Abstract
Introduction: Severity of hypoxic-ischemic encephalopathy (HIE) is traditionally assessed by neurologic exam; however, electroencephalography (EEG) is a more standardized, reproducible measure of neonatal encephalopathy (NE). We aimed to compare two numeric NE scores with neurophysiological measures of encephalopathy, to describe EEG patterns in newborns with low NE scores, and to assess evolution of NE scores within 6 h after birth. Methods: We retrospectively analyzed associations between two NE scores, amplitude-integrated EEG (aEEG), and conventional-video EEG (cEEG) in 321 newborns in a 14-center collaborative NE Registry. Results: There was a significant association between both NE scores and aEEG/cEEG (p < 0.001), with higher scores in newborns with more abnormal aEEG background patterns. A minority of newborns with low NE scores (<4) had abnormal aEEG/cEEG, but all were treated with therapeutic hypothermia (TH). Most newborns with serial NE scores (74%) had evolution of encephalopathy; more newborns had decreasing/improving (48%) than increasing/worsening (26%) NE scores. Newborns with improving versus worsening scores were more likely to have a first NE score completed before 1 h after birth. Conclusion: Both NE scores showed a significant correlation with neurophysiology, but NE scores have limitations. Since HIE evolves in most newborns, serial NE exams are recommended with the initial or at least confirmatory NE exam completed at >1 h of age. aEEG/cEEG may be particularly useful for identifying more substantial NE warranting TH treatment in newborns with mild NE by exam. Data from this study support standardized use of neurophysiology in evaluating asphyxiated, encephalopathic newborns.
Plain Language Summary
This paper describes diagnosis of an important illness in newborns called hypoxic-ischemic encephalopathy, which is an injury to the brain that happens after blood flow and oxygen are decreased. Typically, the condition is identified by doing a physical exam, but we hope to better understand how monitoring brain activity might identify who has the condition in a more standard way. Identification is especially important because this condition can improve or worsen in the first few hours after birth, and it’s not clear what is the best method to determine whether a baby needs treatment for this condition. One of the only treatments for this condition, if it is severe enough, is to cool down the body temperature to protect the brain. Using a device that monitors brain activity, called EEG, might help determine who should receive the cooling treatment.