Benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo (BPPV(BPPV) is is one of the most common causes of vertigo. It occurs secondary to change in posture and typically is associated with nystagmus. The aetiology is thought to be due to changes of position of the otoliths in the inner ear, most commonly into the posterior semicircular canal.

Epidemiology

Commonly affects 50-70 year old female patients ⁶.

Clinical presentation

Classically, benign paroxysmal positional vertigo presents with recurrent, paroxysmal, short-lasting vertigo brought upon by sudden changes in head position, for example, rolling rolling over in bed or hyperextending the neck ⁶. The vertigo occurs abruptly (sometimes seconds) and subsides quickly, usually less than one minute ⁶. Importantly Importantly, there is no hearing loss or tinnitus, and there are no associated symptoms of central nervous system disease ⁶.

This vertigo is associated with nystagmus, that can be elicited to confirm the diagnosis via various clinical manoeuvres depending on the canal that is affected:

• posterior canal BPPV: the Dix-Hallpike manoeuvre reveals upbeating-torsional nystagmus ⁶

• horizontal canal BPPV: the log-roll manoeuvre reveals purely horizontal nystagmus ⁶

• anterior canal BPPV: the Dix-Hallpike manoeuvre reveals downbeating-torsional nystagmus ⁶

Pathology

Normally, semicircular fluid does not move with gravity on its own ⁶. However, in benign paroxysmal positional vertigo, the otolithic crystals from the utricle and saccule become displaced and migrate into the semicircular canals, and when there is change in the static position of the head with respect to gravity, these otoliths move causing the fluid to also move when it ordinarily would not ⁶. This results in false signals to the brain causing a transient illusory sense of rotation (i.e. vertigo) until until the head rests and the otoliths stop moving ⁶.

The otoliths are most commonly displaced into the posterior semicircular canal (in up to 90% of cases), but can also less commonly affect the superior (anterior) canal canal, lateral (horizontal) canal, and even multiple canals at once ⁶. The presence of otoliths in the canals is often idiopathic, but can be secondary to head trauma or a residual effect of other vestibulopathies (e.g. Ménière disease, vestibular neuritis, etc.) ⁶.

Radiographic features

Normally imagingAs otoliths range in size from 10-30μm and the upper limit of the spatial resolution of clinical CT is unremarkable in benign paroxysmal positional vertigo and125μm, their displacement into the semicircular canals cannot be identified with current techniques^{7, 8}.

Imaging is often not necessary because the diagnosis is clear cut from the history and clinical examination. and should generally only be performed to exclude other causes for vertigo

Treatment and prognosis

Although benign paroxysmal positional vertigo often resolves without any treatment, various particle-repositioning manoeuvres can be employed:

• posterior and anterior canal BPPV: Epley manoeuvre or Semont manoeuvre ⁶

• horizontal canal BPPV: barbeque manoeuvre ⁶

History and etymology

Róbert Bárány (1876-1936), arenowned Hungarian otologist, was the first to describe this condition in 1921 ^2,5. Margaret Dix (1911-1981) and Charles Hallpike (1900-1979), British otologists at the National Hospital of Neurology and Neurosurgery, were the first to posit that the cause was the disturbance of the otoliths in the labyrinth ³. From their work resulted the Dix-Hallpike test ³.

See also

• persistent postural-perceptual dizziness (PPPD)