Objective The purpose of this study was to examine the regional cerebral blood-flow (CBF) difference between boys with pure ACHD and normal controls before and after methylphenidate treatment, and also we examined the association between rCBF changes ...
Objective The purpose of this study was to examine the regional cerebral blood-flow (CBF) difference between boys with pure ACHD and normal controls before and after methylphenidate treatment, and also we examined the association between rCBF changes and cognitive characteristics of boys with pure ADHD before and after methylphenidate treatment.
Methods The rCBF of 5 boys with pure AOHD and 5 control boys were examined by Tc-99m ECD brain SFECT and cognitive characteristics by ADS and every 5 ADHD boys took MPH for 12 to 16 weeks After that all ADHD boys took Tc-99m ECD brain SPECT and checked ADS again rCBF difference and changes before and after MPH treatment were quantified and analyzed by using SPM And associations between types of cognitive changes measured by ADS and rCBF changes were examined and quantitative associations between them were also analyzed by using Pearson's coefficient correlation.
Results 1) Before MPH treatment, rCBF of ADHD boys were significantly decreased in left orbitofrontal area and left caudate nucleus compared to normal controls 2) After MPH treatment. rCBF of the same regions were significantly increased. 3) There was positive correlation between the degree of commission error(impulsivity disinhibition) among the ADS variables and the degree of blood-flow decrease in above two areas before MPH treatment but after MPH treatment, only with the degree of rC3F increase in Lt orbitofrontal area.
Conclusion : These results suggest that the pathophysiology of impulsivity of disinhibition of the characteristic symploms of AOHD boys IS associated with hypoactivties of left orbibfrontal area and left caudate nucleus, and MPH pharmacodynamics in ADHD boys is associated to their actions on these two areas.