Peripheral Causes of Vertigo

Table 2: Common peripheral causes of vertigo

Benign paroxysmal positional vertigo (BPPV)

Vestibular neuritis

Labyrinthitis

Meniere’s disease

Herpes zoster oticus (Ramsay Hunt syndrome)

Labyrinthine concussion

Perilymphatic fistula

Acoustic neuroma

Autoimmune inner ear disease (Cogan’s syndrome)

Aminoglycoside toxicity

Semicircular canal dehiscence syndrome

Peripheral vertigo is vertigo attributable to disorders of the inner ear vestibular apparatus or the peripheral neurological pathways.

Inner ear vestibular apparatus

The inner ear labyrinth is comprised of the vestibule (utricle and sacule) and three semicircular canals. These interconnected structures are filled with endolymph and receptors, which inform the brain of the head’s position and movement.

Disorders affecting the labyrinth are the commonest peripheral causes of vertigo, e.g. benign paroxysmal positional vertigo (BPPV), vestibular neuritis and Meniere’s disease.

Common peripheral causes include:

BPPV

Receptors in the utricle contain calcium oxalate crystals, or otoliths, which can become displaced and enter the semicircular canals. This usually occurs in the posterior canal, as it lies inferiorly, and otoliths are more likely to ‘fall’ into this canal.

Displaced otoliths can continue to stimulate movement receptors after cessation of head movement. This has been implicated as the cause for BPPV.

It is thought that the perception of room movement or rotation results from the brain’s attempt to resolve the conflicting information received from the inner ears, various proprioceptors and the eyes.

Classic cases of BPPV exhibit a positive Dix-Hallpike Test and the displaced otoliths can be repositioned with the Epley manoeuvre.

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Posterior semicircular canal otoliths are the commonest cause of BPPV.

Vestibular neuritis

Vestibular neuritis describes inflammation in the vestibular part of the VIIIth cranial nerve, and is thought to result from viral or post-viral inflammation, although there is no clear history of viral infection in 50% of cases.

Vestibular neuritis is associated with relatively rapid onset of severe persistent vertigo, nausea and vomiting.

An unstable gait and abnormal vestibular-ocular reflexes are often seen, but neurological examination is otherwise normal.

Hearing is typically unaffected. When ipsilateral sensorineural hearing loss occurs with vestibular neuritis, the term labyrinthitis is used. Acute symptoms usually last for 1-2 days, and attacks rarely recur.

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When ipsilateral hearing loss is associated with the symptoms of vestibular neuritis the term labyrinthitis is used.

Meniere’s disease

The cause of Meniere’s disease, also called endolymphatic hydrops, is unknown.

It is associated with excess endolymphatic fluid and inner ear dysfunction resulting in recurrent attacks of vertigo, vestibular dysfunction, tinnitus, ear fullness and sensorineural hearing loss.

Exacerbations may last for several days and recur over months to years.

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Meniere’s disease is associated with recurrent vertigo, tinnitus and hearing loss.