(Inside MossRehab Spring 2014) - For those patients with hemiparesis following stroke, hope may come from a novel therapy being investigated at MossRehab that uses mirrors to help increase recruitment of the contralesional brain hemisphere.
Mirror therapy works by creating a visual illusion to potentially strengthen arms or hands. Patients sit with a mirror perpendicular to their body, reflecting the healthy limb and blocking the view of the affected one. When the patient looks into the mirror, the brain is tricked into thinking it sees both limbs as healthy. When the uninjured arm or hand is moved, the brain tries to stimulate the injured side to move as well.
“It’s amazing that simply giving illusory visual feedback to stroke survivors can make them move better,” says Steven Jax, PhD, a Moss Rehabilitation Research Institute (MRRI) scientist who runs the mirror therapy clinical trials and is an expert in motor learning after stroke. “It’s remarkably low-tech and effective.”
According to Jax, mirror therapy not only helps strengthen the arms and hands of people with stroke, but is also especially helpful for people who have arm or hand pain in addition to problems making movements. Jax is currently furthering his research in mirror therapy with a clinical trial of 100 chronic stroke patients who are following a home-based mirror therapy regimen.
“Because this therapy is so simple, it’s possible for almost every stroke survivor with movement problems to be able to use it at home. That’s one of the most exciting parts of the project—training people to give themselves mirror therapy," Jax says.
Providing evidence that mirror therapy could be administered at home would have strong implications for the cost of treating hemiparesis, especially relative to alternative treatments that require significant amounts of therapist time (constraint-induced movement therapy) or expensive equipment (robotic training). Pilot data suggest that home-based mirror therapy could lead to clinically significant improvements in functioning.
The trial is also investigating why some patients benefit from mirror therapy and others do not, even though significant individual differences have been reported.
“What’s desperately needed in rehabilitation is data that helps clinicians select the right therapy for the individual patient,” says John Whyte, MD, PhD, director of the MRRI. “For that purpose, we need to see who the patients are that have the greatest benefit, who has very little benefit, and identify patient characteristics that can predict this in advance so we don’t have to wait for one therapy to fail and then pick another by trial and error."
Jax’s study is important because it is with a large sample size, offering the potential to illustrate variations in treatment benefit.
“He has identified a number of hypotheses about what might account for greater and lesser benefit and has enough subjects and is collecting the right kinds of clinical and imaging data to test these subgroup hypotheses,” concludes Dr. Whyte.