Home-Based Transcranial Direct Current Stimulation to Enhance Cognition in Stroke: Randomized Controlled Trial

Abstract

Background: Transcranial direct current stimulation (tDCS) is a promising tool for improving poststroke cognitive function. Home-based rehabilitation is increasingly required for patients with stroke, and additional benefits are expected if supplemented with remotely supervised tDCS (RS-tDCS). We evaluated the cognitive improvement effect and feasibility of RS-tDCS in patients with chronic stroke. Methods: Twenty-six patients with chronic stroke and cognitive impairment (Korean version of the Montreal Cognitive Assessment [K-MoCA] score <26) were randomized into real and sham RS-tDCS groups and underwent concurrent computerized cognitive training and RS-tDCS. Patients and caregivers underwent training to ensure correct tDCS self-application, were monitored, and treated 5 d/wk for 4 weeks. We investigated several cognition tests including K-MoCA, Korean version of the Dementia Rating Scale-2, Korean-Boston Naming Test, Trail Making Test, Go/No Go, and Controlled Oral Word Association Test at the end of the training sessions and one month later. Repeated-measures ANOVA was used for comparison between the groups and within each group. The adherence rate of the appropriate RS-tDCS session was also investigated. Results: In within-group comparison, unlike the sham group, the real group showed significant improvement in K-MoCA ( P real =0.004 versus P sham =0.132), particularly in patients with lower baseline K-MoCA (K-MoCA 10–17 ; P real =0.001 versus P sham =0.835, K-MoCA 18–25 ; P real =0.060 versus P sham =0.064) or with left hemispheric lesions (left; P real =0.010 versus P sham =0.454, right; P real =0.106 versus P sham =0.128). In between-group comparison, a significant difference was observed in K-MoCA in the lower baseline K-MoCA subgroup (K-MoCA 10–17 ; P time×group =0.048), but no significant difference was found in other cognitive tests. The adherence rate of successful application of the RS-tDCS was 98.4%, and no serious adverse effects were detected. Conclusions: RS-tDCS is a safe and feasible rehabilitation modality for poststroke cognitive dysfunction. Specifically, RS-tDCS is effective in patients with moderate cognitive decline. Additionally, these data demonstrate the potential to enhance home-based cognitive training, although significant differences were not consistently found in between-group comparisons; therefore, further larger studies are needed. Registration: URL: https://cris.nih.go.kr ; Unique identifier: KCT0003427.