Department of Neurosurgery, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany.
Department of Neurosurgery, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
Neurosurg Rev. 2022 Aug;45(4):2869-2875. doi: 10.1007/s10143-022-01803-6. Epub 2022 May 6.
During monitoring of motor evoked potentials (MEP) elicited by transcranial electrical stimulation (TES) for prognostication of postoperative motor deficit, significant MEP changes without postoperative deterioration of motor function represent false-positive results. We aimed to investigate this phenomenon in a large series of patients who underwent resection of supratentorial lesions. TES was applied in 264 patients during resection of motor-eloquent supratentorial lesions. MEP were recorded bilaterally from arm, leg, and/ or facial muscles. The threshold criterion was applied assessing percentage increase in threshold level, which was considered significant if being > 20% higher on affected side than on the unaffected side. Subcortical stimulation was additionally applied to estimate the distance to corticospinal tract. Motor function was evaluated at 24 h after surgery and at 3-month follow-up. Patients with false-positive results were analyzed regarding tumor location, tumor volume, and characteristics of the monitoring. MEP were recorded from 399 muscles (264 arm muscles, 75 leg muscles, and 60 facial muscles). Motor function was unchanged postoperatively in 359 muscles in 228 patients. Among these cases, the threshold level did not change significantly in 354 muscles in 224 patients, while it increased significantly in the remaining 5 muscles in 4 patients (abductor pollicis brevis in all four patients and orbicularis oris in one patient), leading to a false-positive rate of 1.1%. Tumor volume, opening the ventricle, and negative subcortical stimulation did not significantly correlate with false-positive results, while the tumor location in the parietal lobe dorsal to the postcentral gyrus correlated significantly (p = 0.012, odds ratio 11.2, 95% CI 1.8 to 69.8). False-negative results took place in 1.1% of cases in a large series of TES-MEP monitoring using the threshold criterion. Tumor location in the parietal lobe dorsal to the postcentral gyrus was the only predictor of false-positive results.
在使用经颅电刺激（TES）监测运动诱发电位（MEP）以预测术后运动功能缺损时，如果 MEP 发生显著变化而术后运动功能没有恶化，则代表假阳性结果。我们旨在一项大型系列研究中对这一现象进行研究，该研究纳入了 264 例行幕上病变切除术的患者。在 264 例运动区相关的幕上病变切除术患者中，应用 TES 进行监测。双侧上肢、下肢和/或面部肌肉均记录 MEP。采用阈值标准评估阈值水平的百分比增加，如果患侧比健侧高 20%以上，则认为有显著变化。另外还进行皮质下刺激以估计皮质脊髓束的距离。术后 24 小时和 3 个月随访时评估运动功能。分析假阳性结果患者的肿瘤位置、肿瘤体积和监测特征。从 399 块肌肉（264 块上肢肌肉、75 块下肢肌肉和 60 块面部肌肉）记录 MEP。228 例患者的 359 块肌肉术后运动功能无变化。在这 224 例患者的 354 块肌肉中，阈值水平无显著变化，而在另外 4 例患者的 5 块肌肉中显著增加（4 例患者均为拇短展肌，1 例患者为口轮匝肌），导致假阳性率为 1.1%。肿瘤体积、打开脑室和皮质下刺激阴性与假阳性结果无显著相关性，而位于后中央回背侧的顶叶肿瘤位置与假阳性结果显著相关（p=0.012，比值比 11.2，95%可信区间 1.8 至 69.8）。在使用阈值标准的大型 TES-MEP 监测系列中，假阴性结果的发生率为 1.1%。位于后中央回背侧的顶叶肿瘤位置是假阳性结果的唯一预测因素。
