Structural and functional brain abnormalities in children with fetal alcohol spectrum disorders (FASD)

Abstract

Over the past five years, Diffusion Tensor Imaging (DTI) has begun to provide new evidence about the effects of prenatal alcohol exposure on white matter development. DTI, which examines microstructural tissue integrity, is more sensitive to subtle white matter abnormalities than traditional volumetric MRI methods. Thus far, the available DTI data suggest that white matter microstructural abnormalities fall on a continuum of severity in Fetal Alcohol Spectrum Disorder (FASD). Abnormalities are prominent in the corpus callosum, but also evident in major anterior-posterior fiber bundles, corticospinal tracts, and cerebellum. These subtle abnormalities are correlated with neurocognitive deficits, especially in processing speed, non-verbal ability, and executive functioning. The two studies presented here provide evidence of microstructural anomalies in the brains of children who were prenatally exposed to alcohol and demonstrate that those anomalies are associated with disruptions in functional brain connectivity. The majority of the patients in these two investigations were children who did not meet full criteria for Fetal Alcohol Syndrome (FAS). Thus, these data provide evidence that there are genuine consequences of moderate alcohol consumption during pregnancy even in the absence of the full syndrome. Ultimately, these types of sensitive brain measures may serve as indices of change in future longitudinal studies and in studies of interventions for FASD.