A stroke rehabilitation system has been shown to significantly improve arm impairment and function in people with long-term arm weakness after ischaemic stroke.
Long-term loss of arm function after ischaemic stroke is common, and the results of the study show two to three times greater improvement with Vagus Nerve Stimulation (VNS) when it was combined with intense physical therapy, compared to intense physical therapy alone.
Around 80 per cent of people with acute stroke have arm weakness, and as many as 60 per cent still having persistent problems six months later.
In the study – which looked at the system developed by MicroTransponder Inc and involved 108 people in the United States and the United Kingdom with moderate to severe arm problems – trial participants were randomised to intense physical therapy paired with active VNS or intense physical therapy paired with sham VNS (control group).
VNS involves implant surgery and the device stimulates the vagus nerve on the left side of the neck during intensive task-specific rehabilitation.
The vagus nerve connects with areas of the brain that cause release of important neuromodulators or chemicals which, when combined with physical therapy, helps the brain ’re-learn’ movements.
After six weeks of outpatient therapy and a further 90 days of home based therapy, 47 per cent of the people in the VNS group showed a clinically meaningful response versus 24 per cent in the control group.
People who received VNS also showed improvement over the control group in quality of life and activity measures.
Jesse Dawson, professor of stroke medicine at the University of Glasgow and principal investigator of the trial, says: “This is the first study to find clinically and statistically-significant effects of a neuromodulation therapy for people with arm and hand weakness after chronic stroke.
“We saw improvement for the VNS group in both impairment and functional measures compared to controls. In particular, the clinically meaningful response rate doubled with VNS for both impairment and functional outcomes.
“Importantly, the VNS doesn’t work alone – it adds to the effect of intensive rehabilitation.”
Dr Teresa Kimberley, professor and director of the Brain Recovery Lab at MGH Institute of Health Professions, a senior investigator on the project through both the pilot and pivotal studies, adds: “The results of this clinical study suggest that the addition of VNS enhances the effect of best practice stroke rehabilitation.
“We are looking forward to potentially establishing the therapy as part a new standard of care for stroke rehabilitation. “
Efforts to obtain marketing authorisations from regulatory authorities in both the US and the EU are currently underway.
