Children with cerebral palsy who underwent constraint-induced movement therapy (CI therapy) saw a significant increase in grey matter volume in areas of the brain associated with movement, according to a new study from the University of Alabama at Birmingham (UAB).
UAB touted the findings, published online Monday in the journal Pediatrics, as he first to show that structural remodeling of the brain occurs during rehabilitation in a pediatric population.
“It is well understood that CI therapy produces a re-wiring of the brain, leading to functional improvement in motor skills in children and adults who have experienced a brain injury,” Edward Taub, the developer of CI therapy and a study co-author, said in a press release. “This study reinforces the idea that CI therapy also remodels the brain, producing a real, physical change in the brain.”
CI therapy forces the use of the affected side by restraining the unaffected side, according to the American Heart Association. With CI therapy, often used on stroke patients, the therapist constrains the survivor’s unaffected arm in a sling. The survivor then uses his or her affected arm repetitively and intensively for two weeks.
The UAB study examined 10 children with cerebral palsy, ages 2 to 7, who underwent a three- week course of CI therapy.
Changes in grey matter were assessed through voxel-based morphometry (VBM), performed on images acquired through magnetic resonance imaging. Grey matter consists mainly of neuronal cell bodies, glial cells and dendrites, according to UAB.
“We saw increases in grey matter volume in the sensorimotor cortices on both sides of the brain and in the hippocampus,” said Chelsey Sterling, a graduate student in medical psychology and first author of the study. “These increases were accompanied by large improvements in spontaneous arm use in the home environment. Notably, increases in grey matter correlated with improvement in motor activity.”
The correlation between increases in grey matter volume and magnitude of motor improvement raises the possibility of a causal relationship, according to Sterling.
The researchers believe that the observed increase in grey matter could be due to one or more different processes, including an increase in synaptic density, the creation of new neurons or glial cells or the establishment of new blood vessels within the brain.
“An increase in grey matter is indicative that the brain is capable of supporting increased motor activity and function,” said Gitendra Uswatte, a study co-author. “Along with the improvements observed in the dexterity and everyday use of the arm that was the target of rehabilitation, this is a strong indication that a child with cerebral palsy can have substantial gains in motor function when provided with the correct stimulation.”
VBM analysis was performed three weeks prior to therapy, at the beginning of therapy and at the end of the three-week therapy period. The authors saidthat no significant grey matter change was seen during the three weeks before treatment.
The children underwent intensive motor training for three hours each weekday for a three-week period in which the child’s less-affected arm was continuously restrained in a long-arm cast. Each child’s caregiver received a transfer package, which included steps to induce continuation of use of the more-affected arm at home. The MRI scans were performed at Children’s of Alabama.
Taub, a university professor in the Department of Psychology, developed the CI therapy techniques. The therapy has been shown to be effective in improving the rehabilitation of movement after stroke and other neurological injuries in both children and adults.
“The motor improvement and changes in grey matter following CI therapy observed in this study are similar to those observed previously in adults,” Taub said. “It is further evidence that the brain has a remarkable capacity to heal itself when presented with an efficacious rehabilitation intervention such as CI therapy.”
