title: Two subgroups of stapes fixation: otosclerosis and pseudo-otosclerosis.
abstract: OBJECTIVE
  Stapes ankylosis is a disease with variable histopathology and can be caused by otosclerosis or pseudo-otosclerosis. Viral pathogenesis of otosclerosis could be established only by correlative analysis: histologic examination of the stapes footplate and reverse-transcriptase polymerase chain reaction (RT-PCR) amplification of the viral RNA.
  
  
  BACKGROUND
  Presence of the RNA genome of measles virus was demonstrated in the footplates of clinically otosclerotic patients by RT-PCR, and also viral proteins were detected by immunohistochemistry.
  
  
  METHODS
  Nucleic acids were extracted from ankylotic stapes footplates of clinically stapes fixation patients (n = 104). Measles virus genomic nucleoprotein (NP) RNA was amplified by seminested RT-PCR. Amplification results were correlated to postoperative histologic and audiologic findings.
  
  
  RESULTS
  Measles virus RNA was detectable only in histologically otosclerotic stapes footplates (n = 67). Histology for virus negative footplates (n = 37) excluded otosclerosis. Virus negative stapes footplates showed nonotosclerotic, degenerative disorders.
  
  
  CONCLUSIONS
  Stapes ankylosis is a heterogeneous disease causing conductive hearing loss with different etiologies. Nonotosclerotic stapes fixations could be established as pseudo-otosclerosis and may belong to nonspecific, degenerative disorders with variable and noncharacteristic histopathology. Otosclerosis is an inflammatory disease caused by persisting measles virus infection of the otic capsule.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University Medical School of Debrecen, Debrecen, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Karosi
authors.forename: József
authors.initials: J
authors.lastname: Kónya
authors.forename: Mihály
authors.initials: M
authors.lastname: Petkó
authors.forename: László Z
authors.initials: LZ
authors.lastname: Szabó
authors.forename: József
authors.initials: J
authors.lastname: Pytel
authors.forename: József
authors.initials: J
authors.lastname: Jóri
authors.forename: István
authors.initials: I
authors.lastname: Sziklai
mesh_terms: D000328:Adult; D000368:Aged; D000844:Ankylosis / Q000150:complications* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008457:Measles / Q000150:complications* / Q000821:virology; D008459:Measles virus / Q000235:genetics; D008875:Middle Aged; D010040:Otosclerosis / Q000209:etiology* / Q000473:pathology; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012720:Severity of Illness Index; D013199:Stapes / Q000473:pathology* / Q000821:virology
chemical_list: D012367:RNA, Viral