of Kristine Swierkosz Kristjansen's thesis

Tourette syndrome (TS) is neurodevelopmental disorder diagnosed solely on the presence of multiple motoric and at least one vocal tic. Neurally, TS has been associated with an imbalance in the fronto-striatal circuits, resulting in the tics. The heterogeneous nature and the clinical course of TS have led to theories rejecting an understanding of TS as a unitary disorder. Instead, the focus has switched to a spectrum disorder approach or to an understanding of TS as consisting of several subtypes. These approaches, combined with the proposed brain alterations associated with TS, is the motivation for the present project that aimed to investigate TS as more than “just” a matter of tics. We focused on the cognitive abilities and comorbidity also associated with dysfunction of the fronto-striatal circuits to reveal potential subtypes of TS. This study collected data on cognitive abilities, tic severity and several comorbid symptoms in a large well-defined cohort of 199 participants diagnosed with TS, and 51 controls. An overall conclusion for the sub-studies in the project yield that besides tics, cognitive abilities, comorbidity and age play important roles in revealing potential underlying subtypes in TS.