Plasma exchange for severe attacks of inflammatory demyelinating diseases of the central nervous system

Plasma exchange has not been widely accepted as a treatment for multiple sclerosis. However, several uncontrolled studies have suggested that patients with severe attacks of MS and other inflammatory demyelinating disease may improve rapidly after plasma exchange treatment. We recently completed a randomized, sham-controlled, crossover clinical trial of plasma exchange in 22 patients with idiopathic inflammatory demyelinating diseases of the central nervous system. Twelve had MS and ten had other inflammatory demyelinating disease syndromes. Forty-two percent of patients experienced moderate or greater recovery over 2 weeks of active treatment administered every other day while only 6% of patients experienced similar improvement while receiving sham treatment. Three patients who failed the sham treatment subsequently improved rapidly after crossover to active treatment; no patient who failed active treatment improved after crossover to sham. This study illustrates the importance of designing randomized clinical trials based on the treatment regimen and patient population studied in the uncontrolled reports that suggested treatment efficacy. Plasma exchange should be considered for patients with idiopathic inflammatory demyelinating disease syndromes when they have failed corticosteroid therapy.