of lumbar plexus

Motor (kick)

  1. Iliacus & Psoas (before inguinal ligament)
  2. Pectineus (1/2)
  3. Rectus femoris
  4. Vastus lateralis, intermedius, medius.

Sensory

  1. Medial and intermediate cutaneous branch (L2-3)
  2. Saphenous n. → medial leg (L4)
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10
Q

Femoral Neuropathy Etiology, PEx, EDX, Managment

A

Etiology

  1. Iatrogenic from abdominal or pelvic surgery (most common)
  2. Trauma (e.g., fracture, abdominal/pelvic surgery, anterior total hip arthroplasty, direct trauma from cardiac catherization)
  3. Retroperitoneal hematoma
  4. Aortic aneurysm
  5. Tumor
  6. Lymphadenoma
  7. Pelvis mass
  8. Vaginal delivery
  9. Inguinal ligament entrapment
  10. Dancing (Hyperextension)
  11. Radiation
  12. Ischemia

Clinical presentation

  1. Hip flexion weakness (only in injuries above the inguinal ligament)
  2. Weakness of knee extension (quadriceps)
  3. Knee instability (collapse) during gait, lose of extension moment arm.
  4. Decreased sensation over the anterio-medial thigh and medial lower leg.
  5. Patellar reflex can be depressed or absent

NCS

  • Abnormal saphenous nerve SNAP
  • Abnormal CMAP to the rectus femoris

EMG

  • Femoral nerve innervated muscles

Managment

  • Early physical therapy for strengthening and range of motion
  • Ground Reaction AFO or KAFO
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11
Q

Findings suggest lumbar plexopathy or L2-L4 radiculoapthy rather than femoral neuropathy 🔑🔑

A

Femoral Neuropathy

  1. Weak knee extension
  2. Weak hip flexion (above inguinal ligament)
  3. Reduced knee reflex
  4. Sensory loss of anteriomedial thigh
  5. Sensory loss of medial calf

Lumbar Plexus injury

Just taking step back in the lumbar plexus.

  1. Sensory loss in proximal medial thigh (Obturator n.)
  2. Sensory loss in lateral thigh (Lateral femoral cutaneus n.)
  3. Weakness in hip adductions (Obturator n.)
  4. Weak ankle dorsiflexion

L2-L4 Radiculoapthy

  • Same as lumbar plexopathy
  • Paraspinal muscles (low back pain as in any radiculopathy)

Shapiro Table 26.1

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12
Q

Lateral Femoral Cutaneous Nerve

Origin, 6 Etiologies, PEx, EDx, 4 Treatment

A

Origin

  • L2-L3

Etiology

  1. Compression by low grade trauma
  2. Iatrogenic incisions for lower abdominal/pelvic surgeries and laparoscopic hernia repairs
  3. Protuberant abdomen
  4. Pregnancy
  5. Tight clothing
  6. Diabetes
  7. Tumor
  8. Rapid gain or weight loss can also affect the nerve

Clinical presentation & EDX

  • Pure sensory syndrome with no muscle involvement
  • Exacerbated with hip extension or hyperflexion (driving).

EDX (NCS)

  • Abnormal lateral femoral cutaneous nerve SNAP

Treatment

  1. Symptoms may be self-limited, weight reduction.
  2. Removal of compressive clothing should occur (e.g., wide belt, compressive athletic clothing).
  3. Physiotherapy (Heat or TENS)
  4. NSAIDs
  5. Cortisone injections
  6. Capsaicin cream
  7. Lidoderm patches can be helpful.
  8. Tricyclic antidepressants: Amitriptyline
  9. Anti-seizure medications: Gabapentin (Neurontin), pregabalin (Lyrica), or carbamazepine (Tegretol)
  10. Surgical release.
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13
Q

Mention 5 Anatomic variations in the course of the lateral cutaneous nerve of the thigh

A
  1. Posterior to the anterior superior iliac spine (ASIS), across the iliac crest
  2. Anterior to the ASIS and within inguinal ligament
  3. Medial to the ASIS and within sartorius tendon
  4. Between the tendon of the sartorius muscle and the fascia of the iliopsoas
  5. Overlying the fascia of the iliopsoas muscle
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14
Q

How does a femoral nerve lesion differ from an L3 radiculopathy?

