Complex sentence: The cause of BPPV is the presence of normal but misplaced calcium crystals called otoconia, which are normally found in the utricle and saccule (the otolith organs) and are used to sense movement.
Split into simpler sentences: The cause of BPPV is the presence of normal but misplaced crystals called otoconia. Otoconia are normally found in the utricle and saccule and are used to sense movement.