Internal Medicine

0521779407-17 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:18

1156 Peripheral Neuropathies

➣Small fibers: pain & temperature appreciation

➣Large fibers: vibration & joint position sense

■Tendon reflexes depressed or absent

■Ataxia if marked sensory loss

■Localized dysautonomia (eg, cold or discoloration, impaired sweat-

ing) when small fibers affected

tests

■EMG & NCS confirm presence of neuropathy, suggest type of involve-

ment (axonal or demyelination) & identify site of focal involvement

or entrapment

■For polyneuropathy or mononeuropathy multiplex, some or all of the

following tests may be required: CBC, differential count, ESR, FBS,

liver & kidney function tests, TFTs, serum proteins, protein elec-

trophoresis & immunoelectrophoresis, serum autoantibody studies

(eg, anti-Hu, anti-MAG, anti-GM1), serum vitamin B12 & folate, RPR,

HIV serology, CSF cell count & protein level, ANA, genetic studies,

nerve biopsy

differential diagnosis

■Clinical exam distinguishes myelopathies or radiculopathies from

neuropathies

■Clinical onset & course, nature of deficit & results of investigations

distinguish different causes of neuropathy

management

■For acute neuropathy, ensure adequacy of ventilation & cardiovas-

cular function

■Protect airway, maintain blood pressure & assist ventilation as

needed

■Simple analgesics, tricyclic antidepressants, gabapentin or carba-

mazepine may be helpful for neuropathic pain; dose is individual-

ized depending on response & tolerance

■For acute weakness or paralysis, ensure joint mobility by passive

range-of-motion exercises twice daily

specific therapy

■Treat underlying cause of neuropathy when possible

■Guillain-Barre syndrome: plasmapheresis or IVIg, except in mild

cases

■Chronic inflammatory demyelinating neuropathy: steroids, plasma-

pheresis or IVIg