Laboratory of Cognitive Sciences and Neuropsychopharmacology from Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Vitória, ES, Brasil.
Int J Neuropsychopharmacol. 2012 Jun;15(5):601-16. doi: 10.1017/S1461145711001040. Epub 2011 Jul 22.
Frontal lobe dysfunction is a hallmark of alcohol dependence. Recent studies have shown that a simple but powerful technique of cortical modulation--transcranial direct current stimulation (tDCS)--can induce significant cognitive changes. We therefore aimed to assess the clinical and electrophysiological (as indexed by P3) effects of tDCS of left dorsolateral prefrontal cortex (DLPFC) in different types of alcoholic patients according to Lesch's typology. We enrolled 49 alcoholic subjects, aged between 18 and 75 yr, during the subacute abstinence period to participate in this study. Subjects underwent event-related potential (ERP) registration of alcohol-related and neutral sounds before, during and after active tDCS (1 mA, 35 cm², during 10 min) or sham procedure in a counterbalanced and randomized order. Frontal assessment battery (FAB) and five items of the Obsessive Compulsive Drinking Scale were applied at the beginning and at the end of each experimental session. ERP analysis showed an increase in the mean amplitude of P3 associated with alcohol-related sounds after tDCS. This effect was not seen for neutral sounds. This change was more pronounced in Lesch IV alcoholics. Secondary exploratory analysis showed a significant improvement of FAB performance after active tDCS compared to sham tDCS in Lesch IV alcoholics only. We showed clinical and electrophysiological evidence of tDCS-induced frontal activity enhancement that was specific for Lesch IV alcoholics. Given that frontal dysfunction may contribute to the loss of control over drinking behaviour, local increase in frontal activity induced by tDCS might have a beneficial clinical impact in the future.
额叶功能障碍是酒精依赖的一个标志。最近的研究表明，一种简单但强大的皮层调节技术——经颅直流电刺激（tDCS）——可以诱导显著的认知变化。因此，我们旨在根据 Lesch 分类法评估左背外侧前额叶皮质（DLPFC）tDCS 对不同类型酒精患者的临床和电生理（以 P3 为指标）的影响。我们招募了 49 名年龄在 18 至 75 岁之间的急性戒断期的酒精患者参与这项研究。在主动 tDCS（1 mA，35 cm²，持续 10 分钟）或假程序的前后，以平衡和随机的顺序，对患者进行与酒精相关和中性声音的事件相关电位（ERP）记录。在每次实验前后，都进行了额叶评估测验（FAB）和五项目强迫性饮酒量表的评估。ERP 分析显示，tDCS 后与酒精相关的声音的 P3 平均振幅增加。中性声音则没有出现这种效果。Lesch IV 型酗酒者的这种变化更为明显。进一步的探索性分析显示，只有 Lesch IV 型酗酒者在主动 tDCS 后，FAB 表现显著优于假 tDCS。我们提供了 tDCS 诱导的额叶活动增强的临床和电生理证据，这种增强对 Lesch IV 型酗酒者具有特异性。鉴于额叶功能障碍可能导致对饮酒行为的控制丧失，tDCS 引起的额叶活动增加可能在未来具有有益的临床影响。
