title: Reference values for amplitude-integrated EEGs in infants from preterm to 3.5 months of age.
abstract: OBJECTIVE
  Amplitude-integrated electroencephalogram (aEEG) is a valuable tool for the continuous evaluation of functional brain maturation in infants. The amplitudes of the upper and lower margins of aEEGs are postulated to change with maturation and correlate with postmenstrual age (PMA). In this study we aimed to establish reliable reference values of aEEG amplitudes, which provide quantitative guidelines for assessing brain maturation as indicated by aEEG results in neonates and young infants.
  
  
  METHODS
  aEEGs from healthy infants (n = 274) with PMAs that ranged from 30 to 55 weeks were divided into 10 groups according to their PMAs. Two 5-minute segments were selected from each aEEG and were used to automatically calculate the upper and lower margins and bandwidths of the aEEG tracings.
  
  
  RESULTS
  Interobserver agreement was achieved with an overall correlation of 0.99. The upper and lower margins of the aEEGs in both active and quiet sleep clearly rose in infants after the neonatal period. The bandwidth defined as the graphic distance decreased almost monotonically throughout the PMA range from 30 to 55 weeks. The lower margin of the aEEG was positively correlated with PMA, with a larger rank correlation coefficient during quiet sleep (r = 0.89) than during active sleep (r = 0.49).
  
  
  CONCLUSIONS
  Reference values of aEEG amplitudes were obtained for infants with a wide range of PMAs and constituted the basis for the quantitative assessment of aEEG changes with maturation in neonates and young infants. The normative amplitudes of aEEG margins, especially of the lower margin in quiet sleep, are recommended as a source of reference data for the identification of potentially abnormal aEEG results.
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, 19 Xinjiekou Wai St, Beijing 100875, People's Republic of China. zhangdd05@gmail.com
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhang
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Liu
authors.forename: Xinlin
authors.initials: X
authors.lastname: Hou
authors.forename: Congle
authors.initials: C
authors.lastname: Zhou
authors.forename: Yuejia
authors.initials: Y
authors.lastname: Luo
authors.forename: Datian
authors.initials: D
authors.lastname: Ye
authors.forename: Haiyan
authors.initials: H
authors.lastname: Ding
mesh_terms: D000367:Age Factors; D001921:Brain / Q000254:growth & development* / Q000502:physiology; D016022:Case-Control Studies; D002657:Child Development / Q000502:physiology; D002681:China; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D015588:Observer Variation; D011247:Pregnancy; D012016:Reference Values; D013997:Time Factors