This brain imaging study is designed to provide information as to where in the brain the symptoms of Tourette Syndrome (TS) arise. Until recently, imaging studies of brain functioning could be performed only with the use of radioactivity, which often precluded studies of brain function in children. Functional magnetic resonance imaging (fMRI) is a newly developed technology that can image brain functioning without the use of any radioactivity, and therefore with great safety. We have designed an fMRI study that can look at brain function in normal children and in children who have TS while they perform certain tasks. These tasks for the TS children include asking them to allow their tics to express freely, and then asking them to try to inhibit their tics while being scanned. Information from these scans can help us understand which regions of the brain are involved in generating and suppressing tic behaviors. In addition, both the TS and control groups will perform tasks designed to determine which regions of the brain generate and suppress spontaneous movements that are similar to tics. In this way we can assess whether the same brain regions are involved in performing those tasks as the regions that are involved in the generation and inhibition of tics. It is hoped that this information about the underlying causes of TS (its “neural substrate”) will help us devise improved treatments for the disorder.Also, it may be possible in the future to follow the brain functioning of children through time to better understand the causes of tic symptom progression and to learn more about how the medi¬cations used to treat TS produce their effects. Bradley S. Peterson, M.D. Yale School of Medicine New Haven, CT Award $25,000 Tourette Association of America Inc. – Research Grant Award 1996