Timing of Voluntary Movement in Patients With Tourette Syndrome and Chronic Tic Disorder

This study will examine how the brain controls movement in people with Tourette syndrome and chronic tic disorder to determine if the timing of movement is important in whether someone feels "in control" of their movements. Although movements in tic disorders are often characterized as "involuntary," some patients claim that these movements are made voluntarily, or they are unable to decide if they are voluntary or involuntary. Previous experiments have shown that when people are asked to look at a clock and report the time they first decide to make a movement they report times later than the first brain waves associated with movement appear. When they are asked to report the time they first initiate the movement, they report times before the muscles actually begin to move. This study may help determine how the sense of willing and initiating an action is altered in patients with Tourette syndrome and chronic tic disorder, and how people may feel more or less "in control" of their movements. Normal volunteers and patients with Tourette syndrome or chronic tic disorder between 18 and 65 years of age may be eligible for this study. Control subjects must not have any neurological or psychological disorders, and patients with Tourette syndrome of chronic tic disorder must not have any other neurological disorders. Patients with attention deficit hyperactivity disorder (ADHD) may not enroll in this study. All participants will have a medical history, physical examination, and a test to determine their level of attention. Patients will be interviewed about their symptoms and complete psychiatric rating scales. In addition, all participants will undergo the following procedures: Electric shock Participants look at a clock on a computer screen, the hands of which revolves quickly. While looking at the clock, each participant will be given small, non-painful electric shocks and asked, according to the clock, to say when they received the shocks. The shocks are repeated 4