New implant device helps improve stroke-related arm impairment

A stroke rehabilitation system has been shown to help improve arm impairment and functions in patients recovering from strokes, the results of a randomised trial suggest.

Developed by MicroTransponder Inc, the technology’s impact was studied on people who had long-term arm weakness following an ischaemic stroke.

Researchers at the University of Glasgow found ‘two to three times greater improvement’ when the device – called Vagus Nerve Stimulation (VNS) – was combined with ‘intense physical therapy’, rather than physical therapy alone.

Published in The Lancet, the project – which studied 108 people across the UK and US who had ‘moderate to severe arm problems’ after strokes – tested either an ‘active’ or ‘sham’ VNS on participants.

Described by the University as being implanted ‘a bit like a cardiac pacemaker’, the device is said to stimulate ‘the vagus nerve on the left side of the neck’ during ‘intensive task-specific rehabilitation’. Stimulating the nerve in this way releases ‘neuromodulators’ or chemicals that help the brain ‘re-learn’ movements, when combined with the physical therapy.

Of those trialled during six weeks of out-patient therapy and 90 days of home based therapy, Glasgow reports that 47% of the people in the VNS group showed a ‘clinically meaningful response’, while only 24% from the control, or ‘sham’ VNS group did.

Jesse Dawson, principal investigator and Professor of Stroke Medicine at the University of Glasgow, said: “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, PhD, PT, Professor and Director of the Brain Recovery Lab at MGH Institute of Health Professions, and a senior investigator on the project, added: “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.”

The full study can be read online via The Lancet.