Head models of healthy and depressed adults for simulating the electric fields of non-invasive electric brain stimulation

During the past decade, it became clear that the electric field elicited by non-invasive brain stimulation (NIBS) techniques such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) are substantially influenced by variations in individual head and brain anatomy. In addition to structural variations in the healthy, several psychiatric disorders are characterized by anatomical alterations that are likely to further constrain the intracerebral effects of NIBS. Here, we present high-resolution realistic head models derived from structural magnetic resonance imaging data of 19 healthy adults and 19 patients diagnosed with major depressive disorder (MDD). By using a freely available software package for modelling the electric fields induced by different NIBS protocols, we show that our head models are well-suited for assessing inter-individual and between-group variability in the magnitude and focality of tDCS-induced electric fields for two protocols targeting the left dorsolateral prefrontal cortex.

在过去十年间，非侵入性脑刺激技术（如经颅直流电刺激tDCS和经颅磁刺激TMS）引发的电场受到个体头部和脑部解剖结构变化的影响已逐渐明晰。除了健康人群中的结构变异外，多种精神疾病亦以其解剖结构的变化为特征，这些变化可能进一步限制NIBS技术对大脑内部的效应。本研究中，我们基于19名健康成年人和19名被诊断为重度抑郁症（MDD）的患者结构磁共振成像数据，构建了高分辨率、逼真的头部模型。通过运用一款免费软件包模拟不同NIBS方案引发的电场，我们证明了所构建的头部模型非常适合评估针对左侧背外侧前额叶皮层的两种方案中，个体间及组间tDCS引发的电场强度和聚焦性的变异情况。