EFFECTS OF TRANSCRANIAL DIRECT CURRENT STIMULATION FOLLOWED BY TREADMILL TRAINING ON DUAL-TASK WALKING AND CORTICAL ACTIVITY IN CHRONIC STROKE: A DOUBLE-BLINDED RANDOMIZED CONTROLLED TRIAL

Objective To explore the effects of transcranial direct current stimulation followed by treadmill training on dual-task gait performance and contralesional cortical activity in chronic stroke patients. Methods Forty-five chronic stroke participants were randomized into 3 groups: a bilateral transcranial direct current stimulation and treadmill training group; a cathodal transcranial direct current stimulation and treadmill training group; and a sham transcranial direct current stimulation and treadmill training group for 50 min per session (20 min transcranial direct current stimulation followed by 30 min treadmill training), 3 sessions per week for 4 weeks. Outcome measures included cognitive dual-task walking, motor dual-task walking, walking performance, contralesional cortical activity, and lower-extremity motor control. Results The cathodal transcranial direct current stimulation + treadmill training group showed significantly greater improvements in cognitive dual-task walking speed than the other groups (pcathodal vs sham = 0.006, pcathodal vs bilateral = 0.016). In the cathodal transcranial direct current stimulation + treadmill training group the silent period duration increased significantly more than in the other groups (p < 0.05). Changes in motor evoked potentials in the cathodal transcranial direct current stimulation + treadmill training group were greater than those in the sham transcranial direct current stimulation + treadmill training group (p < 0.05). No significant changes were observed in the bilateral transcranial direct current stimulation + treadmill training group. Conclusion Cathodal transcranial direct current stimulation followed by treadmill training is an effective intervention for improving cognitive dual-task walking and modulating contralesional cortical activity in chronic stroke. No beneficial effects were observed after bilateral transcranial direct current stimulation and treadmill training. LAY ABSTRACT Dual-task walking is essential for daily functioning, both at home and socially. This study explored the effects of transcranial direct current stimulation followed by treadmill training on dual-task gait performance and contralesional cortical activity in chronic stroke patients. A total of 45 chronic stroke patients were randomized to 1 of 3 groups: a bilateral transcranial direct current stimulation and treadmill training group, a cathodal transcranial direct current stimulation and treadmill training group, or a sham transcranial direct current stimulation and treadmill training group for 50 min per session, 3 sessions per week for 4 weeks. Cognitive dual-task walking, motor dual-task walking, walking performance, contralesional cortical activity, and lower-extremity motor control of the affected side were measured before and after the intervention. The results show that cathodal transcranial direct current stimulation followed by treadmill training is an effective intervention for improving cognitive dual-task walking and modulating contralesional cortical activity in individuals with chronic stroke.