Regional brain shape abnormalities persist into adolescence after heavy prenatal alcohol exposure.

We assessed regional brain shape abnormalities and spatial relationships between brain shape and abnormalities observed in the underlying tissue in children and adolescents prenatally exposed to large quantities of alcohol. We used high resolution, 3-D, structural magnetic resonance imaging data and novel, whole-brain, surface-based image analysis procedures to study 21 subjects with heavy prenatal alcohol exposure (8-22 years, mean age 12.6 years) and 21 normally developing control subjects (8-25 years, mean age 13.5 years). Significant brain size and shape abnormalities were observed in the alcohol-exposed subjects in inferior parietal/ perisylvian regions bilaterally, where their brains appeared to be narrower than those of the controls in the same general location where they also had increased gray matter density. Highly significant decreased brain surface extent or reduced brain growth was also observed in the ventral aspects of the frontal lobes most prominent in the left hemisphere. For the first time in this report we have mapped brain morphologic abnormalities to the cortical surface in subjects with prenatal alcohol exposure and have shown that the size and shape of the brain is altered in these individuals. The results imply that brain growth continues to be adversely affected long after the prenatal insult of alcohol exposure to the developing brain and the brain regions most implicated, frontal and inferior parietal/ perisylvian, may be consistent with behavioral deficits characteristic of individuals prenatally exposed to alcohol.