A

Abnormalities in the hip adductors in addition to the quadriceps muscles are present in L3 radiculopathies

Neurology Secrets 6th Edition Chapter 32 pg472

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15
Q

How does a femoral nerve lesion in the pelvis differ from a lesion at the inguinal level?

A

Weakness and denervation in the iliopsoas in addition to the quadriceps muscle indicate a femoral nerve lesion in the pelvis

Neurology Secrets 6th Edition Chapter 32 pg472

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16
Q

Root and Branches of Obturator nerve

A

Root

  • L2-L4
  • Anterior division of lumbar plexus
  • Femoral n. → Posterior division of lumbar plexus

Branches:

  1. Adductor brevis
  2. Adductor longus
  3. Adductor magnus (1/2)
  4. Pectineus (1/2)
  5. Obturator externus
  6. Gracilis
  7. Cutaneous branch

Cuccurollo 4th Edition Chapter 5 EDX pg410-411

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17
Q

Sacral Plexopathy (Root - 5 Sensory Branches - 5 Muscle Groups - Reflex) 🔑🔑

A

Root

  • L4-S3

Sensory

  1. Lateral cutaneous nerve of calf (common peroneal nerve)
  2. Superficial peroneal nerve (common peroneal nerve)
  3. Sural nerve (tibial nerve)
  4. Calcanean branches of sural and tibial nerves
  5. Posterior cutaneous nerve of thigh

Motor

  1. Dorsiflexion & eversion (Common peroneal n. → anterior tibial muscles)
  2. Planterflexion & inversion (Tibial n. → posterior tibial muscles)
  3. Knee flexion (Sciatic n. → Hamsting)
  4. Hip extensors (Inferior glute n. → Gmax)
  5. Abductors, internal rotators (Superior glute n. → Gmed, mini, TFL)

Reflexes

  1. Hamsting L5
  2. Ankle jerk S1
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18
Q

Superior Gluteal Nerve Palsy vs Inferior Gluteal Nerve Palsy (Root, Sensory, Motor)

A

💡 No SNAP or CMAP studies exist

Superior Gluteal Nerve

  • Root L4-S1
  • Trendelenburg gait +ve (weak glut medius)
  • Hip abduction and external rotation (glute medius & TFL)

Inferior Gluteal Nerve

  • Root L5–S2 (one root below)
  • Weakness of hip extension (glute max)

Cuccurollo 4th Edition Chapter 5 EDX pg418

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19
Q

What are the divisions of Lumbar plexus and Sacral plexus?

A

Lumbar plexus

  • Anterior → Obturator nerve
  • Posterior → femoral nerve and the lateral femoral cutaneous nerve

Sacral Plexus

  • Anterior → tibial portion
  • Posterior → common peroneal nerve
20
Q

Roots and Branches of Sciatic n.

A

Root

  • Femoral n. L2 - L4
  • Sciatic n. L4 - S2
  • Tibial n. L5 - S2

Before popliteal fossa

  1. Hamstring Muscle
    1. Long head of the biceps femoris
    2. Short head of the biceps femoris (dual innervation with common peroneal n.)
    3. Semitendinosus
    4. Semimembranosus
  2. Adductor magnus (dual innervation with obturator n.)

