Phd in CLINICAL EXPERIMENTAL NEUROSCIENCE AND PSYCHIATRY

Thesis title: FUNCTIONAL AND STRUCTURAL ALTERATIONS IN PEDIATRIC PATIENTS WITH TOURETTE AND OBSESSIVE-COMPULSIVE DISORDER

Tourette Syndrome (TS) is a neurodevelopmental disorder defined by multiple motor or phonic tics accompanied by several comorbidities predominantly Obsessive-compulsive disorder (OCD). Apart from the context of TS, OCD may manifest independently as a disorder characterized by recurrent intrusive thoughts (obsessions) and compulsions. TS and OCD particularly appear as two intertwined disorders since they not only both exhibit repetitive behaviors, whose characterization into complex tics and compulsions might be clinically challenging at times. Accordingly, patients manifesting TS with OCD may exhibit an intermediate clinical phenotype (TS+OCD) which is characterized by the overlapping pathophysiological features of both TS and OCD. Addressing this issue, our first study focused on using a data-driven approach to elucidate functional connectivity patterns in a cohort of drug-naïve children with TS, TS+OCD and OCD and age-matched controls. We revealed significant abnormalities in pre-defined resting state networks (RSNs), especially in the cerebellar network. The findings of our exploratory study provided us with the necessary framework to use a hypothesis driven approach for our follow-up study where we investigated and highlighted the alterations in cerebellar structural and functional connectivity in our drug-naïve children with TS and OCD.