title: Cerebellar morphology in Tourette syndrome and obsessive-compulsive disorder.
abstract: OBJECTIVE
  Neuroanatomical and functional imaging studies have identified the cerebellum as an integral component of motor and language control. Few studies, however, have investigated the role of the cerebellum in Tourette syndrome (TS), a condition defined by the presence of semi-involuntary movements and sounds.
  
  
  METHODS
  Magnetic resonance imaging was conducted in 163 persons with TS and 147 control participants. Multivariate linear regression models were used to explore effects on cerebellar surface morphology and underlying volumes for the main diagnosis effects of TS as well as comorbid obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder. Additionally, the correlations of symptom severity with cerebellar morphology were also assessed.
  
  
  RESULTS
  The TS group demonstrated reduced volumes of the cerebellar hemispheres bilaterally that derived primarily from reduced gray matter in crus I and lobules VI, VIIB, and VIIIA. These decreased regional volumes accompanied increasing tic symptom severity and motoric disinhibition as demonstrated by a finger tapping test. Males had reduced volumes of these same regions compared with females, irrespective of diagnosis. Comorbid OCD was associated with relative enlargement of these regions in proportion to the increasing severity of OCD symptoms.
  
  
  CONCLUSIONS
  The cerebellum is involved in the pathogenesis of TS and tic-related OCD. Baseline gender differences in cerebellar morphology may in part account for the more prevalent expression of TS in males.
authors.affiliation: Columbia College of Physicians and Surgeons, New York State Psychiatric Institute, New York, NY 10032, USA.
authors.forename: Russell H
authors.initials: RH
authors.lastname: Tobe
authors.forename: Ravi
authors.initials: R
authors.lastname: Bansal
authors.forename: Dongrong
authors.initials: D
authors.lastname: Xu
authors.forename: Xuejun
authors.initials: X
authors.lastname: Hao
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Juan
authors.initials: J
authors.lastname: Sanchez
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Peterson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping; D002531:Cerebellum / Q000473:pathology*; D002648:Child; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000473:pathology*; D012720:Severity of Illness Index; D013223:Statistics as Topic; D005879:Tourette Syndrome / Q000473:pathology*; D055815:Young Adult