Tanaka Satoshi, Tashiro Takashi, Gomi Akira, Takanashi Junko, Ujiie Hiroshi
Department of Neurosurgery, Shioya Hospital, International University of Health and Welfare, Yaita, Tochigi, Japan.
Surg Neurol Int. 2011;2:111. doi: 10.4103/2152-7806.83731. Epub 2011 Aug 13.
Intraoperative transcranial motor-evoked potential (TCMEP) monitoring is widely performed during neurosurgical operations. Sensitivity and specificity in TCMEP during neurosurgical operations were examined according to the type of operation.
TCMEP monitoring was performed during 283 neurosurgical operations for patients without preoperative motor palsy, including 121 spinal operations, 84 cerebral aneurysmal operations, and 31 brain tumor operations. Transcranial stimulation at 100-600 V was applied by screw electrodes placed in the scalp and electromyographic responses were recorded with surface electrodes placed on the affected muscles. To exclude the effects of muscle relaxants on TCMEP, compound muscle action potential (CMAP) by supramaximal stimulation of the peripheral nerve immediately after transcranial stimulation was used for compensation of TCMEP.
In spinal operations, with an 80% reduction in amplitude as the threshold for motor palsy, the sensitivity and specificity with CMAP compensation were 100% and 96.4%, respectively. In aneurysmal operations, with a 70% reduction in amplitude as the threshold for motor palsy, the sensitivity and specificity with CMAP compensation were 100% and 94.8%, respectively. Compensation by CMAP was especially useful in aneurysmal operations. In all neurosurgical operations, with a 70% reduction in amplitude as the threshold for motor palsy, the sensitivity and specificity with CMAP compensation were 95.0% and 90.9%, respectively.
Intraoperative TCMEP monitoring is a significantly reliable method for preventing postoperative motor palsy in both cranial and spinal surgery. A 70% reduction in the compensated amplitude is considered to be a suitable alarm point in all neurological operations.
术中经颅运动诱发电位（TCMEP）监测在神经外科手术中广泛应用。根据手术类型对神经外科手术中TCMEP的敏感性和特异性进行了研究。
对283例术前无运动麻痹的患者进行神经外科手术时进行TCMEP监测，包括121例脊柱手术、84例脑动脉瘤手术和31例脑肿瘤手术。通过置于头皮的螺旋电极施加100 - 600V的经颅刺激，并用置于受影响肌肉上的表面电极记录肌电图反应。为排除肌肉松弛剂对TCMEP的影响，经颅刺激后立即对周围神经进行超强刺激的复合肌肉动作电位（CMAP）用于补偿TCMEP。
在脊柱手术中，以波幅降低80%作为运动麻痹阈值时，CMAP补偿的敏感性和特异性分别为100%和96.4%。在动脉瘤手术中，以波幅降低70%作为运动麻痹阈值时，CMAP补偿的敏感性和特异性分别为100%和94.8%。CMAP补偿在动脉瘤手术中尤其有用。在所有神经外科手术中，以波幅降低70%作为运动麻痹阈值时，CMAP补偿的敏感性和特异性分别为95.0%和90.9%。
术中TCMEP监测是预防颅脑和脊柱手术术后运动麻痹的一种非常可靠的方法。在所有神经外科手术中，补偿波幅降低70%被认为是一个合适的报警点。
