Sollmann Nico, Negwer Chiara, Ille Sebastian, Maurer Stefanie, Hauck Theresa, Kirschke Jan S, Ringel Florian, Meyer Bernhard, Krieg Sandro M
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 Munich, Germany; TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 Munich, Germany.
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 Munich, Germany.
J Neurosci Methods. 2016 Jul 15;267:45-54. doi: 10.1016/j.jneumeth.2016.04.002. Epub 2016 Apr 6.
Navigated transcranial magnetic stimulation (nTMS) provides language maps in brain tumor patients. Yet, corresponding data on the visualization of language-related subcortical pathways is lacking. Therefore, this study evaluates the feasibility of nTMS-based diffusion tensor imaging fiber tracking (DTI FT) for subcortical language pathways by a fractional anisotropy (FA) protocol.
DTI FT was performed in 37 patients suffering from left-sided perisylvian brain lesions based on nTMS data exclusively, using the FA-based protocol originally established for the corticospinal tract (CST) by Frey et al. (2012): minimum fiber length was 110mm and the highest individual FA value leading to visualization of white matter tracts was determined as the FA threshold (FAT). Then, deterministic DTI FT using an FA value of 100%, 75%, 50%, and 25% of the individual FAT (with 25% as an additional setting to the original protocol) was performed.
Our approach visualized 9 language-related subcortical white matter pathways. By using 100% FAT, the mean percentage of visualized tracts was 13.5%, whereas DTI FT performed with 75%, 50%, and 25% FAT detected 30.6%, 61.3%, and 93.7% of language-related fiber tracts, respectively.
nTMS language mapping alone is not able to visualize subcortical language-related pathways.
This study shows that nTMS language maps are feasible for DTI FT of language-related pathways within the scope of a FAT-based protocol. Although this approach is novel and might be helpful during scientific neuroimaging and tumor resection, intraoperative validation is needed to go beyond the level of feasibility.
导航经颅磁刺激（nTMS）可为脑肿瘤患者提供语言图谱。然而，关于语言相关皮质下通路可视化的相应数据尚缺乏。因此，本研究通过分数各向异性（FA）方案评估基于nTMS的扩散张量成像纤维束示踪（DTI FT）用于皮质下语言通路的可行性。
仅基于nTMS数据，对37例左侧大脑外侧裂周围脑损伤患者进行DTI FT，采用Frey等人（2012年）最初为皮质脊髓束（CST）建立的基于FA的方案：最小纤维长度为110mm，将导致白质束可视化的最高个体FA值确定为FA阈值（FAT）。然后，使用个体FAT的100%、75%、50%和25%的FA值进行确定性DTI FT（25%作为原始方案的额外设置）。
我们的方法可视化了9条与语言相关的皮质下白质通路。使用100%FAT时，可视化束的平均百分比为13.5%，而使用75%、50%和25%FAT进行的DTI FT分别检测到30.6%、61.3%和93.7%的语言相关纤维束。
单独的nTMS语言图谱无法可视化与语言相关的皮质下通路。
本研究表明，在基于FAT的方案范围内，nTMS语言图谱对于语言相关通路的DTI FT是可行的。尽管这种方法是新颖的，可能在科学神经成像和肿瘤切除过程中有所帮助，但仍需要术中验证以超越可行性水平。
