Neuromodulation for Tourette syndrome: Current Techniques and Future Perspectives

Gilles de la Tourette syndrome (TS) is a chronic tic disorder characterized by both motor and vocal tics, with onset in childhood. Neuropsychiatric symptoms are nearly universal in TS, including attention deficit hyperactivity disorder (ADHD), obsessive compulsive disorders, and anxiety disorders. TS can have substantial effects on quality of life, social and intellectual development, opportunities, relationships and more. There are limited treatment options for TS, such as behavioral therapy or pharmacological interventions, often with unsatisfactory benefit. Neuromodulation has been established as a viable treatment strategy for specific aspects of TS through modulation of neural pathways and networks. Several neuromodulation techniques have been utilized for TS, with deep brain stimulation (DBS) exhibiting the strongest efficacy. The invasive nature of DBS remains a disincentive for its uptake, in conjunction with the fact that tics often reduce in severity in early adulthood. Less invasive neuromodulation approaches have also been explored, but their efficacy remains limited. However, given its efficacy in TS, DBS provides the unique opportunity to record neural activity from deep brain structures, which has been used to investigate pathophysiology and to search for biomarkers of treatment response. This may guide strategies for less invasive neuromodulation therapies. To maximize progress in the field, we suggest several strategies: multicenter data sharing is crucial due to the small number of people treated at single centers, utilization of recording capabilities on recent DBS devices, correlation with the precise location of the implanted electrodes, and the use of pre-clinical studies to better understand the mechanisms of successful neuromodulation for TS.