Abstract：
BACKGROUND: Non-invasive brain mapping using navigated transcranial magnetic stimulation (nTMS) is a valuable tool prior to resection of malignant brain tumors. With nTMS motor mapping, it is additionally possible to analyze the function of the motor system and to evaluate tumor-induced neuroplasticity. Distinct changes in motor cortex excitability induced by certain malignant brain tumors are a focal point of research.
METHODS: A retrospective single-center study was conducted involving patients with malignant brain tumors. Clinical data, resting motor threshold (rMT), and nTMS-based tractography were evaluated. The interhemispheric rMT-ratio (rMTTumor/rMTControl) was calculated for each extremity and considered pathological if it was >110% or <90%. Distances between the corticospinal tract and the tumor (lesion-to-tract-distance - LTD) were measured.
RESULTS: 49 patients were evaluated. 16 patients (32.7%) had a preoperative motor deficit. The cohort comprised 22 glioblastomas (44.9%), 5 gliomas of Classification of Tumors of the Central Nervous System (CNS WHO) grade 3 (10.2%), 6 gliomas of CNS WHO grade 2 (12.2%) and 16 cerebral metastases (32.7%). 26 (53.1%) had a pathological rMT-ratio for the upper extremity and 35 (71.4%) for the lower extremity. All patients with tumor-induced motor deficits had pathological interhemispheric rMT-ratios, and presence of tumor-induced motor deficits was associated with infiltration of the tumor to the nTMS-positive cortex (p = 0.04) and shorter LTDs (all p < 0.021). Pathological interhemispheric rMT-ratio for the upper extremity was associated with cerebral metastases, but not with gliomas (p = 0.002).
CONCLUSIONS: Our study underlines the diagnostic potential of nTMS motor mapping to go beyond surgical risk stratification. Pathological alterations in motor cortex excitability can be measured with nTMS mapping. Pathological cortical excitability was more frequent in cerebral metastases than in gliomas.
METHODS: A retrospective single-center study was conducted involving patients with malignant brain tumors. Clinical data, resting motor threshold (rMT), and nTMS-based tractography were evaluated. The interhemispheric rMT-ratio (rMTTumor/rMTControl) was calculated for each extremity and considered pathological if it was >110% or <90%. Distances between the corticospinal tract and the tumor (lesion-to-tract-distance - LTD) were measured.
RESULTS: 49 patients were evaluated. 16 patients (32.7%) had a preoperative motor deficit. The cohort comprised 22 glioblastomas (44.9%), 5 gliomas of Classification of Tumors of the Central Nervous System (CNS WHO) grade 3 (10.2%), 6 gliomas of CNS WHO grade 2 (12.2%) and 16 cerebral metastases (32.7%). 26 (53.1%) had a pathological rMT-ratio for the upper extremity and 35 (71.4%) for the lower extremity. All patients with tumor-induced motor deficits had pathological interhemispheric rMT-ratios, and presence of tumor-induced motor deficits was associated with infiltration of the tumor to the nTMS-positive cortex (p = 0.04) and shorter LTDs (all p < 0.021). Pathological interhemispheric rMT-ratio for the upper extremity was associated with cerebral metastases, but not with gliomas (p = 0.002).
CONCLUSIONS: Our study underlines the diagnostic potential of nTMS motor mapping to go beyond surgical risk stratification. Pathological alterations in motor cortex excitability can be measured with nTMS mapping. Pathological cortical excitability was more frequent in cerebral metastases than in gliomas.
摘要：
背景：使用导航经颅磁刺激（nTMS）的非侵入性脑图是切除恶性脑肿瘤之前的有价值的工具。使用nTMS电机映射，此外，还可以分析运动系统的功能并评估肿瘤引起的神经可塑性。某些恶性脑肿瘤引起的运动皮质兴奋性的明显变化是研究的重点。
方法：回顾性单中心研究涉及恶性脑肿瘤患者。临床数据,静息运动阈值(RMT)，和基于nTMS的纤维束造影进行了评估。计算每个肢体的半球间rMT比率（rMTTuman/rMTControl），如果>110％或<90％，则认为是病理性的。测量皮质脊髓束和肿瘤之间的距离(病变到束的距离-LTD)。
结果：对49例患者进行评估。16例（32.7％）患者术前运动功能障碍。该队列包括22个胶质母细胞瘤（44.9%），5个中枢神经系统（CNSWHO）肿瘤分类的胶质瘤3级（10.2％），CNSWHO2级胶质瘤6例(12.2%)和脑转移瘤16例(32.7%)。上肢有26例（53.1％）的病理性rMT比率，下肢有35例（71.4％）。所有肿瘤引起的运动缺陷患者均有病理性半球间rMT比率，并且肿瘤诱导的运动缺陷的存在与肿瘤浸润到nTMS阳性皮质（p=0.04）和较短的LTD（所有p<0.021）有关。上肢的病理半球间rMT比率与脑转移有关，但不与胶质瘤（p=0.002）。
结论：我们的研究强调了nTMS运动标测的诊断潜力，超越了手术风险分层。运动皮层兴奋性的病理改变可以用nTMS作图测量。脑转移瘤的病理皮质兴奋性比神经胶质瘤更常见。
方法：回顾性单中心研究涉及恶性脑肿瘤患者。临床数据,静息运动阈值(RMT)，和基于nTMS的纤维束造影进行了评估。计算每个肢体的半球间rMT比率（rMTTuman/rMTControl），如果>110％或<90％，则认为是病理性的。测量皮质脊髓束和肿瘤之间的距离(病变到束的距离-LTD)。
结果：对49例患者进行评估。16例（32.7％）患者术前运动功能障碍。该队列包括22个胶质母细胞瘤（44.9%），5个中枢神经系统（CNSWHO）肿瘤分类的胶质瘤3级（10.2％），CNSWHO2级胶质瘤6例(12.2%)和脑转移瘤16例(32.7%)。上肢有26例（53.1％）的病理性rMT比率，下肢有35例（71.4％）。所有肿瘤引起的运动缺陷患者均有病理性半球间rMT比率，并且肿瘤诱导的运动缺陷的存在与肿瘤浸润到nTMS阳性皮质（p=0.04）和较短的LTD（所有p<0.021）有关。上肢的病理半球间rMT比率与脑转移有关，但不与胶质瘤（p=0.002）。
结论：我们的研究强调了nTMS运动标测的诊断潜力，超越了手术风险分层。运动皮层兴奋性的病理改变可以用nTMS作图测量。脑转移瘤的病理皮质兴奋性比神经胶质瘤更常见。
