Visual evoked potentials in the diagnosis of multiple sclerosis.

A three-year collaborative study was done on 96 patients presenting with signs of neurological dysfunction suggestive of multiple sclerosis. All were tested using Visual Evoked Potentials, with the final diagnosis not known to the tester. Patients with bilateral Visual Evoked Potential P1 wave conduction delays were more likely to have a subsequent diagnosis of MS, than those with unilateral delays, or normal VEPs. The average delay between the onset of the first symptom, and a definitive diagnosis of MS was 3.5 years. The most frequent initial symptom was paresthesias of the lower extremities, followed by blurred vision. This study suggests that the presence of Visual Evoked Potential abnormalities may be useful in the longitudinal diagnostic evaluation of patients with a presumptive diagnosis of multiple sclerosis.