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 (p cathodal vs sham = 0.006, p cathodal 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.