Electroencephalography and optical neuromonitoring predict short-term outcomes in neonates undergoing therapeutic hypothermia for hypoxic-ischemic encephalopathy

Electroencephalography (EEG) and optical neuromonitoring were used to predict short-term outcomes in neonates undergoing therapeutic hypothermia (TH) for hypoxic-ischemic encephalopathy (HIE). Fifty-two neonates undergoing TH for HIE were prospectively recruited. Continuous EEG monitoring was initiated within 24 h of life and a quantitative discontinuity index was calculated. Combined frequency-domain near infrared spectroscopy (FDNIRS) and diffuse correlation spectroscopy (DCS) were initiated within 48 h of life and used to measure cerebral hemoglobin oxygen saturation (SO₂) and a cerebral blood flow index. Using these parameters and hemoglobin concentration measurements, cerebral oxygen extraction fraction (OEF), indices of cerebral oxygen delivery and metabolism (CMRO_2i) as well as cerebral oxygen reserve (CRO₂) were derived. Short-term outcome was classified based on brain injury pattern on magnetic resonance imaging and/or death; as normal-mild, moderate or severe outcome. Results showed that EEG discontinuity index, SO₂ and CRO₂ were higher and OEF lower in neonates with severe compared to normal-mild and moderate outcomes during TH. EEG discontinuity index was the most accurate and earliest parameter to identify moderate vs. severe outcomes while CMRO_2i identified normal-mild vs. moderate outcomes as early as day 2 of TH. Combining EEG and FDNIRS-DCS parameters improved area-under-the-curve, sensitivity and specificity for most of the predictive models.