Mapping the role of vagus nerve stimulation in post-stroke arm motor recovery

 WHY? You somehow incompetently missed all this earlier research?

• vagus nerve (60 posts to July 2012)

This just proves the total incompetence of our fucking failures of stroke associations in not creating a database of stroke research and protocols. We wouldn't waste time on useless research like this!

Mapping the role of vagus nerve stimulation in post-stroke arm motor recovery

• Nicholas Aderinto, 
• Israel Charles Abraham, 
• Gbolahan Olatunji, 
• Emmanuel Kokori, 
• Ahmedyar Hasan & 
• Olivier Uwishema 

Journal of NeuroEngineering and Rehabilitation volume 22, Article number: 215 (2025) Cite this article

Abstract

Objective

To map the scope, nature, and extent of evidence on using Vagus Nerve Stimulation (VNS) for post-stroke arm motor recovery in preclinical and clinical settings, identifying key findings, safety profiles, and evidence gaps to guide future research.

Data sources

Following the Arksey and O’Malley framework and PRISMA-ScR guidelines, we searched PubMed, Embase, Scopus, Cochrane Library, Web of Science, and Google Scholar for studies published up to March 2025. Studies evaluated invasive or transcutaneous auricular VNS (taVNS) for arm or forelimb motor recovery in adult stroke survivors or animal models.

Study selection

The titles and abstracts of selected studies were screened against the eligibility criteria using Covidence software to ensure rigor and transparency. Studies that met the inclusion criteria or required a full-text review were retained. Discrepancies were resolved through discussion or consultation with a third reviewer. A full-text review was done to arrive at a final list of studies.

Data extraction

Data were extracted on study characteristics, intervention protocols, motor outcomes, safety profiles, and evidence gaps.

Data synthesis

A scoping synthesis approach was employed, with scoping synthesis organized by preclinical and clinical findings.

Conclusions

VNS is a promising adjunct to task-specific rehabilitation, enhancing arm motor recovery with a favorable safety profile. taVNS offers a scalable, non-invasive alternative but requires further optimization. Future research should focus on diverse stroke populations, standardize protocols, and investigate synergistic combinations with other rehabilitative strategies to optimize functional outcomes.

Introduction

Stroke remains a leading cause of long-term disability worldwide, with approximately 795,000 new or recurrent cases annually in the United States alone [1]. Among the most debilitating consequences of stroke is upper limb motor impairment, affecting up to 35% of survivors and significantly limiting their ability to perform daily activities [2]. Despite advances in rehabilitation strategies, such as physical and occupational therapy, only 20–30% of patients achieve full arm motor recovery, showing the need for innovative interventions to enhance neuroplasticity and functional outcomes [3].

Vagus nerve stimulation (VNS) is a promising neuromodulatory approach to enhance motor recovery after stroke [4]. Originally developed for epilepsy management, VNS involves the delivery of electrical impulses to the vagus nerve, which projects to key brain regions involved in neuroplasticity, including the cortex and brainstem [4]. Recent preclinical studies have shown that VNS, when combined with motor rehabilitation, enhances synaptic plasticity and promotes the reorganization of motor cortex representations in animal stroke models [4, 5]. These findings have spurred interest in translating VNS to human stroke populations, particularly for addressing arm motor deficits.

Clinical trials exploring VNS in stroke rehabilitation have reported encouraging results [6]. Similarly, non-invasive VNS, which utilizes transcutaneous stimulation of the vagus nerve, has demonstrated feasibility and potential efficacy in early-phase studies, providing a less invasive alternative [7]. However, the literature is heterogeneous, with variations in VNS protocols (invasive vs. non-invasive, stimulation parameters), study designs, and patient populations (acute vs. chronic stroke), necessitating a comprehensive synthesis to map the current evidence base.

Despite its potential, several challenges remain in understanding the role of VNS in post-stroke arm motor recovery. The optimal timing of VNS intervention (acute vs. chronic phase), the ideal stimulation parameters, and the synergy with conventional rehabilitation therapies are not well-established [8]. Additionally, patient-specific factors, such as stroke severity, lesion location, and baseline motor impairment, may influence VNS efficacy but are underexplored [8]. This scoping review maps the extent, nature, and characteristics of evidence on using VNS to improve arm motor recovery in stroke survivors. This scoping review uniquely integrates preclinical and clinical evidence up to March 2025, addressing gaps in prior reviews by including animal studies and focusing on clinical translation challenges.

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