title: Brainstem auditory electrophysiology is supressed in term neonates with hyperbilirubinemia.
abstract: BACKGROUND
  Whether hyperbilirubinemia suppresses electrophysiological activity of the neonatal auditory brainstem remains to be investigated.
  
  
  OBJECTIVE
  To determine whether hyperbilirubinemia suppresses the brainstem auditory electrophysiology in term neonates.
  
  
  METHODS
  Maximum length sequence brainstem auditory evoked response (MLS BAER) was recorded shortly after confirming hyperbilirubinemia in 58 term neonates. Wave amplitudes of the response were analyzed in detail.
  
  
  RESULTS
  Compared with age-matched term controls, the neonates with hyperbilirubinemia showed a significant reduction in the amplitudes of MLS BAER waves III and particularly V at all click rates 91-910/s. The reduction tended to be more significant at higher than lower rates. Wave I amplitude was reduced at 910/s. V/I amplitude ratio was decreased at all click rates. Therefore, the amplitudes of MLS BAER, particularly later, waves were all reduced. The amplitudes of all MLS BAER waves tended to be reduced with the increase in total serum bilirubin level. All wave amplitudes were correlated with the level of total serum bilirubin at some or most click rates.
  
  
  CONCLUSIONS
  Brainstem auditory electrophysiology is suppressed in neonates with hyperbilirubinemia, which related to the severity of hyperbilirubinemia. Wave amplitudes are valuable BAER variables to detect functional impairment of the brainstem and auditory pathway in neonatal hyperbilirubinemia, and are recommended to be used in assessing bilirubin neurotoxicity to the neonatal brain.
authors.affiliation: Division of Neonatology, Children's Hospital, Fudan University, Shanghai, China. Electronic address: zedong.jiang@paediatrics.ox.ac.uk.
authors.forename: Ze D
authors.initials: ZD
authors.lastname: Jiang
authors.affiliation: Division of Neonatology, Children's Hospital, Fudan University, Shanghai, China.
authors.forename: T T
authors.initials: TT
authors.lastname: Liu
authors.affiliation: Division of Neonatology, Children's Hospital, Fudan University, Shanghai, China.
authors.forename: Cao
authors.initials: C
authors.lastname: Chen
mesh_terms: D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D006801:Humans; D006932:Hyperbilirubinemia / Q000150:complications*; D007231:Infant, Newborn; D008297:Male
keywords: Brainstem auditory impairment; Evoked potentials; Hyperbilirubinemia; Neonate; Neurological impairment