A functional magnetic resonance imaging study of tic suppression in Tourette syndrome.
BACKGROUND
The inability to inhibit unwanted behaviors and impulses produces functional debility in a broad range of neuropsychiatric disorders. A potentially important model of impulse control is volitional tic suppression in Tourette syndrome.


METHODS
Tic suppression was studied in 22 adult subjects with Tourette syndrome by using functional magnetic resonance imaging. Images acquired during periods of voluntary tic suppression were compared with images acquired when subjects allowed the spontaneous expression of their tics. The magnitudes of signal change in the images were then correlated with measures of the severity of tic symptoms.


CONCLUSIONS
Significant changes in signal intensity were seen in the basal ganglia and thalamus and in anatomically connected cortical regions believed to subserve attention-demanding tasks. The magnitudes of regional signal change in the basal ganglia and thalamus correlated inversely with the severity of tic symptoms. These findings suggest that the pathogenesis of tics involves an impaired modulation of neuronal activity in subcortical neural circuits.
Peterson
B S
BS
Yale Child Study Center, the Yale University School of Medicine, New Haven, Conn 06520, USA. bradley.peterson@yale.edu
Skudlarski
P
P
Anderson
A W
AW
Zhang
H
H
Gatenby
J C
JC
Lacadie
C M
CM
Leckman
J F
JF
Gore
J C
JC
D000293:Adolescent; D000328:Adult; D001479:Basal Ganglia / Q000033:anatomy & histology; D001921:Brain / Q000033:anatomy & histology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000175:diagnosis; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D012720:Severity of Illness Index; D012737:Sex Factors; D005879:Tourette Syndrome / Q000175:diagnosis* / Q000523:psychology*; D014836:Volition