γ-transcranial alternating current stimulation improves upper-limb motor function in stroke patients and modulates oscillatory imbalance: a pilot randomized controlled trial

作者：Wang Chuangjia, Wei Zhang, Lilin Chen, Shuxian Zhang, Li Huang, Jianjing Li, Yinan Ai, Huaiyuan Huang, J H Xu, H R Zheng · 发表于：Journal of NeuroEngineering and Rehabilitation · 年份：2026 · DOI：10.1186/s12984-026-02103-6 · 研究领域：Transcranial Magnetic Stimulation Studies、Stroke Rehabilitation and Recovery、EEG and Brain-Computer Interfaces

BACKGROUND: Post-stroke cortical oscillatory activity is frequently disrupted, characterized by increased low-frequency oscillation and reduced high-frequency oscillation, which are associated with stroke severity and motor dysfunction. γ-tACS has the potential to entrain brain oscillations and enhance motor performance in healthy individuals, yet evidence in stroke patients is still limited. METHODS: This randomized, double-blind, sham-controlled pilot study enrolled 42 patients with post-stroke upper-limb motor impairment. Participants were randomly assigned to either the γ-tACS group or the sham-tACS group. High-definition tACS was applied over the M1 hotspot (70 Hz, 2 mA peak-to-peak, 20 min/session) for 10 sessions, once daily, in addition to conventional rehabilitation. The primary outcome was the Fugl-Meyer Assessment-Upper Extremity (FMA-UE). Secondary outcomes included the Modified Barthel Index (MBI) and resting-state EEG measures, including spectral power, power-ratio indices, and functional connectivity. RESULTS: A total of 42 participants were included in this trial (γ-tACS, n = 21; sham-tACS, n = 21), and the baseline characteristics were comparable between groups. FMA-UE improved in both groups, but the improvement was greater in γ-tACS group (ΔFMA-UE = 4.64 ± 4.55, P = 0.039, 95%CI=[0.154, 5.799]), whereas between-group differences in MBI improvement were not significant. Baseline EEG showed ipsilesional-contralesional asymmetry, with higher delta power, lower...