Neonatal seizures in preterm newborns: A predictive model for outcome

Background With a reported prevalence of 22.2%, seizures in preterm newborns represent an emergent challenge, because they are often related to adverse outcome. The electroclinical features of preterm infants with neonatal seizures were evaluated in order to predict outcome. Methods From 154 newborns with video-EEG confirmed neonatal seizures admitted to Parma University Hospital between January 1999 and December 2012, we collected 76 preterm newborns with neonatal seizures. Outcome was assessed at least at one year. Student t-test for unpaired data was used to compare means of continuous variables. We applied the χ2 test to compare nominal data between preterm newborns with favorable versus adverse outcome, and between those with seizures versus those with status epilepticus. Then we determined the independent risk factors for adverse outcome with multivariate logistic regression analysis. Results Birth weight, Apgar at 1st minute, neurologic examination, EEG, US brain scans and the presence of neonatal status epilepticus were different between preterm newborns with favorable and adverse outcome (p ≤.049). Furthermore, birth weight, seizure onset, neurologic examination and EEG were different between the group with or without status (p ≤.031). None of the infants with status epilepticus had a favorable outcome compared to 22.3% of those with neonatal seizures (p =.004). We also identified a predictive model that correctly classified outcome in 85.5% of subjects, with a high sensitivity for adverse outcome (>91.5%). Conclusion The presence of neonatal seizures in preterm newborns is highly related to an adverse outcome that can be predicted since the first days of life.