CLINICAL TRIAL article
Front. Neurol.
Sec. Stroke
This article is part of the Research TopicRedefining Stroke Recovery: Current Trends and Recent AdvancesView all 12 articles
Uni-Hemispheric Dual-Site Anodal tDCS (M1-DLPFC) for Upper Limb Motor Function and Spasticity in Chronic Stroke: A Randomized Clinical Trial
Provisionally accepted
- 1Neuroscience Research Center, Trauma Institute, Guilan University of Medical Sciences, Rasht Iran, Rasht, Iran
- 2Guilan University of Medical Sciences, Rasht, Iran
- 3Monash University Faculty of Medicine Nursing and Health Sciences, Melbourne, Australia
- 4University of Social Welfare and Rehabilitation Science, Tehran, Iran
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Background/Objectives: Upper extremity impairment significantly affects motor function and quality of life after stroke. This study investigated the safety and efficacy of a non-invasive brain stimulation approach, uni-hemispheric concurrent dual-site anodal transcranial direct current stimulation (a-tDCS) targeting the primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPFC), to improve upper extremity performance in chronic stroke. Methods: This double-blind, randomized, sham-controlled study involved 38 chronic stroke patients to evaluate the safety and efficacy of uni-hemispheric concurrent dual-site anodal transcranial direct current stimulation (a-tDCS). Participants were randomly assigned to one of two groups: experimental group 1 (a-tDCS at 2 mA targeting M1 and DLPFC concurrently) or experimental group 2 (active a-tDCS at 2 mA over M1 with sham stimulation over DLPFC), with each receiving 20-minute sessions over five consecutive days. Upper extremity motor function (Fugl-Meyer Assessment -FMA) and spasticity (Modified Modified Ashworth Scale -MMAS) were assessed at baseline and 24 hours following the final intervention. The procedure was deemed safe. Statistical analysis involved the U Mann-Whitney test for between-group comparisons and the Wilcoxon signed-rank test for within-group changes.The results demonstrated that uni-hemispheric concurrent dual-site a-tDCS targeting M1 and DLPFC in experimental group 1 did not lead to statistically significant improvements in upper extremity motor function, elbow and wrist flexor spasticity, or range of motion in this cohort of chronic stroke patients. Furthermore, no statistically significant differences were found between experimental group 1 and experimental group 2 (the sham control group) for any of the measured outcomes (P ≥ 0.05). Conclusions: Uni-hemispheric concurrent dual-site a-tDCS targeting both M1 and DLPFC did not demonstrate a superior effect on upper extremity motor recovery compared to a-tDCS applied solely to M1 in chronic stroke patients.
Keywords: chronic stroke, M1-DLPFC stimulation, non-invasive brain stimulation, Spasticity, transcranial direct current stimulation, Upper extremity (UE) function
Received: 09 Jul 2025; Accepted: 22 Dec 2025.
Copyright: © 2025 ezzati, Azarnia, saberi, Jaberzadeh and abdollahi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Somaye Azarnia
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