title: A positive wave at 8 ms (P8) and modified auditory brainstem responses measurement in auditory neuropathy spectrum disorder.
abstract: OBJECTIVE
  Auditory neuropathy spectrum disorder (ANSD) is characterized by absent or atypical auditory brainstem responses (ABR), recordable otoacoustic emissions and/or cochlear microphonics. Modification of ABR stimuli is discussed to improve wave V synchronization in ANSD patients.
  
  
  METHODS
  Ten ANSD children (seven unilateral) underwent ABR measurement with an alternating stimulus (40.5s(-1)), constant rarefaction and condensation stimuli, a reduced click-rate (11.1s(-1)) and a chirp-stimulus.
  
  
  RESULTS
  The results showed no remarkably better synchronization with modified stimuli. Whereas higher levels showed no synchronization, reproducible positive waves at 8 ms (P8) at intensities of 65-85 dB were found in six patients with all stimuli.
  
  
  CONCLUSIONS
  We suggest an ipsilateral auditory origin of the positive potentials at 8 ms. They could be characteristic of synchronization abnormalities in some cases of ANSD.
authors.affiliation: Muenster University Hospital, Department of Phoniatrics and Pedaudiology, Kardinal-von-Galen-Ring 10, 48129 Muenster, Germany. michael.schmidt@uni-muenster.de
authors.forename: Claus-Michael
authors.initials: CM
authors.lastname: Schmidt
authors.forename: Jan Robin
authors.initials: JR
authors.lastname: Huebner
authors.forename: Dirk
authors.initials: D
authors.lastname: Deuster
authors.forename: Antoinette Am
authors.initials: AA
authors.lastname: Zehnhoff-Dinnesen
authors.forename: Arne
authors.initials: A
authors.lastname: Knief
mesh_terms: D000158:Acoustic Impedance Tests; D000293:Adolescent; D001299:Audiometry / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D006313:Hearing Loss, Central / Q000503:physiopathology*; D006801:Humans; D008297:Male; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*