Abstracts

Rationale: We aimed to determine whether electrographic seizures are associated with unfavorable neurodevelopmental outcomes in neonates with hypoxic-ischemic encephalopathy (HIE) managed with therapeutic hypothermia (TH). Methods: We conducted a retrospective cohort study in consecutive neonates who underwent TH for HIE between April 2010 and December 2016. All neonates underwent 96 hours of continuous, conventional EEG monitoring during TH, rewarming, and 24 hours of normothermia. Outcome data were obtained from standardized neonatal, neurologic, and developmental assessments. The association between electrographic seizures and outcome was evaluated using logistic regression. Results: Follow-up data were available for 92 of 132 neonates (70%), with a median follow-up duration of 23 months (range 2-72 months). Electrographic seizures occurred in 38 neonates (30%). Electrographic seizures were associated with increased risk of developmental delays in gross motor skills (OR 3.61, CI 1.25-10.5, p=0.018), fine motor skills (OR 4.28, CI 1.35-13.52, p=0.013), language skills (OR 4.31, CI 1.60-11.66, p=0.004), and social/cognitive skills (OR 6.11, CI 1.85-20.1, p=0.003). Among neonates with seizures, higher seizure burden (> 3 seizures) was associated with increased risk of developmental delay overall (OR 3.23, CI 1.07-9.81, p=0.038). Conclusions: The occurrence of electrographic seizures in neonates with HIE treated with TH were associated with subsequent developmental impairments. Ongoing multivariate analyses will adjust for relevant clinical variables, such as HIE severity. Funding: NINDS K23NS076550