Functional magnetic resonance imaging of verbal learning in children with heavy prenatal alcohol exposure

No abstract

Children with prenatal alcohol exposure (PAE) show deficits in verbal learning and spatial memory, as well as abnormal hippocampal development. The relationship between their memory and neuroanatomic impairments, however, has not been directly explored. Given that the hippocampus is integral for the synthesis and retrieval of learned information and is particularly vulnerable to the teratogenic effects of alcohol, we assessed whether reduced learning and recall abilities in children with fetal alcohol spectrum disorders (FASDs) are associated with abnormal hippocampal volumes. Nineteen children with FASDs and 18 typically developing controls aged 9 to 15 years were assessed for verbal learning and verbal and spatial recall and underwent structural magnetic resonance imaging. Images were analyzed for total intracranial volume and for right and left hippocampal volumes. Results revealed smaller left hippocampi and poorer verbal learning and verbal and spatial recall performance in children with FASDs than controls, as well as positive correlations between selective memory indices and hippocampal volumes only in the FASD group. Additionally, hippocampal volumes increased significantly with age in controls only, suggesting that PAE may be associated with long-term abnormalities in hippocampal development that may contribute to impaired verbal learning and verbal and spatial recall. (JINS, 2008(JINS, , 14, 1022(JINS, -1033

The term "fetal alcohol spectrum disorders" (FASD) denotes the broad spectrum of morphological changes and functional deficits seen in children exposed to alcohol prenatally. While some children on the spectrum show the characteristic pattern of malformations called "fetal alcohol syndrome" (FAS), a significant proportion of alcohol-exposed children do not evidence clinically identifiable morphological alterations. The term "alcohol-related neurodevelopmental disorder" (ARND) is used to label the latter group. The identification of children with ARND has proven to be challenging because of the lack of clinically discernable physical signs. Therefore, some investigators have used the strategy of assessing maternal drinking during pregnancy and then tracking developmental outcomes in offspring longitudinally. Other methods that investigators have utilized to identify children with prenatal alcohol exposure in population-based studies include multi-source surveillance and active case ascertainment. In the current review, we discuss the merits and demerits of these methodologies and then present novel methods of identifying prenatal alcohol exposure (e.g., biomarkers) and subtle effects of morphological alterations and neural effects (e.g., neuroimaging).