Resting-State Network Complexity and Magnitude Are Reduced in Prematurely Born Infants

Abstract

Premature birth is associated with high rates of motor and cognitive disability. Investigations have described resting-state functional magnetic resonance imaging (rs-fMRI) correlates of prematurity in older children, but comparable data in the neonatal period remain scarce. We studied 25 term-born control infants within the first week of life and 25 very preterm infants (born at gestational ages ranging from 23 to 29 weeks) without evident structural injury at term equivalent postmenstrual age. Conventional resting-state network (RSN) mapping revealed only modest differences between the term and prematurely born infants, in accordance with previous work. However, clear group differences were observed in quantitative analyses based on correlation and covariance matrices representing the functional MRI time series extracted from 31 regions of interest in 7 RSNs. In addition, the maximum likelihood dimensionality estimates of the group-averaged covariance matrices in the term and preterm infants were 5 and 3, respectively, indicating that prematurity leads to a reduction in the complexity of rs-fMRI covariance structure. These findings highlight the importance of quantitative analyses of rs-fMRI data and suggest a more sensitive method for delineating the effects of preterm birth in infants without evident structural injury.

The emergence of functional architecture during early brain development

“…Preterm infants exhibited reduced interhemispheric connectivity (Smyser et al, 2013(Smyser et al, , 2010 and impaired lateralization of language areas . Resting state networks as observed in typically developing neonates were present in preterm infants scanned at term equivalent age, yet displayed reductions in connectivity strength of primarily higher order networks (Doria et al, 2010b;Smyser et al, 2016). Similarly, on a whole brain level hallmark network attributes including small world organization, modularity and rich club architecture were found to be preserved while differences were revealed in the quality of connections .…”

Third Trimester Brain Growth in Preterm Infants Compared With In Utero Healthy Fetuses

“…Our findings suggest that even in the absence of structural brain injury, the developmental trajectory of the preterm brain is altered over the third trimester. Evidence of clinical 4 .01 * 14.17 ± 1.6 [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] 13.91 ± 2.7 [8][9][10][11][12][13][14][15][16][17][18][19][20] .66…”

“…11,12 To date, most inferences about thirdtrimester brain development in preterm infants have been based on comparative quantitative MRI measures versus those of term healthy newborns at a single time point at the end of the third trimester (ie, TEA). However, these crosssectional studies at the end of the third trimester were not designed to identify the onset and evolution of impaired brain development in the premature infant.…”

Hemoglobin phase of oxygenation and deoxygenation in early brain development measured using fNIRS

“…A growing number of MRI studies have shown that preterm-born neonates and infants have brain structures with aberrant volumes, morphologies, and networks at term equivalent (2, 3) and school age (4,5). Studies of resting-state fMRI have also shown that the functional connectivity of the cortex is different in term and preterm infants (6). However, it is a matter of controversy whether neonatal MRI of the brain can predict long-term adverse outcomes, such as minor neurological dysfunction (7,8).…”