BACKGROUND Diffuse gliomas have an increased biological aggressiveness across the World Health Organization (WHO) grading system. The implications of glioma grading on the primary motor cortex (M1)-corticospinal tract (CST) excitability is unknown. OBJECTIVE To assess the excitability of the motor pathway with navigated transcranial magnetic stimulation (nTMS). METHODS Retrospective cohort study of patients admitted for surgery with diffuse gliomas within motor eloquent areas. Demographic, clinical, and nTMS-related variables were collected. The Cortical Excitability Score (CES 0 to 2 according to the number of abnormal interhemispheric resting motor threshold (RMT) ratios) was calculated for patients where bilateral upper and lower limb mapping was performed. RESULTS A total of 45 patients were included: 9 patients had a low-grade glioma and 36 patients had a high-grade glioma. The unadjusted analysis revealed an increase in the latency of the motor evoked potential of the lower limb with an increase of the WHO grade (P = .038). The adjusted analysis confirmed this finding (P = .013) and showed a relation between the increase in the WHO and a decreased RMT (P = .037) of the motor evoked responses in the lower limb. When CES was calculated, an increase in the score was related with an increase in the WHO grade (unadjusted analysis-P = .0001; adjusted analysis-P = .001) and in isocitrate dehydrogenase (IDH) wild-type tumors (unadjusted analysis-P = .020). CONCLUSION An increase in the WHO grading system and IDH wild-type tumors are associated with an abnormal excitability of the motor eloquent areas in patients with diffuse gliomas.

中文翻译：

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涉及运动能力区域的弥漫性胶质瘤患者运动兴奋性改变：肿瘤分级的影响

背景弥漫性神经胶质瘤在世界卫生组织（WHO）分级系统中具有增加的生物学侵袭性。胶质瘤分级对初级运动皮层 (M1)-皮质脊髓束 (CST) 兴奋性的影响尚不清楚。目的通过导航经颅磁刺激 (nTMS) 评估运动通路的兴奋性。方法 对运动功能区弥漫性胶质瘤接受手术的患者进行回顾性队列研究。收集了人口统计学、临床和 nTMS 相关变量。对进行双侧上下肢标测的患者计算皮质兴奋性评分（CES 0 至 2，根据异常半球间静息运动阈值 (RMT) 比率的数量）。结果 共纳入 45 名患者：9 名患者患有低级别胶质瘤，36 名患者患有高级别胶质瘤。未经调整的分析显示，随着 WHO 等级的增加，下肢运动诱发电位的潜伏期增加（P = .038）。调整后的分析证实了这一发现 (P = .013)，并表明 WHO 的增加与下肢运动诱发反应的 RMT 降低 (P = .037) 之间存在关系。当计算 CES 时，评分的增加与 WHO 分级（未调整分析 - P = .0001；调整分析 - P = .001）和异柠檬酸脱氢酶 (IDH) 野生型肿瘤（未调整分析）相关-P = .020）。结论 WHO 分级系统和 IDH 野生型肿瘤的增加与弥漫性胶质瘤患者运动功能区的异常兴奋有关。