November 6, 2015 – A new Georgetown University Medical Center (GUMC) study has found that the right side of the brain can take on speech duties when a stroke damages that function on the left side.
The journal Brain today published the study, the first to look at brain structure and gray matter volume in stroke-related speech recovery, and is contradictory to what many neurologists have debated for more than a century.
“Over the past decade, researchers have increasingly suggested that the right hemisphere interferes with good recovery of language after left hemisphere strokes,” explains Dr. Peter Turkeltaub, assistant professor of neurology at GUMC. “Our results suggest the opposite – that right hemisphere compensation improves recovery.”
More Gray Matter
Turkeltaub and his colleagues show in the study that patients who have regained their voice have more gray matter volume in the back of their brains’ right hemispheres compared with those who have not experienced a stroke.
“Our study indicates growth in these brain areas that relates to better speech production after a stroke,” says Turkeltaub who also directs the aphasia clinic at MedStar National Rehabilitation Network (NRH).
And while not likely to end the debate, the new information suggests a new direction in treatment.
Approximately one-third of stroke survivors lose speech and language — a disorder called aphasia.
Most never fully regain their ability to speak.
Turkeltaub says loss of speech occurs in roughly 70 percent of people with left hemisphere strokes have language problems.
“We found that patients who had better than expected speech abilities after their stroke had more gray matter in the back of the right hemisphere compared to stroke patients with worse speech,” the professor explains. “Those areas of the right hemisphere were also larger in the stroke survivors than in the control group.”
Turkeltaub, a member of the Center for Brain Plasticity and Recovery at Georgetown and MedStar NRH, and his colleagues are continuing their study, looking for areas that compensate for other aspects of language use, such as comprehension of speech.
The National Center for Advancing Translational Sciences via the Georgetown-Howard Universities Center for Clinical and Translational Science (KL2TR000102), the Doris Duke Charitable Foundation (2012062), and other entities supported this research.