Kim Heegoo, Kim Jinuk, Lee Gihyoun, Lee Jungsoo, Kim Yun-Hee
Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.
Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06355, Korea.
Brain Sci. 2022 Mar 28;12(4):453. doi: 10.3390/brainsci12040453.
High-definition transcranial direct current stimulation (HD-tDCS) has recently been proposed as a tDCS approach that can be used on a specific cortical region without causing undesirable stimulation effects. In this uncontrolled pilot study, the cortical hemodynamic changes caused by HD-tDCS applied over the ipsilesional motor cortical area were investigated in 26 stroke patients. HD-tDCS using one anodal and four cathodal electrodes at 1 mA was administered for 20 min to C3 or C4 in four daily sessions. Cortical activation was measured as changes in oxyhemoglobin (oxyHb) concentration, as found using a functional near-infrared spectroscopy (fNIRS) system during the finger tapping task (FTT) with the affected hand before and after HD-tDCS. Motor-evoked potential and upper extremity functions were also measured before (T0) and after the intervention (T1). A group statistical parametric mapping analysis showed that the oxyHb concentration increased during the FTT in both the affected and unaffected hemispheres before HD-tDCS. After HD-tDCS, the oxyHb concentration increased only in the affected hemisphere. In a time series analysis, the mean and integral oxyHb concentration during the FTT showed a noticeable decrease in the channel closest to the hand motor hotspot (hMHS) in the affected hemisphere after HD-tDCS compared with before HD-tDCS, in accordance with an improvement in the function of the affected upper extremity. These results suggest that HD-tDCS might be helpful to rebalance interhemispheric cortical activity and to reduce the hemodynamic burden on the affected hemisphere during hand motor tasks. Noticeable changes in the area adjacent to the affected hMHS may imply that personalized HD-tDCS electrode placement is needed to match each patient's individual hMHS location.
高清晰度经颅直流电刺激（HD-tDCS）最近被提出作为一种经颅直流电刺激方法，可用于特定皮质区域而不会产生不良刺激效果。在这项非对照的初步研究中，对26例中风患者应用HD-tDCS于患侧运动皮质区域后引起的皮质血流动力学变化进行了研究。使用一个阳极和四个阴极电极，以1 mA的电流进行HD-tDCS，每天进行四个疗程，每次20分钟，刺激部位为C3或C4。在HD-tDCS前后，使用功能性近红外光谱（fNIRS）系统在患侧手进行手指敲击任务（FTT）期间，测量皮质激活情况，以氧合血红蛋白（oxyHb）浓度变化作为指标。同时在干预前（T0）和干预后（T1）测量运动诱发电位和上肢功能。组统计参数映射分析表明，在HD-tDCS之前，FTT期间患侧和健侧半球的oxyHb浓度均升高。HD-tDCS后，仅患侧半球的oxyHb浓度升高。在时间序列分析中，与HD-tDCS前相比，HD-tDCS后患侧半球在FTT期间的oxyHb浓度平均值和积分值在最接近手部运动热点（hMHS）的通道中显著降低，这与患侧上肢功能的改善一致。这些结果表明，HD-tDCS可能有助于重新平衡半球间皮质活动，并减轻手部运动任务期间患侧半球的血流动力学负担。患侧hMHS相邻区域的明显变化可能意味着需要根据每个患者的个体hMHS位置进行个性化的HD-tDCS电极放置。
