Cerebellar morphology in Tourette syndrome and obsessive-compulsive disorder.
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.
Tobe
Russell H
RH
Columbia College of Physicians and Surgeons, New York State Psychiatric Institute, New York, NY 10032, USA.
Bansal
Ravi
R
Xu
Dongrong
D
Hao
Xuejun
X
Liu
Jun
J
Sanchez
Juan
J
Peterson
Bradley S
BS
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