BPPV Case Studies

BPPV is a mechanical disorder which occurs as a result of the displacement of tiny crystals of calcium carbonate, also called otoconia. Typically, otoconia reside in the otolith organs and play a crucial role in detecting head movement. When the crystals get displaced, often due to trauma, they collect in one of the semicircular canals and cause vertigo symptoms. When the head is still, the otoconia settle within the semicircular canals and there are no vertigo symptoms. When the head is rapidly moved, the otoconia move, which causes overstimulation in that canal. This overstimulation of sensory receptors causes the intense vertigo and triggers nystagmus whenever the head is rapidly moved (Umphred, 2007).
BPPV can be caused by either of the following two pathophysiologies: canalolithiasis or cupulothiasis. Canalolithiasis occurs when the otoconia is free floating within the endolymph of the canal and cupulothiasis occurs when the otoconia adheres to the cupula. The most common type of BPPV occurs in
However, a person with a right posterior canal BPPV will develop a counterclockwise nystagmus when placed in the right head-hanging position. The nystagmus stops when the otoconia stop moving. “Reversal nystagmus” occurs when the person returns to the upright position and the otoconia moves in the opposite direction (Parnes, 2003).
Although not as commonly occurring, lateral or horizontal canal BPPV has been documented to resolve faster than posterior canal BPPV. This is due to the position of the canals in relation to each other. Otoconia entering the lateral canal can exit easier and more naturally than those entering the posterior canal. The cupular barrier in the lateral canal is located at the superior end and with the aid of gravity, crystals can easily float back into the utricle as a result of natural head movements (Parnes,