567 The Influence of Gestational Age (GA) on Total Absolute Band Power (TABP) During the Three First Days of Life

Abstract

Background: Continuous long-term multichannel EEG monitoring of the premature infant is possible. This gives information on the brain's electrical activity during the first days of life. tABP is a measure of the EEG-background activity. We have shown that automated trimming of the exported data by removal of 5% of the highest tABP-values correlates well with the visually edited recordings. It is known that the background activity depends on postconceptional age; however, what happens during the first days of life and whether there are GA dependent differences, remains to be demonstrated. Aim: To analyse EEG background activity of the continuous EEG from day 1 to 3 using tABP and compare two different GA groups during this time period. Methods: 42 healthy infants with GA< 31 wk were included, monitored (NicoletOne monitor) continuously for 3 days soon after birth. 8 EEG 8 electrodes were applied. The infants where divided into two groups Progr 1 GA[24+0] - [27+6] wk and Progr 2 GA [28+0] - [30+6] wk). The mean of tABP medians each day calculated showed a normal distribution and were analysed using ANOVA for repeated measurements. Results: Figure There was a significant difference between the groups throughout the study period.(P< 0.01). However, the increase of tABP from d1-3 within each group did not show any significant difference. Conclusion: This study shows that the background activity is dependant on GA from birth and that the changes with time after birth are independent GA.