Interaction between Preterm White Matter Injury and Childhood Thalamic Growth

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Pediatric Neurology

Background:

• Preterm birth (before 32 weeks' gestational age) is associated with an increased risk of white matter injury (WMI).
• The thalamus plays a critical role in cognitive and motor functions, and its development can be affected by early brain injury.
• Long-term neurodevelopmental outcomes in preterm infants are influenced by a complex interplay of factors, including brain injury and growth patterns.

Purpose of the Study:

• To investigate the relationship between preterm white matter injury (WMI) and thalamic growth.
• To determine how these factors predict neurodevelopmental outcomes at 8 years of age in children born very preterm.

Main Methods:

• A prospective cohort of 114 very preterm infants (24-32 weeks GA) was studied.
• Structural and diffusion tensor MRI were performed at early life, term-equivalent age, and 8 years.
• Cognitive, motor, and visual-motor outcomes were assessed at 8 years, with multivariable regression analysis used to examine relationships.

Main Results:

• School-age thalamic volumes were predicted by neonatal thalamic growth rate, gestational age, sex, and neonatal WMI volume.
• Neonatal WMI volume independently predicted school-age thalamic volume, even after accounting for total cerebral volume.
• An interaction between fractional anisotropy (FA) in thalamocortical tracts at term-equivalent age and early WMI volume influenced school-age thalamic volumes.
• School-age thalamic volumes and neonatal WMI interacted to predict full-scale IQ and motor scores, while thalamic volumes predicted visual-motor scores.

Conclusions:

• In very preterm infants, neonatal thalamic growth and WMI volume are significant predictors of school-age thalamic volumes.
• The interaction between FA and WMI at term suggests dysmaturation as a mechanism for impaired thalamic growth.
• Cognitive outcomes are influenced by the interplay of WMI and thalamic growth, emphasizing the need for a multidimensional approach to assessing brain injury in preterm children.