Electrographic Seizures in Preterm Infants During the First Week of Life Are Associated With Cerebral Injury

Abstract

The aim of the study was to determine the incidence of electrographic seizure activity in a prospective cohort of preterm infants and relate it to the presence of cerebral injury. Infants born <30-wk gestation received a median 74 h of continuous 2-channel EEG with amplitude-integrated EEG monitoring in the first week of life. Infants were classified in the abnormal outcome group if they died in the neonatal period and/or had grades 3-4 intraventricular hemorrhage and/or moderate or severe abnormalities on cerebral MRI. Seizures were defined as rhythmic spike and/or wave activity lasting at least 10 s on the raw EEG trace. Eleven of 51 infants monitored had electrographic seizures. These infants were more premature had lower birth weights and a greater proportion had abnormal outcomes. In four infants, seizures preceded ultrasound findings of grades 3-4 intraventricular hemorrhage. Three of the four infants with seizures and concurrent physiologic recordings displayed concurrent rises in heart rate and one showed a fall in respiratory rate. In conclusion, electrographic seizures were more likely to occur in the sicker and more premature infants with abnormal outcomes. Seizures detected on continuous amplitude-integrated EEG monitoring with the raw EEG were associated with poor outcome.