Benign paroxysmal positional vertigo (BPPV)

Benign paroxysmal positional vertigo is one of the most common causes of vertigo — the sudden sensation that you or your surroundings are spinning. Episodes are brief, typically lasting under a minute, and are almost always triggered by a change in head position: tilting the head up or down, lying down, turning over in bed, or sitting up.

Although BPPV can be distressing, it is rarely dangerous unless it increases the risk of falls.

**Causes:** In many cases no cause is found (idiopathic BPPV). When a cause is identified, it is typically a minor to severe blow to the head. Less commonly, inner-ear disorders, ear surgery, or prolonged positioning on the back (such as in a dentist's chair) are responsible. BPPV is also associated with migraines.

**Key symptoms:** - Dizziness or the sensation of spinning (vertigo) - Loss of balance or unsteadiness - Nausea or vomiting - Abnormal, rhythmic eye movements (nystagmus) accompanying episodes

**Canalith repositioning:** The primary treatment, performed in the clinic, involves a series of slow, deliberate head positions designed to move displaced calcium crystals (otoliths) from the semicircular canals back into the vestibule, where they no longer cause symptoms. Each position is held for about 30 seconds. Most patients respond after one or two sessions.