Wang Yajie, Zhu Chunyue, Zhou Junhong, Fu Tianli, Yan Jinlong, Wang Bangyu, Lü Jiaojiao, Huang Lingyan, Liu Yu
Key Laboratory of Exercise and Health Sciences of the Ministry of Education, Shanghai University of Sport, Shanghai, China.
Hebrew Senior Life Hinda and Arthur Marcus Institute for Aging Research, Harvard Medical School, Boston, MA, United States.
Front Hum Neurosci. 2025 Feb 19;19:1524485. doi: 10.3389/fnhum.2025.1524485. eCollection 2025.
This study investigates the effects of temporal interference stimulation (TI) with different envelope frequencies on the cortical excitability of the primary motor cortex (M1).
In this randomized, double-blind, crossover study, 26 participants completed four separate study visits. During these visits, they received 20 min of three types of TI (10, 20, and 40 Hz envelope frequency) and sham stimulation applied over M1 in a randomized order. Transcranial magnetic stimulation (TMS) was employed to assess motor-evoked potentials (MEP) and resting motor threshold (RMT) over the left M1 (ipsilateral area) and right M1 (contralateral area) before, immediately after, and 30 and 60 min after stimulation.
The blinding efficacy was excellent, and no severe side effects were reported. TI stimulation with varying envelope frequencies affected MEP differently; 20 Hz TI stimulation enhanced the MEP of the ipsilateral M1 with after-effects appearing at 60 min, and no significant differences were observed between the 10 or 20 Hz TI stimulation with sham groups. However, no significant changes in RMT were observed under any of the TI conditions.
20 Hz TI stimulation increased the cortical excitability of the ipsilateral M1, highlighting that frequency is an important factor in the modulatory effect of TI.
本研究调查不同包络频率的时间干扰刺激（TI）对初级运动皮层（M1）皮质兴奋性的影响。
在这项随机、双盲、交叉研究中，26名参与者完成了四次单独的研究访视。在这些访视期间，他们以随机顺序接受了20分钟的三种类型的TI（10、20和40Hz包络频率）以及施加于M1的假刺激。在刺激前、刺激后即刻、刺激后30分钟和60分钟，采用经颅磁刺激（TMS）评估左侧M1（同侧区域）和右侧M1（对侧区域）的运动诱发电位（MEP）和静息运动阈值（RMT）。
盲法效果极佳，未报告严重副作用。不同包络频率的TI刺激对MEP的影响不同；20Hz TI刺激增强了同侧M1的MEP，且在60分钟时出现后效应，10Hz或20Hz TI刺激组与假刺激组之间未观察到显著差异。然而，在任何TI条件下，RMT均未观察到显著变化。
20Hz TI刺激增加了同侧M1的皮质兴奋性，突出表明频率是TI调节作用的一个重要因素。
