Determination of timing of brain injury in preterm infants with periventricular leukomalacia with serial neonatal electroencephalography

Objective. The aim of this study was to determine the timing of brain injury in infants with periventricular leukomalacia (PVL) with serial electroencephalography (EEG) recordings during the neonatal period. Patients and Methods. We evaluated 172 preterm infants having a gestational age <33 weeks and weighing <2000 g. Initial EEG was recorded within 72 hours of life and then recorded once every 1 to 4 weeks. Serial cranial ultrasonography was performed and cystic PVL was diagnosed when multiple cystic formations of >3 mm in diameter were observed. Results. Of the 172 infants studied, 26 were diagnosed as having cystic PVL by ultrasonography. EEG abnormalities were observed in 25 of 26 infants with PVL, although EEG abnormalities were seen in 20 of 146 infants without PVL. The initial EEG recordings were normal in 7 infants, but EEG abnormalities were observed later in 6 of these infants. In these 6 infants, the timing of injury was presumed to be postpartum. Only acute stage abnormalities were observed on initial EEG recording in 14 infants, and the timing of injury was presumed to be just before or around birth. Chronic stage abnormalities were recognized already on initial EEG recordings in the other 5 infants, and the timing of injury was presumed to be some time before birth. Conclusions. Our study indicates that it may be possible to determine the timing of injury in infants with PVL by serial EEG recordings.