The presence of crystalline debris (canaliths, which are calcium carbonate "stones") in the semicircular canals of the inner ear leading to benign paroxysmal positional vertigo. Specifically, an ear condition in which canaliths (also referred to as otoliths) are dislodged from their usual position within the utricle and migrate over time into one of the semicircular canals. When the head is reoriented relative to gravity, the movement of this debris causes abnormal fluid endolymph displacement and a sensation of vertigo.