Right parietal dysfunction in children with attention deficit hyperactivity disorder, combined type: a functional MRI...

Area of Science:

• Neuroscience
• Developmental Psychology
• Pediatrics

Background:

• Attention Deficit Hyperactivity Disorder, combined type (ADHD-CT) is linked to spatial working memory impairments.
• Neural circuit dysfunction in right prefrontal, striatal, and parietal regions is implicated in these deficits.

Purpose of the Study:

• To investigate if decreased neural activation in right prefrontal, striatal, and parietal regions during a mental rotation task, observed in adolescents with ADHD-CT, is also present in children with ADHD-CT.
• To confirm previous findings of striatal-parietal dysfunction in ADHD-CT across different developmental stages.

Main Methods:

• A cross-sectional study involving 12 pre-pubertal boys (8-12 years) with ADHD-CT and 12 age- and IQ-matched healthy controls.
• Functional magnetic resonance imaging (fMRI) was used while participants performed a mental rotation task assessing spatial working memory.

Main Results:

• No significant differences in task accuracy or response times were found between the ADHD-CT group and controls.
• The ADHD-CT group demonstrated significantly reduced activation in right parieto-occipital areas (cuneus, precuneus, BA 19), the right inferior parietal lobe (BA 40), and the right caudate nucleus.

Conclusions:

• Findings in children with ADHD-CT corroborate previous observations of right striatal-parietal dysfunction in adolescents.
• This widespread dysfunction suggests a maturational deficit in ADHD-CT that may be independent of developmental stage.