Closed-Loop Vagus Nerve Stimulation for Poststroke Motor Recovery: A Systematic Review and Meta-Analysis of Movement-Synchronized Neuromodulation.

Authors

Majed Aldehri, Ibrahim Serag, Mohamed Farouk, Mohamed M Elgohary, Ibrahim Alnaami

Published in

Neuromodulation : journal of the International Neuromodulation Society. Oct 08, 2026. Epub Oct 08, 2026.

Abstract

Closed-loop or movement-synchronized vagus nerve stimulation (VNS) has emerged as a promising neuromodulatory strategy to enhance activity-dependent neuroplasticity after stroke. Unlike conventional open-loop stimulation, closed-loop VNS is temporally coupled with motor execution, potentially improving the specificity and efficacy of motor recovery. However, clinical evidence remains fragmented, and no prior meta-analysis has specifically evaluated this approach. This study aimed to systematically assess the effectiveness and safety of closed-loop VNS for upper-limb motor recovery after stroke.
A systematic review and meta-analysis were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic data bases (PubMed/MEDLINE, Scopus, and Web of Science) were searched from inception to March 2026. Randomized controlled trials (RCTs) investigating movement-synchronized VNS in adult patients with a clinical diagnosis of stroke presenting with upper limb motor impairment were included. Primary outcomes were changes in Fugl-Meyer Assessment of Upper Extremity (FMA-UE) and Wolf Motor Function Test (WMFT). Data were pooled using a random-effects model, and effect sizes were expressed as mean difference (MD) or standardized mean difference (SMD) with 95% CI. Risk of bias was assessed using RoB2, and certainty of evidence was evaluated using Grading of Recommendations Assessment, Development, and Evaluation.
Six RCTs comprising 215 participants were included in the quantitative synthesis, with an additional cohort study included qualitatively. Closed-loop VNS demonstrated a significant improvement in FMA-UE scores compared with controls (MD = 2.33, 95% CI 0.95-3.70, p = 0.0009), although with substantial heterogeneity (I² = 89%). WMFT outcomes from four RCTs (n ≈ 177) also favored closed-loop VNS (SMD = 0.62, 95% CI 0.25-0.98, p = 0.0009) with low heterogeneity (I² = 18%). Sensitivity analyses confirmed the stability of the findings, whereas meta-regression showed no significant effect of age. The pooled adverse-event analysis of two implanted VNS trials showed no statistically significant between-group difference, although estimates were highly imprecise. Overall certainty of evidence was moderate.
Closed-loop or movement-synchronized VNS may provide clinically meaningful improvements in upper-limb motor function after stroke; however, the available safety evidence is limited and imprecise, particularly for implanted VNS, and cannot be generalized to noninvasive transcutaneous auricular VNS.

PMID:
43002150
Bibliographic data and abstract were imported from PubMed on 09 Nov 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.