Bihemispheric anodal corticomotor stimulation using transcranial direct current stimulation improves bimanual typing task performance

Transcranial direct current stimulation (tDCS) is associated with improved unimanual skilled hand use. The authors assessed effects of bihemispheric anodal corticomotor tDCS (BAC-tDCS) on bimanual skilled hand use. Twenty-eight nondisabled subjects were randomized to either BAC-tDCS or sham-tDCS, 20 min daily for 5 consecutive days. Performance on a bimanual typing (BT) task and a short-term memory (STM) task was assessed daily and at 1-week follow-up. Mean change between Day 1 and Day 5 in BT score with BAC-tDCS (19.4 points; 95% CI [12.82, 25.99]) was significantly greater (p =.04) than change with sham-tDCS (12.5 points; 95% CI [7.6, 17.3]). Neither group retained improvements in BT score at follow-up. BAC-tDCS had no effect on STM. These results may have implications for interventions to improve hand function in persons with bilateral hand dysfunction.