A comparison of clinical and evoked potential (VEP and median nerve SEP) evolution in patients with MS and potentially related conditions

A clinical and electrophysiological (VEP and median nerve SEP) follow-up was performed in 27 subjects selected among 200 consecutive patients previously examined by multimodality evoked potentials because of MS or potentially related conditions. The mean interval between the examinations was 20 months. There was a concordance between the clinical and electrophysiological evolution for the majority of examined pathways. However, alterations were more frequent for evoked potentials than for clinical symptomatology: six VEPs and 16 SEPs were changed compared to the initial recordings whereas clinical alterations occurred in one eye and 11 arms. Definitely contradictory evolutions were observed in only two arms (in one of the MS patients). Significant deteriorations between examinations occurred for two VEPs and two SEPs, although the recordings remained within normal limits. We conclude that evoked potential recordings are valuable for monitoring and that serial recordings may increase the number of abnormal findings.