Edward Taub, PhD, a psychology professor at UAB, developed constraint-induced movement therapy (CI therapy) to help stroke survivors recover some function in affected limbs. With CI therapy, the therapist constrains the patient’s unaffected arm in a sling, forcing the patient to use the affected arm.
Neurologists have long known that CI therapy produces functional changes in the brains of stroke patients. Now Dr. Taub, graduate student Lynne Gauthier, and a group of collaborators have demonstrated that CI therapy also produces a structural change in the brain, affecting motor areas of the brain and the hippocampus, which is involved in learning and memory.
Changes can be seen “not only on the side that normally produces movement in the affected arm, but it recruits motor areas on the healthy side of the brain to participate in the production of movement on the stroke-affected side,” Taub said.
CI therapy produces better outcomes in children than in adults on a number of measures. The most important result is a large increase in spontaneous use of the more affected arm in normal daily activities. This goes from a before-treatment level of 15 percent, as compared to the less affected arm, to 71 percent after treatment.
Another improvement can be seen in tests of active range of motion, which examine standard types of movement at different joints. CI Therapy improves children’s active range of motion, while reducing spasticity and hypertonicity. Researchers have also seen improvement in adults, but to a lesser extent.
Much of Taub’s data comes from studies on children with cerebral palsy who were treated six hours a day for three weeks, but he and his colleagues with the CI Therapy Research Group at Children’s Hospital have recently found that treatment for three hours a day is just as effective.
“We started out six hours a day for three weeks, then we reduced that to three hours a day for three weeks, then three hours a day for two weeks,” he said. “That’s work in progress. We get just as good results with three hours for two weeks as we do three hours for three weeks, but the main test will be in retention. Does the extra week of therapy give the children better retention?”
Taub added, “There are other measures that are also better in children, which you would expect because it’s a more plastic nervous system. We know that plasticity is involved in the therapeutic effect that CI therapy produces, and therefore one might anticipate a larger effect on the brain in children. We seem to have that, but we’re just in the middle of that work. We can say that there is definitely an increase in the gray matter, but we would like to compare it to adults, and we can’t yet.”
Templates are available for MRI scans on adult brains, but none exist yet for children. The National Institutes of Health announced that a library of templates will be made accessible in December or January.
“That would be valuable to a lot of investigators because there are new computational techniques with what is called structural MRI, which is just regular MRI as opposed to what used to be thought of as the more fancy functional MRI,” Taub said. “We’re trying to solve the problem of determining how best to go about analyzing the children’s brains.”
At Children’s Hospital, a group of therapists led by Angi Griffin, M.S.O.T., works with children who have cerebral palsy due to stroke that occurred either prenatally or at birth.
“In a previous randomized control trial, we had worked with cerebral palsy of all different etiologies and gotten equally good results there,” Taub said. “We’ve also worked with several children with traumatic brain injury, and with brain resections as a result of tumors. Perhaps most interesting is that we’ve worked with two children with hemispherectomy. We’ve gotten results that are just as good as with our cerebral palsy children, which is a testimony to the remarkable plasticity of the immature nervous system because the child is improving very substantially in movement based on one half of the brain.”
He added, “That’s what makes doing research fun. I could have retired some time ago, but what could be more fun, more fascinating than working on problems like this?”
October 2007
