Silent Vascular Catastrophes in the Brain in Term Newborns: Strategies for Optical Imaging

In this review, we describe the phenomenon of intracranial hemorrhage (ICH), which occurs spontaneously within the first 2-3 days of life in full-term newborns without any clinical symptoms, but with long-term neurological outcomes in many cases. We give the estimated frequency and possible mechanisms responsible for silent ICH with main focus on the cerebral blood flow (CBF) and oxygenation measurements using non-invasive optical methods. We overview the current multi-modal technologies that are widely used in clinics and experiments for the study of ICH during the first days of life: magnetic resonance imaging, ultrasonography, cerebral oximetry based on near infrared spectroscopy, as well as laser speckle imaging and diffuse correlation spectroscopy as a priority technology for experimental study of cerebral hemodynamics. We discuss the advantages and disadvantages of these methods. We identify key trends in experimental works and show areas for future research of ICH in term newborns. Future studies will help to improve our ability to optimize prognosis, diagnosis, and treatment of asymptomatic neonates with silent ICH.