Shifting-related brain magnetic activity in attention-deficit/hyperactivity disorder.
BACKGROUND
Current theories suggest a role for frontal-striatal circuits in the pathogenesis of attention-deficit/hyperactivity disorder (ADHD).


METHODS
We used magnetoencephalography (MEG) to measure event-related brain activity during a simplified version of the Wisconsin Card Sorting Test in children with DSM-IV combined type ADHD (ADHD-C) or predominantly inattentive type ADHD (ADHD-PI) and in age- and intelligence-matched control children.


RESULTS
In control children, set-shifting cues evoked a higher degree of activation in the medial temporal lobe (MTL) between 200 and 300 msec than non-shifting cues, with MTL activation predicting later activity in left anterior cingulate cortex (ACC) (at 400-500 msec). This MTL-ACC response pattern was diminished in children with ADHD. By contrast, children with ADHD showed early activity in regions barely activated in control children, such as left inferior parietal lobe and posterior superior temporal gyrus.


CONCLUSIONS
These preliminary data support theories of frontal dysfunction in ADHD but also suggest that deficits in higher-level functions might be secondary to disruptions in earlier limbic processes.
Mulas
Fernando
F
Valencian Institute of Pediatric Neurology, Valencia, Spain.
Capilla
Almudena
A
Fernández
Santiago
S
Etchepareborda
Máximo C
MC
Campo
Pablo
P
Maestú
Fernando
F
Fernández
Alberto
A
Castellanos
F Xavier
FX
Ortiz
Tomás
T
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology* / Q000523:psychology; D002540:Cerebral Cortex / Q000503:physiopathology; D002648:Child; D003463:Cues; D003627:Data Interpretation, Statistical; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology; D012044:Regression Analysis; D013702:Temporal Lobe / Q000503:physiopathology