Neural substrates of self-regulatory control in children and adults with Tourette syndrome.
OBJECTIVE
To identify the neural substrate of self-regulatory control in children and adults with Tourette syndrome (TS).


METHODS
We used event-related functional magnetic resonance imaging (fMRI) to study the neural correlates of cognitive self-regulation during the Simon task. Forty-two people from The Tic Disorder Specialty Clinic who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for diagnosis with TS (24 children; 18 adults) were compared with 37 control subjects (19 children; 18 adults). Patients with TS were excluded from participation if they had any Axis I psychiatric disorder other than obsessive-compulsive disorder (OCD) or attention-deficit hyperactivity disorder (ADHD) prior to the onset of TS. Control participants were excluded if they reported a history of tic disorder, OCD, ADHD, or if they met diagnostic criteria for any Axis I disorder at the time of interview.


RESULTS
We detected greater overall fMRI activation in adults than in children across both diagnostic groups, primarily in frontal and striatal regions. In both groups we also detected an age-related shift away from more general cortical activation toward a more specific reliance on frontostriatal activity, a developmental correlate that was exaggerated in the TS group despite behavioural performances similar to those of control subjects. Moreover, the severity of tics correlated positively with frontal activations across age groups.


CONCLUSIONS
Frontostriatal circuits support cognitive and behavioural control. These circuits likely contribute both to optimal performance in this self-regulatory task and to the regulation of the severity of tics. Adults with persistent TS likely possess deficient activity in these circuits, attributable to either a failure of prefrontal plasticity or to disturbances in striatal functioning.
Raz
Amir
A
McGill University, Sir Mortimer B Davis Jewish General Hospital, Institute of Community and Family Psychiatry, Montreal, Quebec. amir.raz@mcgill.ca
Zhu
Hongtu
H
Yu
Shan
S
Bansal
Ravi
R
Wang
Zhishun
Z
Alexander
Gerianne M
GM
Royal
Jason
J
Peterson
Bradley S
BS
D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology / Q000523:psychology; D001479:Basal Ganglia / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002648:Child; D015897:Comorbidity; D003342:Corpus Striatum / Q000503:physiopathology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006179:Gyrus Cinguli / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007266:Inhibition, Psychological; D007389:Internal-External Control; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000503:physiopathology / Q000523:psychology; D009949:Orientation / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D005879:Tourette Syndrome / Q000503:physiopathology* / Q000523:psychology; D055815:Young Adult