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Quantitative brain magnetic resonance imaging in attention-deficit hyperactivity disorder
F X Castellanos1, J N Giedd, W L Marsh
1Child Psychiatry Branch, National Institute of Mental Health, Bethesda, Md, USA.
Archives of General Psychiatry
|July 1, 1996
Summary
Attention-deficit hyperactivity disorder (ADHD) is associated with smaller total brain volume and altered asymmetry in key brain regions, particularly the caudate nucleus and frontal cortex. These findings suggest dysfunction in right-sided prefrontal-striatal systems in ADHD.
Area of Science:
- Neuroimaging
- Developmental Neuroscience
- Psychiatry
Background:
- Previous anatomical magnetic resonance imaging (MRI) studies in attention-deficit hyperactivity disorder (ADHD) were limited by small sample sizes or focused on single brain regions.
- Neuropsychological deficits in ADHD suggest a network involving basal ganglia and frontal regions.
Purpose of the Study:
- To investigate if volumetric and asymmetry measures of 12 subcortical and cortical brain regions can effectively distinguish individuals with ADHD from controls.
- To conduct a comprehensive morphometric analysis of brain structures implicated in ADHD.
Main Methods:
- Anatomic brain MRIs were acquired for 57 boys with ADHD and 55 healthy controls (aged 5-18 years) using a 1.5-T scanner.
- Volumetric measures of cerebrum, basal ganglia (caudate, putamen, globus pallidus), amygdala, hippocampus, temporal lobe, cerebellum, and prefrontal cortex were assessed, along with right-left asymmetries.
- Midsagittal areas of the cerebellum and corpus callosum were also measured, with high interrater reliability (>0.82).
Main Results:
- Individuals with ADHD exhibited a 4.7% smaller total cerebral volume compared to controls.
- Significant findings in the ADHD group included loss of normal right > left caudate asymmetry, smaller right globus pallidus, smaller right anterior frontal region, smaller cerebellum, and reversed lateral ventricular asymmetry.
- The typical age-related decrease in caudate volume was absent, and increases in lateral ventricular volumes were diminished in ADHD.
Conclusions:
- This comprehensive morphometric analysis supports the hypothesis of right-sided prefrontal-striatal system dysfunction in ADHD.
- The study highlights specific volumetric and asymmetry differences in brain structures that may serve as biomarkers for ADHD.