title: Temporo-parietal dysfunction in Tourette syndrome: Insights from an fMRI study of Theory of Mind.
abstract: Tourette syndrome (TS) is a neurodevelopmental disorder characterized by tics, repetitive movements and vocalizations which are prompted by a sensory-cognitive premonitory urge. Complex tics include environmentally dependent social behaviors such as echoing of other people's speech and actions. Recent studies have suggested that adults with TS can show differences to controls in Theory of Mind (ToM): reasoning about mental states (e.g. beliefs, emotions). In this study, twenty-five adults with uncomplicated TS (no co-morbid disorders, moderate tic severity), and twenty-five healthy age and gender matched controls were scanned with fMRI during an established ToM task. Neural activity was contrasted across ToM trials involving reasoning about false-belief, and matched trials requiring judgments about physical states rather than mental states. Contrasting task conditions uncovered differential fMRI activation in TS during ToM involving the right temporo-parietal junction (TPJ), right amygdala and posterior cingulate. Further analysis revealed that activity within the right TPJ as localised by this task covaried with the severity of symptoms including echophenomena, impulse control problems and premonitory urges in TS. Amygdala activation was also linked to premonitory urges, while activity in the left TPJ during ToM was linked to ratings of non-obscene socially inappropriate symptoms. These findings indicate that patients with TS exhibit atypical functional activation within key neural substrates involved in ToM. More generally, our data could highlight an important role for TPJ dysfunction in driving compulsive behaviors.
authors.affiliation: Department of Neuropsychiatry, BSMHFT National Centre for Mental Health, Birmingham, UK; Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK. Electronic address: clare.eddy@bsmhft.nhs.uk.
authors.forename: Clare M
authors.initials: CM
authors.lastname: Eddy
authors.affiliation: Department of Neuropsychiatry, BSMHFT National Centre for Mental Health, Birmingham, UK; Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
authors.forename: Andrea E
authors.initials: AE
authors.lastname: Cavanna
authors.affiliation: Department of Neuropsychiatry, BSMHFT National Centre for Mental Health, Birmingham, UK; Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
authors.forename: Hugh E
authors.initials: HE
authors.lastname: Rickards
authors.affiliation: Birmingham University Imaging Centre and School of Psychology, College of Life and Environmental Sciences, University of Birmingham, UK.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Hansen
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000000981:diagnostic imaging*; D013702:Temporal Lobe / Q000000981:diagnostic imaging*; D056345:Theory of Mind / Q000502:physiology*; D005879:Tourette Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000523:psychology; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Compulsions; Social cognition; Temporo-parietal junction; Theory of mind; Tics; Tourette syndrome