Benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo (BPPV) 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, BPPV presents with recurrent, paroxysmal, short-lasting vertigo brought upon secondarily to sudden changes in head position, for example, rolling over in bed or hyperextending the neck ⁶. The vertigo arises rapidly (sometimes seconds) and subsides quickly, usually less than one minute ⁶. 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-tortional 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 BPPV otolithic crystals from the utricle and saccule become displaced in 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 temporary false sense of rotation (i.e. vertigo) until the head rests and the otoliths become static again ⁶.

These otoliths are most commonly displaced in the posterior semicircular canal (in up to 90% of cases), but can also less commonly affect the anterior (superior) canal, 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 imaging is unremarkable in BPPV and often not necessary because the diagnosis can be clear cut from the history and clinical examination.   

Treatment and prognosis

Although BPPV 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.