Pattern visual evoked responses in multiple sclerosis.

The latency of the first major positive component of the visual evoked response to pattern reversal was measured from a midoccipital electrode for each eye in 30 patients with a definite diagnosis of multiple sclerosis (MS). Their latencies were compared with those of a group of 18 normal subjects and 18 patients with other neurological diseases. Of 26 MS patients with a measurable response, 77% gave values that were outside the ranges of the two control groups. A total of 75% of the MS patients without history or findings of optic neuritis had an abnormal response. The procedure appears to be useful in detecting asymptomatic lesions of the visual pathways in suspected MS patients.