Jo Jung Mi, Kim Yun-Hee, Ko Myoung-Hwan, Ohn Suk Hun, Joen Bohyun, Lee Kwang Ho
Department of Physical Medicine and Rehabilitation, Stroke and Cerebrovascular Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Am J Phys Med Rehabil. 2009 May;88(5):404-9. doi: 10.1097/PHM.0b013e3181a0e4cb.
We investigated whether anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex affected the working memory performance of patients after a stroke.
Ten patients (mean age 47.7 yrs) with cognitive deficits after a first-ever stroke participated in this single-blind, crossover, and sham-controlled experiment. Each patient was randomly assigned to undergo two transcranial direct current stimulation sessions: anodal dorsolateral prefrontal cortex and sham stimulation within 48 hrs of a washout period. All participants performed a two-back working memory task before and after the administration of the transcranial direct current stimulation. Accuracy (correction rate), recognition accuracy (correction rate-commission error rate), and response time were measured during each experiment.
Repeated-measures analysis of variance indicated a significant interaction effect of transcranial direct current stimulation type and time on the recognition accuracy. Post hoc analyses revealed a significant difference between prestimulation and poststimulation in the anodal stimulation group but not in the sham stimulation group. Regarding the accuracy, the paired t test indicated significant improvement only after anodal transcranial direct current stimulation without a significant interaction effect between the two transcranial direct current stimulation types. The response time was not significantly different in the anodal and sham stimulation groups.
Our results demonstrated that anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex was associated with enhanced working memory performance as indexed by the recognition accuracy in patients after a stroke.
我们研究了经颅直流电刺激左侧背外侧前额叶皮质是否会影响中风后患者的工作记忆表现。
10例首次中风后有认知缺陷的患者（平均年龄47.7岁）参与了这项单盲、交叉、假刺激对照实验。每位患者被随机分配接受两次经颅直流电刺激：在洗脱期48小时内分别接受阳极背外侧前额叶皮质刺激和假刺激。所有参与者在经颅直流电刺激前后均进行了双回溯工作记忆任务。在每次实验中测量准确率（校正率）、识别准确率（校正率-误报率）和反应时间。
重复测量方差分析表明，经颅直流电刺激类型和时间对识别准确率有显著的交互作用。事后分析显示，阳极刺激组刺激前和刺激后存在显著差异，而假刺激组则无显著差异。关于准确率，配对t检验表明，仅在阳极经颅直流电刺激后有显著改善，两种经颅直流电刺激类型之间无显著交互作用。阳极刺激组和假刺激组的反应时间无显著差异。
我们的结果表明，经颅直流电刺激左侧背外侧前额叶皮质与中风后患者的识别准确率所反映的工作记忆表现增强有关。
