Preterm and full-term neonates with electrographically confirmed seizures were compared at the University of Pittsburgh School of Medicine. The incidence of seizures for all neonates admitted to a neonatal ICU was 2.3%. Of 92 neonates with EEG-confirmed seizures seen over a 4 year period, 62 were preterm and 30 were full-term. Seizure frequency of preterm 30 wk neonates was 3.9% and significantly higher than that of older neonates. Clinical seizures were noted in 45% of preterm and 53% of full-term neonates. Seizures were subtle in 71% and 68%, respectively. Ischemic brain lesions were diagnosed in 39% of preterm compared to 77% of full-term neonates. Intraventricular hemorrhage occurred in 45% of preterm and only in 3% of full-term neonates. Mortality was higher in the preterm than in the term populations. 
COMMENT. More than 50% of this cohort had only electrographic expression of seizures. A later onset of seizures in preterm neonates suggests adverse medical complications after birth. One cannot always rely on simultaneous electrographic confirmation of seizures since 16% of patients exhibit electroclinical dissociation.