DISORGANIZED PATTERNS - CHRONIC-STAGE EEG ABNORMALITY OF THE LATE NEONATAL-PERIOD FOLLOWING SEVERELY DEPRESSED EEG ACTIVITIES IN EARLY PRETERM INFANTS

EEG recordings were performed within 72 hours following the birth of 5 5 preterm infants with a gestational age of less than 29 weeks. Sevent een infants (31%) manifested moderately to severely depressed EEG acti vities during this period. Eight of the infants died within a few days after birth, and 9 survived. We recorded EEGs from the surviving infa nts serially throughout the neonatal period, and evaluated EEG finding s in the recovery phase following depressed EEG activities. At 1 to 3 weeks after birth, EEGs revealed an abnormal morphology of background activities in 8 of 9 cases; this was also true of the EEGs of 6 cases at 4 weeks or more of postnatal age. The latter ti cases demonstrated deep white matter injury an cranial ultrasonography, and all of them l ater developed cerebral palsy. Based an the foregoing, EEG findings of early preterm infants in the late neonatal period ape considered a us eful means to detect deep white-matter injury and to allow neurologica l prognosis.