Optical Monitoring in Neonatal Seizures

Abstract

Background: Neonatal seizures remain a significant cause of morbidity and mortality worldwide. The past decade has resulted in substantial progress in seizure detection and understanding the impact seizures have on the developing brain. Optical monitoring such as cerebral near-infrared spectroscopy (NIRS) and broadband NIRS can provide non-invasive continuous real-time monitoring of the changes in brain metabolism and haemodynamics. Aim: To perform a systematic review of optical biomarkers to identify changes in cerebral haemodynamics and metabolism during the pre-ictal, ictal, and post-ictal phases of neonatal seizures. Method: A systematic search was performed in eight databases. The search combined the three broad categories: (neonates) AND (NIRS) AND (seizures) using the stepwise approach following PRISMA guidance. Results: Fifteen papers described the haemodynamic and/or metabolic changes observed with NIRS during neonatal seizures. No randomised controlled trials were identified during the search. Studies reported various changes occurring in the pre-ictal, ictal, and post-ictal phases of seizures. Conclusion: Clear changes in cerebral haemodynamics and metabolism were noted during the pre-ictal, ictal, and post-ictal phases of seizures in neonates. Further studies are necessary to determine whether NIRS-based methods can be used at the cot-side to provide clear pathophysiological data in real-time during neonatal seizures.

Early changes in cerebral metabolism after perinatal hypoxia-ischemia: a study in normothermic and hypothermic piglets

“…In our study, seizures were only detected in the HI group in three out of eight animals. Seizures have been shown to elicit changes in cerebral metabolism and hemodynamics in both animal and human neonates detectable through optical monitoring ( 51 , 52 ). In contrast, we detected no change in oxygen tension, rSO 2 , CBF, or ICP in relation to seizures.…”

Technical feasibility of multimodal imaging in neonatal hypoxic-ischemic encephalopathy from an ovine model to a human case series

“…Neurovascular (and neurometabolic) dynamics is also relevant to adult acute brain injury cases, where normalization of neurovascular coupling may herald recovery of consciousness ( 56 ). Here, the effects of seizure activity on the coupling dynamics of the neural activity (measured with EEG) with the cerebral metabolism, oxygen delivery, and blood volume may be crucial to guide medication ( 36 , 57 ), especially by leveraging optical monitoring in neonates ( 58 ). Other relevant chromophores, cytochrome c oxidase (CCO) and water, can also be investigated with optical monitoring in the neonates ( 58 ), which was developed in another study by adding four different wavelengths (780, 810, 820, and 840 nm) to the low-cost EEG-fNIRS sensor ( https://neuromodec.org/nyc-neuromodulation-online-2020/P18.html ) ( 59 ).…”

“…Here, the effects of seizure activity on the coupling dynamics of the neural activity (measured with EEG) with the cerebral metabolism, oxygen delivery, and blood volume may be crucial to guide medication ( 36 , 57 ), especially by leveraging optical monitoring in neonates ( 58 ). Other relevant chromophores, cytochrome c oxidase (CCO) and water, can also be investigated with optical monitoring in the neonates ( 58 ), which was developed in another study by adding four different wavelengths (780, 810, 820, and 840 nm) to the low-cost EEG-fNIRS sensor ( https://neuromodec.org/nyc-neuromodulation-online-2020/P18.html ) ( 59 ). In that case series ( 59 ), we found that neurometabolic coupling was specifically affected in HIE with sepsis, which may be related to the differences in the stabilization diagrams (see Figure 5 ) between the six severe HIE human perinatal cases and the four severe HIE human perinatal cases with sepsis.…”

“…In that case series ( 59 ), we found that neurometabolic coupling was specifically affected in HIE with sepsis, which may be related to the differences in the stabilization diagrams (see Figure 5 ) between the six severe HIE human perinatal cases and the four severe HIE human perinatal cases with sepsis. Howard et al ( 58 ) highlighted the importance of the estimation of the oxidation state of the CCO (oxCCO) concentration changes in HIE. Here, CCO is essential to generate ATP efficiently during aerobic respiration, so the effects of seizure activity on the background EEG and oxCCO will be important to study its metabolic effects ( 58 ).…”

“…Howard et al ( 58 ) highlighted the importance of the estimation of the oxidation state of the CCO (oxCCO) concentration changes in HIE. Here, CCO is essential to generate ATP efficiently during aerobic respiration, so the effects of seizure activity on the background EEG and oxCCO will be important to study its metabolic effects ( 58 ). Then, Howard et al ( 58 ) reviewed the literature that showed preictal changes in the cerebral hemodynamics that aligns with our perinatal ovine data ( 24 )—see Figure 4 .…”