Region-wise Gray Matter Volume Alterations in Brain of Adolescents with Attention Deficit Hyperactive Disorder : a Voxel Based Morphometric Analysis

Attention Deficit Hyperactive Disorder (ADHD) is a behavioral neuropsychiatric disorder affecting an estimated 5% of school-age children worldwide with symptoms persisting into adulthood in 80% of cases. Presently clinical diagnosis and treatment of ADHD relies on behavioral disturbances than on detecting underlying defective brain regions. Therapeutic outcome in treatment of ADHD may be more positive if defective brain region in clinically diagnosed ADHD is detected by voxel based morphometric (VBM) analysis that measures voxel-wise global and regional focal volume differences in structural magnetic resonance images (sMRI) of brain. This study was designed to detect any region-specific gray matter (GM) volume defects in sMRI of ADHD adolescents by VBM analysis. Thirty sMRI datasets matched for sex, handedness of adolescents aged between 11.66 and 20.47 years (mean age 16.27±2.48 years) obtained from NeuroImage webpage, were selected (Control n=15; ADHD combined type n=15). These sMRI were analyzed by VBM technique and compared using statistical parametric mapping (SPM). Significant regional GM volume deficits (P<0.05) was specifically identified in left cuneus and middle occipital gyrus in ADHD, after voxel-wise false discovery rate correction over the whole brain compared to matched controls. Deficit of GM volume in occipital cortex detected by VBM analysis in ADHD children, suggests defects of visual processing affecting attention mechanisms.