CLINICAL TRIAL article
Front. Hum. Neurosci.
Sec. Brain Imaging and Stimulation
Volume 19 - 2025 | doi: 10.3389/fnhum.2025.1652612
This article is part of the Research TopicTutorials on various neuroimaging and stimulation topicsView all articles
Task-Specific Cortical Mechanisms of taVNS-Paired Task-Oriented Training for Post-Stroke Upper Extremity Dysfunction Under Cognitive Load: An fNIRS Study
Provisionally accepted
- 1Nanjing Medical University, Nanjing, China
- 2Nanjing Normal University, Nanjing, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Objective: This randomized, double-blinded, sham-controlled trial investigated cortical task-specific response patterns underlying upper limb function improvement in subacute stroke patients receiving transcutaneous auricular vagus nerve stimulation (taVNS) paired with task-oriented training (TOT) under varying cognitive loads. Methods: Thirty patients were randomly assigned to either the taVNS or Sham group, both receiving 3 weeks of TOT; the taVNS group received concurrent active stimulation while the Sham group received sham stimulation. Assessments before and after intervention included clinical scales: Fugl-Meyer Assessment-Upper Extremity (FMA-UE), Montreal Cognitive Assessment (MoCA), Fatigue Severity Scale (FSS), and Modified Barthel Index (MBI). Neurophysiological measures comprised heart rate variability (HRV) for taVNS efficacy and motor-evoked potentials (MEPs) for cortical excitability. Functional near-infrared spectroscopy (fNIRS) measured brain activity during motor tasks with low (continuous horizontal movement) and high (goal-directed movement) cognitive loads to analyze neural activity, regional activation, and functional network changes. Results: Post-intervention, the taVNS group showed significantly greater improvements in all HRV indices compared to Sham (P<0.05). Both groups improved significantly in FMA-UE, MoCA, MBI, and FSS scores (P<0.05), with taVNS yielding greater gains (P<0.05). MEPs revealed increased ipsilesional elicitation rates and reduced contralesional latency in the taVNS group relative to Sham (P<0.05). Resting-state fNIRS showed higher ALFF in ipsilesional PFC, DLPFC, and sensorimotor cortex (SMC) post-taVNS, though not significant after correction. Under low cognitive load, ipsilesional M1 and premotor/supplementary motor areas exhibited greater activation post-taVNS (PFDR<0.05). During high cognitive load, ipsilesional PFC and DLPFC activation and nodal clustering/local efficiency in DLPFC increased significantly with taVNS (PFDR<0.05). Conclusion: taVNS combined with TOT enhances autonomic balance, corticospinal excitability, and activates cognition-motor brain regions, modulating functional connectivity. These multi-pathway neuroregulatory effects foster task-specific cortical activation and network efficiency during motor tasks under varying cognitive demands, promoting executive control and cognitive-motor integration to facilitate upper limb recovery post-stroke.
Keywords: Transcutaneous auricular vagus nerve stimulation, Task-oriented training, functional near-infrared spectroscopy, motor-evoked potentials, neuroplasticity, upper extremity rehabilitation
Received: 30 Jun 2025; Accepted: 04 Sep 2025.
Copyright: © 2025 Li, Xu, Wang, Wang, Li, LIN and Jiang. 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:
Feng LIN, Nanjing Medical University, Nanjing, China
Zhongli Jiang, Nanjing Medical University, Nanjing, China
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.