In BPPV, otoconia dislodge and migrate from the utricle into which structure?

In BPPV, otoconia dislodge and migrate from the utricle into which structure?

• A. Cochlea
• B. Semicircular canals
• C. Vestibular nerve
• D. Endolymphatic duct

Answer: (B)

In BPPV, otoconia normally seated in the utricle can break loose and float into the semicircular canals. Once there, head movements cause the crystals to move with the endolymph, tugging on the hair cells in the ampulla and producing a false sensation of rotation—vertigo—with a characteristic brief nystagmus. The posterior semicircular canal is the most commonly affected. The cochlea, vestibular nerve, and endolymphatic duct aren’t the sites where these crystals settle, so they aren’t the correct source of the problem.

In BPPV, otoconia normally seated in the utricle can break loose and float into the semicircular canals. Once there, head movements cause the crystals to move with the endolymph, tugging on the hair cells in the ampulla and producing a false sensation of rotation—vertigo—with a characteristic brief nystagmus. The posterior semicircular canal is the most commonly affected. The cochlea, vestibular nerve, and endolymphatic duct aren’t the sites where these crystals settle, so they aren’t the correct source of the problem.