title: Round window electrocochleography before and after cochlear implant electrode insertion.
abstract: Previous reports have documented the feasibility of utilizing electrocochleographic (ECoG) responses to acoustic signals to assess trauma caused during cochlear implantation. The hypothesis is that intraoperative round window ECoG before and after electrode insertion will help predict postoperative hearing preservation outcomes in cochlear implant recipients.
  
  
  
  Prospective cohort study.
  
  
  
  Intraoperative round window ECoG responses were collected from 31 cochlear implant recipients (14 children and 17 adults) immediately prior to and just after electrode insertion. Hearing preservation was determined by postoperative changes in behavioral thresholds.
  
  
  
  On average, the postinsertion response was smaller than the preinsertion response by an average of 4 dB across frequencies. However, in some cases (12 of 31) the response increased after insertion. The subsequent hearing loss was greater than the acute loss in the ECoG, averaging 22 dB across the same frequency range (250-1,000 Hz). There was no correlation between the change in the ECoG response and the corresponding change in audiometric threshold.
  
  
  
  Intraoperative ECoG is a sensitive method for detecting electrophysiologic changes during implantation but had limited prognostic value regarding hearing preservation in the current conventional cochlear implant patient population where hearing preservation was not intended.
  
  
  
  2b Laryngoscope, 126:1193-1200, 2016.
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, the Ohio State University, Columbus, Ohio, U.S.A.|Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A.
authors.forename: Oliver F
authors.initials: OF
authors.lastname: Adunka
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Giardina
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Formeister
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A.
authors.forename: Baishakhi
authors.initials: B
authors.lastname: Choudhury
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Buchman
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A.
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Fitzpatrick
mesh_terms: D000328:Adult; D000368:Aged; D001300:Audiometry, Evoked Response; D001309:Auditory Threshold; D002648:Child; D002675:Child, Preschool; D019929:Cochlear Implantation / Q000379:methods; D003054:Cochlear Implants; D005260:Female; D034381:Hearing Loss / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D012405:Round Window, Ear / Q000502:physiology*
keywords: Electrocochleography; cochlear implants; cochlear physiology; hearing preservation; intraoperative monitoring