Background/Objectives: Non-invasive motor mapping with navigated transcranial magnetic stimulation (nTMS) is an established diagnostic tool to identify spatial relationships between functional and tumor areas and to characterize motor excitability. Recently, nTMS has been used to analyze the impact of different brain tumor entities on motor excitability. However, entity-specific excitability patterns are not sufficiently validated yet. Methods: We retrospectively analyzed nTMS motor mapping data of 800 motor-eloquent brain tumor patients in this observational study. The motor excitability profile consisted of four nTMS parameters (resting motor threshold (RMT), cortical motor area, amplitude and latency) measured on both hemispheres. The relationship between motor excitability parameters and tumor entity, glioma subtype and motor status were assessed using multiple regressions analyses. Regression models included patient- and tumor-specific factors. Results: Gliomas had more frequent pathologic RMT ratios (OR 1.76, 95%CI: 1.06–2.89,p= 0.030) compared to benign entities. In the subgroup of gliomas, pathologic RMT ratios were more associated with the isocitrate dehydrogenase (IDH)-wildtype status (OR 0.43, 95%CI: 0.23–0.79,p= 0.006) and less so with higher WHO grades (OR 1.61, 95%CI: 0.96–2.71,p= 0.074). This was true for both IDH-mutant astrocytomas (OR 0.43, 95%CI: 0.20–0.91,p= 0.027) and IDH-mutant oligodendrogliomas (OR 0.43, 95%CI: 0.20–0.93,p= 0.031). Motor area enlargement on the tumor hemisphere was more frequently observed in lower WHO-graded gliomas (OR 0.87, 95%CI: 0.78–0.97,p= 0.019). Interestingly, a larger cortical motor area was additionally found for oligodendrogliomas on the healthy hemisphere (OR 1.18, 95%CI: 1.01–1.39,p= 0.041). Motor deficits were related with higher RMT (OR 1.12, 95%CI: 1.05–1.21,p= 0.001), reduced amplitude (OR 0.78, 95%CI: 0.64–0.96,p= 0.019) and prolonged latency (OR 1.12, 95%CI: 1.02–1.24,p= 0.025) in the tumor hemisphere. Conclusions: Neuroplastic phenomena such as adjustment of the motor excitability level and an enlargement of the nTMS-positive motor area were more frequently observed in benign tumors and in IDH-mutated gliomas. Consequently, patients experienced motor deficits less often, suggesting a differentiated susceptibility to resection-related paresis. Future studies will analyze which stimulation paradigms are most effective in stimulating and optimizing neuroplasticity processes to improve the functional outcomes (and thus the quality of life) for patients.
背景/目的：导航经颅磁刺激（nTMS）作为一种无创运动功能区定位技术，已成为评估功能区域与肿瘤空间关系及表征运动兴奋性的成熟诊断工具。近年来，nTMS被用于分析不同脑肿瘤实体对运动兴奋性的影响，但实体特异性兴奋模式尚未得到充分验证。方法：本观察性研究回顾性分析了800例运动功能区脑肿瘤患者的nTMS运动定位数据。运动兴奋性特征包含双侧半球测量的四项nTMS参数（静息运动阈值、皮质运动区面积、振幅及潜伏期）。通过多元回归分析评估运动兴奋性参数与肿瘤实体、胶质瘤亚型及运动状态的关系，回归模型纳入患者及肿瘤特异性因素。结果：与良性肿瘤相比，胶质瘤出现病理性静息运动阈值比值的频率更高（OR 1.76，95%CI：1.06–2.89，p=0.030）。在胶质瘤亚组中，病理性静息运动阈值比值与异柠檬酸脱氢酶野生型状态相关性更强（OR 0.43，95%CI：0.23–0.79，p=0.006），与高级别世界卫生组织分级的关联较弱（OR 1.61，95%CI：0.96–2.71，p=0.074）。这一现象在IDH突变型星形细胞瘤（OR 0.43，95%CI：0.20–0.91，p=0.027）和IDH突变型少突胶质细胞瘤（OR 0.43，95%CI：0.20–0.93，p=0.031）中均得到验证。低级别胶质瘤在肿瘤半球更常出现运动区扩大（OR 0.87，95%CI：0.78–0.97，p=0.019）。值得注意的是，少突胶质细胞瘤在健侧半球也呈现更大的皮质运动区（OR 1.18，95%CI：1.01–1.39，p=0.041）。运动功能障碍与肿瘤半球较高的静息运动阈值（OR 1.12，95%CI：1.05–1.21，p=0.001）、振幅降低（OR 0.78，95%CI：0.64–0.96，p=0.019）及潜伏期延长（OR 1.12，95%CI：1.02–1.24，p=0.025）相关。结论：神经可塑性现象（如运动兴奋性水平调节及nTMS阳性运动区扩大）在良性肿瘤和IDH突变型胶质瘤中更为常见，这类患者运动功能障碍发生率较低，提示其对切除相关瘫痪具有差异化易感性。未来研究将致力于探索最优刺激范式，以有效激活并优化神经可塑性过程，从而改善患者功能预后及生活质量。
肿瘤(癌症)患者之家