Benign Paroxysmal Positional Vertigo, BPPV (sometimes also referred to as BPV) is the most common cause of bouts of vertigo in the general population. The hallmark of BPPV is vertigo, i.e. an abnormal sensation of motion (usually spinning), that lasts for a few seconds or up to a minute.

Doctor with patient experiencing vertigoThe symptoms are brought on by typical head movements, usually neck extension - such as with looking up at a high shelf or at the sky - or rotation to one side. The vertigo will commonly be felt when going to lie down in bed, or when rolling over to one side while in bed, and for this reason it is frequently first noticed at night or upon awakening.

The vertigo associated with BPPV has 3 other characteristic features:

  • Latency - it begins a few seconds after the provocative head movement.
  • Transience - it spontaneously abates if the provocative position is maintained statically for a period of time (usually 30-60 seconds). For this reason, it should more accurately be called “positioning” vertigo, not “positional” vertigo, since it is movement into the position, not maintenance of the position, that provokes the symptoms.
  • Fatigability - repeated performance of the same movement within a short time results in a decrease in the symptoms. In practice, this last feature is frequently unidentified, because people reflexively try to avoid repeating the movement that provoked the vertigo, rather than trying to extinguish the symptoms with repetition.

In some people, BPPV can be so severe that any movement at all will provoke the vertigo, while in others only very specific, identifiable movements will result in vertigo. If the former is the case, the vertigo may be perceived as continuous since it renders one nearly immobile. However, close attention to the symptoms will usually reveal their motion-provoked nature.

BPPV is thought to be caused by displacement of otoliths (mineral crystals) from the vestibule of the inner ear into the semicircular canals. The posterior semicircular canal is most commonly involved, though the superior and horizontal canals can also be affected. The affected ear and canal can be determined by visual inspection of the eye movements that result from specific positioning of the head in the clinician's office.

With this information, the clinician can then choose an appropriate “particle-repositioning maneuver” to facilitate migration of the crystals out of the semicircular canal into a harmless location back in the vestibule. These maneuvers are painless, and take just a few minutes to perform. In the most common form of BPPV, they are successful in curing the disease with one treatment in about 80% of people. Some people require a second session, and some will require even more to relieve the vertigo. For the procedure to be successful, it is important that the clinician be able to reliably identify the side and site of the problem.