Benign paroxysmal positional vertigo (BPPV) is a disorder arising from a problem in the inner ear. Symptoms are repeated, brief periods of vertigo with movement, that is, of a spinning sensation upon changes in the position of the head.
Vestibular disorders can be caused by:
1. Head Trauma (whiplash, sports injuries, workplace injuries) is a frequent cause of vestibular disorders in people under age 50.
2. Vestibular system degeneration – primarily in an elderly population
3. Ear infections such as otitis media; inner ear infection such as labyrinthitis or neuronitis
4. Ototoxicity – high dosage or long term use of certain antibiotics
5. Acoustic neuroma
7. Vascular insufficiency
How is it diagnosed?
Normal medical imaging is not effective in diagnosing BPPV, because it does not show the crystals that have moved into the semi-circular canals. However, when someone with BPPV has their head moved into a position that makes the dislodged crystals move within a canal, the error signals cause the eyes to move in a very specific pattern, called “nystagmus”.
The nystagmus will have different characteristics that allow a trained therapist to identify which ear the displaced crystals are in, and which canal(s) they have moved into. Tests like the Dix-Hallpike or Roll Tests involve moving the head into specific positions, which allow gravity to move the dislodged crystals and trigger the vertigo while the therapist watches for the eye movements, or nystagmus.
There are two types of BPPV: one where the loose crystals can move freely in the fluid of the canal (canalithiasis), and, more rarely, one where the crystals are thought to be ‘hung up’ on the bundle of nerves that sense the fluid movement (cupulolithiasis). With canalithiasis, it takes less than a minute for the crystals to stop moving after a particular change in head position has triggered a spin. Once the crystals stop moving, the fluid movement settles and the nystagmus and vertigo stop. With cupulolithiasis, the crystals stuck on the bundle of sensory nerves will make the nystagmus and vertigo last longer, until the head is moved out of the offending position. It is important to make this distinction, as the treatment is different for each variant.
BPPV can be corrected mechanically. Once the physiotherapist knows which canal(s) the crystals are in, and whether it is canalithiasis or cupulolithiasis, then they can take you through the appropriate treatment maneuver. The maneuvers make use of gravity to guide the crystals back to the chamber where they are supposed to be via a very specific series of head movements called Canalith Repositioning Maneuvers. In the case of cupulolithiasis, they would utilize rapid head movement in the plane of the affected canal to try to dislodge the ‘hung-up’ crystals first, called a Liberatory Maneuver,
90% gives better results by 1-3 treatments, particularly canalithiasis. But it could take longer in cupulolithiasis. It is possible to have more than one canal involved, especially after trauma, in which case vestibular therapist would typically have to correct them one at a time. You may be advised to avoid certain head positions for a few days following treatment.