What is the direct cause of vertigo in typical BPPV?

What is the direct cause of vertigo in typical BPPV?

• A. Inflammation of vestibular nerve
• B. Sensorineural hearing loss
• C. Dislodged otoconia in semicircular canals
• D. Endolymphatic hydrops

Answer: (C)

In typical BPPV, vertigo comes from tiny calcium carbonate crystals (otoconia) that have become dislodged from the utricle and migrate into a semicircular canal, most often the posterior canal. Once in the canal, these free-floating particles move with the endolymph whenever the head changes position relative to gravity. That movement deflects the cupula and the hair cells inside the canal, sending false signals of rotation to the brain and producing brief episodes of spinning vertigo that are triggered by specific head movements. This mechanism is distinct from other causes: inflammation of the vestibular nerve disrupts nerve signaling and is not limited to canal movement; sensorineural hearing loss isn’t the direct trigger of BPPV vertigo; and endolymphatic hydrops (as in Meniere’s disease) involves fluctuating pressure in the inner ear with hearing loss and fullness, not the canalith-induced brief positional vertigo seen in BPPV.

In typical BPPV, vertigo comes from tiny calcium carbonate crystals (otoconia) that have become dislodged from the utricle and migrate into a semicircular canal, most often the posterior canal. Once in the canal, these free-floating particles move with the endolymph whenever the head changes position relative to gravity. That movement deflects the cupula and the hair cells inside the canal, sending false signals of rotation to the brain and producing brief episodes of spinning vertigo that are triggered by specific head movements.

This mechanism is distinct from other causes: inflammation of the vestibular nerve disrupts nerve signaling and is not limited to canal movement; sensorineural hearing loss isn’t the direct trigger of BPPV vertigo; and endolymphatic hydrops (as in Meniere’s disease) involves fluctuating pressure in the inner ear with hearing loss and fullness, not the canalith-induced brief positional vertigo seen in BPPV.