正中神经体感诱发电位P_（22）波的来源及其对偏瘫患者手功能恢复的预测价值

使用耳垂参考电极，在顶、额颅表同步描记正中神经体感诱发电位（Ｍ－ＳＥＰ），可记录到Ｐ＿(１４)、Ｐ＿(２２)、Ｎ＿(３０)和Ｐ＿(１４)、Ｎ＿(２０)、Ｐ＿(２２)两组波。动物实验观察发现，局部麻醉家兔中央前回后，Ｐ＿(２２)波消失；麻醉顶叶对Ｐ＿(２２)波幅无明显影响，证明Ｐ＿(２２)是与手运动相关联的波。分析经ＣＴ证实的３９名偏瘫患者，观察经物理治疗前后Ｐ＿(２２)、Ｎ＿(２０)与手肌力的对应关系，发现Ｐ＿(２２)对判断手功能的预后是个很敏感的指标，若患者Ｐ＿(２２)波分化不清或消失，是手功能预后不好的信号，因此，Ｐ＿(２２)波可考虑作为临床判断手功能预后的电生理指标之一。

INVESTIGATION ON THE ORIGIN OF p_22 IN SEP ELICITED BY MEDIAN NERVE STIMULATION AND ITS SIGNIFICANCE IN PREDICTING THE RECOVERY OF HAND MOVEMENT IN PATIENTS WITH HEMIPARALYSIS

Taking ear-lobe for reference electrode,the somatosensory evoked potential(M-SEP)elic-ited by median nerve stimulation was recorded simultaneously in the parietal and frontal areas.Two groups of waves,P_(14),P_(22),N_(30) and P_(14),N_(20),P_(22),could be found on F_3(F_4).In animal exper-iment,the P_(22) wave disappeared in rabbits after anesthesia of the precentral gyri,but N_(20) stillexisted. The P_(22) wave still existed aner anesthesia of the parietal areas, but N_(20) disappeared.Therefore,P_(22) was proved to be associated with hand movement.In 39 patients withhemiparalysis proved by CT,the relationship between P_22 or N_(20) and the hand myodynamiawas analysed before and after the physiotherapy.It was found that P_(22) was a very sensitive indi-cator for evaluatingthe prognosis of hand function. If P_(22) of the patients cannot be differntiatedclearly or disappeared,the prognosis of hand function is unfavourable. It is suggested that theP_(22) may be a clinial indicator for evaluating the prognosis of hand function.