title: Auditory neuropathy spectrum disorder (ANSD) and cochlear implantation.
abstract: We discuss issues related to cochlear implantation in children with auditory neuropathy spectrum disorder (ANSD). We describe the varied nature of this disease category including the numerous potential causes of auditory neuropathy. The most prevalent etiology for infants with ANSD is associated with prolonged neonatal intensive care unit (NICU) stay. We discuss the potential contribution of cochlear hypoxia to this etiology. The second part of this review describes in detail our own experience at the Hospital for Sick Children in Toronto, with cochlear implantation of children diagnosed with ANSD. We outline the detection, diagnosis, and referral routes for our patients. We provide an overview of our "standard operation procedures" regarding candidacy, and discuss some of the special considerations that need to be applied to children with ANSD. This includes decisions to implant children with better audiometric thresholds that are standard in non-ANSD patients, concerns about the possibility of spontaneous remission and the appropriate timing of implantation. Finally we review an extensive published literature in outcomes after cochlear implantation (CI) in ANSD. This is not a systematic review but rather an exercise to distill out some important reoccurring themes and the general consensus of opinion to date. Our conclusion is that the hearing loss category ANSD, together with its numerous co-morbidities, is far too heterogeneous to make definitive statements about prognosis with CI.
authors.affiliation: Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8; Department of Otolaryngology - Head and Neck Surgery, University of Toronto, 190 Elizabeth Street, Toronto, Ontario, Canada MG5 2N2. Electronic address: rvh@sickkids.ca.
authors.forename: Robert V
authors.initials: RV
authors.lastname: Harrison
authors.affiliation: Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8; Department of Otolaryngology - Head and Neck Surgery, University of Toronto, 190 Elizabeth Street, Toronto, Ontario, Canada MG5 2N2.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Gordon
authors.affiliation: Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8; Department of Otolaryngology - Head and Neck Surgery, University of Toronto, 190 Elizabeth Street, Toronto, Ontario, Canada MG5 2N2.
authors.forename: Blake C
authors.initials: BC
authors.lastname: Papsin
authors.affiliation: Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8.
authors.forename: Jaina
authors.initials: J
authors.lastname: Negandhi
authors.affiliation: Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8; Department of Otolaryngology - Head and Neck Surgery, University of Toronto, 190 Elizabeth Street, Toronto, Ontario, Canada MG5 2N2.
authors.forename: Adrian L
authors.initials: AL
authors.lastname: James
mesh_terms: D001299:Audiometry; D002648:Child; D019929:Cochlear Implantation / Q000379:methods*; D003054:Cochlear Implants; D005260:Female; D006313:Hearing Loss, Central / Q000175:diagnosis / Q000534:rehabilitation* / Q000628:therapy; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000534:rehabilitation*; D006801:Humans; D007223:Infant; D008297:Male
keywords: Auditory dys-synchrony; CI candidacy protocol; Cochlear hypoxia; Cochlear nerve aplasia; High-risk infant; Neonatal hearing screening