1Department of Neurosurgery and.
2Faculty of Advanced Techno-Surgery, Tokyo Women's Medical University, Tokyo, Japan.
J Neurosurg. 2020 May 1;134(5):1490-1499. doi: 10.3171/2020.2.JNS193471. Print 2021 May 1.
Identification of the motor area during awake craniotomy is crucial for preservation of motor function when resecting gliomas located within or close to the motor area or the pyramidal tract. Nevertheless, sometimes the surgeon cannot identify the motor area during awake craniotomy. However, the factors that influence failure to identify the motor area have not been elucidated. The aim of this study was to assess whether tumor localization was correlated with a negative cortical response in motor mapping during awake craniotomy in patients with gliomas located within or close to the motor area or pyramidal tract.
Between April 2000 and May 2019 at Tokyo Women's Medical University, awake craniotomy was performed to preserve motor function in 137 patients with supratentorial glioma. Ninety-one of these patients underwent intraoperative cortical motor mapping for a primary glioma located within or close to the motor area or pyramidal tract and were enrolled in the study. MRI was used to evaluate whether or not the tumors were localized to or involved the precentral gyrus. The authors performed motor functional mapping with electrical stimulation during awake craniotomy and evaluated the correlation between identification of the motor area and various clinical characteristics, including localization to the precentral gyrus.
Thirty-four of the 91 patients had tumors that were localized to the precentral gyrus. The mean extent of resection was 89.4%. Univariate analyses revealed that identification of the motor area correlated significantly with age and localization to the precentral gyrus. Multivariate analyses showed that older age (≥ 45 years), larger tumor volume (> 35.5 cm3), and localization to the precentral gyrus were significantly correlated with failure to identify the motor area (p = 0.0021, 0.0484, and 0.0015, respectively). Localization to the precentral gyrus showed the highest odds ratio (14.135) of all regressors.
Identification of the motor area can be difficult when a supratentorial glioma is localized to the precentral gyrus. The authors' findings are important when performing awake craniotomy for glioma located within or close to the motor area or the pyramidal tract. A combination of transcortical motor evoked potential monitoring and awake craniotomy including subcortical motor mapping may be needed for removal of gliomas showing negative responses in the motor area to preserve the motor-related subcortical fibers.
在切除位于运动区或锥体束内或附近的胶质瘤时，清醒开颅术中识别运动区对于保护运动功能至关重要。然而，有时外科医生无法在清醒开颅术中识别运动区。然而，影响识别运动区失败的因素尚未阐明。本研究旨在评估在位于运动区或锥体束内或附近的胶质瘤患者的清醒开颅术中，肿瘤定位是否与运动区皮质映射中的负皮质反应相关。
2000 年 4 月至 2019 年 5 月，在东京女子医科大学，对 137 例幕上胶质瘤患者行清醒开颅术以保留运动功能。其中 91 例患者因原发性胶质瘤位于运动区或锥体束内或附近而接受术中皮质运动映射，并纳入本研究。MRI 用于评估肿瘤是否定位于中央前回或累及中央前回。作者在清醒开颅术中用电刺激进行运动功能映射，并评估了运动区的识别与各种临床特征（包括定位于中央前回）之间的相关性。
91 例患者中有 34 例肿瘤定位于中央前回。平均切除程度为 89.4%。单因素分析显示，运动区的识别与年龄和定位于中央前回显著相关。多因素分析显示，年龄较大（≥45 岁）、肿瘤体积较大（>35.5cm3）和定位于中央前回与运动区识别失败显著相关（p=0.0021、0.0484 和 0.0015）。定位到中央前回的回归因子的优势比最高（14.135）。
当幕上胶质瘤定位于中央前回时，运动区的识别可能较为困难。当在运动区或锥体束内或附近进行胶质瘤的清醒开颅术时，作者的发现非常重要。对于运动区出现负反应的胶质瘤，可能需要结合皮质运动诱发电位监测和包括皮质下运动映射在内的清醒开颅术，以保留与运动相关的皮质下纤维。
