高精度经颅直流电刺激对踝关节跖背屈疲劳任务中脊髓运动神经元兴奋性的影响  

Effects of High-Definition Transcranial Direct Current Stimulation on Excitability of Spinal Motoneurons under Ankle Dorsi-Plantarflexion Fatigue Task

作　　者：于常晓 占江龙 沈斌 周俊鸿 徐琳峰[1] 傅维杰 YU Changxiao;ZHAN Jianglong;SHEN Bin;ZHOU Junhong;XU Linfeng;FU Weijie(School of Rehabilitation Science,Hangzhou Medical College,Hangzhou 310000,China;Key Laboratory of Exercise and Health Sciences of Ministry of Education,Shanghai University of Sport,Shanghai 200438,China;Harvard Medical School,MA 02115,USA;Hebrew Senior Life Hinda and Arthur Marcus Institute for Aging Research,MA 02131,USA)

机构地区：[1]杭州医学院康复学院,杭州310000 [2]上海体育大学运动健身科技省部共建教育部重点实验室,上海200438 [3]美国哈佛医学院,马萨诸塞州02115 [4]美国希伯来老年研究所,马萨诸塞州02131

出　　处：《医用生物力学》2024年第2期293-298,共6页Journal of Medical Biomechanics

基　　金：国家自然科学基金项目(12272238,11932013);上海市青年拔尖人才开发计划。

摘　　要：目的探究踝关节跖背屈疲劳任务中高精度经颅直流电刺激(high-definition transcranial direct current stimulation,HD-tDCS)对H-反射和M-波的调控效果,为HD-tDCS减轻神经肌肉疲劳的实际应用提供方向。方法招募20名健康青年男性受试者,随机分为真刺激组和假刺激组各10名。对受试者采取连续5 d的单盲HD-tDCS干预(时间20 min;强度2 mA;靶点Cz),干预前1天采集受试者安静条件下的H-反射和M-波,跖屈肌最大自主收缩(maximal voluntary isometric contraction,MVIC)时的M-波,跖屈肌和背屈肌MVIC力矩,并进行一次踝关节跖背屈运动性疲劳任务,以确定受试者达到该任务疲劳的时间。干预后1天进行与第1次疲劳任务相同的运动时间,并进行后测的数据采集。采用重复测量双因素(刺激方案×疲劳前后)方差分析其自变量对受试者肌肉力学特性、α运动神经元传导特性各指标的影响。结果相较于疲劳前,两组疲劳后的自主激活值(voluntary activation,VA)、H-反射最大值(maximal H-reflex,H_(max))、M-波最大值(maximal M-wave,Mmax)、跖屈肌和背屈肌MVIC力矩均显著降低(P<0.05),但相比于真刺激组,假刺激组的VA和背屈肌MVIC力矩下降更为显著(P<0.05)。结论连续5 d的HD-tDCS干预有助于提高脊髓节段α运动神经元的活性,且能抑制跖背屈疲劳诱发的外周“神经-肌肉”接头处信息传递能力的下降。Objective To investigate the effects of high-definition transcranial direct current stimulation(HD-tDCS)on the modulation of the H-reflex and M-wave during ankle dorsiflexion-plantar flexion fatigue tasks to provide direction for the application of HD-tDCS in mitigating neuromuscular fatigue.Methods Twenty healthy young male participants were recruited and randomly assigned to either the real stimulation or sham stimulation group,with 10 participants in each group.The intervention consisted of a 5-day single-blind HD-tDCS application(duration:20 min;intensity:2 mA;target:Cz).Baseline measurements of the H-reflex and M-wave under resting conditions,M-wave during maximal voluntary isometric contraction(MVIC)of the dorsiflexor muscle,and MVIC torque of the dorsiflexor and plantar flexor muscles were obtained.An ankle dorsiflexion fatigue task was performed to determine the time to achieve fatigue for the task.The same fatigue task was repeated and evaluated one day after the intervention.A repeated-measures two-factor(stimulation condition×pre/post fatigue)analysis of variance(ANOVA)was used to analyze the effects of independent variables on the mechanical properties of the muscles andα-motoneuron conduction characteristics.Results After fatigue,voluntary activation(VA),maximal H-reflex(H_(max)),maximal M-wave(Mmax),and dorsiflexor and plantar flexor MVIC torques in both groups were significantly reduced compared with pre-fatigue levels(P<0.05).However,compared to the real stimulation group,the sham stimulation group showed a more significant decline in VA and plantar flexor MVIC torque(P<0.05).Conclusions A continuous 5-day HD-tDCS intervention can effectively increaseα-motoneuron activity at the spinal segment.It can also exert an inhibitory effect on reducing information transmission capacity at the peripheral neuromuscular junction under the ankle dorsi-plantarflexion fatigue task.

关 键 词：高精度经颅直流电刺激 最大自主收缩 神经冲动 皮质-脊髓通路 α运动神经元活性 肌肉疲劳 

分 类 号：R318.01[医药卫生—生物医学工程]