Mapping the neuroanatomical impact of very preterm birth across childhood

Abstract

Those born very preterm (VPT; <32 weeks gestational age) have an increased risk in developing a wide range of cognitive deficits. In early-to-late childhood, brain structure has been shown to be altered in VPT compared to full-term (FT) children; however, the results are inconsistent. The current study examined subcortical volumes, cortical thickness, and surface area in a large cohort of VPT and FT children aged 4-12 years. Structural magnetic resonance imaging (MRI) was obtained on 120 VPT and 146 FT children who returned up to three times, resulting in 176 VPT and 173 FT unique data points. For each participant, Corticometric Iterative Vertex-based Estimation of Thickness was used to obtain global measurements of total brain, cortical grey and cortical white matter volumes, along with surface-based measurements of cortical thickness and surface area, and Multiple Automatically Generated Templates (MAGeT) brain segmentation tool was used to segment the subcortical structures. To examine group differences and group-age interactions, mixed-effects models were used (controlling for whole-brain volume). We found few differences between the two groups in subcortical volumes. The VPT children showed increased cortical thickness in frontal, occipital and fusiform gyri and inferior pre-post-central areas, while thinning occurred in the midcingulate. Cortical thickness in occipital regions showed more rapid decreases with age in the VPT compared to the FT children. VPT children also showed both regional increases, particularly in the temporal lobe, and decreases in surface area. Our results indicate a delayed maturational trajectory in those born VPT.K E Y W O R D S brain structure, child development, magnetic resonance imaging, preterm birth

Decreased cortical thickness mediates the relationship between premature birth and cognitive performance in adulthood

“…In concurrence with our findings in adults, prematurely born children showed reduced CTh in temporoparietal regions and, albeit to a lesser extent, in frontolateral regions, as compared with FT children (Hasler, Brown, & Akshoomoff, 2019; Lax et al, 2013; Sølsnes et al, 2015; Sripada et al, 2018; Zubiaurre‐Elorza et al, 2012). Furthermore, children also showed areas of increased CTh especially in occipital and frontomedial regions (Hasler et al, 2019; Sølsnes et al, 2015; Sripada et al, 2018; Vandewouw et al, 2019). Longitudinal analyses in children aged 4–12 years showed significant widespread decreases of CTh with age in occipital, frontal and temporal lobes bilaterally in both VP and FT children.…”

“…Longitudinal analyses in children aged 4–12 years showed significant widespread decreases of CTh with age in occipital, frontal and temporal lobes bilaterally in both VP and FT children. CTh within limited occipital regions decreased significantly more with age in VP compared to FT children (Vandewouw et al, 2019).…”

“…In some regions, such as temporoparietal associative cortices, the cortex does not seem to reach maximum thickness compared to FT controls, as these areas also show reduced CTh in younger premature‐born children (Hasler et al, 2019; Sølsnes et al, 2015) while CTh should still be increasing (Shaw et al, 2008). However, other cortical areas, for example, in the frontal and occipital lobes, seem to be thicker in younger ages after premature birth compared to FT controls (Hasler et al, 2019; Sølsnes et al, 2015; Vandewouw et al, 2019) with a more rapid decrease in CTh through adolescence as a possible result of delayed developmental processes (Nam et al, 2015). Ultimately, more longitudinal studies are necessary in order to shed more light on cortical growth trajectories in premature‐born individuals through life.…”

Resilience and Vulnerability: Neurodevelopment of Very Preterm Children at Four Years of Age

“…Our findings of increased gray to white matter ratios in the VPT children, despite having overall reduced gray and white matter volumes compared to FT controls, extend these results. As gray matter steadily decreases throughout childhood (Mills et al, 2016 ; Vandewouw et al, 2020 ), increased gray matter in the VPT group is consistent with delayed maturation. Longitudinal studies in VPT children between late childhood and early adolescence have also documented delayed maturation in gray and white matter volumes and slower gains in white matter compared to FT children (Ment et al, 2009 ; Nagy et al, 2009 ), although this does not always continue past adolescence (Karolis et al, 2017 ).…”

Exploring the distribution of grey and white matter brain volumes in extremely preterm children, using magnetic resonance imaging at term age and at 10 years of age

“…There are studies comparing children born very preterm with full term controls during childhood and adolescence that have found either that GM volume was more reduced than WM volume in the preterm children or an equal effect on GM and WM volumes [20,62]. A longitudinal study that compared very preterm children at less than 30 weeks of gestation or weighing less than 1250 g with full term children showed less growth in both GM and WM volumes from term age to 7 years of age, with a dominance in growth reduction in GM volume [20].…”