title: Differences in amplitude among electrode locations on amplitude-integrated electroencephalograms in preterm infants.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Pediatrics, Okazaki City Hospital, Okazaki, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kato
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tsuji
authors.forename: Seiji
authors.initials: S
authors.lastname: Hayashi
authors.forename: Jun
authors.initials: J
authors.lastname: Natsume
authors.forename: Akihisa
authors.initials: A
authors.lastname: Okumura
mesh_terms: D001921:Brain / Q000503:physiopathology*; D058256:Brain Waves; D004566:Electrodes; D004569:Electroencephalography / Q000295:instrumentation*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D011237:Predictive Value of Tests; D047928:Premature Birth / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted