title: Application of a TNF-alpha-inhibitor into the scala tympany after cochlear electrode insertion trauma in guinea pigs: preliminary audiologic results.
abstract: OBJECTIVE
  Cochlear implantation trauma causes both macroscopic and inflammatory trauma. The aim of the present study was to evaluate the effectiveness of the TNF-alpha inhibitor etanercept applied after cochlear implantation trauma on the preservation of acoustic hearing.
  
  
  METHODS
  Guinea pigs were randomly assigned to three groups receiving cochlear implantation trauma by cochleostomy. In one group, the site was sealed by bone cement with no further treatment. A second group was additionally implanted with an osmotic minipump delivering artificial perilymph into the scala tympani for seven days. In the third group, etanercept 1 mg/ml was added to artificial perilymph. Hearing was assessed by auditory brainstem responses at 2, 4, 6, and 8 kHz prior to and after surgery and on days 3, 5, 7, 14, 28.
  
  
  METHODS
  Fifteen healthy guinea pigs.
  
  
  RESULTS
  The trauma led to threshold shifts from 50.3 dB ± 16.3 dB to 68.0 dB ± 19.3 dB. Hearing thresholds were significantly lower in etanercept-treated animals compared to controls on day 28 at 8 kHz and from day 3 onwards at 4 and 2 kHz (p < 0.01; two-way RM ANOVA / Bonferroni t-test).
  
  
  CONCLUSIONS
  The application of etanercept led to preservation of acoustic hearing after cochlear implantation trauma.
authors.affiliation: * Department of Otorhinolaryngology, University Medical Center Göttingen , Germany.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Ihler
authors.forename: Sabrina
authors.initials: S
authors.lastname: Pelz
authors.forename: Melanie
authors.initials: M
authors.lastname: Coors
authors.forename: Christoph
authors.initials: C
authors.lastname: Matthias
authors.forename: Martin
authors.initials: M
authors.lastname: Canis
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D001309:Auditory Threshold / Q000187:drug effects; D019929:Cochlear Implantation / Q000009:adverse effects*; D003054:Cochlear Implants; D000068800:Etanercept; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects; D006168:Guinea Pigs; D034381:Hearing Loss / Q000209:etiology / Q000517:prevention & control*; D007074:Immunoglobulin G / Q000627:therapeutic use*; D007260:Infusion Pumps; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use*; D012533:Scala Tympani / Q000601:surgery; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D007074:Immunoglobulin G; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D000068800:Etanercept
keywords: Cochlear implant; auditory brainstem response; etanercept; guinea pig; tumour necrosis factor-alpha