Development of epilepsy in newborns with moderate hypoxic-ischemic encephalopathy and neonatal seizures

Background: Hypoxic-ischemic encephalopathy (HIE) is one of the most frequent causes of neonatal death or neurological handicaps such as cerebral palsy, mental delay, and epilepsy. Moreover, an acute consequence of HIE are neonatal seizures which can cause an additional brain damage. The neurodevelopmental outcome is known in the mild or severe cases of HIE, but in the moderate conditions the predictivity results, to date, unsatisfying. Objective: The purpose of this prospective study was to appraise the development of post-neonatal epilepsy in a cohort of term infants with moderate HIE and neonatal seizures. Methods: This study considered all newborns admitted to Neonatal Intensive Care Unit of the University of Parma between January 2000 and December 2002 for perinatal asphyxia, then followed by Neonatal Neurology Service. In all patients, neonatal variables such as type of delivery, birth weight, gestational age, Apgar scores, the need for resuscitation and assisted ventilation soon after birth, and arterial-blood pH were analyzed. Results: Ninety-two newborns were enrolled in the study because of perinatal asphyxia. Of these, 27 subjects developed mild HIE, 25 moderate, and five severe HIE. Neonatal seizures were present in 13 subjects with moderate HIE and in all newborns with severe HIE. At the last follow-up, only three infants belonging to patients with severe HIE developed epilepsy. Conclusion: Moderate HIE seems not to be related to post-neonatal epilepsy either if associated or not with neonatal seizures.