In benign paroxysmal positional veigo, calcium carbonate crystals called otoliths, which are usually fixed in a gelatinous otolithic membrane, float freely in the endolymph. Usually, movement is sensed by the movement of this heavy membrane as it stimulates hair-like projections on sensory hair cells fixed to the membrane in the inner ear. In BPPV, the loose crystals aberrantly stimulate the hair cells with ceain head movements. Thus the sensation of veigo is produced. Hair cell death does not cause veigo. Insufficient cardiac output and cerebral blood flow lead to syncope, not veigo.