Munich School of Bioengineering, Technical University of Munich (TUM), 85748 Garching, Germany; Department of Electrical and Computer Engineering, TUM, 80333 Munich, Germany; Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales (UNSW), NSW 2052, Australia.
School of Psychiatry, UNSW, NSW 2052, Australia; Black Dog Institute, NSW 2031, Australia.
Eur Psychiatry. 2019 Aug;60:71-78. doi: 10.1016/j.eurpsy.2019.05.006. Epub 2019 Jun 21.
Electroconvulsive therapy (ECT) is a highly effective treatment for severe psychiatric disorders. Despite its high efficacy, the use of ECT would be greater if the risk of cognitive side effects were reduced. Over the last 20 years, developments in ECT technique, including improvements in the dosing methodology and modification of the stimulus waveform, have allowed for improved treatment methods with reduced adverse cognitive effects. There is increasing evidence that the electrode placement is important for orienting the electrical stimulus and therefore modifying treatment outcomes, with potential for further improvement of the placements currently used in ECT.
We used computational modelling to perform an in-depth examination into regional differences in brain excitation by the ECT stimulus for several lesser known and novel electrode placements, in order to investigate the potential for an electrode placement that may optimise clinical outcomes.
High resolution finite element human head models were generated from MRI scans of three subjects. The models were used to compare regional differences in average electric field (EF) magnitude among a total of thirteen bipolar ECT electrode placements, i.e. three conventional placements as well as ten lesser known and novel placements.
In this exploratory study on a systemic comparison of thirteen ECT electrode placements, the EF magnitude at regions of interest (ROIs) was highly dependent upon the position of both electrodes, especially the ROIs close to the cortical surface. Compared to conventional right-unilateral (RUL) ECT using a temporo-parietal placement, fronto-parietal and supraorbito-parietal RUL also robustly stimulated brain regions considered important for efficacy, while sparing regions related to cognitive functions, and may be a preferrable approach to the currently used placement for RUL ECT. The simulations also found that regional average EF magnitude varied between individual subjects, due to factors such as head size, and results also depended on the size of the defined ROI.
电抽搐疗法（ECT）是治疗严重精神疾病的一种非常有效的方法。尽管其疗效很高，但如果能降低认知副作用的风险，ECT 的使用将会更大。在过去的 20 年中，ECT 技术的发展，包括给药方法的改进和刺激波形的修改，使得可以采用改进的治疗方法，同时减少不良的认知影响。越来越多的证据表明，电极的放置对于引导电刺激很重要，因此可以改变治疗结果，有可能进一步改进目前在 ECT 中使用的电极放置。
我们使用计算模型对几个鲜为人知和新颖的电极放置位置的大脑受 ECT 刺激的区域差异进行了深入研究，以研究一种可能优化临床结果的电极放置位置。
从三个受试者的 MRI 扫描中生成了高分辨率的有限元人头模型。使用这些模型比较了总共 13 个双相 ECT 电极放置位置之间的平均电场（EF）幅度的区域差异，即 3 个常规放置位置和 10 个鲜为人知和新颖的放置位置。
在对 13 种 ECT 电极放置位置进行系统比较的探索性研究中，感兴趣区域（ROI）的 EF 幅度高度依赖于两个电极的位置，特别是靠近皮质表面的 ROI。与传统的右侧单侧（RUL）ECT 使用颞顶部位相比，额顶和眶顶 RUL 也能强有力地刺激被认为对疗效重要的大脑区域，同时又能避免与认知功能相关的区域，这可能是目前 RUL ECT 中使用的放置位置的一种优选方法。模拟还发现，由于头部大小等因素，个体受试者之间的区域平均 EF 幅度存在差异，结果还取决于定义的 ROI 的大小。
