Functional connectivity in preterm infants with intraventricular hemorrhage using fNIRS

IntroductionIntraventricular hemorrhage (IVH) is a common neurological complication following very preterm birth. Resting-state functional connectivity (RSFC) using functional magnetic resonance imaging (fMRI) is associated with injury severity; yet fMRI is impractical for use in intensive care settings. Sensitive bedside neuroimaging biomarkers are needed to characterize injury patterns. Functional near-infrared spectroscopy (fNIRS) measures RSFC through cerebral hemodynamics and has greater accessibility. We aimed to determine comparability of RSFC in preterm infants with IVH using fNIRS and fMRI at term equivalent age (TEA), then examine fNIRS connectivity with the severity of IVH. MethodsVery preterm born infants with IVH were scanned with both modalities at rest at TEA (postmenstrual age=37{+/-}0.92 weeks). Connectivity maps of IVH infants were compared between fNIRS and fMRI with the Euclidean and Jaccard distances. The severity of IVH in relation to fNIRS RSFC strength was examined using generalized linear models. ResultsfNIRS and fMRI RSFC maps showed good correspondence. At TEA, connectivity strength was significantly lower in healthy newborns (p-value = 0.023) and preterm infants with mild IVH (p-value = 0.026) compared to infants with moderate/severe IVH. ConclusionfNIRS has potential to be a new tool for assessing brain injury and monitoring cerebral hemodynamics and a promising marker for IVH severity in very preterm born infants. HighlightsO_LIThere is no previous study combining fNIRS and fMRI focused on preterm neonates with IVH. C_LIO_LIThis is the first study associating functional connectivity strength yielded from fNIRS with severity of IVH. C_LIO_LIGood correspondence of functional connectivity was shown between fNIRS and fMRI. C_LIO_LIPreterm neonates showed increased functional connectivity strength compared to healthy term born neonates. This can potentially be a marker for clinical assessment of severity of IVH. C_LIO_LIfNIRS was demonstrated to have potential as a new bedside neuromonitoring tool for assessing early brain injuries of neonates. C_LI