[Superior semicircular canal dehiscence mimicking otosclerosis: usefulness of imaging]. / Déhiscence du canal semi-circulaire antérieur mimant une otospongiose: intérêt de l'imagerie.

ABSTRACT

OBJECTIVES: To emphasize the role of computerized tomography (CT) in the etiologic work-up of stapes surgery failure. MATERIAL AND METHODS: Helical high resolution CT scan of the temporal bone with axial and coronal views and multiplanar reconstructions was performed in a patient who had undergone unsuccessful stapedectomy. RESULTS: CT scan demonstrated a well located prosthesis, the absence of the radiological hallmarks of otosclerosis, and revealed a superior semicircular canal dehiscence (SSCD). The diagnosis of SSCD was retrospectively considered accountable for the preoperative clinical and audiometric presentation that had mimicked otosclerosis. CONCLUSION: CT is the diagnostic test of choice in elucidating stapes surgery failure (with persistent or recurrent conductive hearing loss), whereas SSCD should be systematically considered among its causes.