The Effect of Transcranial Direct Current Stimulation (tDCS) Electrode Size and Current Intensity on Motor Cortical Excitability: Evidence From Single and Repeated Sessions
The Effect of Transcranial Direct Current Stimulation (tDCS) Electrode Size and Current Intensity on Motor Cortical Excitability: Evidence From Single and Repeated Sessions
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DOI：
10.1016/j.brs.2015.08.003
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发表时间：
2016-01-01
影响因子：
7.7
通讯作者：
Loo, Colleen K.
中科院分区：
文献类型：
--
作者：
Ho, Kerrie-Anne;Taylor, Janet L.;Loo, Colleen K.
背景资料：电流密度被认为是决定tDCS结果的重要因素，并且由电流强度和电极尺寸决定。以前的研究检查这些参数对运动皮层兴奋性的影响，小样本量报告混合的结果。目的/假设：本研究检查了电流强度（1 mA、2 mA）和电极尺寸（16 cm（2）、35 cm（2））对单次和重复tDCS治疗期间运动皮层兴奋性的影响。方法：收集来自7项研究的89名健康受试者的数据进行分析。使用混合效应模型分析单次会议数据，使用混合设计方差分析分析重复会议数据。计算模型被用来检查所产生的电场。结果：阳极tDCS后兴奋性增加的幅度是适度的。对于单次tDCS，与16 cm（2）电极相比，35 cm（2）电极产生的皮质兴奋性增加更大。1 mA和2 mA tDCS产生的皮质兴奋幅度无差异。重复会话数据还显示，35 cm（2）电极的兴奋性增加更大。此外，使用35 cm（2）电极重复tDCS会导致皮质兴奋性累积增加。计算建模预测35 cm（2）电极的电机热点处电场较高。结论：在健康受试者中，2 mA tDCS不一定比1 mA tDCS产生更大的影响。应仔细考虑tDCS电极相对于皮质区域的准确定位、尺寸和方向。(C)2016 Elsevier Inc. All rights reserved.
Background: Current density is considered an important factor in determining the outcomes of tDCS, and is determined by the current intensity and electrode size. Previous studies examining the effect of these parameters on motor cortical excitability with small sample sizes reported mixed results. Objective/hypothesis: This study examined the effect of current intensity (1 mA, 2 mA) and electrode size (16 cm(2), 35 cm(2)) on motor cortical excitability over single and repeated tDCS sessions. Methods: Data from seven studies in 89 healthy participants were pooled for analysis. Single-session data were analyzed using mixed effects models and repeated-session data were analyzed using mixed design analyses of variance. Computational modeling was used to examine the electric field generated. Results: The magnitude of increases in excitability after anodal tDCS was modest. For single-session tDCS, the 35 cm(2) electrodes produced greater increases in cortical excitability compared to the 16 cm(2) electrodes. There were no differences in the magnitude of cortical excitation produced by 1 mA and 2 mA tDCS. The repeated-sessions data also showed that there were greater increases in excitability with the 35 cm(2) electrodes. Further, repeated sessions of tDCS with the 35 cm(2) electrodes resulted in a cumulative increase in cortical excitability. Computational modeling predicted higher electric field at the motor hotspot for the 35 cm(2) electrodes. Conclusions: 2 mA tDCS does not necessarily produce larger effects than 1 mA tDCS in healthy participants. Careful consideration should be given to the exact positioning, size and orientation of tDCS electrodes relative to cortical regions. (C) 2016 Elsevier Inc. All rights reserved.