The posterior canal is the usual one affected. In this situation, when your head is still, the fragment 'sits' at the bottom of the posterior canal. But when the head moves in certain directions the fragment gets carried along with the flow of fluid.
The fragment brushes along the delicate hairs that line the semicircular canal and this bombards messages down the vestibular nerve.
The extra messages from the affected ear conflict with the normal messages from the other ear. The brain becomes very confused and 'reacts' to cause vertigo.
It is not clear why these solid fragments (otoconia) form or drop off from the inside lining of the labyrinth. Most cases of BPPV occur in people over the age of 40. Therefore, it may be an age related thing. BPPV is one of the commonest causes of vertigo in older people. However, some younger people people develop BPPV following an injury to the ear, or following a previous infection in the inner ear. Sometimes it occurs in younger people for no apparent reason. Women are affected about twice as often as men.
What are the symptoms of BPPV?
The main symptom is vertigo. The vertigo lasts just a short time - typically just for 10-20 seconds and usually no longer than a minute. Then goes away completely. The vertigo is usually triggered by a change in head position. For example, getting out of bed and rolling over in bed are two of the most common movements that trigger a short episode of vertigo. Sometimes just looking up triggers an episode of vertigo. With each episode of vertigo you may feel sick (nausea) but it is not common to vomit. The nausea may last an hour or so even though the vertigo lasts just seconds. Between episodes of BPPV you feel well. Many people who develop BPPV realise which head movements trigger their symptoms and so instinctively avoid doing those movements.
In most cases, the symptoms clear away within several weeks or months. The fragments of debris may 'dissolve' or float out from the posterior semicircular canal and lodge in the vestibule where they cause no symptoms. However, after the symptoms have gone, some people have recurrences of symptoms months or years later. In some cases, symptoms persist for years.
Do I need any tests?
The symptoms of BPPV are quite characteristic and so a doctor may well suspect that you have this condition by your symptoms. To confirm the diagnosis your doctor may do a test called the Dix-Hallpike manoeuvre. This will involve you sitting on a doctors couch. The doctor will then ask you to lie back and move your head in certain directions. These set movements in people with BPPV will usually trigger an episode of vertigo.
What is the treatment for BPPV?
The Epley manoeuvre
This simple cure may be tried by your doctor. This often works if you have fragments of debris (otoconia) at the bottom of your posterior semicircular canal (the common situation). This is done by a series of four movements of the head, and after each movement the head is held in the same place for 30 seconds or so.
The movements of the head basically cause the posterior semicircular canal to rotate around in such a way that gravity moves the otoconia fragments out form the posterior canal and into the vestibule where then then settle and cause no symptoms.
Following a successful Epley manoeuvre, to allow the otoconia to settle in their new situation in the vestibule, and to reduce the risk of them falling back into the posterior semicircular canal, the following are commonly advised:
- Do not lie flat for 48 hours. During this time sleep sitting in a chair.
- Do not lie on the affected side for one week.
- Ideally, try to avoid bending over (such as to tie shoelaces) for a week.
Studies report that the Epley manoeuvre is successful in stopping symptoms in about 8 in 10 cases with just one treatment. If the first treatment does not work, there is still a good chance that it will work in a repeat treatment session a week or so later.
If successful, the Epley manoeuvre is one of the few procedures that can be done in a doctors surgery in a few minutes that can dramatically cure a patient of symptoms! If symptoms return at a later date, the manoeuvre can be repeated.
No treatment
If the Epley manoeuvre is not successful, or not done, you can still remain optimistic. BPPV is a condition that often goes away on its own after several weeks or months without any treatment. One study said the condition had resolved in an average of 10 weeks. The otoconia are thought to either 'dissolve' or move to a place in the labyrinth where they cause no symptoms.
Surgery
Surgery is rarely needed as in most cases the condition either improves by itself or can be cured by the Epley manoeuvre. Occasionally, symptoms persist for months or years and cannot be eased. An operation of the inner ear to take out the function of the posterior semicircular canal may then be an option. An ear specialist will advise.
©EMIS and PIP 2006 Updated: November 2006
