Teratogenic Effect of Alcohol on Brain and Behavior

Heavy alcohol exposure can have serious and long-lasting effects on the developing fetal brain. In the last decade, researchers have utilized quantitative structural magnetic resonance imaging (MRI) to examine the brains of living children and adults with histories of heavy prenatal alcohol exposure. In addition to microcephaly, these studies indicated structural abnormalities in various regions of the brain, including the cerebellum, corpus callosum, and the basal ganglia. Most recently, we have utilized novel imaging and analytic techniques to study the brain as a whole in an effort to elucidate more subtle differences than was possible with earlier techniques. Results indicated displacements in the corpus callosum, increased gray matter densities in both hemispheres in the perisylvian regions, and altered gray matter asymmetry in portions of the temporal lobes in the brains of alcohol-exposed subjects. In addition, prominent shape abnormalities were observed in the brains of these subjects, with narrowing in the temporal region and reduced brain growth in portions of the frontal lobe. These results imply that brain growth continues to be adversely affected long after the prenatal insult and that the brain regions most affected may be consistent with the neurocognitive deficits characteristic of individuals prenatally exposed to alcohol. (1) FAS is defined by four criteria maternal drinking during pregnancy, a characteristic pattern of facial abnormalities, growth retardation, and brain damage, which often is manifested by intellectual difficulties or behavioral problems. (2)