title: The neural correlates of tic inhibition in Gilles de la Tourette syndrome.
abstract: Tics in Gilles de la Tourette syndrome (GTS) resemble fragments of normal motor behaviour but appear in an intrusive, repetitive and context-inappropriate manner. Although tics can be voluntarily inhibited on demand, the neural correlates of this process remain unclear. 14 GTS adults without relevant comorbidities participated in this study. First, tic severity and voluntary tic inhibitory capacity were evaluated outside the scanner. Second, patients were examined with resting state functional magnetic resonance imaging (RS-fMRI) in two states, free ticcing and voluntary tic inhibition. Local synchronization of spontaneous fMRI-signal was analysed with regional homogeneity (ReHo) and differences between both states (free ticcing<tic inhibition) were contrasted. Clinical correlations of the resulting differential ReHo parameters between both states and clinical measures of tic frequency, voluntary tic inhibition and premonitory urges were also performed. ReHo of the left inferior frontal gyrus (IFG) was increased during voluntary tic inhibition compared to free ticcing. ReHo increases were positively correlated with participants׳ ability to inhibit their tics during scanning sessions but also outside the scanner. There was no correlation with ratings of premonitory urges. Voluntary tic inhibition is associated with increased ReHo of the left IFG. Premonitory urges are unrelated to this process.
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK; Department of Neurology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany; Department of Paediatric and Adult Movement Disorders and Neuropsychiatry, Institute of Neurogenetics, University of Lübeck, Lübeck, Germany. Electronic address: cganos@gmail.com.
authors.forename: Christos
authors.initials: C
authors.lastname: Ganos
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Kahl
authors.affiliation: Department of Paediatric and Adult Movement Disorders and Neuropsychiatry, Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.
authors.forename: Valerie
authors.initials: V
authors.lastname: Brandt
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.
authors.forename: Odette
authors.initials: O
authors.lastname: Schunke
authors.affiliation: Department of Paediatric and Adult Movement Disorders and Neuropsychiatry, Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Bäumer
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.
authors.forename: Götz
authors.initials: G
authors.lastname: Thomalla
authors.affiliation: Department of Child and Adolescent Psychiatry, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany.
authors.forename: Veit
authors.initials: V
authors.lastname: Roessner
authors.affiliation: Institute of Cognitive Neuroscience, University College London, UK.
authors.forename: Patrick
authors.initials: P
authors.lastname: Haggard
authors.affiliation: Department of Paediatric and Adult Movement Disorders and Neuropsychiatry, Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Münchau
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development, Lentzeallee 94, 14195 Berlin, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Kühn
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000503:physiopathology*; D020323:Tics / Q000503:physiopathology*; D005879:Tourette Syndrome / Q000503:physiopathology*; D055815:Young Adult
keywords: Gilles de la Tourette syndrome; Left inferior frontal gyrus; Resting state functional magnetic resonance imaging; Tic inhibition