title: Dexamethasone eluting electrodes for cochlear implantation: Effect on residual hearing.
abstract: OBJECTIVE
  The aim of this study was to compare a cochlear implant electrode array loaded with dexamethasone (DXM) with a conventional passive electrode array for the preservation of residual hearing in gerbils.
  
  
  METHODS
  Thirty Mongolian gerbils (Meriones unguiculatus) were implanted with an eluting electrode loaded with DXM (1 and 10%) on one side and a conventional passive electrode on the other side. Hearing thresholds were determined by tone bursts auditory brainstem responses at 4-6 weeks post-implantation and 1-year post-implantation for older gerbils.
  
  
  RESULTS
  After 4-6 weeks post-implantation, residual hearing was statistically more preserved with electrode arrays loaded with DXM, regardless of concentration, for the frequencies 16 000 Hz (P = 0.0008), 4000 Hz (P = 0.0038), 1000 Hz (P = 0.0349), and 500 Hz (P = 0.0030). After 1 year, the difference in favor of the DXM+ electrode array was found statistically significant only for the frequency 16 000 Hz (P = 0.0103) but against it for the frequencies 1000 Hz (P = 0.0368) and 500 Hz (P = 0.0010).
  
  
  CONCLUSIONS
  Electrode array with prolonged release of DXM improved short-term preservation of residual hearing after implantation for the frequencies 500, 1000, 4000, and 16 000 Hz in gerbils. The long-term results at 1 year confirmed these data for higher frequencies, but must be verified for the lower frequencies of 500 and 1000 Hz.
authors.forename: D
authors.initials: D
authors.lastname: Douchement
authors.forename: A
authors.initials: A
authors.lastname: Terranti
authors.forename: J
authors.initials: J
authors.lastname: Lamblin
authors.forename: J
authors.initials: J
authors.lastname: Salleron
authors.forename: F
authors.initials: F
authors.lastname: Siepmann
authors.forename: J
authors.initials: J
authors.lastname: Siepmann
authors.forename: C
authors.initials: C
authors.lastname: Vincent
mesh_terms: D000818:Animals; D001309:Auditory Threshold / Q000502:physiology; D019929:Cochlear Implantation / Q000295:instrumentation* / Q000379:methods; D003907:Dexamethasone / Q000008:administration & dosage*; D004567:Electrodes, Implanted; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005849:Gerbillinae; D005938:Glucocorticoids / Q000008:administration & dosage*; D006309:Hearing / Q000187:drug effects*
chemical_list: D005938:Glucocorticoids; D003907:Dexamethasone
keywords: Cochlear implant; Corticosteroids; Dexamethasone; Gerbils; Inner ear; Residual hearing