Imaging Cognitive Motor Control in Tourette Syndrome

Grant Type
Grant Year
Institution Location
Institution Organization Name
Yale University
Investigators Name
Li, Chiang-shan Ray, MD, PhD

Tourette Syndrome (TS) has long been regarded as a disorder of involuntary movement. That is, the “tics” are thought to be the result of a deficit in motor response inhibition. On the other hand, many people with TS report a premonitory feeling or an “urge” to move prior to the generation of tics. This observation has led some investigators to liken TS to Obsessive Compulsive Disorder (OCD) and to propose a shared neural process between TS and OCD. The present study is designed to determine whether TS is caused by impaired motor response inhibition or is indeed an OC-spectrum disorder. By combining functional magnetic resonance imaging with a stops signal task, we propose to investigate the processes of cognitive motor control in people with TS. In previous studies we examined the neural processes of motor response inhibition and error processing during the stops signal task. These studies showed that a deficit of motor response inhibition manifested as diminished activation of the dorsomedial prefrontal cortical region of the brain, while error processing engaged a distinct neural circuit of the dorsal anterior cingulated and sub cortical brain regions. People with OCD showed heightened error-related responses. These results provide us with a unique platform to distinguish between the two hypotheses about how tics are generated. Thus, altered regional brain activation related to response inhibition would suggest a deficit related to motor control in TS patients; while heightened reactivity to response errors would suggest an etiological link between TS and OCD. Results from this study may have important treatment implications for patients with TS. Chiang-shan Ray Li, M.D., Ph.D., James Leckman, M.D. Yale University School of Medicine, New Haven, CT Award: $75,000 Commentary: Many individuals with TS also have OCD. It is not clear whether these two disorders result from a common alteration or whether they are caused by changes in different parts of the brain. In this grant, Drs. Li and Leckman will use a neuroimaging procedure to examine activity in specific regions of the brain in individuals with TS and OCD while they perform certain tasks. These studies could provide insight into how tics are generated and enlighten the community about treatment options. Tourette Association of America Inc. – Research Grant Award 2009-2010