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MORE THAN 40 chronic stroke patients have now taken part in a unique study of whether training with robot-assisted virtual reality can improve paralyzed hand and arm functions by rewiring their brains. Could playing songs on the keyboard of a virtual piano, hammering down imaginary pegs, catching birds on a computer screen to place in a birdbath, or destroying objects in a fake outer space alter the landscape of a damaged brain? And would it work as well as dose-matched, repetitive practice of a task performed as a more conventional therapy, which calls for hours of grueling, one-on-one physical therapy?
The answer to these two questions is: Yes. As it turns out, in this kind of neuro-biological situation, hard work doesn't always pay better. "Of course, the virtual reality (VR) therapy is more fun," explains Principal Investigator Alma Merians, PT, PhD, SHRP chair and professor, Department of Rehabilitation and Movement Sciences, "but the real issue is the intensity. We were able to deliver the intensity of lots of movement in a non-grueling way. In a clinical physical therapy intervention, someone might do 300 repetitions of a movement or exercise. But even that happens only rarely." Patients can usually complete just 85 repetitions of an exercise for about an hour per day. Meanwhile, "In VR, we can have people do 2,000 repetitions and they never even know or feel it because they are just busy playing a game."
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Merians is part of a collaborative team of researchers from both the UMDNJ-School of Health Related Professions (SHRP) Laboratory for Movement Neuroscience and the New Jersey Institute of Technology's (NJIT) Laboratory for Movement Rehabilitation. "There is a great deal of overlap and cross-talk between the teams at UMDNJ and NJIT. We submit joint publications and grant applications regularly, serve on the committees of each other's students, and meet several times a week formally and informally," explains Eugene Tunik, PT, PhD, a principal investigator as well as an SHRP assistant professor of rehabilitation and movement science. (See box: "Who's Who on the VR Team?")
These engineers, neuroscientists and physical therapists are still analyzing data and seeking more stroke survivors to participate in their study but as the results of this phase of the clinical trial become clearer, the team is amazed by how much their data supports the efficacy of VR. Tunik says, "Though virtual reality training is new, at the very least, we see that it can give you comparable results to conventional therapy. Additionally, it may have certain advantages, such as having a tremendous entertainment and motivational component to engage the patient, as well as the ability to provide calculated assistance or resistance to movements and sophisticated visual feedback." Merians adds, "The interesting part is that we are finding therapeutically subtle and positive differences in the way the brain changes neuro-biologically with VR therapy."
Participants come to UMDNJ first to have their brains scanned for a pre-training baseline picture and then head to NJIT to spend three hours, five days a week in their lab performing personalized hand and arm exercises while doing enjoyable virtual reality tasks in gaming simulations on a computer. The game library, designed "inhouse," as Tunik explains, has 13 options to suit each patient's interest, level and type of impairment. Playing is straightforward. Yet, "Every action is grounded in neuroscience with robot-controlled algorithms," Tunik says.
Inside the brain, "We know that we can increase blood flow to very specific areas that have not been working properly," Tunik continues, especially in patients where the damage is confined to a narrow or specific part that controls motor function. In some VR simulations, the participant sits at a computer using his or her good hand to play. On the screen, however, the image is rigged to make it look like the limb corresponding to the paralyzed hand is doing the work. By doing so, the brain is tricked into believing the motionless limb is moving. "We activate the motor centers that would be controlling that bad hand or arm," Tunik says. "This is really a robust platform to make changes in the brain and behavior."
Meanwhile, Hamid Bagce, an MD-PhD student at UMDNJ-NJMS and GSBS-Newark, and other students, have been using functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) to understand the effects of the VR training on neural reorganization in the participants' brains. They test the players' brains before they start training and after two weeks of training, as well as a few months later. Bagce explains, "The VR is producing changes that are more consistent than what we see in the control group's patients who are receiving dose-matched repetitive task practice without VR. While both groups are showing expansion of brain activity indicating that multiple areas of the brain are communicating, the VR participants are exhibiting more neural interaction and connectivity even four months after completing the training." Bagce says that it makes him think of studying in med school. "Two students can learn something and both get the same grade on a test but will one of them do better later on when they have to take the boards because they have learned it a different way?" He's predicting that the VR group will get the better grade.
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A next step for the research is to
look at all this brain re-mapping and
match therapy to individual patients. "For
example," Bagce says, "someone with a
lesion in their motor-cortex area might
respond better or worse to VR than someone
with a stroke in their sub-cortical
area." And Tunik agrees, "Our Holy Grail is
to be able to say to a stroke patient,
‘Here are your deficits, your functions and
your brain lesion. Based on this evidence,
we suggest a particular therapy.'"
— Maryann Brinley