Objective: A voxel based investigation of cerebral blood flow was conducted to identify brain function differences in the resting state between children with Attention Deficit Hyperactivity Disorder (ADHD) and normal controls.
Method: Using DSM-IV criteria, we selected 40 children with pure ADHD by various assessment scales, psychometric tools and a neuropsychological battery. All patients were examined by (99m)Tc-HMPAO brain SPECT. Seventeen normal controls were recruited from age, sex, and IQ-matched children whose previous SPECT, MRI, EEG and psychometric and neuropsychological findings had been normal. Using SPM methods, we compared SPECT images of ADHD patients and those of 17 control subjects on a voxel by voxel basis using t-statistics. Voxels with a p-value of less than 0.01 were considered to be significantly different.
Result: Decreased cerebral blood flow in right lateral prefrontal cortex, right middle temporal cortex, both orbital prefrontal cortex and both cerebellar cortices were found in children with ADHD compared to the controls. In addition, the ADHD group showed increased blood flow in some parietal and occipital lobes (posterior brain regions) compared to the control group.
Conclusion: Although the results should be interpreted cautiously, this study confirms the presence of functional defects in the prefrontal cortex and reports new problems in the limbic area, somatosensory areas and in the cerebellum during the resting state of brains of ADHD children.