Course of visual evoked potentials in multiple sclerosis: electroclinical correlations and pathophysiological...

Twenty-five MS patients had VEPs recorded at 1-year interval. Abnormal VEPs were observed at least once in 21 patients. They were the only means of assessing the lesional dissemination in nine patients. Their contribution in the diagnostic classification is such that the proportion of "definite" cases rises from 44 to 80% of the 25 cases. The degree of abnormality of the VEPs had no relation to the disability status or to the whole severity of the disease. The main feature was the variability of the VEP latencies at a 1-year interval: they seem to follow the remittent progressive course of the disease whether visual pathways are clinically affected or not. These results are interpreted in light of the pathophysiological data of the disease. In the cases with improvement of normalization of the second VEPs, in plaque edema may be an important mechanism, sometimes free of demyelination so that perfect restitutio ad integrum may occur.