Differences in amplitude among electrode locations on amplitude-integrated electroencephalograms in preterm infants

Abstract

To assess differences in amplitude among electrode locations on amplitude-integrated electroencephalograms (aEEGs) in preterm infants and change therein between preterm age and term-equivalent age (TEA), we investigated aEEGs in preterm infants at both 30-32 wk post-conceptional age (PCA) and TEA. The median values of upper- and lower-margin amplitudes were quantitatively calculated every 5 min (Med-UMA5 and Med-LMA5, respectively), and peak, median, and bottom values were extracted at each location for the trans-frontal, trans-central, trans-occipital, fronto-central, and centro-occipital electrodes. In 38 clinically stable preterm infants studied, most measurement items showed significant differences among the electrode locations at both preterm age and TEA. At 30-32 wk PCA, the bottom of Med-LMA5 was significantly higher for the trans-frontal electrodes than for the trans-central electrodes. In contrast, all measurements for Med-LMA5 were significantly lower for the trans-frontal electrodes than for the trans-central electrodes. Amplitudes on aEEGs were significantly different among the electrode locations in preterm infants, and locational differences in amplitude changed between preterm age and TEA. It is necessary to understand the differences in amplitudes among the electrode locations on aEEGs in infants to appropriately evaluate them.