Contents
Introduction
Vertigo is the hallucination of rotation due to the abnormal stimulation of the hair cells of the vestibular system.
Vestibular System
The vestibular system is composed of
1) 3 Semicircular Canals which detect rotation
2) Utricle which detects linear movement
3) Saccule which detects linear movement
Common Causes of Vertigo
1) Benign Paroxysmal Postional Vertigo
2) Ménière’s Disease
3) Vestibular Neuronitis
4) Acoustic Neuroma
Benign Paroxysmal Positional Vertigo
Pathology
BPPV occurs when debris from the utricle becomes dislodged and is carried in the endolymph to the semicircular canals (most commonly the posterior semicircular canal due to gravity). This debris stimulates the hair cells of the inner ear, leading to activation of the vestibulocochlear nerve, and the hallucination of rotation.
Features
· Induced by a change in position
· Vertigo lasts anywhere from a few seconds to a few minutes
· Associated Nausea
· Torsional Nystagmus that lasts up to one minute, can be fatigued and has a latent period of 5 to 10 seconds prior to onset.
Dix Hallpike Test
This is a diagnostic manoeuvre in BPPV. The patient’s head is rotated to 45° before they are quickly laid down with their head in 20° extension. The eyes are then observed for the characteristic torsional nystagmus.
Epley Manoeuvre
The Epley Manoeuvre is used in the management of BPPV. It uses gravity to move the debris out of the semicircular canals and back into the utricle.
· Turn the head 45° towards the affected side and lie down for 5 minutes
· Turn the head 90° to the other side and lie down for 5 minutes
· Role over onto the front for 5 minutes
· Go back to the sitting position for 30 seconds
Ménière’s Disease
Pathology
Ménière’s Disease is thought to be due to endolymphatic hydrops (excess fluid in the inner ear)
Features
Ménière’s Disease typically occurs as acute episodes of:
1) Vertigo
a. Recurrent
b. Spontaneous
c. Lasts anywhere from several minutes to several hours
d. Associated nausea and vomiting
2) Tinnitus
a. Gets progressively worse
3) Fluctuating hearing loss
a. Sensorineural hearing loss
b. Affects the lower frequencies
c. Gets progressively worse
d. Usually unilateral but can be bilateral
4) Sense of aural pressure/fullness
Some patients with Ménière’s disease will suffer from drop attacks, which are sudden unexplained falls without a loss of consciousness
Management
There is no cure for Ménière’s disease, hence the management focuses on symptomatic relief and the prevention of future attacks
Acute attack – Antihistamine (Cinnarizine) or a Vestibular sedative (Prochlorperazine) if severe
Prophylaxis – Low salt diet and/or betahistine, but there is little evidence of efficacy
Vestibular Neuronitis
Vestibular Neuronitis is a viral infection of the vestibular nerve. It may follow an upper respiratory tract infection
Features
· Sudden onset vertigo lasting from several days to several weeks
· Associated nausea and vomiting
· No hearing loss or tinnitus
· Causes a horizontal nystagmus
Management
Vestibular neuronitis is treated with vestibular sedatives such as Prochlorperazine. This may lead to vestibular hypofunction, causing patients to have poor balance, in which case vestibular rehabilitation exercises may be useful.
Acoustic Neuroma
An acoustic neuroma is a benign tumour of the Schwann cells of the Vestibulcochlear Nerve
Features
· Unilateral hearing loss (affecting the ear on the same side as the tumour)
· Poor balance
· Vertigo (in the later stages)
· Signs of a raised intracranial pressure (if the tumour is large)
Management
· Surgical resection +/- radiotherapy
