Tanaka Satoshi
Department of Neurosurgery, Numata Neurosurgery and Cardiovascular Hospital.
No Shinkei Geka. 2023 May;51(3):398-407. doi: 10.11477/mf.1436204763.
Motor evoked potential(MEP)is the most widely used intraoperative neurophysiological monitoring measure. It includes cortical direct stimulation MEP(dMEP), which directly stimulates the primary motor cortex of the frontal lobe identified by short-latency somatosensory evoked potentials, and transcranial MEP(tcMEP), which involves high-current or high-voltage transcranial stimulation using cork-screw electrodes installed in the scalp. dMEP is performed in brain tumor surgery close to the motor area. tcMEP is simple, safe, and widely used in spinal and cerebral aneurysm surgeries. The increase in sensitivity and specificity with compound muscle action potential(CMAP)after peripheral nerve stimulation normalization performed in MEP to remove the effect of muscle relaxants is unclear. However, tcMEP for decompression in compressive spinal and spinal nerve diseases may predict the recovery of postoperative neurological symptoms with CMAP normalization. The anesthetic fade phenomenon can be avoided with CMAP normalization. The cutoff rate of loss of amplitude that causes postoperative motor paralysis in intraoperative MEP monitoring is 70%-80%, and setting an alarm at each facility based on this is necessary.
运动诱发电位（MEP）是术中应用最广泛的神经生理监测手段。它包括皮质直接刺激运动诱发电位（dMEP），即通过短潜伏期体感诱发电位确定额叶的初级运动皮质并直接进行刺激，以及经颅运动诱发电位（tcMEP），它涉及使用安装在头皮上的螺旋电极进行高电流或高电压经颅刺激。dMEP用于靠近运动区的脑肿瘤手术。tcMEP操作简单、安全，广泛应用于脊柱和脑动脉瘤手术。在MEP中进行外周神经刺激归一化以消除肌肉松弛剂的影响后，复合肌肉动作电位（CMAP）的敏感性和特异性增加情况尚不清楚。然而，用于压迫性脊髓和脊神经疾病减压的tcMEP可能通过CMAP归一化预测术后神经症状的恢复情况。通过CMAP归一化可避免麻醉消退现象。术中MEP监测导致术后运动麻痹的波幅损失截断率为70%-80%，各机构有必要据此设置警报。
