In the United States, someone has a stroke on average of every 40 seconds. Stroke is one of the leading causes of disability in the world, making it an important topic for scientific study. Researchers from the University of Texas at Dallas recently began testing vagus nerve stimulation (VNS) as a treatment for the rehabilitation of stroke victims. They found that high levels of neuroplasticity resulted from VNS paired with movement therapy in rats, which may result in better stroke rehabilitation for humans.

In vagus nerve stimulation, an electrical pulse is applied to the brain via the vagus nerve. Previous research has established that stimulating the vagus nerve releases the neurotransmitters acetylcholine and norepinephrine, which are known to promote learning and memory in the brain. It is also an FDA-approved treatment for depression and epilepsy.

The UT researchers designed a study to determine whether there would be changes in the brain’s primary motor cortex when VNS was paired with a specific movement. Rats that had experienced strokes such that their ability to pull a handle was impaired were divided into two groups: one to received physical training only, and one to receive physical training paired with VNS. After five days of treatment, the team analyzed the rats’ brains. They found that the rats that received VNS and targeted physical training showed significant evidence of neuroplasticity; there were major organizational changes in the rats’ movement control systems. There were no such changes in the rats who did not receive VNS.

Most human victims of stroke receive some form of physical therapy in conjunction with pharmaceutical treatments, but up to 70% of stroke patients still suffer from long-term impairments. This research suggests a faster, more effective method for treating movement impairments resulting from stroke.

“For years, the majority of stroke patients have received treatment with various drugs and/or physical rehabilitation. Medications can have widespread effects in the brain … In some cases the side effects outweigh the benefits. Through the use of VNS, we are able to use the brain’s natural way of changing its neural circuitry and provide specific and long lasting effects,” explained Dr. Navid Khodaparast, postdoctoral researcher at UT Dallas’ School of Behavioral and Brain Sciences and lead author of the study.

This study is published in the journal Cerebral Cortex.

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