PNS2

Question 1

Polyneuropathy (peripheral neuropathy)

Answer 1

• symmetric
• motor, sensory, autonomic, or combo
• progressive

Question 2

peripheral neuropathy- motor, sensory

Answer 2

• motor- weakness, atrophy, hypo or areflexia
• large fiber- position/vibratory sense
• small fiber- pain/T sense

Question 3

peripheral neuropathy- sx

Answer 3

• pain, sensory loss, weakness- symmetrical, distal portions of limbs
• legs affected 1st
• “stocking-glove”

Question 4

peripheral neuropathy- etiology

Answer 4

• diabetes (most common), uremia
• hereditary
• alcohol
• idiopathic- at least 25%
• infectious- lyme dz, HIV
• immune- GBS, CIDP, monoclonal gammopathy
• B12 def
• drug induced- vinca alkaloids, phenytoin, isoniazid, amiodarone, nitrofurantoin

Question 5

Hereditary motor sensory polyneuropathies (HMSN)

Answer 5

• Charcot-Marie-Tooth neuropathies:
• type 1 (most common)- demyelinative
• type II- axonal

Question 6

HMSN I (CMT I)

Answer 6

• AD
• 1-2 decade
• diff walking or running 1st
• distal symmetric atrophy
• areflexia
• mild sensory loss
• skeletal deformities- hammer toes, high arches
• EMG- slowing of motor n conduction velocities (demyelination!)

Question 7

HMSN II (CMT II)

Answer 7

• AD
• adulthood
• distal symmetric atrophy
• areflexia
• mild sensory loss
• EMG- normal conduction velocities (axonal loss)

Question 8

Other hereditary polyneuropathies

Answer 8

-porphyria- defect in heme biosyn

Question 9

Acquired Demyelinated Polyneuropathies

Answer 9

• Acute infl demyelinating polyneuropathy (AIDP- Guillain Barre syndrome)
• Chronic infl demyelinating polyneuropathy (CIDP)
• Multifocal motor neuropathy

Question 10

Guillain Barre syndrome

Answer 10

• acute/subacute ascending motor paralysis
• antecedent illness, surgery, immunization
• viral syndrome- EBV, mycoplasma pneumoniae, campylobacter jejuni enteritis
• HIV
• Hodgkin’s dz

Question 11

Guillain Barre syndrome- sx’s

Answer 11

• asc, symmetric weakness
• hypo or absent DTRs
• minimal sensory sx’s
• possible resp failure!

Question 12

Guillain Barre syndrome- key lab findings

Answer 12

• CSF- albumino-cytologic dissociation- inc protein, normal cell count, normal glucose
• NCVs- slow conduction velocity

Question 13

Guillain Barre syndrome- tx

Answer 13

• Supportive care- swallowing, respiration, CV, infection, DVT
• plasma exchange or IVIG

Question 14

Guillain Barre syndrome- prognosis

Answer 14

• 25% require mechanical ventilator support
• 90% recover in wks to months
• death- 4-10%
• persistent disability- 20%
• poor prognosis- low amplitude motor n responses and/or denervation (axonal involvement)

Question 15

Guillain Barre syndrome- variant

Answer 15

Miller-Fisher syndrome

• ophthalmoplegia, ataxia, areflexia
• GQ1b ab’s

Question 16

Chronic infl demyelinating polyneuropathy (CIDP

Answer 16

• slower to evolve and more persistent (than GB)
• de novo or as sequelae of GB
• progressive or relapsing course
• tc- IVIG, steroids, plasma exchange, immunosuppressive agents

Question 17

Multifocal motor neuropathy

Answer 17

• slowly progressive distal weakness of hands > feet
• GM-1 ab (50-80%)
• tx- IVIG

Question 18

Diabetes Mellitus- forms

Answer 18

Most common cause of neuropathy!!!

• distal sensorimotor neuropathy
• CN III
• mononeuropathy (carpal tunnel)
• autonomic neuropathy
• lumbosacral plexopathy (diabetic amyotrophy)

Question 19

HIV neuropathies

Answer 19

(30-50% of AIDS pts)

• distal symmetrical polyneuropathy
• acute infl demyelinating polyneuropathy
• chronic infl demyelinating polyneuropathy

Question 20

peripheral polyneuropathy- blood tests for specific conditions

Answer 20

• lyme ab titer
• aANCA- systemic vasculitis
• anti MAG- MGUS assoc
• anti GM1- multifocal motor neuropathy
• Anti GQ1b- miller fisher syndrome