PNS2 Flashcards
Polyneuropathy (peripheral neuropathy)
- symmetric
- motor, sensory, autonomic, or combo
- progressive
peripheral neuropathy- motor, sensory
- motor- weakness, atrophy, hypo or areflexia
- large fiber- position/vibratory sense
- small fiber- pain/T sense
peripheral neuropathy- sx
- pain, sensory loss, weakness- symmetrical, distal portions of limbs
- legs affected 1st
- “stocking-glove”
peripheral neuropathy- etiology
- 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
Hereditary motor sensory polyneuropathies (HMSN)
- Charcot-Marie-Tooth neuropathies:
- type 1 (most common)- demyelinative
- type II- axonal
HMSN I (CMT I)
- 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!)
HMSN II (CMT II)
- AD
- adulthood
- distal symmetric atrophy
- areflexia
- mild sensory loss
- EMG- normal conduction velocities (axonal loss)
Other hereditary polyneuropathies
-porphyria- defect in heme biosyn
Acquired Demyelinated Polyneuropathies
- Acute infl demyelinating polyneuropathy (AIDP- Guillain Barre syndrome)
- Chronic infl demyelinating polyneuropathy (CIDP)
- Multifocal motor neuropathy
Guillain Barre syndrome
- acute/subacute ascending motor paralysis
- antecedent illness, surgery, immunization
- viral syndrome- EBV, mycoplasma pneumoniae, campylobacter jejuni enteritis
- HIV
- Hodgkin’s dz
Guillain Barre syndrome- sx’s
- asc, symmetric weakness
- hypo or absent DTRs
- minimal sensory sx’s
- possible resp failure!
Guillain Barre syndrome- key lab findings
- CSF- albumino-cytologic dissociation- inc protein, normal cell count, normal glucose
- NCVs- slow conduction velocity
Guillain Barre syndrome- tx
- Supportive care- swallowing, respiration, CV, infection, DVT
- plasma exchange or IVIG
Guillain Barre syndrome- prognosis
- 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)
Guillain Barre syndrome- variant
Miller-Fisher syndrome
- ophthalmoplegia, ataxia, areflexia
- GQ1b ab’s
Chronic infl demyelinating polyneuropathy (CIDP
- 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
Multifocal motor neuropathy
- slowly progressive distal weakness of hands > feet
- GM-1 ab (50-80%)
- tx- IVIG
Diabetes Mellitus- forms
Most common cause of neuropathy!!!
- distal sensorimotor neuropathy
- CN III
- mononeuropathy (carpal tunnel)
- autonomic neuropathy
- lumbosacral plexopathy (diabetic amyotrophy)
HIV neuropathies
(30-50% of AIDS pts)
- distal symmetrical polyneuropathy
- acute infl demyelinating polyneuropathy
- chronic infl demyelinating polyneuropathy
peripheral polyneuropathy- blood tests for specific conditions
- lyme ab titer
- aANCA- systemic vasculitis
- anti MAG- MGUS assoc
- anti GM1- multifocal motor neuropathy
- Anti GQ1b- miller fisher syndrome
