The present study aimed to investigate the long-term effects of gait intervention with transcranial alternating current stimulation (tACS) synchronized with gait cycle frequency on the cortical control of muscle activity during gait, using coherence analyses, in patients after stroke. Eight chronic post-stroke patients participated in a single-blinded crossover study, and 7 patients completed the long-term intervention. Each patient received tACS over the primary motor cortex foot area on the affected side, which was synchronized with individual gait cycle frequency, and sham stimulation during treadmill gait in a random order. Electrical neuromuscular stimulation was used to assist the paretic ankle movement in both conditions. After gait intervention with tACS, beta band (15-35 Hz) coherence, which is considered to have a cortical origin, significantly increased in the paretic tibialis anterior (TA) muscle during 6-min of over-ground gait. The change in beta band coherence in the paretic TA muscle was positively correlated with the change in gait distance. These results indicate that gait intervention with tACS synchronized with gait cycle frequency may induce gait-specific plasticity that modulates the common neural drive to the TA motoneurons on the paretic side during gait and leads to changes in gait function in patients after stroke.

中文翻译：

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步态同步振荡脑刺激调节中风后患者脚踝肌肉的常见神经驱动：一项初步研究

本研究旨在通过相干性分析，调查与步态周期频率同步的经颅交流电刺激 (tACS) 步态干预对中风后患者步态期间肌肉活动的皮层控制的长期影响。8 名慢性卒中后患者参加了一项单盲交叉研究，7 名患者完成了长期干预。每位患者在患侧的初级运动皮层足部区域接受 tACS，这与个人步态周期频率同步，并在跑步机步态期间以随机顺序进行假刺激。在这两种情况下，电神经肌肉刺激用于辅助麻痹性踝关节运动。在使用 tACS 进行步态干预后，β 波段 (15-35 Hz) 相干性被认为具有皮质起源，在地面步态的 6 分钟内，胫骨前肌 (TA) 肌肉显着增加。麻痹性 TA 肌肉中 β 带相干性的变化与步态距离的变化呈正相关。这些结果表明，与步态周期频率同步的 tACS 步态干预可能会诱导步态特异性可塑性，从而在步态期间调节对麻痹侧 TA 运动神经元的共同神经驱动，并导致中风后患者的步态功能发生变化。