Stimulation of a nerve during movement practice improves motor function

May 15, 2018

Arm and hand weakness is common following stroke and affects more than 50% of stroke patients. This condition can adversely affect one’s quality of life and daily living. The traditional approach to treatment is through the use of upper-limb exercises based on ‘repetitive task-specific practice’ (RTP). This practice helps the patient progress towards a specific treatment goal while promoting improvements in the stroke-affected areas of the brain. Used alone, RTP is effective, but here at Strokemark, we’re all about trying new things. And one of those new things is using transcutaneous auricular vagus nerve stimulation (taVNS) to support RTP.

 

Traditionally, vagus nerve stimulation hasn’t been the most pleasant experience. It uses a device that doctors implant directly into the nerve that controls a number of unconscious body processes. However, taVNS is different in that it stimulates the nerve via a noninvasive device placed in the ear. The nerve stimulation is the same, and the effect on stroke-affected areas appears to be the same. But, does it have a place in post-stroke recovery?

Testing out taVNS

In a pilot study, a team of researchers from the UK looked at taVNS in 13 patients who experienced a stroke more than three months before the study. Each patient got 18 one-hour sessions using the taVNS system. Over the course of each session, each patient completed at least 300 RTP-type arm movements. Of the 13 patients, only three reported minor side effects (one lightheadedness, two general tiredness). Overall, patients reported more significant improvements in the stroke-affected arm and hand compared with what could be expected with RTP alone. So while taVNS is still in its infancy, the studies suggest that it could be both well-tolerated and effective in patients with stroke.

Could taVNS take a leading role alongside conventional RTP in post-stroke arm and hand recovery? Researchers need to conduct further studies, but the results are certainly encouraging.

 

The lead author of this study is Jessica N. Redgrave, Sheffield Institute of Translational Neuroscience, Department of Neuroscience, University of Sheffield, Sheffield, United Kingdom.

Editorial note:

A therapy that was effective but unpleasant, now got a little easier while remaining effective.

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