BPPV affects which inner ear structure?

BPPV affects which inner ear structure?

• A. The utricle
• B. The cochlea
• C. The semicircular canals with dislodged otolith from the utricle
• D. The tympanic membrane

Answer: (C)

BPPV occurs when otoliths (calcium carbonate crystals) that normally reside in the utricle become dislodged and float into the semicircular canals. When the head changes position, these free-floating crystals move with the endolymph and inappropriate stimulation of the hair cells in the canal (canalithiasis) or adherence to the cupula (cupulolithiasis) produces brief, intense vertigo and nystagmus. The semicircular canals detect angular head movement, so disruption here directly causes positional vertigo. The cochlea handles hearing, and the tympanic membrane is part of the middle ear—neither is involved in BPPV, making the description of the semicircular canals with dislodged otoliths from the utricle the correct fit.

BPPV occurs when otoliths (calcium carbonate crystals) that normally reside in the utricle become dislodged and float into the semicircular canals. When the head changes position, these free-floating crystals move with the endolymph and inappropriate stimulation of the hair cells in the canal (canalithiasis) or adherence to the cupula (cupulolithiasis) produces brief, intense vertigo and nystagmus. The semicircular canals detect angular head movement, so disruption here directly causes positional vertigo. The cochlea handles hearing, and the tympanic membrane is part of the middle ear—neither is involved in BPPV, making the description of the semicircular canals with dislodged otoliths from the utricle the correct fit.