[The Effect of the Disease Duration on the Changes of the Visual Evoked Potentials and Contrast Sensitivity in Multiple Sclerosis].

The most sensitive methods to detect pathological changes in the visual system are the method of recording visual evoked potentials and the psychophysical method of measuring contrast sensitivity. Described in the literature features of functional disorders of the visual system in patients with multiple sclerosis are controversial. The results of the study allowed us to make an assumption about the depen-dence of the nature and severity of changes of the evoked potentials and contrast sensitivity and the duration of disease in patients with multiple sclerosis. In some patients with disease duration from 3 to 10 years there are irregularities in the magno-channels (reduced amplitude component P1), in others-- parvo-channels (amplitude reduction N 1) without increasing the latency, in patients with a disease duration of 10 to 14 years--both channels dysfunction (decreased amplitude components P1 and N1) with an increase of latency. The data indicate heterogeneity of pathophysiological changes upon increase of the degree of demyelination and damage of optic nerve fibers in multiple sclerosis.