Functional MRI studies in children with attention deficit hyperactivity disorder

Objective: To investigate the brain activation map during Go-NoGo tasks in children with attention deficit hyperactivity disorder (ADHD) and matched controls using functional MRI. Methods: Block designed BOLD functional MRI scan covering the whole brain was performed on 10 boys having ADHD and 11 healthy boys. The 2 groups were matched by age, sex, and handedness. Executing advanced inhibitory Go-NoGo tasks served as stimuli for all subjects. The fMRI data was analyzed by SPM99 (Statistical Parametric Mapping) software with statistic t-test to generate the activation map. Results: (1) The normal children showed significant activations in left thalamus and right cingulate gyrus and fewer activations in right middle frontal gyrus during stimulate controlled Go task, but the children with ADHD showed less activations in left thalamus. (2) In response controlled Go task, the normal children showed activations in right insula, cingulate gyrus and left frontal gyrus, while the ADHD children showed lower power of response in the right middle frontal gyrus.(3) In NoGo task, right middle frontal gyrus was the dominant activated regions, and left anterior cingulate, left middle frontal gyrus and right thalamus also had some activations in normal children, while the activations of right prefrontal decreased and the thalamus increased in ADHD boys. Conclusion: In children with ADHD, some dysfunctional brain areas, mainly the prefrontal lobe and anterior cingulate gyrus were found. Thalamus was also involved according to the brain activation map