Visual Evoked Potential in Diagnosis of Multiple Sclerosis

Comparison of the results of visual evoked potential (VEP) in time domain and frequency domain between multiple sclerosis (MS) suspected patients and normal indivisuals. Eleven MS suspected patients with normal visual findings and 20 normal individuals were tested by VEP. Results were compared between two groups. The time domain results showed no significant difference between the two groups. Results of the frequency domain showed that Fmod value in the MS group (4.11.4 Hz) was less than the value in normal subjects (7.92.8 Hz) but, the number of peaks in power spectrum in the MS group (3.80.9) was more than the value in normal subjects (1.50.3). (P<0.001) Decreased nerve conduction velocity, nerve impulse blockage, and refractory period increase in MS may cause low pass shift in frequency spectrum that may lead to Fmod decrease and increase the number of peaks in spectrum. These finding may be useful for early diagnosis of MS.