Esmaeilpour Zeinab, Schestatsky Pedro, Bikson Marom, Brunoni André R, Pellegrinelli Ada, Piovesan Fernanda X, Santos Mariana M S A, Menezes Renata B, Fregni Felipe
Neural Engineering Laboratory, Department of Biomedical Engineering, City College of New York, City University of New YorkNew York, NY, USA; Biomedical Engineering Department, Amirkabir University of TechnologyTehran, Iran.
Neurology Service Hospital de Cínicas de Porto Alegre, Department of Internal Medicina, Universidade Federal do Rio Grande do Sul (UFRGS)Porto Alegre, Brazil; Hospital Moinhos de VentoPorto Alegre, Brazil.
Front Hum Neurosci. 2017 Feb 23;11:71. doi: 10.3389/fnhum.2017.00071. eCollection 2017.
: Transcranial direct current stimulation (tDCS) is investigated to modulate neuronal function including cognitive neuroscience and neuropsychiatric therapies. While cases of human stimulation with rudimentary batteries date back more than 200 years, clinical trials with current controlled stimulation were published intermittently since the 1960s. The modern era of tDCS only started after 1998. : To review methods and outcomes of tDCS studies from old literature (between 1960 and 1998) with intention of providing new insight for ongoing tDCS trials and development of tDCS protocols especially for the purpose of treatment. : Articles were identified through a search in PubMed and through the reference list from its selected articles. We included only non-invasive human studies that provided controlled direct current and were written in English, French, Spanish or Portuguese before the year of 1998, the date in which modern stimulation paradigms were implemented. : Fifteen articles met our criteria. The majority were small-randomized controlled clinical trials that enrolled a mean of approximately 26 subjects (Phase II studies). Most of the studies (around 83%) assessed the role of tDCS in the treatment of psychiatric conditions, in which the main outcomes were measured by means of behavioral scales and clinical observation, but the diagnostic precision and the quality of outcome monitoring, including adverse events, were deficient by modern standards. Compared to modern tDCS dose, the stimulation intensities used (0.1-1 mA) were lower, however as the electrodes were typically smaller (e.g., 1.26 cm), the average electrode current density (0.2 mA/cm) was approximately 4× higher. The number of sessions ranged from one to 120 (median 14). Notably, the stimulation session durations of several minutes to 11 h (median 4.5 h) could markedly exceed modern tDCS protocols. Twelve studies out of 15 showed positive results. Only mild side effects were reported, with headache and skin alterations the most common. : Most of the studies identified were for psychiatric indications, especially in patients with depression and/or schizophrenia and majority indicated some positive results. Variability in outcome is noted across trials and within trials across subjects, but overall results were reported as encouraging, and consistent with modern efforts, given some responders and mild side effects. The significant difference with modern dose, low current with smaller electrode size and interestingly much longer stimulation duration may worth considering.
经颅直流电刺激（tDCS）被用于研究调节神经元功能，包括认知神经科学和神经精神治疗。虽然使用简陋电池进行人体刺激的案例可以追溯到200多年前，但自20世纪60年代以来，关于电流控制刺激的临床试验断断续续地发表。tDCS的现代时代直到1998年之后才开始。
为了回顾旧文献（1960年至1998年）中tDCS研究的方法和结果，旨在为正在进行的tDCS试验以及tDCS方案的制定提供新的见解，尤其是用于治疗目的。
通过在PubMed中搜索以及从其选定文章的参考文献列表中识别文章。我们仅纳入了在1998年之前（现代刺激范式实施的年份）发表的、提供可控直流电且用英语、法语、西班牙语或葡萄牙语撰写的非侵入性人体研究。
15篇文章符合我们的标准。大多数是小型随机对照临床试验，平均纳入约26名受试者（II期研究）。大多数研究（约83%）评估了tDCS在精神疾病治疗中的作用，其主要结果通过行为量表和临床观察来衡量，但按照现代标准，诊断准确性和结果监测质量（包括不良事件）存在不足。与现代tDCS剂量相比，所使用的刺激强度（0.1 - 1 mA）较低，然而由于电极通常较小（例如1.26厘米），平均电极电流密度（0.2 mA/cm²）大约高出4倍。疗程数量从1次到120次不等（中位数为14次）。值得注意的是，刺激疗程持续时间从几分钟到11小时（中位数为4.5小时），可能明显超过现代tDCS方案。15项研究中有12项显示出阳性结果。仅报告了轻微的副作用，最常见的是头痛和皮肤改变。
大多数被识别的研究针对精神疾病适应症，尤其是抑郁症和/或精神分裂症患者，并且大多数显示出一些阳性结果。在不同试验之间以及同一试验中不同受试者之间，结果存在差异，但总体结果据报道令人鼓舞，并且鉴于有一些反应者和轻微副作用，与现代研究结果一致。与现代剂量的显著差异、较小电极尺寸下的低电流以及有趣的是长得多的刺激持续时间可能值得考虑。
