Departments of1Neurosurgery and.
2Anesthesiology and Intensive Care Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin.
J Neurosurg. 2021 Jul 30;136(2):589-600. doi: 10.3171/2020.12.JNS204028. Print 2022 Feb 1.
Visualization of subcortical language pathways by means of diffusion tensor imaging-fiber tracking (DTI-FT) is evolving as an important tool for surgical planning and decision making in patients with language-suspect brain tumors. Repetitive navigated transcranial magnetic stimulation (rTMS) cortical language mapping noninvasively provides additional functional information. Efforts to incorporate rTMS data into DTI-FT are promising, but the lack of established protocols makes it hard to assess clinical utility. The authors performed DTI-FT of important language pathways by using five distinct approaches in an effort to evaluate the respective clinical usefulness of each approach.
Thirty patients with left-hemispheric perisylvian lesions underwent preoperative rTMS language mapping and DTI. FT of the principal language tracts was conducted according to different strategies: Ia, anatomical landmark based; Ib, lesion-focused landmark based; IIa, rTMS based; IIb, rTMS based with postprocessing; and III, rTMS enhanced (based on a combination of structural and functional data). The authors analyzed the respective success of each method in revealing streamlines and conducted a multinational survey with expert clinicians to evaluate aspects of clinical utility.
The authors observed high usefulness and accuracy ratings for anatomy-based approaches (Ia and Ib). Postprocessing of rTMS-based tractograms (IIb) led to more balanced perceived information content but did not improve the usefulness for surgical planning and risk assessment. Landmark-based tractography (Ia and Ib) was most successful in delineating major language tracts (98% success), whereas rTMS-based tractography (IIa and IIb) frequently failed to reveal streamlines and provided less complete tractograms than the landmark-based approach (p < 0.001). The lesion-focused landmark-based (Ib) and the rTMS-enhanced (III) approaches were the most preferred methods.
The lesion-focused landmark-based approach (Ib) achieved the best ratings and enabled visualization of the principal language tracts in almost all cases. The rTMS-enhanced approach (III) was positively evaluated by the experts because it can reveal cortico-subcortical connections, but the functional relevance of these connections is still unclear. The use of regions of interest derived solely from cortical rTMS mapping (IIa and IIb) leads to cluttered images that are of limited use in clinical practice.
通过弥散张量成像纤维追踪（DTI-FT）对皮质下语言通路进行可视化，正在成为语言可疑脑肿瘤患者手术规划和决策的重要工具。重复经颅磁刺激（rTMS）皮质语言映射可提供额外的功能信息。将 rTMS 数据纳入 DTI-FT 的努力是有前途的，但缺乏既定的方案使得评估其临床实用性变得困难。作者采用五种不同的方法进行 DTI-FT，以评估每种方法的各自临床实用性。
30 例左半球脑旁病变患者接受术前 rTMS 语言映射和 DTI。根据不同策略进行主要语言束的 FT：Ia，基于解剖学标志；Ib，基于病变的标志；IIa，基于 rTMS；IIb，基于 rTMS 并进行后处理；III，rTMS 增强（基于结构和功能数据的组合）。作者分析了每种方法显示流线的各自成功率，并进行了一项多国家专家临床医生调查，以评估临床实用性的各个方面。
作者观察到基于解剖学的方法（Ia 和 Ib）具有高度的有用性和准确性评分。rTMS 基于束描记术（IIb）的后处理导致更平衡的感知信息含量，但并未改善手术规划和风险评估的有用性。基于标志的束描记术（Ia 和 Ib）在描绘主要语言束方面最成功（成功率为 98%），而 rTMS 基于束描记术（IIa 和 IIb）经常未能显示流线，并且提供的束描记术比基于标志的方法不完整（p <0.001）。病变聚焦的基于标志的方法（Ib）和 rTMS 增强的方法（III）是最受青睐的方法。
病变聚焦的基于标志的方法（Ib）获得了最佳评分，并能够在几乎所有情况下可视化主要语言束。专家们对 rTMS 增强的方法（III）进行了积极评价，因为它可以揭示皮质下皮质连接，但这些连接的功能相关性仍不清楚。仅使用皮质 rTMS 映射的感兴趣区域（IIa 和 IIb）会导致图像混乱，在临床实践中用途有限。
