title: The anarchic brain in action: the contribution of task-based fMRI studies to the understanding of Gilles de la Tourette syndrome.
abstract: OBJECTIVE
  Gilles de la Tourette syndrome (GTS) is a frequent neurological disorder characterized by the production of tics, and frequently associated with obsessive-compulsive disorder or attention-deficit hyperactivity disorder. The aim of this article is to summarize the contribution of imaging activation techniques to the study of the syndrome.
  
  
  RESULTS
  GTS has been studied with a variety of functional MRI (fMRI)/PET activation paradigms to characterize the origin of tics or their suppression, and how they compare physiologically with voluntary actions or response inhibitions. Current studies indicate overactivations of prefrontal and premotor cortices, including the supplementary motor area, and subcortical structures. Resting state functional connectivity studies complement activation studies in showing perturbed connectivity of cortico-subcortical networks. Several such findings correlate with the severity of the disease.
  
  
  CONCLUSIONS
  fMRI activation techniques are contributing a system-level neurophysiological description of GTS and bridge the gap between animal models and clinical observations. fMRI clarifies brain networks involved in different aspects of GTS phenomenology with some good clinical face validity. A future generation of fMRI studies should have higher ambitions and contribute, for example, to treatment optimization including the identification of ideal targets for deep brain stimulation in drug-resistant cases; however, such goals will be achieved only through controlled large-scale cooperative studies.
authors.affiliation: aPsychology Department, University of Milano-Bicocca bNeuroMi-Milan Center for Neuroscience, Milan, Italy cSobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK dTourette Center, IRCCS Galeazzi efMRI Unit, IRCCS Galeazzi, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Zapparoli
authors.forename: Mauro
authors.initials: M
authors.lastname: Porta
authors.forename: Eraldo
authors.initials: E
authors.lastname: Paulesu
mesh_terms: D059907:Functional Neuroimaging / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009415:Nerve Net / Q000503:physiopathology*; D005879:Tourette Syndrome / Q000503:physiopathology*