EMBARGOED FOR RELEASE UNTIL 4 PM ET, July 23, 2001

Study Ties Stuttering to Anatomical Differences in the Brain

St. Paul, Minn. -

Stuttering has been long thought to be caused by emotional factors, but researchers who studied adults with persistent stuttering found that these individuals had anatomical irregularities in the areas of the brain that control language and speech. The study results, reported in the July 24 issue of Neurology, the scientific journal of the American Academy of Neurology, provide the first evidence that anatomic abnormalities within the areas of the brain that control speech and language puts an individual at risk for the development of stuttering. Using MRI scans to measure the brains of 16 persistent developmental stuttering (PDS) patients and 16 controls, the right and left temporal lobe were found to be significantly larger in the adults with PDS, according to neurologist and study author Anne Foundas, MD, at Tulane University in New Orleans, LA. In addition, irregularities in the shape of the brain were much more prevalent among the patients with PDS than among the control group that was studied. The study group included 12 right-handers (nine men and three women), and four left-handed men, which approximates the distribution of those reported in population studies of those who stutter. Besides attempting to determine a correlation between the shape and size of brain features and stuttering, the study sought to determine whether sex and writing hand preference influenced PDS. "Our data indicated that sex and writing hand seemed to be related to some anatomic features. For example, the Pars Triangularis was significantly larger in left than right-handers, and the Pars Triangularis and Pars Opercularis [adjacent portions of the frontal lobe] was larger in men than women," according to Foundas. The study was supported by grants from the National Institute of Health, Tulane-LSU General Clinical Research Center and the Department of Veterans Affairs South Central Mental Illness Research, Education, Clinical Center.

The American Academy of Neurology is the leading voice in brain health. As the world’s largest association of neurologists and neuroscience professionals with more than 44,000 members, the AAN provides access to the latest news, science and research affecting neurology for patients, caregivers, physicians and professionals alike. The AAN’s mission is to enhance member career fulfillment and promote brain health for all. A neurologist is a doctor who specializes in the diagnosis, care and treatment of brain, spinal cord and nervous system diseases such as Alzheimer's disease, stroke, concussion, epilepsy, Parkinson's disease, multiple sclerosis, headache and migraine.

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