Disruption of Tic Expression Using Closed Loop Deep Brain Stimulation

Grant Type
Grant Year
Institution Location
Institution Organization Name
Bar-Ilan University Israel
Investigators Name
Bar-Gad, Izhar, PhD

Our current TSA-funded project is focused on shedding light on the involvement of the cortico-basal ganglia (CBG) loop in the neurophysiological basis of Tourette syndrome (TS) and the application of Deep Brain Stimulation (DBS) for reducing the symptoms of TS. In this study we are using a model of TS: injection of bicuculline (a GABA antagonist), into the dorsolateral putamen which leads to the formation of motor tics. Simultaneous multi-electrode recordings are performed in different brain structures along the CBG loop to unravel the mechanism of the transformation between the tonic disinhibition of the putamen and the phasic expression of the tics and its interaction with normal movement. Quantification of the behavior and movement parameters in conjunction with their neuronal manifestation enables us to test correlative and causal relations between the factors and the concurrent encoding of normal and abnormal movement. DBS which is a widely adopted treatment for multiple disorders associated with the CBG loop has been successfully used to treat severe cases of TS. In our current project we utilize our existing results regarding tic encoding along the CBG loop to define improved DBS protocols. We use the neurophysiological recording concurrently with stimulation in the output nucleus of the basal ganglia, the globus pallidus internus, to test for changes in the tic expression. Thus, the project combines a scientific goal of understanding the neurophysiological changes underlying tic formation with the clinical goal of providing the basis for stimulation-based treatments aimed at reducing these tics. Izhar Bar-Gad, Ph.D. Bar Ilan University, Ramat Gan, Israel Award: $75,000 Commentary: In a previous TSA-funded project this investigator studied the changes in nerve cell activity that occur in a specific brain pathway (the cortico-basal ganglia loop), in people with Tourette syndrome (TS). In this study, nerve cell activity and its relation to both normal movement and abnormal movement (tics) will be quantified and used to determine Deep Brain Stimulation (DBS) parameters. This will enable clinicians to improve DBS treatments used for severe cases of TS. Tourette Association of America Inc. – Research Grant Award 2011-2012