Practical application of patterned visual evoked responses in multiple sclerosis.

Pattern reversal visual evoked potentials (VEP) were studied in a control group of 72 subjects and in 60 patients with multiple sclerosis. The recording system consisted of a visual stimulator for pattern production on a commercial TV connected to an EMG machine for displaying and averaging of the response. The normal values of latency, the upper limit of normality and right-left differences in our control group were compared with those given by different authors. Likewise a comparison of the positive VEP results in MS was carried out. The reasons for the variability of results were briefly discussed and the importance of control studies for each laboratory starting VEP recording was stressed. This test can easily be carried out in every clinical neurophysiological laboratory and it provides an excellent and rapid technique for the investigation of patients with suspected multiple sclerosis.