In 1980, John Epley, MD, published his set of maneuvers for BPPV -- benign paroxysmal positional vertigo. BPPV is a dizziness of short duration that is provoked by changes in head position.
The dizziness in BPPV is due to gravity sensors, called otoconia, coming loose from their position in the inner ear or vestibular system. Once loose, the otoconia travel to other parts of the vestibular system and then register inaccurate information to the brain. This inaccurate information, in the brain, is reflected as dizziness.
The Epley Maneuver, designed to treat the most common form of BPPV -- the posterior semicircular canal variant, uses gravity and head position to help the otoconia travel within the inner ear on a path to the utricle. The utricle is the sensory apparatus from which the otoconia break off from to start the BPPV process.
At the end of the Epley maneuver, the patient is returned to the upright sitting position and the otoconia, having been manipulated through the Epley maneuver, end up being deposited into the utricle again. When properly performed, the Epley maneuver gets rid of the inaccurate information being given to the brain from loose otoconia and thusly improves or eradicates the sensation of dizziness.