Electric Field Model of Transcranial Electric Stimulation in Nonhuman Primates: Correspondence to Individual Motor Threshold.
Electric Field Model of Transcranial Electric Stimulation in Nonhuman Primates: Correspondence to Individual Motor Threshold.
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DOI：
10.1109/tbme.2015.2425406
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发表时间：
2015-09
期刊：
影响因子：
--
通讯作者：
Peterchev AV
中科院分区：
文献类型：
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作者：
Lee WH;Lisanby SH;Laine AF;Peterchev AV
开发用于模拟非侵入性脑刺激的真实非人类灵长类动物 (NHP) 头部模型的管道，并将这些模型与经验阈值测量结合使用，以证明该模型捕获个体解剖变异性。基于结构 MRI 数据，我们在四只恒河猴中创建了由右侧单侧 (RUL) 电休克治疗 (ECT) 诱导的电场 (E 场) 模型。通过 RUL 电极对同一受试者进行经颅电刺激 (TES) 来测量个体运动阈值 (MT)。个体间的解剖差异导致固定刺激电流幅度下大脑中电场强度中值有 57% 的变化。 MT 刺激电流的个性化将目标运动区域的电场变化减少了 27%。测量的 MT 与模拟电极电流和电场强度的比率之间存在显着相关性（r2 = 0.95，p = 0.026）。探索性分析显示该比率与解剖参数显着相关，包括上电极到皮质距离、顶点到皮质距离和脑体积（r2 > 0.96，p < 0.02）。对于 0.2 ms 刺激脉冲宽度，神经激活阈值估计为 0.45 ± 0.07 V/cm。这些结果表明，我们的个体特异性 NHP 电场模型适当地捕捉了与 TES/ECT 剂量相关的个体解剖变异性。由于受试者数量较少，这些发现是探索性的。这项工作可以为 ECT 和其他脑刺激干预措施的 NHP 研究提供见解，帮助将结果与临床研究联系起来，并最终产生更合理的脑刺激剂量范式。
To develop a pipeline for realistic head models of nonhuman primates (NHPs) for simulations of noninvasive brain stimulation, and use these models together with empirical threshold measurements to demonstrate that the models capture individual anatomical variability. Based on structural MRI data, we created models of the electric field (E-field) induced by right unilateral (RUL) electroconvulsive therapy (ECT) in four rhesus macaques. Individual motor threshold (MT) was measured with transcranial electric stimulation (TES) administered through the RUL electrodes in the same subjects. The interindividual anatomical differences resulted in 57% variation in median E-field strength in the brain at fixed stimulus current amplitude. Individualization of the stimulus current by MT reduced the E-field variation in the target motor area by 27%. There was significant correlation between the measured MT and the ratio of simulated electrode current and E-field strength (r2 = 0.95, p = 0.026). Exploratory analysis revealed significant correlations of this ratio with anatomical parameters including of the superior electrode-to-cortex distance, vertex-to-cortex distance, and brain volume (r2 > 0.96, p < 0.02). The neural activation threshold was estimated to be 0.45 ± 0.07 V/cm for 0.2 ms stimulus pulse width. These results suggest that our individual-specific NHP E-field models appropriately capture individual anatomical variability relevant to the dosing of TES/ECT. These findings are exploratory due to the small number of subjects. This work can contribute insight in NHP studies of ECT and other brain stimulation interventions, help link the results to clinical studies, and ultimately lead to more rational brain stimulation dosing paradigms.