The impact of premature extrauterine exposure on infants’ stimulus-evoked brain activity across multiple sensory systems

Abstract

Prematurity can result in widespread neurodevelopmental impairment, with the impact of premature extrauterine exposure on brain function detectable in infancy. A range of neurodynamic and haemodynamic functional brain measures have previously been employed to study the neurodevelopmental impact of prematurity, with methodological and analytical heterogeneity across studies obscuring how multiple sensory systems are affected. Here, we outline a standardised template analysis approach to measure the evoked response magnitudes for visual, tactile, and noxious stimulation within individual infants (n=15) using EEG. By studying a cohort of very preterm infants longitudinally (n=10), we observe that the evoked response template magnitudes are significantly associated with age-related maturation. In a subsequent cross-sectional study, we observe significant differences in visual and tactile response template magnitudes between infants born in the very preterm and late preterm periods (n=10 and 8), age-matched at study. These findings demonstrate the significant impact of premature extrauterine exposure on brain function and suggest that prematurity can accelerate maturation of the visual and tactile sensory system in infants born very prematurely. This study highlights the value of using a standardised multi-modal evoked-activity analysis approach to assess premature neurodevelopment, and will likely complement resting-state EEG and behavioural assessments in the study of the functional impact of developmental care interventions.

Development of neonatal brain functional centrality and alterations associated with preterm birth

“…With the brain undergoing dramatic changes in functional activity during the third trimester, infants born prematurely during this sensitive period are vulnerable to the influence of developmentally unexpected sensory stimuli which is not age-appropriate and significantly different from the womb in duration, complexity and intensity (Beltrán et al 2021; Mellado et al 2021). Such exposure to inadequate and/or inappropriate visual, auditory and motor stimuli may contribute to subtle brain changes both in primary cortices and associative areas, which can in turn translate into long-lasting sensorimotor alterations (El-Metwally and Medina 2020).…”

“…This suggests that preterm birth affects the regions which are showing the most substantial development during the perinatal period. Given the crucial role of sensory input in neurodevelopment (Mellado et al 2021), preterm infants exposed to developmentally unexpected stimulation of motor and visual networks (i.e ex utero versus in utero experience) may show accelerated maturation along normal developmental trajectories or adopt adverse and/or compensatory mechanisms as an adaptive response to cope with the environment (De Asis-Cruz et al 2020; Eyre et al 2021; Mellado et al 2021). This may in turn result in the altered patterns of functional centrality we observe in preterm-born infants in the current study.…”