Abstract
Benign positional vertigo (BPV) is caused by detached otolith debris that enters the semicircular canal and moves with changes in head position. Movement in the plane of the affected canal triggers brief but violent episodes of vertigo. The posterior semicircular canal variant (PC-BPV) is by far the most common because once the debris enters the canal it becomes trapped and can remain there for months and even years. We are just beginning to understand how the otolithic membrane is formed, how it is maintained and what happens to otolithic debris floating in the endolymphatic space.