title: Value of intracochlear electrically evoked auditory brainstem response after cochlear implantation in patients with narrow internal auditory canal.
abstract: OBJECTIVE
  Cochlear implantation in patients with narrow internal auditory canal (IAC) can result in variable outcomes; however, preoperative evaluations have limitations in accurately predicting outcomes. In this study, we analyzed the outcomes of cochlear implantation in patients with narrow IAC and correlated the intracochlear electrically evoked auditory brainstem response (EABR) findings to postoperative performance to determine the prognostic significance of intracochlear EABR.
  
  
  METHODS
  Retrospective case series at a tertiary hospital.
  
  
  METHODS
  Thirteen profoundly deaf patients with narrow IAC who received cochlear implantation from 2002 to 2008 were included in this study. Postoperative performance was evaluated after at least 12 months of follow-up, and postoperative intracochlear EABR was measured to determine its correlation with outcome. The clinical significance of electrically evoked compound action potential (ECAP) was also analyzed.
  
  
  RESULTS
  Patients with narrow IAC showed postoperative auditory performances ranging from CAP 0 to 4 after cochlear implantation. Intracochlear EABR measured postoperatively demonstrated prognostic value in the prediction of long-term outcomes, whereas ECAP measurements failed to show a significant correlation with outcome.
  
  
  CONCLUSIONS
  Consistent with the advantages of intracochlear EABR over extracochlear EABR, this study demonstrates that intracochlear EABR has prognostic significance in predicting long-term outcomes in patients with narrow IAC. Intracochlear EABR measured either intraoperatively or in the early postoperative period may play an important role in deciding whether to continue with auditory rehabilitation using a cochlear implant or to switch to an auditory brainstem implant so as not to miss the optimal timing for language development.
authors.affiliation: Department of Otorhinolaryngology, Kwandong University College of Medicine, Goyang, South Korea.
authors.forename: Mee Hyun
authors.initials: MH
authors.lastname: Song
authors.forename: Mi Ran
authors.initials: MR
authors.lastname: Bae
authors.forename: Hee Nam
authors.initials: HN
authors.lastname: Kim
authors.forename: Won-Sang
authors.initials: WS
authors.lastname: Lee
authors.forename: Won Sun
authors.initials: WS
authors.lastname: Yang
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D019929:Cochlear Implantation; D003638:Deafness / Q000503:physiopathology / Q000601:surgery*; D007758:Ear, Inner / Q000473:pathology*; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009929:Organ Size; D011379:Prognosis; D012189:Retrospective Studies