Exploration of Glutamatergic System With PET Radiotracer in Gilles de la Tourette Patients: Pilot Study (GlutaTour)

Gilles de la Tourette syndrome is a neuropsychiatric disorder characterized by motor and vocal tics often associated with psychiatric comorbidities (obsessive compulsive disorder, anxiety and depressive syndrome, impulsivity). The pathophysiology of Gilles de la Tourette syndrome remains unclear. It would involve an alteration of striatal-cortico-thalamic cortical circuits resulting in dopaminergic dysfunction. But glutamatergic hypothesis is also discussed from pharmacological, biochemical and genetic arguments. Exploration of glutamatergic system can be done in humans in vivo using a new radiotracer: the [18F] FNM (Fluoroethylnormemantine), a derivative of memantine. In the present study, aim of the study 1) to show the glutamatergic system "in vivo" in patients with Tourette's syndrome and 2) to perform correlations between various motor and behavioral symptoms and the pattern of brain fixation for this radiotracer. To do that, a pilot study will be conducted in 12 patients with Tourette's who will be evaluated in terms of motor (tics) and behavioral (OCD, anxiety, depression, impulsivity) symptoms. Each patient will have a PET-scan exam and a brain MRI exam. Data analysis will be carried out from two different approaches: first by region of interest, and secondly, without topographic a priori with the Statistical Parametric Mapping (SPM) software.