The predictive value of cerebrospinal fluid electrophoresis in 'possible' multiple sclerosis.

We undertook a prospective study of 183 patients with monosymptomatic demyelination to determine the predictive value of the finding of cerebrospinal oligoclonal banding (OB) for the subsequent development of clinically definite multiple sclerosis. The results of this study indicate that patients with monosymptomatic demyelination who are OB positive are at significantly higher risk than those who are OB negative to develop clinically disseminated disease over the period of follow-up in this study. Positive OB is associated with a higher frequency of electrophysiological abnormalities than negative OB, suggesting that OB development correlates with the degree of biological dissemination. The observation that some patients develop OB during the course of the disease has practical implications for the follow-up of patients with unifocal disease and negative banding.