Department of Psychology, University of Tehran, Tehran, Iran.
School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran.
PLoS One. 2024 Aug 16;19(8):e0306422. doi: 10.1371/journal.pone.0306422. eCollection 2024.
Schizophrenia (SCZ) is characterized by cognitive deficits that are linked to prefrontal cortex dysfunction. While transcranial direct current stimulation (tDCS) shows promise for improving cognition, the effects of intensified 3mA tDCS protocols on brain physiology are unknown. This project aims to elucidate the neurophysiological and cognitive effects of an intensified prefrontal tDCS protocol in SCZ.
The study is designed as a randomized, double-blind, 2-arm parallel-group, sham-controlled, trial. Forty-eight participants with SCZ and cognitive impairment (measured via a set of executive functions tests) will be randomly allocated to receive either a single session of active (n = 24) or sham (n = 24) tDCS (20-min, 3-mA). The anodal and cathodal electrodes are positioned over the left and right DLPFC respectively. The stimulation occurs concurrently with the working memory task, which is initiated precisely 5 minutes after the onset of tDCS. Structural and resting-state (rs-fMRI) scans are conducted immediately before and after both active and sham tDCS using a 3 Tesla scanner (Siemens Prisma model) equipped with a 64-channel head coil. The primary outcome will be changes in brain activation (measures vis BOLD response) and working memory performance (accuracy, reaction time).
The results of this study are helpful in optimizing tDCS protocols in SCZ and inform us of neurocognitive mechanisms underlying 3 mA stimulation. This study will additionally provide initial safety and efficacy data on a 3 mA tDCS protocol to support larger clinical trials. Positive results could lead to rapid and broader testing of a promising tool for debilitating symptoms that affect the majority of patients with SCZ. The results will be made available through publications in peer-reviewed journals and presentations at national and international conferences.
精神分裂症（SCZ）的特征是认知缺陷，这些缺陷与前额叶皮层功能障碍有关。虽然经颅直流电刺激（tDCS）显示出改善认知的潜力，但强化 3mA tDCS 方案对大脑生理的影响尚不清楚。本项目旨在阐明强化前额叶 tDCS 方案对 SCZ 的神经生理和认知影响。
该研究设计为一项随机、双盲、2 臂平行组、假对照试验。48 名认知障碍的 SCZ 患者（通过一系列执行功能测试测量）将被随机分配接受单次或单次或假（n = 24）tDCS（20 分钟，3mA）。阳极和阴极电极分别放置在左和右背外侧前额叶皮层上。刺激与工作记忆任务同时进行，在 tDCS 开始后 5 分钟精确启动。使用配备 64 通道头部线圈的 3T 扫描仪（西门子 Prisma 模型），在接受主动和假 tDCS 前后立即进行结构和静息状态（rs-fMRI）扫描。主要结果将是大脑激活（BOLD 反应测量）和工作记忆表现（准确性、反应时间）的变化。
本研究的结果有助于优化 SCZ 中的 tDCS 方案，并为我们提供了 3mA 刺激的神经认知机制的信息。该研究还将提供关于 3mA tDCS 方案的初步安全性和疗效数据，以支持更大的临床试验。阳性结果可能导致对影响大多数 SCZ 患者的衰弱症状的有前途的工具进行快速和更广泛的测试。结果将通过在同行评议期刊上发表文章和在国家和国际会议上发表演讲来提供。
