title: MRI brain abnormalities in cochlear implant candidates: how common and how important are they?
abstract: OBJECTIVE
  To investigate the incidence of abnormal findings on brain MRI in paediatric cochlear implantation candidates.
  
  
  METHODS
  Retrospective review of brain MRI scans of cochlear implant patients between 2000 and 2009 who underwent MRI brain as part of their pre-operative work-up.
  
  
  RESULTS
  MRI scans of 162 patients were reviewed (76 female patients and 86 male patients). The mean age at time of MRI scan was 3 years 8 months. Abnormalities were detected/ reported in 49 patients (30%). The total number of abnormalities detected was 51 (two patients had two separate abnormalities each). Of the abnormalities 82% could be related to known pre-existing conditions. 18% of the abnormalities were incidental/unexpected. Incidental/unexpected abnormalities were found in 9 patients (6%). Four of the patients with incidental abnormalities required referral and further investigations (2.5%). The most common abnormality detected was white matter changes (70%). All the white matter changes were related to pre-existing known medical conditions.
  
  
  CONCLUSIONS
  At our institution abnormalities detected by pre-operative brain MRI scans on cochlear implant candidates are common (30%). The majority of abnormalities are related to known pre-existing medical conditions. Incidental findings are rare (4%) and approximately half of them required further investigation or referral.
authors.affiliation: Department of Otolaryngology, Great Ormond Street Hospital, London, United Kingdom. nicojonas@gmail.com
authors.forename: N E
authors.initials: NE
authors.lastname: Jonas
authors.forename: J
authors.initials: J
authors.lastname: Ahmed
authors.forename: J
authors.initials: J
authors.lastname: Grainger
authors.forename: C G
authors.initials: CG
authors.lastname: Jephson
authors.forename: M E
authors.initials: ME
authors.lastname: Wyatt
authors.forename: B E
authors.initials: BE
authors.lastname: Hartley
authors.forename: Dawn
authors.initials: D
authors.lastname: Saunders
authors.forename: L A
authors.initials: LA
authors.lastname: Cochrane
mesh_terms: D001927:Brain Diseases / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D002675:Child, Preschool; D019929:Cochlear Implantation; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000150:complications / Q000601:surgery*; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies