Shimoyama I, Miyanaga F, Nishizawa S, Uemura K, Morita Y
Department of Neurosurgery, Hamamatsu University School of Medicine, Japan.
Doc Ophthalmol. 1995;91(4):363-70. doi: 10.1007/BF01214654.
Most of the reports on visual evoked cortical potentials have dealt with peak latency or amplitude. An early negative deflection at about 20 ms, however, was reported to coincide with the initial signal to the monkey cortex. We studied the initial signal to the human cortex in nine volunteers by taking into account prestimulus fluctuation. Visual evoked cortical potentials were recorded for an interval 10 ms before and 92.4 ms, after a flash stimulus, by means of a neck reference. The amplitudes of the response before the flash stimulus and at each succeeding 5-ms interval after the stimulus were tested with a t-test. The grand average of the visual evoked cortical potentials showed an initial negative peak at 22.3 ms over the frontal poles, a second negative peak at 52.4 ms over the central area, and a third negative peak at 74.7 ms over the occipital areas. The topographic maps corresponding to the peaks of the visual evoked cortical potentials were the same as those of the dynamic t-values. The visual evoked cortical potential and t-values with the bipolar and source derivations showed a marked response beginning around 40 ms over the posterior head. This statistical analysis is an easy method to standardize evoked potentials and to identify deflections.
大多数关于视觉诱发电位的报告都涉及峰潜伏期或波幅。然而，据报道，在约20毫秒时出现的一个早期负向偏转与传入猴皮层的初始信号同时出现。我们通过考虑刺激前的波动，对9名志愿者的传入人类皮层的初始信号进行了研究。通过颈部参考电极，在闪光刺激前10毫秒和刺激后92.4毫秒的时间段内记录视觉诱发电位。用t检验对闪光刺激前及刺激后每个连续5毫秒间隔的反应波幅进行测试。视觉诱发电位的总体平均值显示，在额极上方22.3毫秒处有一个初始负峰，在中央区上方52.4毫秒处有第二个负峰，在枕区上方74.7毫秒处有第三个负峰。与视觉诱发电位峰值相对应的地形图与动态t值的地形图相同。双极导联和源导联的视觉诱发电位及t值显示，在头后部约40毫秒左右开始出现明显反应。这种统计分析是一种标准化诱发电位和识别偏转的简便方法。
