ELECTRICAL BRAIN ACTIVITY IN PRETERM INFANTS AT RISK FOR INTRACRANIALHEMORRHAGE

We studied the effect of preterm birth on electroencephalographic back ground activity in 20 infants < 32 weeks' gestation. Six infants devel oped periventricular-intraventricular hemorrhage during the study peri od. Four-channel 24-h cassette recordings were obtained on day 1, 3-5 and 7-9. For each of the 24-h recordings, the percentage of the time s howing stage I (continuous activity), stage II (mixed activity) and st age III (discontinuous activity) epochs was calculated. In infants wit hout periventricular-intraventricular hemorrhage, a positive linear re lationship between gestational age and continuous activity and a negat ive linear relationship between gestational age and discontinuous acti vity existed in the first day recordings; in infants with periventricu lar-intraventricular hemorrhage, such relationships were not found. To determine if the changes in continuous and discontinuous activities d uring the first week of extrauterine life were different from the expe cted changes during a corresponding time in utero, we calculated the e xpected amounts of stage I and III changes for each infant. The actual changes were not significantly different from the expected values in both study groups. However, during the onset and/or extension of periv entricular-intraventricular hemorrhage, depression of the electroencep halographic background activity was found.