183 - Multicenter study of EEG background and neurodevelopmental impairment (NDI) in neonates with hypoxic-ischemic encephalopathy (HIE)

Poster Number: 183
Publication Number: 183.137

Hannah C. Glass, University of California, San Francisco, School of Medicine, San Francisco, CA, United States; Adam L. Numis, University of California, San Francisco, School of Medicine, San Francisco, CA, United States; Bryan Comstock, University of Washington School of Medicine, Seattle, WA, United States; Niranjana Natarajan, University of Washington School of Medicine, Seattle, WA, United States; Fernando F. Gonzalez, University of California, San Francisco, School of Medicine, San Francisco, CA, United States; Ulrike Mietzsch, University of Washington School of Medicine, Seattle, WA, United States; Dennis E.. Mayock, UWMC, Lake Forest Park, WA, United States; Gregory M. Sokol, Indiana University School of Medicine, Indianapolis, IN, United States; Sandra Juul, Sandra Juul, Bellevue, WA, United States; Shavonne Massey, Childrens Hospital of Philadelphia, Philadelphia, PA, United States; Krisa P. Van Meurs, Stanford University School of Medicine, Menlo Park, CA, United States; Cameron Thomas, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Patrick Heagerty, University of Washington, seattle, WA, United States; Yvonne Wu, UCSF, San Francisco, CA, United States; Courtney J. Wusthoff, Stanford, Palo Alto, CA, United States

Background: Predicting neurodevelopment for neonates with HIE is important for clinical decision-making and communication with parents.

Objective:

To examine the relationship between EEG background and NDI in neonates with HIE, we analyzed a sub-set of children enrolled in the HEAL trial (Epo vs placebo in neonates who received hypothermia) who were evaluated with EEG throughout cooling.

Design/Methods: An artifact-free period of EEG ≥60 minutes was selected at onset of recording and at 24, 36, 48, and 72 hours after birth. At each time point, two neurophysiologists classified background as normal, excessively discontinuous, or severely abnormal (i.e., burst suppression, low voltage suppressed, or status epilepticus). To determine the predominant background pattern, we calculated the arithmetic mean of the EEG background (normal=0; discontinuous=1; severely abnormal=2) at each time point, and classified infants into the following 5 categories: “predominantly normal” (mean=0), “normal/discontinuous” (0< mean < 1), “predominantly discontinuous” (mean=1), “discontinuous/severely abnormal” (1< mean < 2), or “predominantly severely abnormal” (mean=2). NDI was characterized at 22-36 months based on presence of cerebral palsy, Gross Motor Function Classification Score, and cognitive score of the Bayley Scales of Infant Toddler Development, 3rd edition. Primary outcome was death or severe NDI. Neurodevelopment was also evaluated as a 5-level ordinal measure: No NDI, mild, moderate, or severe NDI, or death. We used generalized linear regression models with robust standard errors to assess the relative risk of death or severe NDI by EEG characteristic in both unadjusted and adjusted (treatment group, sex, HIE severity, site) analyses.

Results: Among 142 neonates, EEG was predominantly normal in 35 (25%), normal/discontinuous in 68 (48%), predominantly discontinuous in 11 (8%), discontinuous/severely abnormal in 16 (11%), and predominantly severely abnormal in 12 (8%). There were no differences by study group (Epo vs placebo). The clinical characteristics of children with (n=39, 26%) or without (n=111, 74%) a severely abnormal EEG background at any of the 5 time points are in Table 1. EEG background measures were associated with death or NDI at two years (Figures 1, 2).

Conclusion(s): This large, multicenter cohort, with standardized neurophysiology review supports existing literature demonstrating a strong association between EEG background and neurodevelopmental outcome. Future work will examine the predictive value of EEG background along with early clinical and neuroimaging risk factors for NDI.