Aberrant White Matter Organization Correlated With Neurodevelopment Outcomes in Tetralogy of Fallot: An Atlas-Based Diffusion Tensor Imaging Study.

Background: White matter injury (WMI) and impaired neurodevelopment are common in children with congenital heart disease. However, the effect of WMI on neurodevelopmental outcomes is still rarely reported. In this study, we aimed to investigate microstructural changes in white matter (WM) and its relationship with neurodevelopmental outcomes and further explore the underlying neurophysiological mechanisms of neurocognitive impairments in the tetralogy of Fallot (ToF).

Method: Diffusion tensor imaging (DTI) data were acquired in preschool-aged children with ToF (n = 29) and normal controls (NC, n = 19), and neurodevelopmental assessments were performed with the Wechsler Preschool and Primary Scale of Intelligence in ToF. The differences in DTI metrics including fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were evaluated between ToF and NC. Correlations between WM microstructural changes and neurodevelopmental outcomes were further analyzed.

Results: Significant WM differences were found in the uncinate fasciculus, cingulum hippocampus, superior longitudinal fasciculus, and corticospinal tract between children with ToF and NC. Impaired WM integrity was correlated with the verbal comprehension index and working memory index in ToF.

Conclusions: This study demonstrated WM microstructure injury, and this injury is related to worse language and working memory performance in preschool-aged children with ToF. These findings suggested that DTI metrics may be a potential biomarker of neurocognitive impairments in ToF and can be used to predict future neurodevelopmental outcomes, which also provide new insights into the underlying neurophysiological mechanisms of neurocognitive impairments in ToF.