DTI of adult visual pathways after severe neonatal hypoxia-ischemic cerebral injury

Abstract

This study employs in vivo diffusion tensor imaging (DTI) to determine the long-term outcomes of microstructural integrity along the visual pathways after severe neonatal hypoxic-ischemic (HI) injury to the entire ipsilesional visual cortex in rats at postnatal day 7. Quantitative analyses showed that, compared to age-matched normal brains, a significantly lower FA but higher λ//, λ┴ and diffusion trace value were observed in the ipsilesional posterior optic tract in the HI-injured brains at postnatal day 60, whereas significantly lower FA but mildly lower λ// and higher λ┴ and trace were observed in the ipsilesional prechiasmatic optic nerve and contralesional anterior and posterior optic tracts. The results of this study are potentially important in determining and improving the functional consequences of the brain lesion after most compensatory and reparative phases have been passed.