Multimodal Neuromonitoring in Neonatal Hypoxic-Ischemic Encephalopathy and the Association with Neurodevelopmental...

To assess in neonates with hypoxic-ischemic encephalopathy (HIE) whether multimodal neuromonitoring, using near-infrared spectroscopy and amplitude-integrated electroencephalography (aEEG), correlates with cerebral injury observed on brain magnetic resonance imaging (MRI) as well as neurodevelopmental outcome (NDO).

Neonates born at >35 weeks and >1800 g undergoing therapeutic hypothermia were included in this prospective-retrospective, multicenter study. The aEEG pattern, cerebral tissue oxygenation (rScO₂), burden of rScO₂≥95%, arterial blood pressure, heart rate, and cerebrovascular autoregulation were monitored during therapeutic hypothermia and rewarming from 0 to 24, 24 to 48, 48 to 72, and 72 to 96 hours. Early cerebral MRI was assessed using a validated quali-quantitative score. NDO was assessed using Bayley Scales of Infant Development cognitive and motor scores at 24 months.

In 128 neonates with a median Thompson score of 9, greater seizure burden (beta coefficient, B_24-48h = 3.21, 95% CI limits, 95%CI [2.01, 4.41]), absent sleep-wake-cycling (B_24-48h = -5.53, 95%CI [-8.29, -2.77]), and a higher burden of rScO₂≥95% (B_0-24h = 0.34, 95%CI [0.07, 0.61]) were associated with worse cerebral injury on MRI. Cognitive and motor scores inversely correlated with aEEG abnormalities, rScO₂, burden of rScO₂≥95%, and absent sleep-wake-cycling, whereas higher arterial blood pressures between 0 and 24 hours were associated with higher NDO scores.

Combined abnormal aEEG characteristics and rScO₂, but not cerebrovascular autoregulation assessed as cerebral oximetry index or tissue oxygenation heart rate-reactivity index, correlated significantly with brain injury on MRI and NDO after hypoxic-ischemic encephalopathy. These findings provide valuable clinical information and, in future studies, may support identification of infants who might benefit from adjuvant therapies.