Investigations and treatment of chronic inflammatory demyelinating polyradiculoneuropathy and other inflammatory demyelinating polyneuropathies

PURPOSE OF REVIEW: The evaluation of demyelinating polyneuropathies and the data for treatment of inflammatory demyelinating peripheral neuropathies, particularly chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), will be discussed. RECENT FINDINGS: A large clinical trial showed short and long-term efficacy of intravenous immunoglobulin (IVIG) for the treatment of CIDP and the US Food and Drug Administration approved the use of IVIG (Gamunex) as a treatment for CIDP. Recent trials for other agents for CIDP treatment have not proved as promising, with a large study of methotrexate failing to show significant benefit. There are recent cases of monoclonal antibodies (e.g. rituximab, alemtuzumab) showing benefit in patients with CIDP, but the side effect profiles can be worrisome. SUMMARY: Clinical history, neurological exam, spinal fluid examination, and electrophysiological evaluation remain mainstays for the diagnosis of demyelinating inflammatory polyradiculoneuropathy. Genetic testing and nerve biopsy are important diagnostic tools in some patients. Potential treatments for immune-mediated demyelinating polyradiculoneuropathies are varied, with the authors generally favoring IVIG and/or corticosteroids as first-line agents. Plasma exchange can be helpful in selected patients. Data for efficacy of other oral immunomodulatory agents are based primarily on case reports and case series, and have not been uniformly positive. The use of monoclonal antibodies (particularly rituximab) may have promise, but further research needs to be done, and the risks need to be carefully considered.