Abstract
Low birth-weight (LBW) and very low birth-weight (VLBW) newborns have increased risks of brain injuries, growth failure, motor difficulties, developmental coordination disorders or delay, and adult-onset vascular diseases. However, relatively little is known of the neurobiologic underpinnings. To clarify the pathophysiologic vulnerabilities of such neonates, we applied several advanced techniques for assessing brain physiology, namely T2-relaxation-under-spin-tagging (TRUST) magnetic resonance imaging (MRI) and phase-contrast (PC) MRI. This enabled quantification of oxygen extraction fraction (OEF), global cerebral blood flow (CBF), and cerebral metabolic rate of oxygen (CMRO2). A total of 50 neonates (LBW-VLBW, 41; term controls, 9) participated in this study. LBW-VLBW neonates were further stratified as those with (LBW-VLBW-a, 24) and without (LBW-VLBW-n, 17) structural MRI (sMRI) abnormalities. TRUST and PC MRI studies were undertaken to determine OEF, CBF, and CMRO2. Ultimately, CMRO2 proved significantly lower (p = 0.01) in LBW-VLBW (vs term) neonates, both LBW-VLBW-a and LBW-VLBW-n subsets showing significantly greater physiologic deficits than term controls (p = 0.03 and p = 0.04, respectively). CMRO2 and CBF in LBW-VLBW-a and LBW-VLBW-n subsets did not differ significantly (p > 0.05), although OEF showed a tendency to diverge (p = 0.15). However, OEF values in the LBW-VLBW-n subset differed significantly from those of term controls (p = 0.02). Compared with brain volume or body weight, these physiologic parameters yield higher area-under-the-curve (AUC) values for distinguishing neonates of the LBW-VLBW-a subset. The latter displayed distinct cerebral metabolic and hemodynamic, whereas changes were marginal in the LBW-VLBW-n subset (i.e., higher OEF and lower CBF and CMRO2) by comparison. Physiologic imaging may therefore be useful in identifying LBW-VLBW newborns at high risk of irreversible brain damage.
Highlights
Preterm newborns of low birth weight (LBW, ≤2,500 g) or very low birth weight (VLBW, ≤1,500 g) present a substantial public health problem
Term controls included nine neonates, each undergoing clinically indicated magnetic resonance imaging (MRI) based on certain clinical signs/symptoms, umbilical cord blood gas analysis, or other routine blood testing at birth
All values were similar for the Low birth-weight (LBW)-very low birth-weight (VLBW) and term groups and both LBW-VLBW subsets (LBW-VLBW-a and LBW-VLBWn) (p > 0.05)
Summary
Preterm newborns of low birth weight (LBW, ≤2,500 g) or very low birth weight (VLBW, ≤1,500 g) present a substantial public health problem. Most LBW and VLBW preterm infants show catchup gains in height and weight, they are still at increased risk of brain injuries (Martinussen et al, 2005), growth failure (Tchamo et al, 2016), motor difficulties, developmental coordination disorders or delay (Burns et al, 2009), adult-onset vascular diseases (Blencowe et al, 2013; Christian et al, 2013), and type 2 diabetes (Barker, 2003). It appears that catch-up or postnatal accelerated growth in LBW and VLBW neonates may adversely affect cognitive function (Estourgie-van Burk et al, 2009). Better understanding of neonatal brain functions, cerebral oxygen metabolism and hemodynamics, may provide important pathophysiologic insights in this setting
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
