title: Sudden deafness due to intralabyrinthine haemorrhage: a possible rare late complication of head and neck irradiation.
abstract: BACKGROUND
  Radiation injury resulting in sudden, late onset sensorineural hearing loss is a recognised complication in patients who have received head and neck irradiation. We describe the magnetic resonance imaging (MRI) of the internal acoustic canal (IAC) of 3 such patients and postulate a cause for these findings.
  
  
  METHODS
  A total of 63 patients were referred for MRI IAC for sudden-onset sensorineural hearing loss. Of these patients, only 5 patients had abnormal MRI finding in the affected ear and the remaining patients had normal studies. Two patients had acoustic neuromas. Three patients demonstrated high T1-weighted signal in the labyrinths of the affected ears and had past histories of head and neck irradiation. The MRI findings and medical records of these 3 patients were reviewed and described in this case series.
  
  
  RESULTS
  High labyrinthine signal on unenhanced T1-weighted images in the symptomatic ear of these patients was observed, suggesting the possibility of haemorrhage. In the patient who had a history of brain tumour, susceptibility artifacts were also seen in the right hemipons on the gradient-echo images, indicating the presence of paramagnetic substances from previous therapy.
  
  
  CONCLUSIONS
  We postulate that labyrinthine haemorrhage is a rare, late complication of head and neck irradiation, resulting in sudden sensorineural hearing loss.
authors.affiliation: Department of Diagnostic Radiology, Changi General Hospital, Singapore. shirodka@yahoo.co.uk
authors.forename: Angeline C C
authors.initials: AC
authors.lastname: Poh
authors.forename: Tiong Yong
authors.initials: TY
authors.lastname: Tan
mesh_terms: D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006319:Hearing Loss, Sensorineural / Q000209:etiology*; D003639:Hearing Loss, Sudden / Q000209:etiology*; D006470:Hemorrhage / Q000150:complications*; D006801:Humans; D007759:Labyrinth Diseases / Q000150:complications*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D013997:Time Factors