Paired VNS for upper limb function after stroke (IDE Study)
Research type
Research Study
Full title
A Randomized Pilot Study Assessing Vagus Nerve Stimulation (VNS) During Rehabilitation for Improved Upper Limb Function after Stroke (MicroTransponder’s Vivistim System)
IRAS ID
171693
Contact name
W Brent Tarver
Contact email
Sponsor organisation
MicroTransponder, Inc.
Clinicaltrials.gov Identifier
Duration of Study in the UK
1 years, 8 months, 31 days
Research summary
Research Summary
This study will be randomised and controlled with blinded endpoint assessment. There will be 10 to 15 participants per study group (total; only 3 to 5 per study group in the UK). We will include participants who have suffered an ischaemic stroke at least 6 months prior to enrolment and who have disability due to arm weakness. All subjects who complete baseline will be implanted with the Vivistim System. Participants will be randomised to two treatment groups; the first group will receive intensive rehabilitation therapy (control) and the second will receive vagal nerve stimulation (investigational treatment) during their intensive rehabilitation therapy . Vagal nerve stimulation (VNS) involves implantation of a device (similar to a cardiac pacemaker but that stimulates the vagus nerve in the neck rather than the heart). Stimulation of the vagus nerve may cause release of important chemicals in the brain which help the brain recover after stroke. The purpose of the study is to determine whether VNS is safe, tolerated and feasible after stroke and to gather preliminary evidence of efficacy. By this we mean does VNS during intensive rehabilitation therapy provide incremental benefit above and beyond the intensive rehabilitation therapy itself. Control subjects will receive VNS during rehabilitation after the randomized portion of the study.
Summary of Results
In this study, 17 people with long term arm weakness after a stroke were included. People were randomised to receive rehabilitation with Vagus nerve stimulation or rehabilitation with sham or dummy stimulation. A Vagus nerve stimulator is an electrical device a little bit like a cardiac pacemaker. It is inserted under general anaesthetic under the skin on the left side of the chest and a lead is then tunnelled under the skin to connect to the Vagus nerve on the left hand side. Experimental studies have suggested that stimulating the Vagus nerve causes the release of chemicals which should help bring recovery onto the surface of the brain. We wanted to explore whether stimulating the Vagus nerve during physiotherapy sessions leads to greater recovery of the arm compared to the physiotherapy alone.
In order to do this, all participants were implanted with the device but for the first 18 weeks of the study, the device was inactivated in half of the people. This was decided randomly and allowed us to compare in an unbiased fashion, whether the Vagus nerve stimulation had an effect. All the participants had six weeks of physiotherapy in the outpatient clinic and then delivered their own physiotherapy at home for a further 90 days. During the therapy sessions brief pulses of Vagus nerve stimulations were delivered. In the people who were allocated to the dummy or sham group, the device delivered a pretend stimulation. We measured their arm function at the start of the study, during and at the end of the study.
We found that at the end of treatment, 88% of people who received the Vagus nerve stimulation had a good response in their arm compared to 33% of people who received only the rehabilitation.
After the main part of the study was finished, the people who initially received the dummy stimulation were given a course of the active stimulation. This gave significant improvements similar to that seen in the people that had the Vagus nerve stimulation in the first place.
During the study one person had an infection following the device implantation which resolved with antibiotics. One person developed a vocal cord palsy, which casues a hoarse voice. This improved and is a well known side effect of Vagus nerve stimulator implants.
In summary, this small study provides promising data that Vagus nerve stimulation might improve outcomes during intensive rehabilitation therapy in people with long term arm problems after stroke. A large and definitive study is now required.REC name
West of Scotland REC 4
REC reference
15/WS/0022
Date of REC Opinion
26 Mar 2015
REC opinion
Further Information Favourable Opinion