| Magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) offer unique, noninvasive methods of measuring in vivo , quantitative neuroanatomy and neurochemistry, respectively. The main purpose of the present study was to identify and compare the neuro-anatomical and neuro-chemical abnormalities that are associated with prenatal exposure to alcohol in both fetal alcohol syndrome (FAS) diagnosed children and those diagnosed with fetal alcohol effects (FAE). Neuro-anatomical and -chemical data of 3 age-, sex-, and race-balanced groups of children, (1) FAS-diagnosed, (2) FAE-diagnosed, and (3) non-exposed controls were compared. Effects of exposure, regardless of diagnosis, were found in the caudate nucleus and the corpus callosum. Specifically, both of these brain regions were significantly smaller in the FAS and FAE subjects than in the controls. Furthermore, the mid-sagittal area of the corpus callosum was disproportionately decreased in the FAS subjects compared to the controls, with the FAE subjects demonstrating a trend towards this effect. The left caudate nucleus of both the FAS and FAE subjects also demonstrated a marginal increase in the ratio N-acetyl-aspartate to creatine (NAA:Cr). Absolute concentrations revealed that the increase in the ratio of NAA:Cr was due to an increase in NAA alone. Although its exact function in the CNS is unknown, NAA is believed to be a neuronal marker due to its exclusive localization to neurons. Some also speculate a role for NAA in myelination. Increased NAA in the prenatal alcohol-exposed subjects could indicate a lack of normal program cell death, dendritic pruning and/or myelination during development. The present study demonstrates that prenatal alcohol-exposed children, with or without facial dysmorphology, have abnormal brain anatomy and chemistry. |
