Tanaka Satoshi, Akimoto Jiro, Hashimoto Ryo, Takanashi Junko, Oka Hidehiro
Department of Neurosurgery, IMS Miyoshi General Hospital, Saitama, Japan.
Center of Brain and Health Science, Aomori University, Aomori, Japan.
J Neurol Surg A Cent Eur Neurosurg. 2019 Mar;80(2):102-108. doi: 10.1055/s-0038-1676623. Epub 2018 Dec 24.
Although intraoperative motor-evoked potential (MEP) monitoring is widely performed during neurosurgical operations, evaluating its results is controversial.
The cutoff point of MEP monitoring should be determined not only to predict but also to prevent postoperative neurologic deficits.
MEP monitoring was performed during 484 neurosurgical operations for patients without definitive preoperative motor palsy including 325 spinal operations, 102 cerebral aneurysmal operations, and 57 brain tumor operations, all monitored by transcranial stimulation, and 34 brain tumor operations monitored under direct cortical stimulation. To exclude the effects of muscle relaxants on MEP, the compound muscle action potential (CMAP), measured immediately after transcranial stimulation or direct cortical stimulation at supramaximal stimulation of the peripheral nerve, was used for normalization. The cutoff points, sensitivity, and specificity of MEP recorded during neurosurgery were examined by receiver operating characteristic (ROC) analyses and categorized according to the type of operation and stimulation.
In spinal operations under transcranial stimulation, amplitude reduction of 77.9% and 80.6% as cutoff points for motor palsy with and without CMAP normalization, respectively, provided a sensitivity of 100% and specificity of 96.8% and 96.5%. In aneurysmal operations under transcranial stimulation, cutoff points of 70.7% and 69.6% offered specificities of 95.2% and 95.7% with and without CMAP normalization, respectively. The sensitivities for both were 100%. In brain tumor operations under direct stimulation, cutoff points were 83.5% and 86.3% with or without CMAP normalization, respectively, and the sensitivity and specificity for both were 100%.
An amplitude decrease of 80% in brain tumor operations, 75% in spinal operations, and 70% in aneurysmal operations should be used as the cutoff points.
尽管术中运动诱发电位（MEP）监测在神经外科手术中广泛应用，但对其结果的评估仍存在争议。
确定MEP监测的截断点，不仅用于预测，还用于预防术后神经功能缺损。
对484例术前无明确运动麻痹的患者进行神经外科手术时进行MEP监测，其中包括325例脊柱手术、102例脑动脉瘤手术和57例脑肿瘤手术，均采用经颅刺激监测，34例脑肿瘤手术采用直接皮质刺激监测。为排除肌肉松弛剂对MEP的影响，将经颅刺激或直接皮质刺激后立即在周围神经最大刺激下测量的复合肌肉动作电位（CMAP）用于标准化。通过受试者操作特征（ROC）分析检查神经外科手术中记录的MEP的截断点、敏感性和特异性，并根据手术类型和刺激方式进行分类。
在经颅刺激下的脊柱手术中，分别以77.9%和80.6%的幅度降低作为有无CMAP标准化时运动麻痹的截断点，敏感性分别为100%，特异性分别为96.8%和96.5%。在经颅刺激下的动脉瘤手术中，截断点分别为70.7%和69.6%，有无CMAP标准化时的特异性分别为95.2%和95.7%。两者的敏感性均为100%。在直接刺激下的脑肿瘤手术中，截断点分别为83.5%和86.3%（有无CMAP标准化），两者的敏感性和特异性均为100%。
脑肿瘤手术中幅度下降80%、脊柱手术中75%、动脉瘤手术中70%应作为截断点。
