Structural Mechanisms of Dual-Target tDCS in Stroke Hemiparetic Hand

Multimodal MRI-Based Study of the Structural Mechanisms Underlying Interhemispheric Network Reorganization Induced by Dual-Target tDCS in Stroke Hemiparetic Hand

This is a single-center, randomized, single-blind study investigating the effects of dual-target transcranial direct current stimulation (tDCS) combined with task-oriented functional electrical stimulation on upper limb recovery in patients with non-acute post-stroke hemiplegia. A total of 56 participants will be recruited and randomly assigned (1:1) to the dual M1 tDCS group or sham stimulation group. The intervention is delivered five times per week for four weeks, with 20 sessions in total. Multimodal MRI (T1W, T2W, and DTI) will be used to assess structural and network-level reorganization of sensorimotor pathways, including the corticospinal tract, in response to tDCS.

The primary outcome is the Broetz hand function score, evaluated at baseline, post-intervention, and six-month follow-up. Secondary outcomes include Fugl-Meyer Assessment of the upper extremity (FMA-UE) and multimodal MRI-derived measures of white matter integrity. This study aims to elucidate the structural constraints underlying sensorimotor network lateralization and to identify responder and non-responder profiles based on corticospinal tract damage, providing mechanistic insight into individualized tDCS-based neurorehabilitation after stroke.

Study Overview

• Status: Not yet recruiting
• Conditions: Stroke
• Intervention / Treatment: Device: tDCS; Device: Sham tDCS

• Study Type: Interventional
• Enrollment (Estimated): 56
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Diagnosed with stroke according to the "Diagnostic Criteria for Major Cerebrovascular Diseases in China, 2019", confirmed by cranial CT or MRI.
2. First-ever unilateral subcortical stroke (involving the corona radiata, basal ganglia, thalamus, internal capsule, etc.).
3. Age 30-75 years.
4. Right-handed prior to stroke onset.
5. Stroke onset ≥ 2 weeks.
6. Hemiplegic hand function at Brunnstrom Stage I-III.
7. Written informed consent provided by the patient or legally authorized representative.

Exclusion Criteria:

1. Any contraindications to MRI.
2. History of other neurological disorders or substance abuse.
3. Unstable conditions or rapidly progressive/malignant diseases, e.g., severe atrial fibrillation.
4. Severe skin allergies.
5. Inability to cooperate with basic communication or assessments, such as severe aphasia.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active Dual M1 tDCS	Device: tDCS; Bilateral M1 high-definition transcranial direct current stimulation (HD-tDCS) at 2 mA for 20 minutes per session, delivered five times per week for 4 weeks (total 20 sessions). Electrodes are placed over the left and right primary motor cortices. Each session is combined with task-oriented hand rehabilitation exercises targeting the affected upper limb. This intervention is designed to modulate interhemispheric sensorimotor network reorganization and promote hand function recovery after stroke.
Sham Comparator: Sham Dual M1 tDCS	Device: Sham tDCS; Bilateral M1 sham HD-tDCS: electrodes placed identically to the active group, with current ramped up and down for 10 seconds at the start and end of each 20-minute session, without sustained stimulation. Sessions are also combined with task-oriented hand rehabilitation exercises. This sham intervention serves as a control to evaluate the efficacy of active tDCS on interhemispheric network reorganization and hand function recovery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Broetz Hand Function Score	Baseline (T0), post-intervention (T1, after 4 weeks), 6-month follow-up (T2)

Collaborators and Investigators

• Sponsor: The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School

Study record dates

Study Major Dates

• Study Start (Estimated): May 6, 2026
• Primary Completion (Estimated): June 30, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: May 17, 2026
• First Submitted That Met QC Criteria: May 17, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 17, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Stroke; Therapeutics; Behavioral Disciplines and Activities; Electric Stimulation Therapy; Convulsive Therapy; Psychiatric Somatic Therapies; Electroshock; Psychological Techniques; Transcranial Direct Current Stimulation
• Other Study ID Numbers: MQ2025041 (Other Grant/Funding Number: General (Youth) Medical Research Project of Jiangsu Provincial Health Commission)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No