title: Normative amplitude-integrated EEG measures in preterm infants.
abstract: OBJECTIVE
  Assessing qualitative patterns of amplitude-integrated electroencephalography (aEEG) maturation of preterm infants requires personnel with training in interpretation and an investment of time. Quantitative algorithms provide a method for rapidly and reproducibly assessing an aEEG recording independent of provider skill level. Although there are several qualitative and quantitative normative data sets in the literature, this study provides the broadest array of quantitative aEEG measures in a carefully selected and followed cohort of preterm infants with mild or no visible injury on term-equivalent magnetic resonance imaging (MRI) and subsequently normal neurodevelopment at 2 and 7 years of age.
  
  
  METHODS
  A two-channel aEEG recording was obtained on days 4, 7, 14 and 28 of life for infants born ⩽30 weeks estimated gestational age. Measures of amplitude and continuity, spectral edge frequency, percentage of trace in interburst interval (IBI), IBI length and frequency counts of smooth delta waves, delta brushes and theta bursts were obtained. MRI was obtained at term-equivalent age and neurodevelopmental testing was conducted at 2 and 7 years of corrected age.
  
  
  RESULTS
  Correlations were found between increasing postmenstrual age (PMA) and decreasing maximum amplitude (R= -0.23, P=0.05), increasing minimum amplitude (R=0.46, P=0.002) and increasing spectral edge frequency (R=0.78, P=4.17 × 10(-14)). Negative correlations were noted between increasing PMA and counts of smooth delta waves (R= -0.39, P=0.001), delta brushes (R= -0.37, P=0.003) and theta bursts (R= -0.61, P=5.66 × 10(-8)). Increasing PMA was also associated with a decreased amount of time spent in the IBI (R= -0.38, P=0.001) and a shorter length of the maximum IBI (R= -0.27, P=0.03).
  
  
  CONCLUSIONS
  This analysis supports a strong correlation between quantitatively determined aEEG measures and PMA, in a cohort of preterm infants with normal term-equivalent age neuroimaging and neurodevelopmental outcomes at 7 years of age, which is both predictable and reproducible. These 'normative' quantitative values support the pattern of maturation previously identified by qualitative analysis.
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: Z A
authors.initials: ZA
authors.lastname: Vesoulis
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Paul
authors.affiliation: Department of Physics, Washington University in St Louis, St Louis, MO, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Mitchell
authors.affiliation: Newborn Research Centre, The Royal Women's Hospital, Melbourne, VIC, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Wong
authors.affiliation: Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: T E
authors.initials: TE
authors.lastname: Inder
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Mathur
mesh_terms: D004569:Electroencephalography; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D012016:Reference Values; D012890:Sleep / Q000502:physiology