title: Round window electrocochleography and speech perception outcomes in adult cochlear implant subjects: comparison with audiometric and biographical information.
abstract: OBJECTIVE
  Intraoperative round window (RW) electrocochleography (ECoG) can help predict speech perception outcomes in adult cochlear implant (CI) recipients.
  
  
  BACKGROUND
  Speech perception outcomes using CIs are highly variable. Recent data demonstrated that intraoperative ECoG could account for nearly half the variance in postoperative word scores. The present study seeks to update this correlation with a larger sample size and determine if addition of clinical variables improves the prediction.
  
  
  METHODS
  Intraoperative RW ECoG was performed in adult subjects undergoing CI. Amplitudes of the ongoing response to tone bursts of multiple frequencies at 85 to 95 dB HL were summed to obtain the total response (ECoG-TR). ECoG-TR was correlated with postoperative speech perception scores. Multiple linear regression was used to combine clinical factors with the ECoG-TR.
  
  
  RESULTS
  The ECoG-TR accounted for 40% of the variance in CNC word scores (n = 32). The preoperative pure tone average (PTA) was the only clinical factor with a significant correlation (r² = 20%). The ability to predict word scores using ECoG-TR and PTA, or after addition of age and duration of hearing loss, was not significantly different from using ECoG-TR alone. For 2 outliers, ECoG-TR predicted a better word score than obtained.
  
  
  CONCLUSIONS
  The measurement of cochlear physiology before CI, reduced to a single variable, is a better predictor of postoperative speech perception than common clinical factors. Additional analysis of the outliers showed that waveform morphology can provide distinct information in individual cases.
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, U.S.A.
authors.forename: Joseph H
authors.initials: JH
authors.lastname: McClellan
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Formeister
authors.forename: William H
authors.initials: WH
authors.lastname: Merwin
authors.forename: Margaret T
authors.initials: MT
authors.lastname: Dillon
authors.forename: Nathan
authors.initials: N
authors.lastname: Calloway
authors.forename: Claire
authors.initials: C
authors.lastname: Iseli
authors.forename: Craig A
authors.initials: CA
authors.lastname: Buchman
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Fitzpatrick
authors.forename: Oliver F
authors.initials: OF
authors.lastname: Adunka
mesh_terms: D000328:Adult; D000368:Aged; D001299:Audiometry; D001300:Audiometry, Evoked Response; D019929:Cochlear Implantation / Q000379:methods*; D003054:Cochlear Implants; D003638:Deafness / Q000601:surgery; D004594:Electrophysiology / Q000379:methods; D005260:Female; D006801:Humans; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012405:Round Window, Ear / Q000503:physiopathology* / Q000601:surgery; D013067:Speech Perception / Q000502:physiology*