Division of Neuroanesthesia and Intraoperative Neuromonitoring, Department of Anesthesiology, Intensive Care and Pain Therapy, Klinikum St. Georg gGmbH, Leipzig, Germany.
Clin Neurophysiol. 2013 May;124(5):1025-30. doi: 10.1016/j.clinph.2012.10.014. Epub 2012 Nov 29.
This study was to investigate the utility of motor evoked potential monitoring elicited by transcranial electrical stimulation (tcMEP) during CEA in addition to the established median nerve somatosensory evoked potentials (mSSEPs).
We retrospectively reviewed data from 600 patients undergoing CEA under general anesthesia with monitoring of mSSEPs and tcMEPs in a multicenter study. MSSEP and tcMEP parameters were recorded during internal carotid artery (ICA) cross clamping and compared with the postoperative motor outcome, demographic and patient history data.
The intraoperative monitoring of tcMEPs was successful in 594 of the patients (99%) and selective shunt was performed in 29 of them (4.83%). Nine of the patients showed a transient contralateral loss of tcMEPs, without changes in mSSEPs and required intervention (1.5% "false-negative"). Three of them showed postoperative motor deficits. The time period from tcMEP loss to intervention was significantly longer (p = 0.01) in this group compared to the patients without postoperative motor deficit.
TcMEPs during CEA may be an adjunct to mSSEP monitoring to avoid "false-negative" mSSEP results, as mSSEPs seem to lack specificity for detecting isolated ischemia of corticospinal pathway.
TcMEPs seem to improve postoperative outcome, especially in case of a timely correction of cerebral ischemia.
本研究旨在探讨经颅电刺激诱发运动诱发电位（tcMEP）监测在颈动脉内膜切除术（CEA）中的应用价值，该技术除了现有的正中神经体感诱发电位（mSSEPs）监测以外。
我们回顾性分析了在多中心研究中 600 例行全身麻醉下 CEA 监测 mSSEPs 和 tcMEPs 的患者数据。记录 ICA 夹闭期间的 MSSEP 和 tcMEP 参数，并与术后运动结果、人口统计学和患者病史数据进行比较。
594 例患者（99%）tcMEP 术中监测成功，其中 29 例（4.83%）选择性分流。9 例患者出现短暂的对侧 tcMEP 丧失，mSSEPs 无变化，需要干预（1.5%“假阴性”）。其中 3 例术后出现运动功能障碍。与术后无运动功能障碍的患者相比，该组患者 tcMEP 丧失至干预的时间明显更长（p = 0.01）。
CEA 期间的 tcMEPs 可能是 mSSEP 监测的辅助手段，可以避免“假阴性”的 mSSEP 结果，因为 mSSEPs 似乎缺乏特异性，无法检测皮质脊髓束的孤立性缺血。
tcMEPs 似乎可以改善术后结果，尤其是在及时纠正脑缺血的情况下。
