Benign paroxysmal positional vertigo

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Benign paroxysmal positional vertigo (BPPV) is a closely defined condition caused by debris (formed from dislodged particles of otoconia) in a semicircular canal. It is a form of Peripheral vestibular disorder.

It is the the most common cause of rotatory vertigo. It may affect all age groups and frequently follows a head injury or a bad cold. It is traditionally diagnosed by the Hallpike manoeuvre and treated by the Epley manoeuvre or physiotherapy.

Contents

Aetiology

BPPV is the commonest form of vertigo, accounting for up to 20% of all forms of dizziness[1]. It may occur at any age but is more common in the elderly. It is very uncommon in childhood, where a more common alternative diagnosis should be considered. In one study, undiagnosed BPPV was present in 9% of elderly patients[2]. Causes of BPPV include

However half of all cases are Idiopathic.

Pathology

BPPV is thought to be due to accumulation of otoconia in the semicircular canal. Otoconia are small crystals of calcium carbonate that form the weights on the ends of the macula hair cells, which can be shed from the utricle. In BPPV, loose otoconia may enter the semi circular canals (classically the posterior canal), giving the sensation of abnormal movement when the head is turned in the plane of the curvature of the canal.

LogoKeyPointsBox.pngThe Dix Hallpike test swings the head around the arc which swishes the gravel around the canal being tested so that vertigo and nystagmus are stimulated.

Since the posterior canal opening to the vestibule is in the back wall to the same side as the canal, one of the mechanisms for its occurrence is for a fall onto the back of the head to tip the particles into the posterior semicircular canal opening, and hence into the canal, which is closed at its lower end. This converts a rotational acceleration detector into a gravitector, so that every time the head is moved into a position which causes the gravel to swoosh round the canal, the crista is activated, and vertigo and nystagmus result.

This is the basis for the Dix Hallpike test, which swings the head around the arc which swishes the gravel around the canal being tested so that vertigo and nystagmus are stimulated. This can occur in the other canals but much less commonly. When the gravel was first seen moving in the posterior canal at surgery, a treatment was devised to relieve the symptoms. This was originally a movement of the whole upper body onto one side, and then onto the other (done by sitting with the legs over the side of a bed, and then throwing oneself to one side and then the other for several times.) The Semont manoevre. This was originally devised as a habituation therapy, but seemed to cure the condition from time to time.

The Epley manoeuvre was then devised as more precise way of actually tipping the debris out, and is best seen on a mechanical model, since although it is a fairly simple manoevre, it is difficult to describe or remember without realising the orientation and position of the posterior semicircular canal in the head. There is a 95% success rate with this manoevre, and if it is not successful (when done correctly) the diagnosis of BPPV becomes doubtful. There are, of course many other causes of vertigo related to position, but this is common and easily diagnosed and treated, so it becomes the first step in the management of vertigo related to position.

Clinical features

In BPPV, patients develop a characteristic vertigo. This lasts for only a few seconds, and follows a particular movement of the head. This is typically turning from one side to the other whilst lying in bed (one side is invariably worse, and the posterior canal on the downward side is affected.) The vertigo is rotatory in nature, and shows fatiguability, that is, if the action is repeated, the vertigo becomes less each time. BPPV may not be present all of the time, and several days may occur between each episode.

Investigations

An otological and neurological examination is mandatory in all cases of vertigo.

Treatment

Treatments are designed to remove loose otoconia from the posterior semicircular canal, either by excluding them or returning them to the utricle.

Conservative treatment

Most cases of BPPV are self limiting at will resolve with no treatment. Various sets of exercises have been designed to help sufferers of BPPV. These include Cawthorne Cooksey exercises and Brandt Daroff exercises [4].

Clinic treatments

The two classic treatments are the Epley manouvre[5] and the Semont manouvre[6]. These are both canalith repositioning techniques. Meta-analysis shows a success rate of 81%, compared to 37% in placebo groups [7].

Surgical treatment

For symptomatic BPPV that lasts for a year or longer, and fails to respond to above treatments, surgical procedures may need to be used. These include posterior canal plugging, singular neurectomy or posterior canal obliteration.

References

  1. Dizziness and Balance. Hain TC (2006)
  2. Oghalai, J. S., et al. (2000). "Unrecognized benign paroxysmal positional vertigo in elderly patients." Otolaryngol Head Neck Surg 122(5): 630-4.
  3. Ishiyama A, Jacobson KM, Baloh RW. Migraine and benign positional vertigo. Ann Otol Rhinol Laryngol. 2000;109:377-380
  4. Brandt T, Steddin S, Daroff RB. Therapy for benign paroxysmal positioning vertigo, revisited. Neurology 1994 May;44(5):796-800.
  5. Epley JM. The canalith repositioning procedure: For treatment of benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 1992 Sep;107(3):399-404.
  6. Semont A, Freyss G, Vitte E. Curing the BPPV with a liberatory maneuver. Adv Otorhinolaryngol 1988;42:290-293.
  7. http://www.dizziness-and-balance.com/disorders/bppv/bppv%20trials.htm BPPV Controlled treatment trials. Hain TC (2006)
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