Pairing a physical therapy task aimed at improving the function of an upper limb in rodents along with vagus nerve stimulation (VNS) demonstrated a doubled long-term recovery rate relative to current therapy methods, suggest researchers from The University of Texas at Dallas.
The recovery rate was not only in the performance of the targeted task, but also in similar muscle movements that were not specifically rehabbed, the researchers add in their study, published recently in the journal Stroke.
“Our experiment was designed to ask this new question: After a stroke, do you have to rehabilitate every single action?” says Dr Michael Kilgard, associate director of the Texas Biomedical Device Center (TxBDC) and Margaret Forde Jonsson, professor of Neuroscience in the School of Behavioral and Brain Sciences.
“If VNS helps you, is it only helping with the exact motion or function you paired with stimulation? What we found was that it also improves similar motor skills as well, and that those results were sustained months beyond the completion of VNS-paired therapy.”
“This study tells us that if we use this approach on complicated motor skills, those improvements can filter down to improve simpler movements,” adds Kilgard, in a media release from University of Texas at Dallas.
The vagus nerve controls the parasympathetic nervous system, which oversees elements of many unconscious body functions, including digestion and circulation.
The UT Dallas study’s application of VNS strengthens the communication path to the neurons that are taking over for those damaged by stroke. The experiments showed a threefold-to-fivefold increase in engaged neurons when adding VNS to rehab, the release continues.
“We have long hypothesized that VNS is making new connections in the brain, but nothing was known for sure,” states Dr Seth Hays, the TxBDC director of preclinical research and assistant professor of bioengineering in the Erik Jonsson School of Engineering and Computer Science, part of the research team. “This is the first evidence that we are driving changes in the brain in animals after brain injury. It’s a big step forward in understanding how the therapy works–this reorganization that we predicted would underlie the benefits of VNS.”
The researchers are working on an at-home rehab system targeting the upper limbs, they note in the release.
“We’ve designed a tablet app outlining hand and arm tasks for patients to interact with, delivering VNS as needed,” Meyers shares. “We can very precisely assess their performance and monitor recovery remotely. This is all doable at home.”
[Source(s): University of Texas at Dallas, Science Daily]