Benign paroxysmal positional vertigo (BPPV) is a common disorder affecting the balance system. Specifically, otoliths (so called crystals) become loose and float uncontrolled in the inner ear fluid spaces. These otoliths are heavier than the surrounding fluids and therefore they can accumulate in certain areas of the inner ear, mostly the posterior balance canal.
With certain positional changes such as rolling over in bed, the crystals push against sensory elements within this balance canal. This in turn provides an unnatural stimulation resulting in a spinning sensation (vertigo). Once all crystals have moved into their new position, the vertigo subsides and the affected individual is typically free of any further symptoms. This explains the classic presentation featuring balance spells lasting less than a minute with positional changes. Also, hearing is not affected.
In most cases, the ENT physician can easily diagnose BPPV by triggering the vertigo through putting the head in a certain position. Similarly, a certain sequence of head positions can remove the otoliths from the affected balance canal into another portion of the inner ear that is less susceptible. The success rates of this repositioning maneuver (Epley maneuver) range at about 80%. Some individuals require a more thorough management including repeated repositioning procedures. In very rare cases, surgery may become necessary to obliterate the affected balance canal.