SIDE-TO-SIDE DIFFERENCES IN VISUAL EVENT-RELATED POTENTIALS BUT NOT VEP IN PATIENTS WITH MULTIPLE-SCLEROSIS - A REPORT OF 3 CASES

Three patients with definite multiple sclerosis (MS) and acute loss of visual acuity on one side but without side-to-side differences in vis ual evoked potential (VEP) latencies revealed prolongation of visual e vent-related potentials (ERP) on the impaired side, These patients rep resent 5.1% of a cohort with clinical optic mononeuritis and 21.4% of a cohort with clinical optic mononeuritis but no side-to-side differen ces in VEP. The data suggest, that in some cases, side different measu rement of ERP (rather than VEP) is an appropriate method to prove the sensory or cognitive impairment in patients with RIS and clinical opti c mononeuritis.