OBJECTIVES: Although previous studies have shown a certain effect for affected upper extremity motor function for constraint-induced movement therapy (CIMT) with transcranial direct current stimulation (tDCS), there is insufficient evidence to make treatment recommendations. Here, we aimed to determine whether the addition of anodal-tDCS and peripheral neuromuscular electrical stimulation (PNES) to CIMT is superior to CIMT alone for improving upper extremity function in patients with chronic stroke. METHODS: This retrospective study included patients with chronic hemiparesis following a stroke who underwent CIMT at a college hospital between 2012 and 2018. The participants had either received CIMT alone (five-hour training sessions per day for 10 consecutive weekdays) or CIMT combined with anodal-tDCS and PNES. RESULTS: A total of 25 patients met all eligibility criteria, and 19 and 6 patients were included in the CIMT alone and CIMT combined with anodal-tDCS and PNES groups, respectively. Both groups showed significant improvement in all outcomes following CIMT (p <
0.05). The Fugl-Meyer assessment showed a significant difference between the groups in the CIMT combined with anodal-tDCS and PNES group (p = 0.047). CONCLUSIONS: Preconditioning interventions, including tDCS and PNES, may be good methods for further enhancing the effectiveness of CIMT.