title: Somatosensory evoked potentials in very preterm infants.
abstract: OBJECTIVE
  Cross-sectional and longitudinal reference values of cortical N(1) peak latency of the median nerve SEP in very preterm infants.
  
  
  METHODS
  In infants in a placebo control group within an L-thyroxine supplementation trial, born at less than 30 weeks' gestation, cortical N(1) peak latency was measured at 2 weeks, at term and at 6 months corrected age. Cross-sectional N(1) latency values obtained in 50 infants and complete series of longitudinal values obtained in 15 infants were analyzed in relation to postmenstrual age (PMA).
  
  
  RESULTS
  Mean N(1) latency decreased from 66 ms at 2 weeks to 38 ms at term and 20 ms at 6 months corrected age. Possible confounding factors did not have any significant effect on N(1) latency at 2 weeks or at term age except cranial ultrasound abnormalities at 2 weeks of age.
  
  
  CONCLUSIONS
  Longitudinal N(1) latency values were consistent with cross-sectional N(1) latency values. The observed N(1) latency at term and at 6 months corrected age suggest that extrauterine maturation of the somatosensory pathway in infants born at less than 30 weeks' gestation is delayed by extrauterine life.
authors.affiliation: Department of Neonatology, Emma Children's Hospital Academic Medical Center, University of Amsterdam, H3N-148, P.O. Box 22700, 1100 DE, Amsterdam, The Netherlands. b.j.smit@amc.uva.nl
authors.forename: B J
authors.initials: BJ
authors.lastname: Smit
authors.forename: B W
authors.initials: BW
authors.lastname: Ongerboer de Visser
authors.forename: L S
authors.initials: LS
authors.lastname: de Vries
authors.forename: F W
authors.initials: FW
authors.lastname: Dekker
authors.forename: J H
authors.initials: JH
authors.lastname: Kok
mesh_terms: D003430:Cross-Sectional Studies; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008137:Longitudinal Studies; D008297:Male; D008475:Median Nerve / Q000502:physiology*; D010919:Placebos; D011930:Reaction Time; D012016:Reference Values; D013974:Thyroxine / Q000627:therapeutic use*
chemical_list: D010919:Placebos; D013974:Thyroxine