After popliteal fossa

  1. Tibial n. → posterior leg
  2. Peroneal n. “Fibular” → anterio-lateral
21
Q

Sciatic n. Neuropathy Etiology, PEx, EDx

A

Etiology

  1. Hip trauma
  2. Hip replacement
  3. Pelvic fracture
  4. Gluteal Injection
  5. Hematoma
  6. Penetrating wounds
  7. Gravid uterus
  8. Piriformis syndrome
  9. Femur fracture
  10. Baker Cyst

Clinical presentation (Sensory - Motor - Reflex)

  • Sensory loss of common peroneal (lateral - deep - superficial), tibial & sural n.
  • Weakness in foot planterflexion (tibial n.) and dorsiflexion (common peroneal n.)
  • Weakness of knee flexion (hamstring weakness)
  • Lateral hamstring and Achilles reflexes may be abnormal

NCS “Routine 3 Sural - Tibial - Peroneal”

  • Abnormal superficial peroneal (fibular) and sural sensory nerves SNAPs
  • Abnormal tibial nerve CMAP → Medial Gastrocnemius or Hamstrings
  • Abnormal peroneal (fibular) nerve CMAP → EDB Muscle

EMG

  • Abnormal activity in all sciatic innervated musculature
  • Important to include short and long heads of the biceps femoris in sciatic injury.

Cuccurollo 4th Edition Chapter 5 EDX pg412

22
Q

Deep Peroneal vs Common Peroneal vs Sciatic Neuropathy 🔑🔑

A

Deep Peroneal (DF & Webspace)

  1. Sensory loss in webspace great toe
  2. Weakness of foot dorsiflexion (Tibialis anterior, Extensor hallucis longus)
  3. Tinel’s sign at fibular neck (Conduction slowing/block at fibular neck)
  4. Reduced CMAP in Extensor digitorum brevis (EDB)

Common Peroneal = Deep + Superficial Peroneal (Eversion, anteriolateral sensation)

  1. Weakness of foot eversion (Peroneus longus, Low peroneal CMAP)
  2. Sensory loss in lateral calf
  3. Sensory loss in dorsum of foot (Abnormal peroneal SNAP)

Sciatic Nerve = Common Peroneal + Tibial n. (Planterflexion, posterior sensation)

  1. Weakness of foot inversion (Tibialis posterior, Flexor digitorum longus, Low tibial CMAP)
  2. Weakness of knee flexion (Short head of biceps femoris)
  3. Sensory loss in lateral knee (Abnormal sural SNAP)
  4. Sensory loss in sole foot
23
Q

List 2 DDx for Sciatic neuropathy

A

💡 Go up to the root

  1. L5 or S1 radiculopathy
  2. Lumbosacral plexopathy
24
Q

Roots and Branches of Tibial n. 🔑🔑

A

💡 Memory aid: Sciatic is for the ankle and posterior legs Peroneal n. = Ankle DF, eversion Sciatic n. = Ankle PF, inversion, Knee flex

Root

  • Femoral n. L2 - L4
  • Sciatic n. L4 - S2
  • Tibial n. L5 - S2

Knee Flexion

  1. Semitendinousus
  2. Semimembranosus
  3. Long head of biceps femoris
  4. Branch to adductor magnus

Ankle Planterflexion, Inversion

  1. Popliteus
  2. Plantaris
  3. Gastrocnemius
  4. Soleus
  5. Sural sensory nerve
  6. Tibial posterior
  7. Flexor digitorum longus
  8. Flexor hallucis longus

Calcaneus & Sole

  1. Medial plantar n.
    1. Abd. hallucis
    2. Flexor digitorum brevis
    3. Flexor hallucis brevis
    4. Sensory medial sole, first to third toes
  2. Lateral plantar n.
    1. Abd. digiti quinti
    2. Flexor digiti quinti
    3. Add hallucis
    4. Interossei
    5. Sensory lateral sole, 4th & 5th toes
  3. Calcaneal nerve (sensory)
25
Q

Flexor Retinaculum Contents (5) 🔑🔑 MOCK

26
Q

Tarsal Tunnel Etiology, PEx, EDx, Treatment 🔑🔑 OSCE

A

Etiology

  • Compression under the flexor retinaculum in the medial ankle.

