不同脑网络经颅直流电刺激方案对健康成年人步态特征的特异性调控效果研究

Specific modulatory effects of different network-based transcranial direct current stimulation on gait characteristics in healthy adults

目的:基于额顶网络(FPN)、背侧注意网络(DAN)、默认网络(DN)三个步态相关脑网络,制定不同的脑网络经颅直流电刺激(Network t DCS)方案以期实现特异性调控步速和步态变异性、提高步行功能的目的。方法:本研究招募健康成年人,随机分3组,分别接受不同的刺激方案:兴奋FPN抑制DN(FPN+/DN-t DCS)、兴奋DAN抑制DN(DAN+/DN-t DCS)、假刺激(Sham)。在刺激前和刺激后即刻进行常速、快速和双任务条件的步态任务测试。采用双因素重复测量方差分析评估三种刺激方案对不同条件下的步态时空参数和步态变异性的影响。结果:本研究共纳入72例受试者,其中64例完成测试。干预前后常速、快速和双任务步行条件下步态时空参数指标和常速步行条件下步态变异性的改变均无显著交互效应。快速步态任务中,步幅变异性(F=3.671,P=0.031)和双支撑时间变异性(F=3.879,P=0.026)存在显著交互效应;双任务步行条件下,步宽变异性(F=3.940,P=0.025)、步速变异性(F=3.936,P=0.025)和双支撑时间变异性(F=4.913,P=0.011)存在交互效应。结论:DAN+/DN-t DCS可有效降低健康成年人复杂任务的步态变异性、提升步态稳定性;但FPN+/DN-t DCS方案并未特异性提升不同条件下的步速水平。

Objective:To develop three tDCS protocols based on the gait-related brain networks:the frontoparietal network(FPN),the dorsal-attention network(DAN),and the default network(DN),with the aim of specifically modulating gait speed and gait variability and improving walking function.Method:In this study,healthy adults were recruited and randomly divided into 3 groups receiving different stimulation protocols:simultaneously enhancing the excitability of FPN and suppressing the excitability of DN(i.e.,FPN+/DN-tDCS),enhancing the excitability of DAN and suppressing the excitability of DN(i.e.,DAN+/DN-tDCS),and sham stimulation(Sham group).Normal,fast and dual-task gait tests were performed immediately before/after electrical stimulation,and spatiotemporal parameters and variability indicators of gait were collected.Two-way repeated measures ANOVA was used to assess the effects of three stimulation on gait characteristics under different conditions.Result:A total of 72 subjects were included in this study,64 of whom completed all tests.There were no significant interaction effects observed on gait spatiotemporal parameters in three conditions(normal,fast,dualtask walking conditions)and gait variability in normal walking between pre-and post-intervention assessments.In the fast gait task,there were significant interaction effects observed for stride length variability(F=3.671,P-0.031)and double support time variability(F=3.879,P-0.026).In the dual-task gait task,there were significant interaction effects observed for stride width variability(F-=3.940,P=0.025),gait speed variability(F=3.936,P=0.025),and double support time variability(F=4.913,P=0.011).Conclusion:The DAN+/DN-tDCS protocol were effective in reducing gait variability and improving gait stability during complex tasks in healthy adults.However,the FPN+/DN-tDCS protocol did not specifically improve gait speed under different conditions.