Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired, immune-mediated demyelinating peripheral neuropathy, essentially the chronic counterpart to Guillain-Barré syndrome (see that entry), distinguished by its progressive or relapsing course over more than 8 weeks, in contrast to the monophasic, rapidly evolving course of GBS.

Symmetric, progressive or relapsing proximal and distal weakness of the limbs, with sensory involvement (paresthesia, reduced vibration and proprioception) and globally reduced or absent deep tendon reflexes. Unlike typical axonal neuropathies, weakness is often as prominent proximally as distally. Course may be chronic progressive, stepwise, or relapsing-remitting.

Nerve conduction studies are central, showing features of demyelination (reduced conduction velocity, conduction block, prolonged distal latencies, temporal dispersion) across multiple nerves. CSF shows elevated protein with a normal or only mildly elevated cell count (albuminocytologic dissociation, as in GBS). MRI of nerve roots/plexus may show enhancement or hypertrophy. Exclude mimics: diabetic neuropathy, paraproteinemia-associated neuropathy (serum protein electrophoresis and immunofixation), and hereditary neuropathies.

• First line, roughly equal efficacy: IVIG 0.4 g/kg/day IV for 5 days as an induction course, repeated maintenance infusions (commonly every 3 to 4 weeks) as needed; or corticosteroids (prednisolone 1 mg/kg/day PO, or IV methylprednisolone pulses, tapered slowly over months); or plasma exchange
• Steroid-sparing immunosuppressants (azathioprine, mycophenolate, or, for refractory disease, rituximab or cyclophosphamide) are used for long-term maintenance or steroid-refractory disease
• Physiotherapy and rehabilitation for functional support
• Relapse is common on tapering treatment, and long-term maintenance therapy is often required; regular reassessment of ongoing treatment necessity is important given the risk of treatment-related side effects with prolonged immunosuppression

Referral: neurology for diagnosis, nerve conduction studies, and long-term immunomodulatory management.