Transcranial Direct Current Stimulation Enhances Dual-task Performance in Stroke

Stroke often impairs lower limb control, resulting in gait abnormalities and difficulties in dual-task performance, such as walking while engaging in cognitive activities. This study examines the effects of a single session of transcranial direct current stimulation (tDCS) targeting the left dorsolateral prefrontal cortex (DLPFC) on dual-task walking performance in individuals with chronic stroke. Using a cross-over design, participants will undergo two sessions (active or sham tDCS, 7 ± 2 days apart) of stimulation at 2 mA for 30 minutes. Walking performance will be measured using single and dual-task conditions combining motor (e.g., 20 m walk) and cognitive tasks (e.g., word association, random number recall). Primary outcomes include walking speed (m/s), stride length (m), and dual-task cost (DTC) for mobility and cognitive speed. The study aims to evaluate tDCS as a potential tool to reduce DTC, improve dual-task performance, and improve daily function and quality of life in stroke survivors. Results may guide the development of tailored dual-task interventions in stroke rehabilitation.

Inclusion Criteria: * age between 50 and 80 years * at least 6 months post-first-ever stroke with unilateral motor deficits * ability to walk independently for at least 10 m without the use of walking aids * a score of 24 or higher on the Mini-Mental State Examination (MMSE) Exclusion Criteria: * unstable medical conditions, such as heart failure, uncontrolled hypertension, or cancer * presence of other comorbidities that could interfere with gait * history of contraindications to tDCS, such as epilepsy or metal implants * history of head injury, head surgery, or lower limb orthopedic issues