Inflammatory demyelinating neuropathies

Abstract

Early and effective treatment of chronic inflammatory demyelinating polyneuropathy (CIDP) is important to minimize axonal degeneration that occurs secondary to demyelination. The disease course is invariably chronic, so long-term treatment is often required, and adverse effects and costs are important considerations in devising a treatment plan. CIDP responds to prednisone, but long-term treatment can result in significant adverse effects. Azathioprine, mycophenolate mofetil, and cyclosporine can be used as steroid-sparing agents and may facilitate more rapid and successful tapering of prednisone. Intravenous immunoglobulin (IVIg) and plasma exchange are also effective in the treatment of CIDP and can be used in patients who are unresponsive to prednisone or develop steroid-related adverse effects. IVIg may also be used as a first-line treatment, but its cost can be a limiting factor. A few uncontrolled studies have suggested that pulsed weekly methylprednisolone is both effective and well tolerated in the long-term treatment of CIDP. Treatments based on rituximab or cyclophosphamide have also been used in resistant disease. Variants of CIDP have been described on the basis of their association with specific antibodies or immunoglobulins and their response to specific immunomodulatory treatments. Multifocal motor neuropathy with conduction block responds to IVIg in the majority of patients. However, weakness may slowly worsen over time, and some patients become unresponsive. Anecdotal reports suggest that rituximab may be useful in patients who develop progressive disease. Placebo-controlled trials in anti-myelin-associated glycoprotein neuropathy suggest that rituximab is effective and, with a combination of prednisone and cyclophosphamide, numbness and strength may improve. Other treatments that may be effective include plasma exchange and IVIg. Treatment is generally started with prednisone, IVIg, or plasma exchange. Rituximab and cyclophosphamide are used only in progressive, treatment-resistant disease because of the potential for serious adverse effects.