Functional connectivity in preterm infants with intraventricular hemorrhage using fNIRS

Introduction Intraventricular 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. Methods Very 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. Results fNIRS 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. Conclusion fNIRS 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. Highlights ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Health Sciences Research Ethics Board of Western University gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors