正常人短潜时体感诱发电位的N_(20)研究

The N_(20) of Short Latency Somatosensory Evoked Potentials in 90 Normal Subjects

本文报告90例正常人SSEP的N_(20)各参数测试值,并阐明N_(20)的发生机制及其正、负相电位的意义。测试和分析N_(20)有助于确定脑部病灶位于皮层或皮层下或两者兼有。作为判断指标a/w、b/x及(b/x)/(a/w)较其它参数为好,而N_(20)的负相电位a及正相电b单独用作判断指标意义不大,但两侧波幅之比值(da、db)却具有一定价值。

The N_(20) of short latency somatosensory evoked potentials (SSFP) in 90 nor- mal subjects with 180 sides-were studied. The original principles and senses of its positive and negative potentials were expounded. The focuses in cortex or subcortex or both could be localized by analysing the changes of N_(20). The a/w, b/x, b/x : a/w are more accurate in judging the SSEP. Although the a and b potentials alonely had little significance the ratios of N_(20) from two sides (da, db) are of certain value.