A 3-year-old child who survived bacterial meningitis develops profound bilateral sensorineural hearing loss and is planned for cochlear implantation. MRI shows partial ossification of the cochlea. In which part of the cochlea does ossification typically begin after meningitis?
- A Apical turn of the scala vestibuli
- B Modiolus of the middle turn
- C Basal turn of the scala tympani ✓
- D Round window membrane only
Correct answer: C. Basal turn of the scala tympani
Explanation
Post-meningitic labyrinthitis ossificans characteristically starts as fibrous tissue followed by new bone in the scala tympani of the basal turn, near the round window, because inflammatory debris settles in this dependent region. This is why preoperative imaging focuses on basal turn patency, and why drill-out of the scala tympani or a split-array electrode may be needed. The apical turn and modiolus are involved late, if at all.
Reference: Cummings Otolaryngology: Head and Neck Surgery, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.