PTOTSystematic ReviewJournal of neuroengineering and rehabilitation2025

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

Nicholas Aderinto, Israel Charles Abraham, Gbolahan Olatunji and 3 others

PMID 41094520

WHAT IT FOUND

In chronic stroke survivors, included studies reported implanted vagus nerve stimulation paired with arm therapy had larger upper-limb function gains than control therapy, with mild voice or cough effects.

Ear stimulation had weaker motor effects.

Key findings

01The review mapped 10 studies published from 2014 to 2023: four rat-model studies and six clinical studies, with clinical sample sizes from 12 to 108.

02In clinical studies, invasive VNS paired with arm rehabilitation was reported to produce FMA-UE gains of 5.8-14.8 points versus 2.8-3.79 points in controls, with 47% responders in the N=108 trial.

03Invasive VNS adverse events included mild dysphonia, cough, and incision-site pain in less than 10% of participants, with one vocal cord palsy in the N=108 trial; taVNS showed only transient skin redness.

STILL TO COME

How it was doneWhat they foundWhat it means for PTsWhat it means for OTs

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What it does not show

This is a scoping review, not a meta-analysis, and it maps evidence rather than testing whether VNS causes improvement. The search was limited to English-language studies, so relevant non-English evidence may be missing. Most studies focused on chronic ischemic stroke, leaving acute, subacute, and hemorrhagic stroke underexplored. Clinical samples were small to moderate and stimulation protocols varied, so results may not generalise. Preclinical work used rat forelimb tasks, which may not translate to complex human arm movements. taVNS motor outcomes were often secondary, so its motor effect is less clear. Long-term safety beyond the available follow-up is not well established.

The easy way to misread this

Do not conclude that VNS alone improves arm recovery. In the included clinical studies, VNS was delivered together with intensive task-specific rehabilitation, so the contribution of any single component cannot be separated. Also, this scoping review maps heterogeneous evidence rather than proving efficacy.

Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →