The effect of meninges on the electric fields in TES and TMS. Numerical modeling with adaptive mesh refinement.
The effect of meninges on the electric fields in TES and TMS. Numerical modeling with adaptive mesh refinement.
复制标题
脑膜对 TES 和 TMS 电场的影响。
DOI：
10.1016/j.brs.2022.04.009
复制
发表时间：
2022
影响因子：
7.7
通讯作者：
Makarov,SergeyN
中科院分区：
文献类型：
--
作者：
Weise,Konstantin;Wartman,WilliamA;Knösche,ThomasR;Nummenmaa,AapoR;Makarov,SergeyN
背景在对大脑中的经颅电刺激（TES）和经颅磁刺激（TMS）进行建模时，由于高计算成本，脑膜（硬脑膜、蛛网膜和软脑膜）经常被忽略。目的以头部图像分割为基础模型，研究脑脊膜各层对TES和TMS皮层电场的影响。方法利用16例受试者的T1/T2 MRI数据，采用边界元快速多极子方法和自适应网格加密技术，以合理的计算代价精确求解该问题并建立方法收敛性。我们比较电场的存在和不存在的各种脑膜的两个大脑区域（M 1手和DLPFC）和几个不同的TES和TMS设置。结果脑脊膜存在于脑脊液体积中时，局灶性TES的皮质最大电场平均增加约30%。它们对最大场的影响可以通过将CSF电导率从1.65 S/m降低到约0.85 S/m来模拟。与此形成鲜明对比的是，皮层中的TMS电场仅受到脑膜层的微弱影响，并且当包括脑膜时，平均略有下降（约6%）。结论定量分析了脑膜对皮层TES和TMS电场的影响。局灶性TES和TMS结果非常一致。焦点TES结果也与先前的相关研究有很好的一致性。脑膜层的求解器和网格生成器（与SimNIBS兼容）可在线获得。
Background When modeling transcranial electrical stimulation (TES) and transcranial magnetic stimulation (TMS) in the brain, the meninges–dura, arachnoid, and pia mater–are often neglected due to high computational costs. Objective We investigate the impact of the meningeal layers on the cortical electric field in TES and TMS while considering the headreco segmentation as the base model. Method We use T1/T2 MRI data from 16 subjects and apply the boundary element fast multipole method with adaptive mesh refinement, which enables us to accurately solve this problem and establish method convergence at reasonable computational cost. We compare electric fields in the presence and absence of various meninges for two brain areas (M 1 HAND and DLPFC) and for several distinct TES and TMS setups. Results Maximum electric fields in the cortex for focal TES consistently increase by approximately 30% on average when the meninges are present in the CSF volume. Their effect on the maximum field can be emulated by reducing the CSF conductivity from 1.65 S/m to approximately 0.85 S/m. In stark contrast to that, the TMS electric fields in the cortex are only weakly affected by the meningeal layers and slightly (∼ 6%) decrease on average when the meninges are included. Conclusion Our results quantify the influence of the meninges on the cortical TES and TMS electric fields. Both focal TES and TMS results are very consistent. The focal TES results are also in a good agreement with a prior relevant study. The solver and the mesh generator for the meningeal layers (compatible with SimNIBS) are available online.