Polyneuropathy, Chronic Inflammatory

Key Features

• Clinically similar to Guillain-Barré syndrome but with relapsing or progressive course over months or years and autoimmune dysfunction is generally less common

• In the relapsing form, partial recovery may occur after relapses, or no recovery between exacerbations

• Remission may occur spontaneously, but frequently there is progression to severe functional disability

• Usually ascending, symmetric weakness

• Paresthesias more variable

Clinical Findings

• A symmetric sensory, motor, or mixed deficit, which may be most marked distally or proximally

• See Guillain-Barré Syndrome

Diagnosis

• Electrodiagnostic studies

  • Marked slowing of motor and sensory conduction and focal conduction block

  • Signs of partial denervation may be present due to secondary axonal degeneration

• Nerve biopsy

  • May show chronic perivascular inflammatory infiltrates in endoneurium and epineurium without accompanying evidence of vasculitis

  • However, normal nerve biopsy or the presence of nonspecific abnormalities does not exclude the diagnosis

Treatment

• Corticosteroids

  • Prednisone, 60–80 mg once daily orally for 2–3 mo

  • If no response has occurred despite 3 mo of treatment, a higher dose may be tried

  • In responsive cases, the dose is gradually tapered, but most patients become corticosteroid dependent, often requiring prednisone, 20 mg orally on alternate days, on a long-term basis

• Cytotoxics

  • Patients unresponsive to corticosteroids may benefit from a cytotoxic drug, such as azathioprine

• Intravenous immunoglobulin (IVIG)

  • Can be used in place of or in addition to corticosteroids

  • Best used as initial treatment in pure motor syndromes (2 g/kg over 2–5 days followed by 1 g/kg every 3 weeks)

  • A weekly regimen of 0.2–0.4 g/kg of a 20% subcutaneous immunoglobulin solution is an effective alternative but has not been compared directly to corticosteroids or IVIG

• Plasma exchange

  • When both IVIG and corticosteroids are ineffective, plasma exchange may be worthwhile

• Rituximab has shown promise