Clinical presentation (Sensory - Motor - Provocation)

💡 Heel (calcaneal) sensation may be spared (branch before the tunnel)

  • Perimalleolar pain, numbness radiating to the sole of the foot
  • Pain at rest while the patient is sitting or in bed
  • Intrinsic foot weakness.
  • Positive Tinel’s sign at the medial ankle

DDX

  1. Plantar fasciitis
  2. Stress fractures of the hindfoot, particularly the calcaneus
  3. S1 Radiculopathy
  4. Peripheral neuropathies (Diabetic & Alcoholic)
  5. Inflammatory arthritides

https://emedicine.medscape.com/article/1236852-differential

NCS

  • SNAP: Abnormal plantar nerve. Spared calcaneal nerve.
  • CMAP: Abnormal medial and lateral plantar nerve

EMG

  • Abnormal activity in the tibial nerve innervated muscles

Treatment

  1. NSAIDs
  2. Local corticosteroid injections
  3. Orthoses to correct biomechanical abnormalities: Overpronation or excessive supination pr Ankle–foot orthosis with dorsiflexion stop (weak planterflexion eccentric contraction)

Cuccurollo 4th Eiditon Chapter 5 EDX pg413

27
Q

Tarsal Tunnel vs Tibial Mononeuropathy vs S1 Radiculogpthy in PEx 🔑🔑

A

Tarsal tunnel syndrome

  • Exacerbated by standing and walking
  • +ve Tinel sign

Proximal tibial mononeuropathy

  • Plantar flexion and inversion weakness (Gastrocnemius & Soleus)
  • Depressed or absent Achilles reflex (Gastrocnemius)

S1 Radiculopathy (Root)

  • Back (paraspinals), buttock, and posterior thigh pain
  • Weak hip extension (hamstrings and gluteus maximus)
  • Exaggerated Achilles reflex
28
Q

List 5 DDx for heel pain 🔑🔑 MOCK

A
  1. Planter Fascitis
  2. Haugland Syndrome
  3. Achilles Tendonitis (athlete)
  4. Retrocalcaneal Bursitis
  5. Calcaneal Stress Fracture
  6. Fat pad atrophy (eldarly)
  7. Sever’s Disease (pediatric)
28
Q

Posterior tibial nerve vs Planter Fasciitis (2)

A
  1. Sensory loss in the lateral or medial plantar distribution, often sparing the heel
  2. +ve Tinel sign over the flexor retinaculum at the medial malleolus.
29
Q

Causes of false positive study in posterior tibial neuropathy. False amplitude drop?

A

💡 False study = technical errors

  1. Thick foot calluses
  2. Edema.
  3. Foot and ankle deformity
30
Q

Whats is High heeled shoes nerve palsy

A
  • Compression of Deep peroneal N under extensor retinaculum aka anterior tunnel syndrome
  • Foot weakness and atrophy of EDB
  • Numbness and paresthesias in the first and second web space
  • Pain over the dorsum of the foot and relieved with motion
31
Q

Roots and Branches of peroneal (fibular) n. 🔑🔑

A

Root

  • Femoral n. L2 - L4
  • Sciatic n. L4 - S2
  • Peroneal n. L4 to S1
  • Tibial n. L5 - S2

Branches

  1. Short head biceps femoris (above popliteal fossa)
  2. Sural n. (popliteal fossa with tibial nerve)
  3. Common peroneal n. (fibular head)
    1. Lateral cut. branch
    2. Superficial peroneal n.
      1. Evertors (Peroneus longus, Peroneus brevis)
      2. Sensory (Medial & Lateral cutaneous nerve)
    3. Deep peroneal n.
      1. Planterflexion (Tibialis anterior, EHL, EDL, EDB)
      2. Peroneus tertius
      3. Sensory first webspace (Dorsal distal cutaneous nerve)

Cuccurollo 4th Edition Chapter 5 EDX pg414

32
Q

Common Peroneal (fibular) Neuropathy 6 Etiology, PEx (1 important) & EDX (1 important). 🔑🔑

A

Etiology

  1. Prolonged leg crossing
  2. Weight loss
  3. Poor positioning during surgery
  4. Poor cast application
  5. Occupational (squatting, kneeling, strawberry picker palsy)
  6. Trauma or fracture
  7. Fibular Tunnel Syndrome
  8. Lesion (ganglion, cysts, tumor)
  9. Metabolic disorders such as diabetes

Clinical presentation

  • Weakness of the dorsiflexors (Foot drop, foot slap, steppage gait)
    • Tibialis anterior (TA)
    • Extensor digitorum longus (EDL)
    • Extensor hallucis longus (EHL)
  • Sensory loss over lateral leg and dorsal foot
  • Positive Tinel’s sign may be noted at the fibular head.

