颈动脉内膜剥脱术中的体感诱发电位监测

Monitoring of somatosensory evoked potential during carotid endarterectomy

目的探讨颈动脉内膜剥脱术(IONM)中体感诱发电位(SEP)监测脑缺血的有效性。方法对70例IONM患者进行术中SEP监测,其中男性63例,女性7例;单侧狭窄53例,双侧狭窄17例,狭窄程度均在70%以上。胫后神经刺激,记录双侧皮层的SEP,将P40波幅下降50%作为脑缺血的预警信号,潜伏期延长3ms作为参考。结果44例无变化,23例波幅下降50%但稳定且略有回升,3例波幅下降50%,且升高血压也无明显改善,1例波形扁平且无恢复。结论SEP监测可提示颈动脉阻断后的脑灌注状态是监测脑血流灌注的理想手段,但阴性不能完全排除术后可能出现的神经功能障碍。

Objective To evaluate the value of somatosensory evoked potential （SEP） during carotid endarterectomy in monitoring cerebral ischemia. Methods Seventy patients （63 males and 7 females） with a mean age of 65.6 years were included in this study. Their SEP was monitored. Unilatateral stricture was found in 53 patients and bilateral stricture was found in 17 patients, the stricture rate was over 70%. Tibial nerves were stimulated, SEP in bilateral cortex was recorded, and 50% reduction in P40 wave amplitude was used as the warning signal of cerebral ischemia. Results Types Ⅰ, Ⅱ, and Ⅲ SEP wave forms were found in 44, 23, and 3 patients, respectively, but type Ⅳ SEP was not found in any patients. Conclusion SEP monitoring can indicate the cerebral perfusion state after carotid endarterectomym and is an ideal method for monitoring cerebral blood perfusion. However, nerve dysfunction cannot be completely excluded only based on its negative results.