Dysfunctional attentional networks in children with attention deficit/hyperactivity disorder: evidence from an event-related functional magnetic resonance imaging study.
BACKGROUND
Although there is evidence for attentional dysfunction in children with attention deficit/hyperactivity disorder (ADHD), the neural basis of these deficits remains poorly understood.


METHODS
We used event-related functional magnetic resonance imaging (fMRI) to investigate brain activations related to three particular aspects of attention: alerting, reorienting, and executive control. Sixteen medication-naive boys with ADHD and 16 healthy boys, aged 8 to 12 years, were studied.


RESULTS
Behaviorally, children with ADHD showed a significant impairment only in their executive control system compared to healthy subjects. Neurally, children with ADHD (relative to controls) recruited deviant brain regions for all three attentional networks: less right-sided activation in the anterior cingulate gyrus during alerting, more fronto-striatal-insular activation during reorienting, and less fronto-striatal activation for executive control. ADHD symptom severity was associated with dysregulation of the blood oxygen level dependent (BOLD) signal within the putamen during reorienting and executive control.


CONCLUSIONS
Our results demonstrated altered brain mechanism in ADHD associated with all three attentional networks investigated. For alerting and executive attention, our data indicate a deviant mechanism of cortical control, while ADHD children may have adopted altered strategies for reorienting of attention. Our results also stress the etiological role of functional abnormalities in the putamen in medication-naive ADHD.
Konrad
Kerstin
K
Department of Child and Adolescent Psychiatry, University Hospital Aachen, Germany. kkonrad@ukaachen.de
Neufang
Susanne
S
Hanisch
Charlotte
C
Fink
Gereon R
GR
Herpertz-Dahlmann
Beate
B
D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000378:metabolism; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology; D003342:Corpus Striatum / Q000378:metabolism; D005071:Evoked Potentials / Q000502:physiology*; D005625:Frontal Lobe / Q000378:metabolism; D006179:Gyrus Cinguli / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011699:Putamen / Q000378:metabolism; D011930:Reaction Time / Q000502:physiology; D012720:Severity of Illness Index
D010100:Oxygen