Hippocampal volume reduction is associated with intellectual functions in adolescents with congenital heart disease

BACKGROUND: Adolescents undergoing early cardiopulmonary bypass surgery for congenital heart disease (CHD) may demonstrate a variety of neurocognitive impairments. These impairments can affect overall intellectual functions, but also specific memory deficits, language, and executive functions. As the hippocampus is a critical structure involved in these functions, we sought to determine whether hippocampal volume was reduced in adolescents with CHD and whether altered volumes were related to functional outcome. METHODS: At a mean age of 13.8 y, 48 adolescent survivors of childhood cardiopulmonary bypass surgery for CHD and 32 healthy controls underwent neurocognitive testing and cerebral magnetic resonance imaging. Images were quantitatively analyzed using an automated regional segmentation tool (FSL-FIRST). RESULTS: Adolescents with CHD had 10% lower total hippocampal volumes compared with controls. After controlling for total brain volume, total hippocampal volume correlated with total IQ, with working memory, and verbal comprehension in CHD patients, but not in controls. CONCLUSIONS: In adolescent survivors of cardiopulmonary bypass surgery for CHD, specific brain regions such as the hippocampus may show long-term persistent alteration and correlate with intellectual deficits, particularly with verbal and memory functions