BPPV

The most common cause of vertigo, caused by displaced inner ear crystals

Overview

Benign paroxysmal positional vertigo, BPPV, is the most common cause of vertigo. It produces brief episodes of intense spinning, usually lasting under a minute, triggered by changes in head position such as rolling over in bed, looking up, or bending forward. It occurs when otoconia, tiny calcium carbonate crystals normally embedded in the utricle, become dislodged and move into one of the semicircular canals, most often the posterior canal, where they cause the fluid to move abnormally and falsely signal rotation. Diagnosis relies on positional tests such as the Dix Hallpike manoeuvre, which provoke characteristic nystagmus. Canalith repositioning manoeuvres, such as the Epley manoeuvre described by John Epley in 1992, are the main treatment and are performed by clinicians to guide the crystals back out of the canal. Medications have only a limited role. BPPV is more common with increasing age and after head injury, and recurrence is common.