The Effect of Preterm Birth on Thalamic and Cortical Development

Abstract

Preterm birth is a leading cause of cognitive impairment in childhood and is associated with cerebral gray and white matter abnormalities. Using multimodal image analysis, we tested the hypothesis that altered thalamic development is an important component of preterm brain injury and is associated with other macro- and microstructural alterations. T1- and T2-weighted magnetic resonance images and 15-direction diffusion tensor images were acquired from 71 preterm infants at term-equivalent age. Deformation-based morphometry, Tract-Based Spatial Statistics, and tissue segmentation were combined for a nonsubjective whole-brain survey of the effect of prematurity on regional tissue volume and microstructure. Increasing prematurity was related to volume reduction in the thalamus, hippocampus, orbitofrontal lobe, posterior cingulate cortex, and centrum semiovale. After controlling for prematurity, reduced thalamic volume predicted: lower cortical volume; decreased volume in frontal and temporal lobes, including hippocampus, and to a lesser extent, parietal and occipital lobes; and reduced fractional anisotropy in the corticospinal tracts and corpus callosum. In the thalamus, reduced volume was associated with increased diffusivity. This demonstrates a significant effect of prematurity on thalamic development that is related to abnormalities in allied brain structures. This suggests that preterm delivery disrupts specific aspects of cerebral development, such as the thalamocortical system.

Multimodal image analysis of clinical influences on preterm brain development

“…In previous studies of similar cohorts, we and others have observed decreased frontotemporal volume, increased thalamic diffusivity, and decreased FA in the central white matter with increasing prematurity 7, 10, 12, 35. Here, we show these changes are coupled, independent of age at scan and total intracranial volume, and exacerbated by comorbid markers of neonatal sickness.…”

The emergence of functional architecture during early brain development

“…Besides the event of preterm birth itself posing substantial risk to the establishment of healthy and fully operational brain network organization, prematurity is frequently accompanied by postnatal illness that may amplify the detrimental effects on early brain wiring. Not surprisingly, preterm birth is associated with impaired brain development reflected in reduced brain volumes, diminished cortical gyrification and delayed maturation of gray and white matter structures (Ball et al, 2012;Keunen et al, 2012;Rathbone et al, 2011;Shimony et al, 2016;Volpe, 2009). These deficits are also present in the absence of focal brain injury and have been noted to persist through childhood (Counsell et al, 2008;Fischigómez et al, 2015;Monson et al, 2016).…”

Neonatal brain microstructure correlates of neurodevelopment and gait in preterm children 18–22 mo of age: an MRI and DTI study

“…The thalamus and basal ganglia are known to mediate motor processes and have been found to be vulnerable to injury in infants (7,39); which could partially explain impaired motor and cognitive function associated with preterm birth. In preterm compared to term infants, decreased thalamus volume (39) and impaired thalamocortical connectivity (40) have been reported.…”