A 38-year-old woman complains of dizziness and oscillopsia whenever she hears loud music, and says her own voice sounds unusually loud in the affected ear. Pure tone audiogram shows a low-frequency air-bone gap with normal acoustic reflexes. High resolution CT of the temporal bone confirms the diagnosis. The definitive surgical treatment is:
- A Stapedotomy
- B Endolymphatic sac decompression
- C Middle cranial fossa approach with plugging of the dehiscent canal ✓
- D Translabyrinthine vestibular nerve section
Correct answer: C. Middle cranial fossa approach with plugging of the dehiscent canal
Explanation
Tullio phenomenon with autophony, a low-frequency conductive loss, and preserved acoustic reflexes defines superior semicircular canal dehiscence, confirmed on high resolution CT. The reflexes remain intact because the third window shunts energy away from the cochlea rather than fixing the stapes, which kills the otosclerosis distractor. Definitive repair is resurfacing or plugging of the dehiscent canal via the middle fossa approach. Stapedotomy addresses otosclerosis, nerve section destroys hearing, and sac decompression is for Meniere's disease.
Reference: Cummings Otolaryngology: Head and Neck Surgery, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.