Neurovascular Interactions in the Neurologically Compromised Neonatal Brain

Abstract

Neurological brain injuries such as hypoxic ischaemic encephalopathy (HIE) and associated conditions such as seizures have been associated with poor developmental outcome in neonates. Our limited knowledge of the neurological and cerebrovascular processes underlying seizures limits their diagnosis and timely treatment. Diffuse optical tomography (DOT) provides haemodynamic information in the form of changes in concentration of de/oxygenated haemoglobin, which can improve our understanding of seizures and the relationship between neural and vascular processes. Using simultaneous EEG-DOT, we observed distinct haemodynamic changes which are temporally correlated with electrographic seizures. Here, we present DOT-EEG data from two neonates clinically diagnosed as HIE. Our results highlight the wealth of mutually-informative data that can be obtained using DOT-EEG techniques to understand neurovascular coupling in HIE neonates.

Optical Monitoring in Neonatal Seizures

“…A total of 11 clinical studies were identified [ 43 , 46 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 ], of which eight were case reports [ 43 , 46 , 75 , 77 , 78 , 79 , 80 , 82 ] and three were cohort studies [ 74 , 76 , 81 ]. The studies reported on NIRS parameters, HbO 2 , HHb, HbT, HbD, rSO 2 , FTOE and CCO.…”

“…Pre-ictal changes in cerebral haemodynamics were reported in four studies [ 43 , 46 , 80 , 82 ]. Singh et al [ 43 , 80 ] reported an increase in all haemoglobin parameters (HbO 2 , HHb and HbT) prior to the onset of seizures. These changes were reported as remarkably consistent between seizure events.…”

“…These changes were reported as remarkably consistent between seizure events. A widespread increase in HbT was described 10 s prior to seizure onset using a diffuse optical tomography (DOT) imaging system [ 43 , 80 ]. Wallois et al [ 82 ] also reported an initial increase in HbO 2 , HHb and HbT in all seizures except for five left-sided seizures where an initial drop in HbO 2 was clearly observed with an increase in HHb.…”

“…During the ictal phase, four studies reported changes in haemoglobin parameters [ 43 , 46 , 80 , 82 ]. Mitra et al [ 46 ] presented the changes during individual seizures in detail in relation to electrical changes.…”

Construction and validation of a database of head models for functional imaging of the neonatal brain

“…By using a structural prior to model field propagation within the head, imaging techniques such as DOT are enabled which produce images that spatially localise activation on the cortex (rather than relying on the position of sources and detectors on the scalp to interpret results, as is done in conventional fNIRS). In the last two decades, a large body of research applying DOT to the study of the neonatal brain has been established, such as studies of functional activation (Austin et al, 2006; Hebden, 2003; Karen et al, 2019; White, Liao, Ferradal, Inder, & Culver, 2012), neuropathology (Chalia et al, 2016; Dempsey et al, 2014; Plomgaard et al, 2016; Singh et al, 2016), and monitoring the brain for extended periods (Brigadoi et al, 2019). Previous work with infants has also employed prior structural information as a space to which functional data can be registered (Papademetriou et al, 2013).…”