title: Evaluation of a novel, noninvasive, objective test of auditory nerve function in cochlear implant candidates.
abstract: OBJECTIVE
  To investigate whether the objective noninvasive recording of the electrically evoked amplitude modulation following response (EAMFR) can be applied for the assessment of auditory nerve function before cochlear implant surgery.
  
  
  METHODS
  Prospective clinical study from January 2005 to August 2008.
  
  
  METHODS
  Cochlear Implant Program at the Charité University Hospital (Berlin, Germany).
  
  
  METHODS
  One hundred twenty-one patients with severe to total bilateral sensorineural hearing impairment.
  
  
  METHODS
  Diagnostic.
  
  
  METHODS
  All EAMFR thresholds were correlated with the mean intraoperative electrically evoked compound action potential (ECAP) thresholds. In a subgroup of 16 patients, the objective thresholds of the EAMFR were compared with the subjective auditory thresholds for the electrical stimuli applied. The intraindividual left-right concordance of the EAMFR and ECAP thresholds was investigated in 22 patients with bilateral implants.
  
  
  RESULTS
  The EAMFR-auditory nerve function test produced clear responses in all patients examined. The threshold of auditory perception for the applied stimuli correlated highly significantly with the EAMFR threshold (r = 0.89, p < 0.01). The correlation between the EAMFR and mean ECAP thresholds was again highly significant (r = 0.49, p < 0.01). In all patients with bilateral implants, the ear with the lower preoperative EAMFR threshold was also the one with the lower intraoperative mean ECAP threshold.
  
  
  CONCLUSIONS
  These results indicate that the objective noninvasive recording of EAMFR seems to be a useful diagnostic tool for the evaluation of the auditory nerve function in cochlear implant candidates, especially in children or in adult patients who require objective examination.
authors.affiliation: Department of Otolaryngology, University Hospital Charité Campus Virchow Klinikum, Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Gräbel
authors.forename: Anke
authors.initials: A
authors.lastname: Hirschfelder
authors.forename: Christian
authors.initials: C
authors.lastname: Scheiber
authors.forename: Heidi
authors.initials: H
authors.lastname: Olze
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000368:Aged; D001309:Auditory Threshold / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D019929:Cochlear Implantation; D003056:Cochlear Nerve / Q000502:physiology*; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000601:surgery / Q000628:therapy; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013686:Telemetry; D055815:Young Adult