Flash VEPにおいて短潜時に反応が現れる症例の検討

Short latency response in flash VEP

　flash VEPのN₁の潜時を20歳以上の244症例について検討した。明確な陽性波と陰性波が得られた症例のうち，49例が潜時が60ミリ秒以下の陰性波を示した。このうち43眼25例では潜時が短い反応のみを示し，39眼24例では．通常のN₁とP₂と比べて遅くにもうひとつの反応を示した。潜時が短いこれら82眼のうち，26眼（32％）では，網膜より中枢側の障害により，視力0.1未満であった。

We evaluated the latency period of visual evoked potential (VEP) by flash stimulation in 244 cases over 20 years of age. There were 49 cases who showed distinct positive and negative waves with the latency period shorter than 60 msec for negative waves. In these 49 cases, 43 eyes, 25 cases, showed only one short latency response. The other 39 eyes, 24 cases, showed another delayed response after the usual N1 and P2 waves. In these 82 eyes with short latency response, 26 eyes, 32%, showed visual acu-ity of 20/200 or less due to lesions between the retina and the cerebral cortex.