Prognostic value of electroencephalography in hypoxic-ischemic encephalopathy

Background: Hypoxic-ischemic encephalopathy (HIE) is one of the main causes of neurodevelopmental disorders. We developed a model that has diagnostic and prognostic value in predicting the neurodevelopmental outcomes in newborns with HIE. HIE staging allows us to start therapeutic interventions early in newborns with suspected encephalopathy. Methods: This was a retrospective study in a cohort of 58 full-term neonates with clinical suspicion of HIE. We assessed electroclinical variables at birth [etiology of hypoxia, neonatal seizures, HIE stages based on Sarnat criteria, use of therapeutic hypothermia, neuroimaging tests and electroencephalography (EEG) findings] and two years of follow up (EEG findings, development of epilepsy, the presence of cognitive deficits, behavioral issues, language problems, visual or hearing disturbances, and cerebral palsy). Results: There was a high electro-clinical correlation to severe HIE (88.8%) and moderate HIE (50%). There was a considerable proportion of patients affected by mild HIE, based on clinical examination, who presented with an abnormal EEG (32.3%). There is a relationship between the onset of neonatal seizures, epilepsy, and severe HIE diagnosed with EEG (88.9%). A higher percentage of patients with moderate and severe HIE, based on EEG findings, present abnormal results in cranial ultrasound and cerebral magnetic resonance imaging (62.5%). At two years of age, functional neurodevelopment disturbances were observed most frequently in patients affected with severe and moderate HIE based on EEG. Conclusions: This study shows a model with diagnostic and prognostic value in predicting newborns' neurodevelopmental outcomes with suspected HIE. This knowledge allows us to assess the role of performing serial EEG in patients with suspected HIE and the relevance of EEG findings in the prognosis of neurodevelopmental disorders.