title: Prevalence and risk factors for auditory neuropathy spectrum disorder in a screened newborn population at risk for hearing loss.
abstract: OBJECTIVE
  To determine the prevalence of Auditory Neuropathy Spectrum Disorder (ANSD) among infants with sensorineural hearing loss (SNHL) and discuss the risk factors.
  
  
  METHODS
  The study group was comprised of children diagnosed with ANSD. Criteria for inclusion in the study group were as follows: permanent sensorineural hearing loss (SNHL); normal transient evoked or distortion product OAEs; absent or elevated middle-ear muscle reflexes (MEMR); severely abnormal or absent ABR waveform. All newborns were screened via a two-stage protocol, involving OAEs and ABR for the repeatedly referred cases and all neonates with one or more risk factors.
  
  
  RESULTS
  From 2002 to 2011, 9419 infants whose hearing ability was uncertain or who had risk factors for hearing loss were investigated. From this population, 352 were diagnosed with SNHL. Of these 352 children, 18 (5.1%) were diagnosed with ANSD. In the ANSD group, prematurity and low birth weight (<1500 g) were observed in 5 cases; ototoxical medication in 8 cases; mechanical ventilation in excess of 5 days in 5 cases. Hyperbilirubinemia was observed in 7 cases, but severe hyperbilirubinemia requiring an exchange transfusion was not observed; 4 patients had no risk factors, 6 patients had only one risk factor, and the 8 remaining had two or more risk factors.
  
  
  CONCLUSIONS
  Auditory Neuropathy Spectrum Disorder is not an extremely rare hearing disorder. Screening for hearing loss via OAEs, MEMR and ABR examinations concurrently are essential for the accurate diagnosis of ANSD.
authors.affiliation: Department of Pediatric Surgery, Division of Otolaryngology, Medical University of Silesia, Upper Silesian Center for Child Health, Medyków 16 street, 40-752 Katowice, Poland. ibielecki@sum.edu.pl
authors.forename: Ireneusz
authors.initials: I
authors.lastname: Bielecki
authors.forename: Anna
authors.initials: A
authors.lastname: Horbulewicz
authors.forename: Teresa
authors.initials: T
authors.lastname: Wolan
mesh_terms: D001299:Audiometry; D001304:Auditory Diseases, Central / Q000175:diagnosis* / Q000503:physiopathology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D006932:Hyperbilirubinemia / Q000453:epidemiology; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D015997:Neonatal Screening; D015995:Prevalence; D012021:Reflex, Abnormal / Q000502:physiology*; D012022:Reflex, Acoustic / Q000502:physiology*; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors