the presence of calculi in the cupula of the posterior semicircular duct.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
be·nign par·ox·ys·mal positional ver·ti·go
a recurrent, brief form of positional vertigo occurring in clusters; believed to result from displaced remnants of utricular otoconia into the semicircular ducts, usually the posterior.
Farlex Partner Medical Dictionary © Farlex 2012
benign paroxysmal positional vertigoA form of transient vertigo caused by utricular degeneration which liberates otoconia: otoconia drift into the lower part of the vestibule, the ampulla of the posterior semicircular canal; once there, the otoconia alter the cupola’s specific gravity, changing its response characteristics from a purely angular acceleration detector to one that is stimulated by linear movements and gravity.
BPPV is a common form of vertigo, more common in older adults.
Closed head injury, vestibular neuronitis, infections, post-stapedectomy.
History—e.g., single bouts of severe vertigo of < 1 min in duration after a change in head position, often more severe on one side, when bending, looking to take an object off a shelf or tilting the head back; the episodes are clustered in time and separated by remissions lasting months or more; Hallpike maneuver.
Particle repositioning maneuver; occlusion of affected canal using a bone chop:fibrinogen glue plug; most BPPV resolves spontaneously within several months of onset, especially following head injury; persistent, near-disabling symptoms may mandate surgery: singular neurectomy, vestibular neurectomy or posterior semicircular canal occlusion.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.