Serial evoked potential studies in patients with definite multiple sclerosis. Clinical relevance.

Twelve patients with clinically definite multiple sclerosis were examined both clinically and electrophysiologically at repeated intervals over one year to determine the clinical relevance of data obtained by serial multimodality evoked potential studies. We frequently found a disparity between the clinical and electrophysiologic changes, and also an excessive variability between test sessions of the responses to stimulation of a clinically involved afferent pathway even when the clinical deficit was stable. Our findings indicate that though evoked potential studies may provide information of diagnostic relevance, their role in monitoring disease progression has not been established.