Non-invasive Brain Stimulation & Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia.
Department of Rehabilitation, Nutrition and Sport, School of Allied Health, La Trobe University, Melbourne, Australia.
Brain Connect. 2020 Nov;10(9):520-531. doi: 10.1089/brain.2020.0756. Epub 2020 Oct 23.
Transcranial pulsed current stimulation (tPCS) is an emerging noninvasive brain stimulation technique that has shown significant effects on cortical excitability. To date, electrophysiological measures of the efficiency of monophasic tPCS have not been reported. We aimed to explore the effects of monophasic anodal and cathodal-tPCS (a-tPCS/c-tPCS) at theta (4 Hz) and gamma (75 Hz) frequencies on theta and high gamma electroencephalography (EEG) oscillatory power. In a single-blind, randomized, sham-controlled crossover design, 15 healthy participants were randomly assigned into 5 experimental sessions in which they received a-PCS/c-tPCS at 4 and 75 Hz or sham stimulation over the left primary motor cortex (M1) for 15 min at an intensity of 1.5 mA. Changes in theta and high gamma oscillatory power were recorded at baseline, immediately after, and 30 min after stimulation using EEG at rest with eyes open. a-tPCS at 4 Hz showed a significant increase in theta power compared with sham, whereas c-tPCS at 4 Hz had no significant effect on theta power. a-tPCS at 75 Hz produced no changes in high gamma power compared with sham. Importantly, c-tPCS at 75 Hz led to a significant reduction in high gamma power compared with baseline, as well as compared with c-tPCS at 4 Hz and sham stimulation. The results demonstrate the modulation of oscillatory brain activity by monophasic tPCS, and highlight the need for future studies on a larger scale to confirm these initial findings. Impact statement Transcranial pulsed current stimulation (tPCS) is a novel brain stimulation technique. Recently, tPCS has been introduced to directly modulate brain oscillations by applying pulsatile current over the target brain area. Using both anodal and cathodal monophasic tPCS at theta and gamma frequencies, we demonstrate the ability of the stimulation to modulate brain activity. The present findings are the first direct electroencephalography evidence of an interaction between tPCS and ongoing oscillatory activity in the human motor cortex. Our work recommends tPCS as a tool for investigating human brain oscillations and open more studies in this area.
经颅脉冲电流刺激（tPCS）是一种新兴的非侵入性脑刺激技术，已显示出对皮质兴奋性的显著影响。迄今为止，单相 tPCS 效率的电生理测量尚未报道。我们旨在探索单相阳极和阴极 tPCS（a-tPCS/c-tPCS）在θ（4Hz）和γ（75Hz）频率下对θ和高γ脑电图（EEG）振荡功率的影响。在一项单盲、随机、假对照交叉设计中，15 名健康参与者被随机分配到 5 个实验中，他们在左初级运动皮层（M1）上接受 1.5mA 强度的 4 和 75Hz 的 a-tPCS/c-tPCS 或假刺激 15 分钟。在静息睁眼状态下使用 EEG 记录刺激前、刺激后即刻和刺激后 30 分钟时θ和高γ振荡功率的变化。与假刺激相比，4Hz 的 a-tPCS 显示出θ功率的显著增加，而 4Hz 的 c-tPCS 对θ功率没有显著影响。与假刺激相比，75Hz 的 a-tPCS 对高γ功率没有变化。重要的是，与基线相比，75Hz 的 c-tPCS 导致高γ功率显著降低，与 4Hz 的 c-tPCS 和假刺激相比也是如此。结果表明单相 tPCS 可调节脑振荡活动，并强调需要进行更大规模的未来研究来证实这些初步发现。影响陈述经颅脉冲电流刺激（tPCS）是一种新型的脑刺激技术。最近，通过在目标脑区施加脉动电流，tPCS 已被引入来直接调节脑振荡。使用θ和γ频率的阳极和阴极单相 tPCS，我们证明了刺激调节脑活动的能力。本研究结果首次直接提供了 tPCS 与人类运动皮层中现有振荡活动相互作用的脑电图证据。我们的工作推荐 tPCS 作为研究人类脑振荡的工具，并在该领域开展更多的研究。
