Accelerated corpus callosum development in prematurity predicts improved outcome

Thompson, Deanne K., Lee, Katherine J., van Bijnen, Loeka, Leemans, Alexander, Pascoe, Leona, Scratch, Shannon E., Cheong, Jeanie, Egan, Gary F., Inder, Terrie E., Doyle, Lex W., Anderson, Peter J.


Human Brain Mapping 36 (10), p. 3733-3748


Objectives: To determine: (1) whether corpus callosum (CC) size and microstructure at 7 years of age or their change from infancy to 7 years differed between very preterm (VP) and full-term (FT) children; (2) perinatal predictors of CC size and microstructure at 7 years; and (3) associations between CC measures at 7 years or trajectories from infancy to 7 years and neurodevelopmental outcomes. Experimental design: One hundred and thirty-six VP (gestational age [GA] <30 weeks and/or birth weight <1,250 g) and 33 FT children had usable magnetic resonance images at 7 years of age, and of these, 76 VP and 16 FT infants had usable data at term equivalent age. The CC was traced and divided into six sub-regions. Fractional anisotropy, mean, axial, radial diffusivity and volume were measured from tractography. Perinatal data were collected, and neurodevelopmental tests administered at 7 years' corrected age. Principal observations: VP children had smaller posterior CC regions, higher diffusivity and lower fractional anisotropy compared with FT 7-year-olds. Reduction in diffusivity over time occurred faster in VP than FT children (P≤0.002). Perinatal brain abnormality and earlier GA were associated with CC abnormalities. Microstructural abnormalities at 7 years or slower development of the CC were associated with motor dysfunction, poorer mathematics and visual perception. Conclusions: This study is the first to demonstrate an accelerated trajectory of CC white matter diffusion following VP birth, associated with improved neurodevelopmental functioning. Findings suggest there is a window of opportunity for neurorestorative intervention to improve outcomes.