Reference values for three channels of amplitude-integrated EEG using the Brainz BRM3 cerebral function monitor in normal term neonates: a pilot study

Abstract

Background: Amplitude-integrated electroencephalography (EEG) is a form of continuous EEG using a select number of electrodes (2-4), which can be used for bedside monitoring of brain functions in critically ill neonates. There is a paucity of normative amplitude-integrated EEG data for term healthy neonates especially for unilateral channels that are available for newer cerebral function monitors.

Objective: To define absolute amplitudes for all three available channels and also to determine if route of delivery or presence of a caput succedaneum would affect amplitude-integrated EEG amplitude voltages.

Methods: This is a prospective observational study of 80 healthy term neonates (gestational age ≥ 38 weeks) who had three-channel amplitude-integrated EEG recorded for 90 minutes within 12 hours of birth using the Brainz BRM3 cerebral function monitor.

Results: Median maximum and median minimum voltages obtained were 16.96 μV and 8.13 μV for the cross-cerebral (CC), 14.42 μV and 7.13 μV for the right unilateral, and 13.16 μV and 6.51 μV for the left unilateral aEEG channels, respectively. There were no statistically significant difference amplitude voltages for any channel based on route of delivery. The presence of a caput succedaneum was associated with a decrease in the median and mean of the maximum and minimum amplitude voltages for CC channel. Median maximum and median minimum voltages for the CC channel among the caput and normal scalp examination groups were 14.62 μV vs 17.27 μV (P = 0.022) and 7.21 μV vs 8.24 μV (P = 0.004), respectively. Similarly, mean maximum and mean minimum voltages for the CC channel were 15.42 μV vs 17.59 μV (P = 0.038) and 7.27 μV vs 8.25 μV (P = 0.005) in the caput and normal scalp examination groups, respectively.

Keywords: amplitude-integrated electroencephalography (aEEG); cerebral function monitor (CFM); continuous low voltage (CLV); continuous normal voltage (CNV); cross-cerebral channel (CC); electroencephalography (EEG).