title: Correlation of cochlear nerve size and auditory performance after cochlear implantation in postlingually deaf patients.
abstract: OBJECTIVE
  Cochlear implantation (CI) yields outstanding results in postlingual deafness, but outcomes of auditory performance after CI are variable. Thus far, it has been difficult to accurately predict patient prognoses after CI.
  
  
  OBJECTIVE
  To assess whether cochlear nerve (CN) size as measured with parasagittal magnetic resonance imaging (MRI) is correlated with auditory performance after CI in postlingually deaf patients.
  
  
  METHODS
  Retrospective study. All MRI results were reviewed by the same observer, who was blinded to the participants' information.
  
  
  METHODS
  A university tertiary care center.
  
  
  METHODS
  All 102 postlingually deaf adults who underwent CI during the period August 2010 through June 2012 were eligible to participate. Thirty-four patients were excluded because MRI was not performed or was not of sufficient quality for assessment. Sixty-eight postlingually deaf adults (mean [range] age, 49 [16-77] years) were enrolled.
  
  
  METHODS
  Cochlear implantation.
  
  
  METHODS
  Size of the CN and auditory performance.
  
  
  RESULTS
  The mean (SD) cross-sectional area (CSA) of the CN was 0.922 (0.229) mm2 and tended to decrease with age; however, there was no significant correlation between the size of the CN and age. The cause of deafness also did not affect the size of the CSA. However, CSA was negatively associated with both the duration of deafness (P < .001) and degree of hearing loss (P = .008 for the difference in CSA between ears with no more than 80-dB hearing loss [n = 25] and ears with at least 101-dB hearing loss [n = 65]). Interestingly, CSA was positively correlated with auditory performance after CI (P = .04).
  
  
  CONCLUSIONS
  We suggest that measuring the size of the CN with parasagittal MRI can yield information that is helpful in preoperative counseling of patients.
authors.affiliation: Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Bo Gyung
authors.initials: BG
authors.lastname: Kim
authors.forename: Hyo Jin
authors.initials: HJ
authors.lastname: Chung
authors.forename: Jeong Jin
authors.initials: JJ
authors.lastname: Park
authors.forename: Sera
authors.initials: S
authors.lastname: Park
authors.forename: Sung Huhn
authors.initials: SH
authors.lastname: Kim
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D019929:Cochlear Implantation; D003056:Cochlear Nerve / Q000473:pathology*; D003638:Deafness / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome