Cerebral Cortex Advance Access published online on May 14, 2008
Cerebral Cortex, doi:10.1093/cercor/bhn064
Alterations in Midline Cortical Thickness and Gyrification Patterns Mapped in Children with 22q11.2 Deletions
1 Department of Psychiatry & Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, 2 Department of Psychology, 3 Laboratory of Neuro Imaging and Brain Mapping Division, Department of Neurology, University of California-Los Angeles, Los Angeles, CA 90024, USA, 4 M.I.N.D. Institute, University of California-Davis, Sacramento, CA 95616, USA, 5 Division of Human Genetics, 6 Clinical Genetics, The Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
Address correspondence to Carrie E. Bearden, PhD, University of California, Los Angeles, 300 Medical Plaza, Suite 2265, Los Angeles, CA 90095. Email: cbearden{at}mednet.ucla.edu.
The 22q11.2 deletion syndrome (velocardiofacial/DiGeorge syndrome) is a neurogenetic condition associated with visuospatial deficits, as well as elevated rates of attentional disturbance, mood disorder, and psychosis. Previously, we detected pronounced cortical thinning in superior parietal and right parieto-occipital cortices in patients with this syndrome, regions critical for visuospatial processing. Here we applied cortical pattern-matching algorithms to structural magnetic resonance images obtained from 21 children with confirmed 22q11.2 deletions (ages 8–17) and 13 demographically matched comparison subjects, in order to map cortical thickness across the medial hemispheric surfaces. In addition, cortical models were remeshed in frequency space to compute their surface complexity. Cortical maps revealed a pattern of localized thinning in the ventromedial occipital–temporal cortex, critical for visuospatial representation, and the anterior cingulate, a key area for attentional control. However, children with 22q11.2DS showed significantly increased gyral complexity bilaterally in occipital cortex. Regional gray matter volumes, particularly in medial frontal cortex, were strongly correlated with both verbal and nonverbal cognitive functions. These findings suggest that aberrant parieto-occipital brain development, as evidenced by both increased complexity and cortical thinning in these regions, may be a neural substrate for the deficits in visuospatial and numerical understanding characteristic of this syndrome.
Key Words: brain mapping • cognition • genetics • MRI • velocardiofacial syndrome