Transcranial Direct Current Stimulation for Neurogenic Overactive Bladder Symptoms Among People With Stroke

Transcranial Direct Current Stimulation for Neurogenic Overactive Bladder Symptoms Among People With Stroke: a Randomized Controlled Pilot Trial

Neurogenic overactive bladder (nOAB) is a common and distressing sequela following stroke, significantly impairing quality of life and imposing a substantial financial burden. Existing pharmacological options often present adverse effects, while standard non-pharmacological treatments, such as pelvic floor muscle training (PFMT), face compliance and efficacy limitations in individuals with functional impairments. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique capable of modulating neuronal excitability and cortical plasticity. Targeting the supplementary motor area (SMA) via tDCS may regulate pelvic floor muscle (PFM) and detrusor activities. However, clinical evidence evaluating tDCS as an adjuvant to PFMT for stroke survivors with nOAB is lacking. This randomized controlled pilot trial aims to evaluate the feasibility, preliminary effectiveness, and cost-utility of active tDCS combined with PFMT compared to sham tDCS plus PFMT in stroke survivors suffering from nOAB.

Study Overview

• Status: Not yet recruiting
• Conditions: Stroke; Neurogenic Overactive Bladder
• Intervention / Treatment: Device: Active transcranial direct current stimulation (tDCS); Behavioral: Pelvic floor muscle training (PFMT); Device: Sham transcranial direct current stimulation (tDCS)

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Daniel KY Zheng, PhD; Phone Number: +852 53205956; Email: daniel.zheng@polyu.edu.hk
• Study Contact Backup: Name: Daniel KY Zheng, PhD; Phone Number: +852 53205956; Email: kangyong.zheng@connect.polyu.hk

Study Locations

• China
  • Hong Kong
    • Hong Kong, Hong Kong, China, 999077
      • The Hong Kong Polytechnic University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged between 18-80 years with onset of stroke within one and twelve months of enrollment and having overactive bladder (OAB) symptoms;
• Experiencing moderate (scoring 6-11 points on the Overactive Bladder Symptom Score [OABSS]) to severe OAB (scoring ≥ 12 points on OABSS);
• Obtaining a Mini-Mental State Examination (MMSE) score of ≥ 24.

Exclusion Criteria:

