Findings of a new study show that areas outside those damaged by a stroke can take over their functions.
Findings from the world’s largest study to use neuroimaging of stroke patients will “substantially change the treatment of chronic stroke patients,” according to the study author, Julius Fridriksson, director Aphasia Laboratory, and associate professor, Department of Communication Sciences and Disorders, Arnold School of Public Health, University of South Carolina, who found that brain cells that are outside of the area of the brain damaged by a stroke can take on new roles, allowing patients to regain an ability to communicate.
"For years, we heard little about stroke recovery because it was believed that very little could be done," Fridriksson said. "But this study shows that the adult brain is quite capable of changing, and we are able to see those images now.”
For the study, 26 patients with aphasia were included, as roughly 35% of stroke patients experience speech and/or communication issues. "When someone has brain damage as a result of a stroke, the recovery is expected to be limited," noted Fridriksson. Indeed, is has long been believed that any recovery in language function for patients with aphasia is limited to the days and weeks after a stroke.
However, the current study—in which participants underwent fMRI multiple times before and after 30 hours of traditional speech therapy—showed that recovery in the brain can allow for a patient’s communication abilities to improve in the longer-term. Use of fMRI allowed Fridriksson to identify healthy areas of he brain that “take over” the functions of the areas damaged by a stroke.
"The areas that are immediately around the section of the brain that was damaged become more 'plastic,' " Fridriksson said. "This 'plasticity,' so to speak, increases around the brain lesions and supports recovery. In patients who responded well with the treatment for anomia [difficulty in recalling words and names], their fMRI showed evidence that areas of the brain took over the function of the damaged cells." Improved recovery was not seen in patients who didn’t experience these changes.
"Knowing where the brain has been damaged -- and the section that is taking over that function -- will enable us to better use electrical stimulation to promote recovery," said Fridriksson. "It is believed that electrical currents to the brain will promote secretions of neurotransmitters that support brain plasticity," he said. "This could dramatically improve the quality of life for stroke patients."