Vagus Nerve Stimulation Paired With Rehabilitation for Upper Limb Motor Impairment and Function After Chronic Ischemic Stroke: Subgroup Analysis of the Randomized, Blinded, Pivotal, VNS-REHAB Device Trial.
Jesse Dawson, Navzer D Engineer, Steven C Cramer and 19 others
PMID 36226541WHAT IT FOUND
Pairing vagus nerve stimulation with rehabilitation improved arm function more than sham stimulation, and this benefit was consistent across age, sex, time since stroke, and impairment severity.
You do not need to screen for specific subgroups to predict who will respond.
Key findings
01The mean difference in Fugl-Meyer Assessment Upper Extremity (FMA-UE) scores between the VNS and control groups was 2.6 points immediately after therapy and 3.0 points at 90 days, both favoring VNS.
02The treatment effect was similar across subgroups defined by age, sex, country, stroke severity, time from stroke, paretic side, and cortical involvement, with no significant interaction effects.
03There were no significant differences in the rate of serious adverse events or device-related adverse events between the VNS and control groups across subgroups.
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 was a post-hoc analysis, meaning it was not pre-registered and may lack statistical power to detect small differences between subgroups. The sample size (108) was too small to analyze complex interactions, such as older females versus older males. Patients with very severe arm weakness (FMA-UE score <20) and those with significant sensory impairment were excluded, so the results do not apply to these groups. The study did not assess corticospinal tract excitability, a known predictor of recovery, so it cannot determine if VNS response depends on this physiological factor.
Declared interests
The trial was funded by MicroTransponder Inc., the manufacturer of the VNS device. Several authors are employees of MicroTransponder, and others have received consulting fees or grants from the company or related entities.
The easy way to misread this
Do not assume this treatment works for all stroke survivors. The study excluded people with very severe arm weakness (FMA-UE <20) and significant sensory impairment. Additionally, because this is a post-hoc analysis funded by the device manufacturer, the consistency of the effect across subgroups should be viewed as suggestive rather than definitive proof that no predictors exist.