title: Cochlear Implant Outcomes in Cochlea Nerve Aplasia and Hypoplasia.
abstract: To assess cochlear implant (CI) outcomes, and factors affecting outcomes, for children with aplasia/ hypoplasia of the cochlea nerve. We also developed a new grading system for the nerves of the internal auditory meatus (IAM) and cochlea nerve classification.
  
  
  
  Retrospective patient review.
  
  
  
  Tertiary referral hospital and cochlear implant program.
  
  
  
  Children 0 to 16 years inclusive with a CI who had absent/hypoplastic cochlea nerve on magnetic resonance imaging (MRI).
  
  
  
  Cochlear implant.
  
  
  
  MRI, trans-tympanic electrical auditory brainstem response, intraoperative electrical auditory brainstem response, Neural Response Telemetry, Categories of Auditory Perception score, Main mode of communication.
  
  
  
  Fifty CI recipients (26 males and 24 females) were identified, 21 had bilateral CIs, 27 had developmental delay. MRI showed cochlea nerve aplasia in 64 ears, hypoplasia in 25 ears, and a normal nerve in 11 ears. Main mode of communication was analyzed for 41 children: 21 (51%) used verbal language (15 speech alone, 5 speech plus some sign, 1 bilingual in speech and sign), and 20 (49%) used sign language (10 sign alone, 9 sign plus some speech, 1 tactile sign). Seventy-three percent of children used some verbal language. Cochlea nerve aplasia/ hypoplasia and developmental delay were both significant factors affecting main mode of communication. Categories of Auditory Performance scores were available for 59 CI ears; 47% with CN Aplasia (IAM nerve grades 0-III) and 89% with CN hypoplasia (IAM nerve grade IV) achieved Categories of Auditory Performance scores of 5 to 7 (some verbal understanding) (p = 0.003).
  
  
  
  Our results are encouraging and useful when counselling families regarding the likelihood of language outcomes and auditory understanding.
authors.affiliation: *Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney †Sydney Children's Hospital Network (Children's Hospital at Westmead) ‡The Sydney Cochlear Implant Centre §Sydney Medical School, University of Sydney ||Department of Linguistics, Faculty of Human Sciences, Macquarie University, Sydney, NSW, Australia ¶The Royal National Throat Nose and Ear Hospital, London, U.K.
authors.forename: Catherine S
authors.initials: CS
authors.lastname: Birman
authors.forename: Harry R F
authors.initials: HR
authors.lastname: Powell
authors.forename: William P R
authors.initials: WP
authors.lastname: Gibson
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Elliott
mesh_terms: D000293:Adolescent; D001307:Auditory Perception / Q000502:physiology; D002648:Child; D019929:Cochlear Implantation / Q000379:methods; D003054:Cochlear Implants; D003056:Cochlear Nerve / Q000002:abnormalities*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D034381:Hearing Loss / Q000151:congenital* / Q000601:surgery*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D016896:Treatment Outcome