Electrophysiological, neuropsychological and clinical findings in multiple sclerosis patients receiving interferon beta-1b: a 1-year follow-up

We assessed serial event-related potentials (ERPs) as well as neuropsychological and clinical test findings in a group of multiple sclerosis (MS) patients (n = 14) treated with interferon beta-1b (INF-beta-1b) compared to normal controls (n = 14). All investigations were done within 1 week before INF-beta-1b therapy was started and 12 months later. An auditory oddball paradigm was employed. No significant differences in the N100, P200, N200 or P300 latencies between patients and control group were found, but 3 out of 14 MS patients developed abnormal P300 latencies (more than 2 standard errors from the mean) after 1 year of INF-beta-1b therapy. This was not reflected by the respective neurological impairment as assessed by the Expanded Disability Status Scale score. ERPs might be a useful tool in clinical studies in order to evaluate drug effects on cognition, but for a final statement, the analysis of ERPs in a larger group of patients is required.