UT Dallas Researchers Find Early Success in New Treatment for Stroke Recovery
Posted by: Ayesha Khan October 1, 2013
Stroke is a leading cause of death and disability across the world. However, with advanced and interventional medical care, the mortality and the morbidity of stroke can be fairly reduced. Researchers and scientists are initiating and implementing advanced treatment options to hasten stroke recovery. The latest research conducted by scientists at The University of Texas at Dallas is another step towards the promotion of optimal well-being in stroke patients.
The lead author of the study, and postdoctoral researcher at School of Behavioral and Brain Sciences, Dr. Navid Khodaparast, commented:
“Stroke is a leading cause of disability worldwide. Every 40 seconds, someone in the U.S. has a stroke. Our results mark a major step in the development of a possible treatment.”
Details of the study:
The research report, published in the scientific journal Neurobiology of Disease, discussed the outstanding pace of recovery observed in the forelimbs of animals that underwent vagus nerve stimulation. The FDA has approved nerve stimulation studies for the management of certain diseases and disorders; for example epilepsy and depression can be managed by Vagus Nerve Stimulation (VNS) that involve transmission of an electrical impulse via nerve to send information to brain regarding physical status of the body.
Khodaparast and his associates conducted extensive experimentation to stimulate the vagus nerve in rats that were incapable of pulling the handle as a result of previous stroke. He timed the VNS when the rats were in the rehabilitation phase and observed that vagus nerve stimulation leads to the release of chemicals like norepinephrine and acetylcholine in nervous tissue that are linked to higher cognitive functions, such as memory and learning. Khodaparast paired the rehabilitative training with nerve stimulation and observed remarkable recovery in rats.
According to Khodaparast, the aim of most rehabilitative activities is to improve the neuroplasticity (or ability of brain to change/ adapt) in order to achieve the lost function. However, only 30% stroke patients respond positively to rehabilitative interventions while 70% remain impaired for longer periods of time.
“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 and the effects can last for long periods of time. 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.”
Limitation of the study:
Khodaparast explained that the results of the research have limited potential, since animal subjects were mostly young and healthy, unlike elderly human subjects that are very often stricken with stroke. In addition, the overall pace of recovery in human subjects is also limited due to c-morbid medical conditions like hypertension and diabetes. However, the research team remains hopeful, since vagus nerve stimulation is a potentially effective tool in promoting rehabilitation in stroke patients.
Future developments and scope the study:
The research team at UT Dallas is planning to continue the experimental research in animal subjects who are chronically impaired. Khodaparast is hoping that the therapy and technique may somehow help stroke patients in future too. The partner company of this study, MicroTransponder Inc., is currently working at initiating a small clinical trial in humans at University of Glasgow in Scotland.
Senior author of the study and professor in neuroscience at UT Dallas, Dr. Michael Kilgard, commented:
“There is strong evidence that VNS can be used safely in stroke patients because of its extensive use in the treatment of other neurological conditions.”
Currently, Kilgard is also working on the interventional study to manage tinnitus (ringing in ears) with the help of vagus nerve stimulation. The study discussing the positive effects of vagus nerve stimulation in the promotion of brain adaptability was first published in the 2011 Nature paper featuring the work of Kilgard.
Other researchers from UT Dallas who also contributed in the study include Dr. Andrew Sloan and Dr. Seth Hays, postdoctoral fellows; Daniel Hulsey, graduate student; Andi Ruiz and Maritza Pantoja, undergrad student; and associate professor in neuroscience, Dr. Robert Rennaker II (who is also the director of the Texas Biomedical Device Center and head of the Department of Bioengineering)