Effects of rTMS Combined With Dual-Task Gait Training on Walking and Cognition After Stroke

The Hong Kong Polytechnic University184 enrolled

Overview

This randomized, double-blind, placebo-controlled trial will investigate whether repetitive transcranial magnetic stimulation (rTMS) applied to the dorsolateral prefrontal cortex (DLPFC) can enhance the effects of dual-task gait training in people with chronic stroke. Participants will be randomly allocated to receive either active rTMS or sham rTMS immediately before the same standardized dual-task gait training program. The intervention includes 12 sessions over 3 weeks. Outcomes will be assessed at baseline, immediately after training, and at 4-week follow-up. Co-primary outcomes are dual-task mobility and cognitive performance during walking, quantified using dual-task cost (DTC) for gait speed and cognitive-task performance during dual-task walking (e.g., Serial 7s; Shopping List Recall). Secondary outcomes include balance/mobility, community participation, mood/sleep measures, and fall incidence. To explore mechanisms, prefrontal cortex activity during single- and dual-task walking will be recorded using functional near-infrared spectroscopy (fNIRS), and mediation analyses will examine whether changes in PFC activity explain intervention effects.

Cognitive-motor interference after stroke can reduce walking safety and functional independence, especially during everyday dual-task situations. Dual-task gait training can improve performance, but response varies, potentially due to limitations in executive control and prefrontal network engagement. The DLPFC is central to attention and executive function; therefore, rTMS targeting the DLPFC may prime relevant neural circuits and improve responsiveness to subsequent dual-task training. This study is a parallel-group, randomized, double-blind, placebo-controlled trial. Community dwelling adults with chronic unilateral stroke will be recruited and randomized 1:1. Participants and outcome assessors will be blinded. Both groups will complete 12 supervised sessions over 3 weeks. In each session, participants will first receive either: Active rTMS to the DLPFC of the affected hemisphere (5 Hz; 90% resting motor threshold; total 1,200 pulses), or Sham rTMS using the placebo side of the coil with similar auditory sensations. Dual-task gait training will begin shortly after stimulation. Training will combine functional walking/balance tasks with progressively challenging cognitive tasks (e.g., mental arithmetic, verbal fluency, working memory tasks, and a shopping-list recall task), with difficulty adjusted to participant ability. Assessments will be conducted at baseline, post-intervention, and 4-week follow-up. Co-primary outcomes are DTC of gait speed and cognitive performance during dual-task walking.

Study Type

Interventions

active rTMS with dual-task trainingOTHER

Participants will receive active rTMS targeting the DLPFC of the affected hemisphere before each training session: 5 Hz, 90% resting motor threshold (RMT), 10-second trains with 30-second inter-train intervals, total 1,200 pulses (≈ 16 minutes) per session. Dual-task gait training will start within \~10 minutes after rTMS. The program includes 12 sessions over 3 weeks.

sham rTMS with dual-task trainingOTHER

Participants will receive sham rTMS delivered using the placebo side of the same coil at the same DLPFC target location and with identical session duration and procedures (≈ 16 minutes) before each training session. Dual-task gait training will start within \~10 minutes after sham stimulation. The program includes 12 sessions over 3 weeks.

Eligibility

Sex: ALLMin age: 50 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Unilateral ischemic or hemorrhagic hemispheric stroke * Age ≥ 50 years -≥ 6 months post-stroke * Medically stable * Able to walk independently ≥ 1 minute (assistive device allowed) * Able to follow commands * mRS 1-3 * MoCA ≥ 22 Exclusion Criteria: * Other neurological disorders * Cerebellar/brainstem injury * TMS contraindications (e.g., pacemaker, intracranial metal, seizure history, pregnancy) * Contraindications to exercise (e.g., unstable angina) * Severe aphasia (NIHSS item 9 ≥ 2) * Pain/illness limiting performance * Concurrent formal rehabilitation elsewhere * RMT cannot be determined * Fails TMS safety screening

Outcomes

Primary Outcomes

Dual-task cost (DTC) of walking speed (%)

Walking speed (m/s) measured during single-task walking and dual-task walking (walking + Serial 7s; walking + Shopping List Recall). DTC computed as (single-task - dual-task) / single-task × 100%; higher DTC indicates greater cognitive-motor interference. Speed will be averaged across three 45-s trials per condition.