• Presence of metallic implants in the cranium, intracardiac lines, increased intracranial pressure, cardiac pacemaker, cochlear implants, tumour, and skull abnormalities;
• Family history of epilepsy/seizures;
• Contraindications to transcranial magnetic stimulation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active transcranial direct current stimulation (tDCS) + pelvic floor muscle training (PFMT)	Device: Active transcranial direct current stimulation (tDCS); Participants will receive active tDCS (1.5 mA for 20 minutes; current density 0.06 mA/cm²) 3 times per week for 8 weeks. tDCS will be conducted using two 5 x 7 cm² surface electrodes connected to a battery-powered stimulator (Neuroelectrics Instrument Controller, v 2.0). The anodal electrode will be placed over the supplementary motor area, and the cathodal electrode over the contralateral supraorbital region.; Behavioral: Pelvic floor muscle training (PFMT); Immediately following tDCS, participants will receive supervised, individual (1:1) PFMT for 30 minutes per session, consisting of pelvic floor contraction exercises (contracting the urethra/shortening the penis and controlling passage of gas), each held for 10 seconds and followed by 10 seconds of relaxation. PFMT will be performed 3 times per week for 8 weeks.
Sham Comparator: Sham transcranial direct current stimulation (tDCS) + pelvic floor muscle training (PFMT)	Behavioral: Pelvic floor muscle training (PFMT); Immediately following tDCS, participants will receive supervised, individual (1:1) PFMT for 30 minutes per session, consisting of pelvic floor contraction exercises (contracting the urethra/shortening the penis and controlling passage of gas), each held for 10 seconds and followed by 10 seconds of relaxation. PFMT will be performed 3 times per week for 8 weeks.; Device: Sham transcranial direct current stimulation (tDCS); Participants will receive sham tDCS (active current for 30 seconds, then turned off) 3 times per week for 8 weeks. tDCS will be conducted using two 5 x 7 cm² surface electrodes connected to a battery-powered stimulator (Neuroelectrics Instrument Controller, v 2.0). The anodal electrode will be placed over the supplementary motor area, and the cathodal electrode over the contralateral supraorbital region.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overactive bladder symptoms severity	Overactive bladder symptoms severity will be assessed using Overactive Bladder Symptom Score (OABSS). The total score of OABSS ranges from 0 to 15, with a higher score indicating higher symptom severity.	Baseline and post-intervention at 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recruitment Rate	Number of participants recruited and screened per week during the recruitment period. The unit of measure is participants/week.	Through study completion, an average of 1 year.
Time to Complete Recruitment	Total time required to recruit the full study sample. The unit of measure is weeks.	Through study completion, an average of 1 year.
Retention Rate	Percentage of enrolled participants who complete assessments at 8 weeks post-intervention, calculated as (number completing 8-week assessment / number enrolled) × 100. The unit of measure is %.	Baseline to 8 weeks
Adherence to Intervention	Percentage of total prescribed intervention sessions attended, calculated as (number of sessions attended / number of sessions prescribed) × 100. The unit of measure is %.	Baseline to 8 weeks
Adverse Events	Number of participants in each group who experience adverse events, monitored throughout the intervention.	Baseline to 8 weeks
Detrusor Wall Thickness	Detrusor wall thickness measured using the Mindray Consona N9 ultrasound system (Sonos Medical Limited) with a convex transducer of 3-6 MHz. An increase in detrusor wall thickness indicates detrusor overactivity. The unit of measure is millimeter (mm).	Baseline and post-intervention at 8 weeks
Bladder Neck Elevation	Bladder neck elevation, a surrogate measure of pelvic floor muscle strength, will be measured using the Mindray Consona N9 ultrasound system (Sonos Medical Limited). Greater bladder neck elevation indicates stronger pelvic floor muscle strength. The unit of measure is millimeter (mm).	Baseline and post-intervention at 8 weeks
Health-Related Quality of Life	Health-related quality of life will be assessed using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire. The score ranges from -0.864 to 1.0, where 1.0 indicates full health and higher scores indicate better health-related quality of life.	Baseline and post-intervention at 8 weeks
Healthcare Costs	Healthcare Costs will be collected using the Client Service Receipt Inventory (CSRI) to calculate total healthcare-related costs per participant from both healthcare provider and societal perspectives. The unit of measure is Hong Kong Dollars (HKD).	Baseline and post-intervention at 8 weeks.
Incontinence-related quality of life	Incontinence-related quality of life will be assessed using the Incontinence Quality of Life Questionnaire (I-QoL). The I-QoL score ranges from 0-100, with higher scores indicating higher quality of life.	Baseline and post-intervention at 8 weeks

Collaborators and Investigators

• Sponsor: The Hong Kong Polytechnic University
• Investigators: Principal Investigator: Priya Kannan, PhD, The Hong Kong Polytechnic University

Study record dates

Study Major Dates

• Study Start (Estimated): September 14, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: August 2, 2026
• First Submitted That Met QC Criteria: August 12, 2026
• First Posted (Actual): August 17, 2026

Study Record Updates

• Last Update Posted (Actual): August 21, 2026
• Last Update Submitted That Met QC Criteria: August 19, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Stroke; Transcranial direct current stimulation; Overactive bladder
• Additional Relevant MeSH Terms: Urogenital Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Male Urogenital Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Lower Urinary Tract Symptoms; Urological Manifestations; Urinary Bladder Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Stroke; Urinary Bladder, Overactive
• Other Study ID Numbers: HSEARS20260727002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Because the IPD will contain sensitive privacy data of the participants, it will not be suitable to be shared.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes