Microstructural Maturation of the Splenium of Corpus Callosum and Cognitive and Motor Outcome in Very Preterm Infants

Abstract

Introduction: Common brain injuries of preterm infants do not entirely explain the incidence of neurodevelopmental impairment observed in this population. Evidence suggests an association with microstructural maturation of the splenium of corpus callosum. This study aimed to investigate a correlation between microstructural maturation of the splenium of corpus callosum and neurodevelopmental outcome in very preterm infants.

Method: In a cohort study of 373 very preterm infants, we used fractional anisotropy (FA) and apparent diffusion coefficient (ADC) derived from diffusion tensor imaging at term equivalent age (TEA) to quantitatively reflect microstructural maturation of the splenium of corpus callosum, and standardized follow-up assessments of cognitive and motor function at 24 months corrected age and 5 years chronological age. Correlation was tested by Spearman's rank correlation coefficients and multivariate regression analysis.

Results: At 24 months, we found significantly lower FA and higher ADC values in infants with abnormal mental indices, psychomotor developmental indices, and fine motor function. Scores of all three correlated positively with FA and negatively with ADC. Aged 5 years, lower FA values correlated significantly with abnormal overall motor function, and higher ADC values correlated significantly with abnormal full-scale intelligence quotient (FSIQ) and overall motor function. Scores of FSIQ, overall, and fine motor function correlated negatively with ADC.

Conclusion: The results emphasize an association between microstructural maturation of the splenium of corpus callosum at TEA and neurodevelopmental outcome, and suggest that ADC may be more strongly linked to these outcomes than FA, especially in the long-term.

Keywords: MRI at term equivalent age; Microstructural brain maturation; Neurodevelopmental outcome; Preterm infants; Splenium of corpus callosum.