Increased Midbrain Gray Matter Seen With Tourette's Syndrome


Reuters Health Information 2006. ? 2006 Reuters Ltd.

NEW YORK (Reuters Health) Mar 15 -

Increased gray matter, primarily in the left mesencephalon, is seen in patients with Tourette's syndrome, a finding that directly supports a theory of the disease proposed more than 20 years ago, new research shows.
In 1983, neurologist Dr. Orrin Devinsky proposed that midbrain disturbances play a key pathogenic role in Tourette's syndrome. Since then, there has been little direct evidence to support his theory.
Dr. Mark Hallett, from the National Institutes of Health in Bethesda, Maryland, and colleagues tested Devinsky's hypothesis using voxel-based morphometric analysis of high-resolution MRIs, a novel approach in this setting. The focus was on whether the gray matter volumes of 31 Tourette's syndrome patients differed from those of 31 healthy controls.
A significant increase in left midbrain gray matter volume was seen in Tourette's syndrome patients compared with controls, the researchers report in the February issue of the Annals of Neurology. Otherwise, no significant differences in brain structure were noted between the groups.
"This study is the first to our knowledge to demonstrate that there are robust disturbances in midbrain gray matter when Tourette's syndrome patients are compared with controls," the authors state. Still, these study patients represent just a small subset of the Tourette's syndrome population and further studies are needed to confirm this finding in other Tourette's syndrome groups, such as children and adults who are asymptomatic.
Ann Neurol 2006;59:381-385.