 Lisa Paquette |
 Jessica Wisnowski |
Multiple prior studies of term neonates with congenital heart disease (CHD) have documented delayed brain maturation (both in utero and in the preoperative postnatal period), particularly in term infants with single ventricle physiology, further increasing their risk for injury or adverse neurodevelopmental outcome. In contrast, very few studies exist of preterm neonates with congenital heart disease. Prematurity and congenital heart disease are independent risk factors for adverse neurodevelopmental outcome, and it follows that having both further increases the risk. In our paper we examined the cerebral microstructure of preterm infants with CHD in relation to prematurity and injury, hoping to gain insights into the complex combination of risks portending adverse neurodevelopment in infants with CHD. We found that diffuse microstructural abnormalities are seen in preterm neonates with congenital heart disease when compared with term neonatal controls without CHD. When we removed the cases of preterm CHD that demonstrated punctate white matter lesions (a current imaging correlate of periventricular leukomalacia), microstructural abnormalities remained in the splenium of the corpus callosum, a structure involved in mediating visual-spatial function. In contrast, there was very little difference in microstructure between the preterm CHD group and preterm neonates without CHD.
Our study is unique, as it is one of the first to use tract-based spatial statistics (TBSS) to analyze diffusion tensor imaging data from neonates with CHD. We did methodological validation of the TBSS technique by also performing comparative manual region-of-interest (ROI) diffusion tensor quantitative metric measurements, and delineated comparable results.