"This is preliminary research and it should continue to see how therapy does reorganize the brain," she added. "This is an important step in building the [body] of information that shows therapy really does bring change."
Functional MRI brain scans were used to measure the thickness of participants' cerebral cortex at the beginning and end of the study and also to measure interactions between brain areas while at rest. Compared to controls, those who stuttered had reduced thickness and strength of interactions in the pars opercularis, an area important in speech and language production. They also had stronger interactions in the cerebellum compared to the controls.
For those receiving speech therapy, the cerebellum's circuitry and connectivity were reduced to the same level as that of the control group who didn't stutter, suggesting that cerebellum changes are a result of the brain compensating for stuttering, Lu said.
"Our findings also showed that the human brain is highly plastic," she said. Given the appropriate therapy, she said, "the brain will be able to reorganize itself and help to reduce stuttering."
More research is needed, Lu and Grossman agreed, including long-term follow-up to clarify the effect of this and other speech therapies on stutterers.
The U.S. National Library of Medicine offers more information about stuttering.
SOURCES: Chunming Lu, Ph.D., assistant professor, cognitive neuroscience, Beijing Normal University, China; Heather Grossman, Ph.D., clinical director, American Institute for Stuttering, New York City; Aug. 8, 2012, Neurology, online
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