[Visual evoked potentials from different unpatterned stimuli in normal subjects and subjects with multiple sclerosis].
A study of VEP was carried out by stimulation with white and red flashes in 20 normal subjects and 58 patients with definite or possible Multiple Sclerosis (MS). In normal subjects, the VEP obtained with the red flash exhibited a simplified waveform and a significantly higher latency of the III and IV peaks than with the white flash. This is due to the different spectral component of the stimulation, which specifically excites foveal receptors whose fibers have a smaller diameter and therefore a lower conduction velocity. The subjects with definite or probable MS showed average VEP latencies which were significantly higher than those of normal subjects. A comparison of the results obtained with the two types of stimulation demonstrates that the red flash reveals a higher number of modified VEPs, thus pointing out even subclinical impairments of the visual pathways.
D000328:Adult; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology*; D010775:Photic Stimulation
Potenziali evocati visivi (PEV) da differenti stimoli non strutturati in soggetti normali e con sclerosi multipla (SM).