The aim of this study to investigate the effect of combined bilateral tDCS and VR-based therapy on distal upper extremity training in patients with stroke. We hypothesized that experimental group (VR-based training with dual-tDCS) would improve distal upper extremity function rather than control group (VR-based training with dual sham tDCS).

This is a double-blind, randomized controlled study. Patients were randomly assigned to 1 : 1 ratio to experimental group (VR-based training with dual-tDCS; VR-Dual) or the control group (VR-based training with dual sham tDCS; VR-Sham) . For both conditions, VR-Dual and VR-Sham group commenced at the same time (20 minutes). The therapist and patients were blinded as to whether the patients received real or sham tDCS. The study was approved by the Ethics Committee of the National Rehabilitation Center, Korea, and all participants provided written informed consent before enrollment.

Inclusion Criteria:

• first-time ischemic or hemorrhagic stroke
• unilateral upper extremity functional deficits after stroke
• presence of a score of at least 3 points on the Medical Research Council (MRC)
• a score ≥ 4 on the Brunnstrom stage
• a score ≥ 25 on the Korean version of the Mini-Mental Status Exam (K-MMSE)

Exclusion Criteria:

• age < 20 years
• wrist and finger spasticity with the Modified Ashworth Scale (MAS) score ≥ 2
• uncontrolled hypertension, heart problems, infection, or any history of seizure or epilepsy
• neurological disorders that cause motor deficits
• being unable to perform the task or to understand instructions
• presence of pacemaker, pregnancy, cognitive impairment, or psychiatric disorders