NCS

  • Abnormal superficial peroneal (fibular) SNAP
  • CMAP: Abnormal EDB (Conduction block: below and above the fibular head)

EMG

  • Abnormal activity in the muscles innervated by the superficial and deep peroneal (fibular) nerves.

Cuccurollo 4th Edition Chapter 5 EDX pg414

33
Q

Common Peroneal (fibular) Neuropathy vs Sciatic vs L5 Radiculopathy 🔑🔑

A

💡 Sensory - Motor - Reflex

Common peroneal (fibular) nerve injury

  • Weak dorsiflexors, weak EHL (anterior compartment)
  • Weak enversion (lateral compartment)
  • Sensory loss over lateral leg and dorsal of foot

Sciatic

  • Weak knee flexors (hamstring)
  • Weak planterflexion & inversion (posterior compartment)
  • Sensory loss over sural n. and tibial n. (calcaneal and sole of foot)
  • Reduced hamstring reflex

L5 Radiculopathy

  • Weak hip abduction
  • Sensory loss of posterior and lateral thigh
34
Q

Anterior tarsal tunnel syndrome: Definition, Causes, PEx, EDX.

A

Anterior tarsal tunnel syndrome

  • Entrapment of the deep peroneal (fibular) nerve under the inferior extensor retinaculum of the ankle.

Causes

  1. Compression from footwear (high boots, tight shoes, highheeled shoes)
  2. Intrinsic etiologies (osteophyte, ganglion cyst, lipoma)
  3. Trauma (ankle sprains or fractures).

Presentation

  • Foot pain, weakness, and atrophy (EDB).
  • Numbness and paresthesias in the first and second web space

EDX

  1. SNAP: Abnormal deep peroneal (fibular) SNAP (first web space)
  2. CMAP: Abnormal peroneal (fibular) CMAP with recording at the EDB
  3. EMG: Abnormal activity in deep peroneal (fibular) innervated muscles
35
Q

Superficial peroneal (fibular) neuropathy: Innervation, Causes, PEx, EDX

A

Innervation:

  • First it innervates the peroneus longus and brevis (yellow)
  • Continues distally as a pure sensory nerve (green)

Causes

  1. Trauma
  2. Ankle sprain
  3. Compartment syndrome
  4. Lipoma.

Presentation

  • Pain, numbness, and/or paresthesias in the loss of sensation in distal anterolateral calf and dorsal foot (except for the first webspace).
  • Foot eversion weakness (if injury is more proximal)

EDX

  1. Abnormal superficial peroneal (fibular) SNAP
  2. Superficial peroneal (fibular) CMAP not available
  3. Abnormal activity in the peroneus longus and/or peroneus brevis

Cuccurollo 4th Edition Chapter 5 EDX pg416-417

36
Q

How is a peroneal nerve palsy differentiated from an L4–L5 radiculopathy? 🔑🔑

A

The invertors of the foot (posterior tibial muscle) are abnormal in L4–L5 radiculopathies and spared in peroneal nerve lesions.

Neurology Secrets 6th Edition Chapter 32 EDX pg472

37
Q

What is Strawberry pickers palsy? or slimmer palsy?

A

Peroneal nerve palsy around fibular head

38
Q

List 4 postpartum causes for common peroneal nerve injury

List 2 Advices to the surgeon for nerve injury reduction?

