Monday, August 16, 2010

Benign paroxysmal positional vertigo (BPPV) is a common clinical disorder characterized by brief recurrent spells of vertigo (dizziness) often brought about by certain head position changes, such as looking up, turning over in bed, or straightening up after bending over. BPPV is an important cause of vertigo with a prevalence of 11 to 64 per 100,000. In one study, 9% of elderly patients that underwent a comprehensive evaluation for nonbalance-related problems were found to have previously unrecognized BPPV. Delays in the proper diagnosis and treatment of this condition are still common, and can lead to unnecessary costs and limitations of function. The importance of recognizing this condition is underscored by the ease and effectiveness of treatment techniques that eliminate symptoms and the need for expensive testing.

BPPV is caused when small calcium carbonate particles that form in part of the middle ear move into one of the semicircular canals. When the calcium carbonate crystals move within the semicircular canal they cause vertigo. When this happens the eyes develop jerky movements (called nystagmus). The presence of nystagmus during the exam help make the diagnosis.

The reason for these calcium crystals are formed is not well understood. The calcium debris may break off following trauma or viral infections, but in many instances it seems to occur without identifiable illness or trauma. It may have to do with age-related changes in the protein. Patients with BPPV have recently been found to have more osteopenia and osteoporosis than matched controls, and those with recurrent BPPV tended to have the lowest bone density scores.

Treatment is to move a patient’s head in the correct direction to move the calcium crystals into a region of the middle ear where they will be normally adsorbed. Once gone, the symptoms resolve. If properly done, the repositioning maneuver eliminates BPPV immediately in greater than 85% of patients..

At present, the generally accepted recurrence rate of BPPV after successful treatment is 40 to 50% at 5 years of average follow up. There does appear to be a subset of individuals prone to multiple recurrences.

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