Abstract
Objective:
Examination of cerebral cortical structure in children with AttentionโDeficit/Hyperactivity Disorder (ADHD) has thus far been principally limited to volume measures. In the current study, an automated surfaceโbased analysis technique was used to examine the ADHDโassociated differences in additional morphologic features of cerebral cortical gray matter structure, including surface area, thickness, and cortical folding.
Methods:
MPRAGE images were acquired from 21 children with ADHD (9 girls) and 35 typically developing controls (15 girls), aged 8โ12 years. Statistical difference maps were used to compare mean cortical thickness between groups along the cortical surface. Cortical volume, surface area, mean thickness, and cortical folding were measured within regions of interest, including the right/left hemispheres, frontal, temporal, parietal, and occipital lobes within each hemisphere, and subโlobar regions.
Results:
Children with ADHD showed a decrease in total cerebral volume and total cortical volume of over 7 and 8%, respectively; volume reduction was observed throughout the cortex, with significant reduction in all four lobes bilaterally. The ADHD group also showed a decrease in surface area of over 7% bilaterally, and a significant decrease in cortical folding bilaterally. No significant differences in cortical thickness were detected.
Conclusions:
Results from the present study reveal that ADHD is associated with decreased cortical volume, surface area, and folding throughout the cerebral cortex. The findings suggest that decreased cortical folding is a key morphologic feature associated with ADHD. This would be consistent with onset early in neural development and could help to identify neurodevelopmental mechanisms that contribute to ADHD. Hum Brain Mapp 2009. ยฉ 2007 WileyโLiss, Inc.