Alterations in frontostriatal pathways in children born very preterm

AIM Children born very preterm (<32wks' gestation) are at risk of white matter injury, particularly in frontostriatal pathways that mediate executive functioning. However, it is unclear whether very preterm children without evidence of neonatal brain injury manifest long-term white matter microstructural differences once they reach school age and if this is related to cognitive impairments. METHOD Twenty school-aged children born very preterm (11 males, nine females; mean age 8y 6mo, standard error [SE] 1.68mo, range 7y 7mo-9y 6mo; gestational age range 24-30wks, mean gestational age 26.9wks, SE 0.4wk; birthweight 988g, SE 46g, range 570-1424g) without evidence of neonatal brain injury, and 20 sex-and age-matched term-born children (mean age 8y 4.8mo, SE 1.92mo; range 7y 2mo-9y-10.8mo) underwent neurodevelopmental assessment and diffusion tensor imaging. RESULTS Fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were calculated within all white matter pathways and within frontostriatal projections. Children born preterm had decreased fractional anisotropy in the territories of the left external capsule, superior longitudinal fasciculus, uncinate fasciculus, and inferior fronto-occipital fasciculus. Measures of intelligence were negatively correlated with frontostriatal fractional anisotropy only in males born preterm. INTERPRETATION Results indicate that very preterm-born children exhibit white matter disturbances that persist into middle childhood, with potential sex differences in the association between these white matter alterations and cognitive function.