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Benign paroxysmal positional vertigo, or BPPV, is a common disorder causing short episodes of vertigo in response to changes in head position that stimulate the posterior semicircular canal of the inner ear.
Vertigo is a specific sensation of spinning. People with vertigo feel as if they, their surroundings, or both are moving or spinning.
A change in head position—typically turning the head over on the pillow on first awakening in the morning, or tipping the head backward to reach a high shelf—triggers most episodes of this disorder. BPPV usually develops when calcium particles that are normally embedded in one part of the inner ear (the utricle and saccule) are displaced and move into another part of the inner ear (the posterior semicircular canal). The inner ear contains three semicircular canals, which help with balance (see Biology of the Ears, Nose, and Throat: A Look Inside the Ear ). The posterior canal, unlike the anterior and horizontal canals, is in the best position to receive most of the loose particles through gravity during the night. As they collect, they form a chalky sludge and may further form into a mass that exaggerates the movement of fluid in the canal when the head changes position. The result is overstimulation of nerve receptors (hair cells) inside the posterior canal, making the brain feel as if the head were moving much faster than it is. This information does not match that from the eyes and from position sensors in the joints. This mismatch results in a brief episode of vertigo. Particles may be displaced from the utricle and saccule as people age. Or, displacement may be caused by ear infections, injury, prolonged bed rest, ear surgery, head injury, or blockage of an artery to the inner ear.
This type of vertigo can be frightening, but it is usually harmless and disappears by itself. It may be accompanied by nausea, vomiting, and a specific type of nystagmus (the rapid jerking movement of the eyes in one direction alternating with a slower drift back to the original position). An episode of vertigo begins 5 to 10 seconds after the head moves and lasts less than a minute. Episodes usually subside on their own in weeks. Occasionally, they persist for months and can cause dehydration due to nausea and vomiting. No hearing loss or noise in the ears (tinnitus) occurs.
Diagnosis
Diagnosis is based on a description of the symptoms and the circumstances in which they occur.
Usually, the test used is the Dix-Hallpike maneuver, which stimulates the posterior semicircular canal and triggers vertigo and nystagmus in people with BPPV or other types of vertigo. The person sits on the examining table with the head turned 45 degrees to the right. Then the person lies down backwards so that the head remains turned at 45 degrees and hangs over the examining table by about 20 degrees. In BPPV, there is a delay of about 5 to 10 seconds before vertigo and nystagmus occur, but the delay may be as long as 30 seconds. Symptoms last 10 to 30 seconds. Maintaining the gaze on a single location (visual fixation) can shorten or even abolish nystagmus, so the maneuver is ideally done with the person wearing Frenzel lenses (which make it impossible to visually fixate on anything). If the maneuver is repeated several times, the intensity of the vertigo and nystagmus decreases (called habituation) in people who have BPPV. However, in people who have vertigo due to a brain disorder (such as stroke and multiple sclerosis), which is more serious, the Dix-Hallpike maneuver triggers symptoms immediately. The vertigo persists as long as the head is held in the same position, and habituation does not occur when the maneuver is repeated.
Treatment
BPPV is easily treated. The particles simply need to be moved out of the posterior semicircular canal and back to where they came from. Doing so requires a somersault-like maneuver of the head, called the canalith repositioning maneuver or Epley maneuver. This maneuver immediately cures vertigo in about 90% of people. Repeating the maneuver cures an additional 5%. In some people, the vertigo recurs. If it does, the maneuver is repeated. People can be taught how to do the maneuver at home in case vertigo recurs. For the 5% of people who are not cured with the maneuver, drugs may be used.
Very rarely, surgery is needed. Occasionally, the horizontal canal is affected, and rolling oneself like a log can relieve the symptoms.
Last full review/revision October 2007 by Michael Jacewicz, MD
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