Neural Engineering Laboratory, Department of Biomedical Engineering, The City College of City University of New York, 160 Convent Ave, Steinman Hall, T-403B, New York, NY, USA.
Neuroimage Clin. 2013 May 31;2:759-66. doi: 10.1016/j.nicl.2013.05.011. eCollection 2013.
Recent studies show that acute neuromodulation of the prefrontal cortex with transcranial direct current stimulation (tDCS) can decrease food craving, attentional bias to food, and actual food intake. These data suggest potential clinical applications for tDCS in the field of obesity. However, optimal stimulation parameters in obese individuals are uncertain. One fundamental concern is whether a thick, low-conductivity layer of subcutaneous fat around the head can affect current density distribution and require dose adjustments during tDCS administration. The aim of this study was to investigate the role of head fat on the distribution of current during tDCS and evaluate whether dosing standards for tDCS developed for adult individuals in general are adequate for the obese population. We used MRI-derived high-resolution computational models that delineated fat layers in five human heads from subjects with body mass index (BMI) ranging from "normal-lean" to "super-obese" (20.9 to 53.5 kg/m(2)). Data derived from these simulations suggest that head fat influences tDCS current density across the brain, but its relative contribution is small when other components of head anatomy are added. Current density variability between subjects does not appear to have a direct and/or simple link to BMI. These results indicate that guidelines for the use of tDCS can be extrapolated to obese subjects without sacrificing efficacy and/or treatment safety; the recommended standard parameters can lead to the delivery of adequate current flow to induce neuromodulation of brain activity in the obese population.
最近的研究表明，经颅直流电刺激（tDCS）对前额叶皮层的急性神经调节可以减少食欲、对食物的注意力偏差和实际的食物摄入量。这些数据表明 tDCS 在肥胖领域具有潜在的临床应用。然而，肥胖个体的最佳刺激参数尚不确定。一个基本的问题是头部周围厚厚的、低导电性的皮下脂肪层是否会影响电流密度分布，并在 tDCS 给药期间需要进行剂量调整。本研究旨在探讨头部脂肪在 tDCS 过程中对电流分布的作用，并评估一般针对成年人制定的 tDCS 剂量标准是否足以适用于肥胖人群。我们使用 MRI 衍生的高分辨率计算模型，对来自 BMI 从“正常瘦”到“超级肥胖”（20.9 至 53.5kg/m(2)）的五个人类头部的脂肪层进行了描绘。这些模拟得出的数据表明，头部脂肪会影响大脑中的 tDCS 电流密度，但当加入头部解剖结构的其他组成部分时，其相对贡献较小。受试者之间的电流密度变化似乎与 BMI 没有直接和/或简单的联系。这些结果表明，可以将 tDCS 使用指南推断应用于肥胖患者，而不会牺牲疗效和/或治疗安全性；推荐的标准参数可以导致输送足够的电流来诱导肥胖人群的大脑活动的神经调节。
