Effect of Spinal Cord Ischemia on Spinal Cord Evoked Potetials in the Canine

对8只胸主动脉交叉夹持致动脉缺血麻醉犬，记录脊髓诱发电位（ESCP）和坐骨神经脊髓诱发电位（ESCP）。并比较了它们的波形和振幅。实验结束48小时后，将T-1至S-5段脊髓整体切除，进行病理组织学研究。电生理结果显示，腰膨出水平记录的ESCP N2振幅、ESCP N3振幅和坐骨ESCP的恢复比率与组织病理损伤和神经转归相关。脊髓组织病理学检查显示，从下胸椎到腰膨出的大部分脊髓均出现缺血性改变，且不同程度有不同的变化。且腰膨出部位后角较前角受损，因此有必要监测ESCP和坐骨ESCP的N3振幅。

In eight anesthetized canines that had arterial ischemia produced by crossclamping of thoracic aorta, evoked spinal cord potentials (ESCP) and aciatic nerve spinal cord potentials (sciatic ESCP) were recorded. And their waveforms and amplitudes were compared. Further, after 48-hour the completion of experiment, the spinal cord from T-1 to S-5 was removed en bloc and studied pathohistologically. In the electrophysiological findings, the recovery ratio of the N2 amplitude of the ESCP,the N3 amplitude of ESCP and the sciatic ESCP recorded at the level of intumescentia lumbaris was correlated with the histopathological damages and neurological outcome. Histopathologic examination of the cord revealed that ischemic changes were especially found at the greater portion from lower thoracic region to intumescentia lumbaris and their changes were differentiated each levels. And posterior horns were damaged rather than anterior horns at intumescentia lumbaris, therefore it is necessary to monitor the N3 amplitude of ESCP and the sciatic ESCP.