A

Causes

  1. Retroperitoneal bleed
  2. Hip dislocation (Sciatic nerve, peroneal division)
  3. Cephalopelvic disproportion
  4. Iatrogenic obstetric injuries (retractor)

Advices

  1. Extremes of flexion, external rotation, and abduction of the hip should be avoided to prevent compression as the nerve passes under the inguinal ligament.
  2. Retractors are also a potential source of injury during surgery, and care should be taken with placement to avoid compressing the nerve as it passes the psoas muscle.
39
Q

List 6 DDx for Foot Drop 🔑🔑 Dr. Dia’a

List 4 Causes for Atraumatic Peroneal Palsy

A
  1. Central: Stroke, Tumor
  2. Spinal cord pathology: Tumor, SCI
  3. Root: L5 Radiculopathy
  4. Lumbosacral Plexopathy
  5. Mononeuropathy: Sciatic neuropathy, Common or Deep peroneal neuropathy
    1. Habitual leg crossing
    2. Prolonged knee flexion activities (strawberry picker palsy)
    3. Repetitive squatting
    4. Severe weight loss
  6. Polyneuropathy
  7. Motor neuropathy
  8. Diabetic neuropathy
  9. CMT (Demyelinating sensorimotor neuropathy)
40
Q

Write down NCS study protocol for Foot Drop in case of common peroneal n. palsy at fibular head 🔑🔑 Dr. Dia’a

A

Stimulation Site

Peroneal nerve above and below the fibular head

Recording Site

Either the EDB in the foot or the anterior tibialis

Result

Focal conduction block (50% drop in CMAP comparing above and below the fibular head)

41
Q

History of guy with foot drop and weakness of dorsiflexion 🔑🔑 Dr. Dia’a

What one muscle to test on EMG?

What finding that suggests sciatic injury?

Which muscle to EMG if you want to r/o siactic injury in foot drop?

A

Isolated injury

  • Extensor digitorum brevis (EDB) → Deep peroneal nerve

Injury around fibular

  • Proneous longus → Superficial peroneal nerve

Sciatic Injury in the thighs

  • Short head of the biceps femoris → Siactic nerve
  • Medial gastrocnemius → Tibial nerve
42
Q

How would you differentiate clinically (motor and sensory) that the problem of the foot drop is secondary to RT peroneal injury around fibula versus L5 radiculopathy? (2 Marks) 🔑🔑

In EDX study which muscles will be mostly affected when you do needle EMG to diagnose L5 radiculopathy versus RT peroneal nerve injury at the knee (fibular head). Mention 5

A

Sensory

  • L5 dermatomal distribution.
  • Peroneal nerve distribution.

Motor

  • Plantar flexion and inversion, knee flexion, glut med affected in L5 radiculopathy
  • Muscle mentioned above are Intact in peroneal nerve injury

EMG for L5 Root

  1. Paraspinals L5
  2. FDL
  3. Tibialis post
  4. Short head of biceps
  5. Glute Medius
43
Q

List four major fascial compartments of the lower leg, and list a major nerve contained in each compartment. 🔑🔑MOCK

A
  1. Anterior: deep peroneal nerve
  2. Lateral: common/ superficial peroneal nerve
  3. Deep posterior: tibial nerve
  4. Superficial posterior: sural
44
Q

What is mononeuritis multiplex (MNM); what is the pathologic lesion With what disease is it most commonly associated. 🔑 🔑 Write the EDX findings

A

Mononeuritis multiplex (MNM)

  • Sensory and motor axonal polyneuropathy, nerve biopsy for definitive diagnosis

Causes

  1. Diabetes mellitus
  2. Vasculitis (Rheumatoid Arthritis or SLE)
  3. Amyloidosis
  4. AIDP or CIDP
  5. Infections (HIV)
  6. Infiltration (Lymphoma, Cancer)

Presentation

  • Primarily affects pain and temperature (small fiber nerves)
  • Migratory arthralgias and myalgias.

NCS

  • Increased CV in chronic conditions
  • Decreased amplitude

EMG

  • Abnormal Spontaneous Activity: FIBs, PSWs, CRDs
  • MUAP: Decreased
  • Recruitment: Decreased, Polyphasic potentials of increased duration and amplitude

Cuccurollo 4th Edition Chapter 5 EDX pg418-419

PassPMR - 04 Electrodiagnostic Medicine (8 decks)

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