Christova Monica, Rafolt Dietmar, Gallasch Eugen
Department of Physiology, Medical University of Graz, Austria; Department of Physiotherapy, University of Applied Sciences FH-Joanneum, Austria.
Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Austria.
Behav Brain Res. 2015;287:27-33. doi: 10.1016/j.bbr.2015.03.028. Epub 2015 Mar 21.
Transcranial direct current stimulation (tDCS) protocols applied over the primary motor cortex are associated with changes in motor performance. This transcranial magnetic stimulation (TMS) study examines whether cathodal tDCS prior to motor training, combined with anodal tDCS during motor training improves motor performance and off-line learning. Three study groups (n=36) were trained on the grooved pegboard test (GPT) in a randomized, between-subjects design: SHAM-sham stimulation prior and during training, STIM1-sham stimulation prior and atDCS during training, STIM2-ctDCS stimulation prior and atDCS during training. Motor performance was assessed by GPT completion time and retested 14 days later to determine off-line learning. Cortical excitability was assessed via TMS at baseline (T0), prior training (T1), after training (T2), and 60 min after training (T3). Motor evoked potentials (MEP) were recorded from m. abductor pollicis brevis of the active left hand. GPT completion time was reduced for both stimulated groups compared to SHAM. For STIM2 this reduction in time was significantly higher than for STIM1 and further off-line learning occurred after STIM2. After ctDCS at T1, MEP amplitude and intracortical facilitation was decreased and intracortical inhibition was increased. After atDCS at T2, an opposite effect was observed for STIM1 and STIM2. For STIM2 these neuromodulatory effects were retained until T3. It is concluded that application of atDCS during the training improves pegboard performance and that additional priming with ctDCS has a positive effect on off-line learning. These cumulative behavioral gains were indicated by the preceding neuromodulatory changes.
应用于初级运动皮层的经颅直流电刺激（tDCS）方案与运动表现的变化相关。这项经颅磁刺激（TMS）研究考察了运动训练前的阴极tDCS与运动训练期间的阳极tDCS相结合是否能改善运动表现和离线学习。三个研究组（n = 36）在有槽钉板测试（GPT）中接受训练，采用随机、组间设计：假刺激组（SHAM）在训练前和训练期间均接受假刺激；刺激1组（STIM1）在训练前接受假刺激，训练期间接受阳极tDCS；刺激2组（STIM2）在训练前接受阴极tDCS，训练期间接受阳极tDCS。通过GPT完成时间评估运动表现，并在14天后重新测试以确定离线学习情况。在基线（T0）、训练前（T1）、训练后（T2）以及训练后60分钟（T3）通过TMS评估皮层兴奋性。从主动左手的拇短展肌记录运动诱发电位（MEP）。与假刺激组相比，两个刺激组的GPT完成时间均缩短。对于刺激2组，时间缩短显著高于刺激1组，且刺激2组之后出现了进一步的离线学习。在T1进行阴极tDCS后，MEP波幅和皮层内易化降低，皮层内抑制增加。在T2进行阳极tDCS后，刺激1组和刺激2组观察到相反的效应。对于刺激2组，这些神经调节作用一直持续到T3。研究得出结论，训练期间应用阳极tDCS可改善钉板测试表现，而额外的阴极tDCS预刺激对离线学习有积极影响。这些累积的行为改善由之前的神经调节变化所表明。
