Benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is the most common and most treatable cause of vertigo. In most cases, a simple maneuver that takes less than a few minutes to do resolves the problem. BPPV is caused by misplaced calcium carbonate crystals (otoconia) in the semicircular canal of the inner ear that have broken free from the utricle. When these crystals break free, they either remain loose in one of three different semicircular canals or attach to the hair cells within a canal. Several different types of treatment maneuvers have been described. The maneuver to use varies according to the semicircular canal involved and whether the crystals are loose or attached to the hair cells.