Neural Engineering Laboratory, Department of Biomedical Engineering, The City College of New York of CUNY, New York, NY 10031, USA.
Neuroimage. 2013 Jan 15;65:280-7. doi: 10.1016/j.neuroimage.2012.09.062. Epub 2012 Oct 5.
The field of non-invasive brain stimulation has developed significantly over the last two decades. Though two techniques of noninvasive brain stimulation--transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS)--are becoming established tools for research in neuroscience and for some clinical applications, related techniques that also show some promising clinical results have not been developed at the same pace. One of these related techniques is cranial electrotherapy stimulation (CES), a class of transcranial pulsed current stimulation (tPCS). In order to understand further the mechanisms of CES, we aimed to model CES using a magnetic resonance imaging (MRI)-derived finite element head model including cortical and also subcortical structures. Cortical electric field (current density) peak intensities and distributions were analyzed. We evaluated different electrode configurations of CES including in-ear and over-ear montages. Our results confirm that significant amounts of current pass the skull and reach cortical and subcortical structures. In addition, depending on the montage, induced currents at subcortical areas, such as midbrain, pons, thalamus and hypothalamus are of similar magnitude than that of cortical areas. Incremental variations of electrode position on the head surface also influence which cortical regions are modulated. The high-resolution modeling predictions suggest that details of electrode montage influence current flow through superficial and deep structures. Finally we present laptop based methods for tPCS dose design using dominant frequency and spherical models. These modeling predictions and tools are the first step to advance rational and optimized use of tPCS and CES.
在过去的二十年中，非侵入性脑刺激领域得到了显著发展。尽管两种非侵入性脑刺激技术——经颅直流电刺激（tDCS）和经颅磁刺激（TMS）——正在成为神经科学研究和一些临床应用的既定工具，但相关技术也显示出一些有前途的临床结果，但其发展速度却并不相同。其中一种相关技术是颅电刺激（CES），它是一种经颅脉冲电流刺激（tPCS）。为了进一步了解 CES 的机制，我们旨在使用基于 MRI 的有限元头部模型来模拟 CES，该模型包括皮质和皮质下结构。分析了皮质电场（电流密度）峰值强度和分布。我们评估了 CES 的不同电极配置，包括耳内和耳上的配置。我们的结果证实，大量电流通过颅骨到达皮质和皮质下结构。此外，根据刺激模式的不同，在皮质下区域（如中脑、脑桥、丘脑和下丘脑）产生的感应电流与皮质区域的电流相似。头部表面电极位置的增量变化也会影响被调节的皮质区域。高分辨率建模预测表明，电极刺激模式的细节会影响浅层和深层结构中的电流流动。最后，我们提出了基于笔记本电脑的 tPCS 剂量设计方法，使用主导频率和球体模型。这些建模预测和工具是推进 tPCS 和 CES 合理优化使用的第一步。
