RESULTS In ADHD patients the middle and inferior frontal gyri , basal ganglia , and cerebellum were most often affected by MPH .
The middle and inferior frontal gyri were frequently affected by MPH during inhibitory control tasks .
Throughout nine task-based fMRI studies investigating MPH 's effect on the brains of pediatric patients with ADHD , MPH result ed in increased activation within frontal lobes , basal ganglia , and cerebellum .
In most cases , this increase " normalized " activation of at least some brain areas to that seen in typically developing children
OBJECTIVE Attention-deficit/hyperactivity disorder ( ADHD ) is a psychiatric disorder affecting 5 % of children .
Methylpheni date ( MPH ) is a common medication for ADHD .
Studies examining MPH 's effect on pediatric ADHD patients ' brain function using functional magnetic resonance imaging ( fMRI ) have not been compiled .
The goals of this systematic review were to determine ( 1 ) which areas of the brain in pediatric ADHD patients are modulated by a single dose of MPH , ( 2 ) whether areas modulated by MPH differ by task type performed during fMRI data acquisition , and ( 3 ) whether changes in brain activation due to MPH relate to clinical improvements in ADHD-related symptoms .
Impulsiveness as a timing disturbance: neurocognitive abnormalities in attention-deficit hyperactivity disorder during temporal processes and normalization with methylphenidate
We argue that impulsiveness is characterized by compromised timing functions such as premature motor timing , decreased tolerance to delays , poor temporal foresight and steeper temporal discounting . A model illustration for the association between impulsiveness and timing deficits is the impulsiveness disorder of attention-deficit hyperactivity disorder ( ADHD ) . Children with ADHD have deficits in timing processes of several temporal domains and the neural substrates of these compromised timing functions are strikingly similar to the neuropathology of ADHD . We review our published and present novel functional magnetic resonance imaging data to demonstrate that ADHD children show dysfunctions in key timing regions of prefrontal , cingulate , striatal and cerebellar location during temporal processes of several time domains including time discrimination of milliseconds , motor timing to seconds and temporal discounting of longer time intervals . Given that impulsiveness , timing abnormalities and more specifically ADHD have been related to dopamine dysregulation , we tested for and demonstrated a normalization effect of all brain dysfunctions in ADHD children during time discrimination with the dopamine agonist and treatment of choice , methylpheni date . This review together with the new empirical findings demonstrates that neurocognitive dysfunctions in temporal processes are crucial to the impulsiveness disorder of ADHD and provides first evidence for normalization with a dopamine reuptake inhibitor
RESULTS In ADHD patients the middle and inferior frontal gyri , basal ganglia , and cerebellum were most often affected by MPH .
The middle and inferior frontal gyri were frequently affected by MPH during inhibitory control tasks .
Throughout nine task-based fMRI studies investigating MPH 's effect on the brains of pediatric patients with ADHD , MPH result ed in increased activation within frontal lobes , basal ganglia , and cerebellum .
In most cases , this increase " normalized " activation of at least some brain areas to that seen in typically developing children
OBJECTIVE Attention-deficit/hyperactivity disorder ( ADHD ) is a psychiatric disorder affecting 5 % of children .
Methylpheni date ( MPH ) is a common medication for ADHD .
Studies examining MPH 's effect on pediatric ADHD patients ' brain function using functional magnetic resonance imaging ( fMRI ) have not been compiled .
The goals of this systematic review were to determine ( 1 ) which areas of the brain in pediatric ADHD patients are modulated by a single dose of MPH , ( 2 ) whether areas modulated by MPH differ by task type performed during fMRI data acquisition , and ( 3 ) whether changes in brain activation due to MPH relate to clinical improvements in ADHD-related symptoms .