Abstract: Objective To evaluate the effectiveness of cathodal transcranial direct current stimulation(c-tDCS) on the upper extremities of patients with stroke. Methods Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMbase, Web of Science, Ovid,China Biology Medicine disc (CBMdisc), China National Knowledge Infrastructure, Wanfang Data and VIP Database for Chinese Technical Periodicals were searched for the randomized controlled trials (RCTs) of c-tDCS in the treatment of the upper extremities of patients with
stroke from the date of establishment of the databases to July 2013. The bibliographies of the retrieved studies were also searched. 2 independent researchers evaluated the included studies using the risk of bias provided by Cochrane Library. The extracted data were analyzed by RevMan 5.1 software. Results A total of 10 trials were discovered. Compared with the sham tDCS group, the c-tDCS group which stimulated the area of primary motor cortex (M1) did not increase the score of Fugl- Meyer Assessment (upper extremity) [WMD=0.11, 95%CI: -5.77~5.99, Z=0.04, P=0.97] and Jebsen-Taylor Test [WMD=-1.52, 95%CI: -4.94~1.90, Z=0.87, P=0.38]. According to the Jadad Score of included studies, 2 of them were of low quality and 8 of them were of high quality. Conclusion Currently, no evidence shows that c-tDCS can improve the upper extremities function of stroke patients more than sham tDCS.

Key words: stroke, upper extremities, electric stimulation therapy, systematic review, randomized controlled trial