A patient with bilateral cochlear otosclerosis treated with sodium fluoride develops worsening balance and oscillopsia. Vestibular testing reveals bilateral vestibular hypofunction. The fluoride therapy is thought to have accelerated which pathological process?
- A Perilymphatic fibrosis obliterating the vestibular labyrinth
- B Destruction of vestibular hair cells by direct ototoxic effect
- C Remodeling of the otic capsule with replacement of dense bone by immature woven bone ✓
- D Autoimmune-mediated vestibular neuritis
Correct answer: C. Remodeling of the otic capsule with replacement of dense bone by immature woven bone
Explanation
In otosclerosis, the active phase (otospongiosis) involves replacement of dense otic capsule bone by vascular, immature woven bone. Sodium fluoride promotes maturation and calcification of this spongiotic bone into dense lamellar bone. Worsening balance during therapy may reflect ongoing otic capsule remodeling rather than a direct ototoxic effect of fluoride, which is not inherently ototoxic.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.