Efficacy of transcranial direct current stimulation for post-stroke urinary incontinence: study protocol for a randomized controlled trial.

BACKGROUND: Post-stroke urinary incontinence is a prevalent and debilitating complication that severely impacts patient recovery and quality of life. Although pelvic floor muscle training is a recognized standard rehabilitative intervention, its clinical efficacy in stroke survivors is often suboptimal, largely because it addresses peripheral muscle function without mitigating the underlying central neurological deficits that disrupt micturition control. Emerging evidence suggests that neuromodulation via transcranial direct current stimulation can enhance neuroplasticity in cortical motor areas. This trial aims to address the current therapeutic gap by evaluating whether the synergistic combination of central neuromodulation and peripheral muscle training provides superior therapeutic benefits for post-stroke urinary incontinence recovery compared to pelvic floor muscle training alone.

METHODS: This randomized controlled trial will randomly assign an aggregate of 50 eligible patients into two groups. Participants allocated to the intervention group (n = 25) will undergo PFMT coupled with active, low-frequency tDCS over M1, whereas those in the control group will receive identical PFMT alongside sham tDCS. The 20 treatment sessions will be administered on a schedule of five sessions per week across four consecutive weeks for every participant. The primary outcome is leakage episodes. The secondary outcomes are defined as simplified cystometry, the International Consultation on Incontinence Questionnaire Urinary Incontinence Short Form (ICIQ-UI SF), Overactive Bladder Symptom Score (OABSS), Incontinence Quality of Life Questionnaire Score (I-QOL), surface electromyography (sEMG), Neurogenic Bowel Dysfunction Score and the number of urinations.

DISCUSSION: This randomized controlled trial protocol evaluates a novel intervention combining tDCS targeting the contralesional M1 with PFMT for post-stroke urinary incontinence. To address a critical gap in stroke rehabilitation, the study designs a rigorous double-blind, sham-controlled design to explore the combined effects of central neuromodulation and peripheral muscle training. A comprehensive assessment will be used to generate robust evidence of this innovative intervention. The findings are expected to contribute to an effective neurorehabilitation strategy, potentially transforming clinical approaches to this common yet under-addressed complication and significantly enhancing the quality of life for stroke survivors.

TRIAL REGISTRATION: URL: https://www.chictr.org.cn ; Unique identifier: ChiCTR2500099178. Registered on 2025-03-19.