Meniere's Disease

This is a disorder of the inner ear caused by a change in fluid volume in the labyrinth. The membranous labyrinth is necessary for hearing and balance and is filled with endolymph. An increase in endolymph can cause the membranous labyrinth to dilate - endolymphatic hydrops. This leads to rupture of the endolymph membrane and mixing of endolymph and perilymph, which causes the symptoms of Menieres; disturbed hearing and positional sense. Between attacks, there is pressure-dependent loss of cochlear and vestibular neurones with distortion of structures of the labyrinth.^1,2

It is usually idiopathic, but rarely may be caused by labyrinthitis due to viral/bacterial infection or trauma, eg temporal bone fracture. Recent research has shown that autoimmunity and the anti-phospholipid syndrome may have a role.³

Prevalence

Estimates vary due to differing diagnostic criteria. 1 in 1,000 to 1 in 20,000 population.^4,5

• Mainly affects patients aged 20-50 years.
• Equal male and female incidence.
• In about 8% of cases it is a familial condition with uncertain patterns of inheritance.⁶
• The condition is rare in children.

Symptoms

All three should be present:

• Paroxysmal vertigo, normally lasting 20 mins - 24 hours, often with nausea and nystagmus. At least two episodes of vertigo lasting >20 mins are required to fulfil the diagnostic criteria.
• Fluctuating sensorineural hearing loss. Usually low frequency loss predominates.
• Tinnitus (usually low tone with blowing character) and/or subjective feeling of fullness in the ear. Rarely accompanied by vestibular drop attacks.

Signs

There are no confirmatory signs but cardiovascular and neurological examination are advisable to look for other causes of similar symptoms.
Hallpike's manoeuvre is used to diagnose benign paroxysmal positional vertigo (BPPV)

• Benign paroxysmal positional vertigo (BPPV). Clinical diagnosis made by response to head movement tests.⁷
• Vertigo associated with migraine
• Drug reactions
• Otitis media or externa
• Labyrinthitis or vestibular neuronitis
• Ischaemic disease of vertebrobasilar system
• Functional or psychological illness
• Labyrinthine fistula
• Acoustic neuroma
• Medical conditions such as autoimmunity, hypothyroidism and anaemia can sometimes mimic Meniere's
• Cerebellar disease
• Cogan's syndrome⁸
• Neurosyphilis

Audiometry confirms the classical pattern of sensorineural hearing loss.
Further investigations such as neuroimaging will depend on the degree of suspicion of other pathology.
Electrocochleography (ECOG) and electronystagmography (ENG) are sometimes used in specialist investigation.⁹

The aim of therapy is to:

• Alleviate acute attacks
• Reduce severity and frequency of attacks
• Improve hearing and reduce the impact of tinnitus

Drugs

• Acute attacks; vertigo and nausea can be alleviated by prochlorperazine and cinnarizine.
• Prophylaxis; usually use betahistine or diuretics.¹⁰ There is little evidence for the effectiveness of these treatments, with the possible exception of betahistine.¹¹ Response to prophylactic agents varies between individuals, so it is worth trying different drugs until a satisfactory response is achieved. Their mode of action is uncertain.

Surgical

Approximately 20% of cases are severe and uncontrolled by medication. These patients may need an ablative procedure to manage their vertigo, which can be medical (local gentamicin¹²) or surgical. They aim to selectively destroy balance receptors, while preserving cochlear function (hearing).

Supportive measures

• A low salt diet may be beneficial.¹³
• Hearing aids tailored to pattern of hearing loss.
• Avoidance of loud noise to which there may be intolerance.
• Sound therapy and relaxation/distraction techniques for tinnitus. See internet section below for helpful patient information.
• After an acute attack of vertigo, patients naturally tend to sit still. Encourage them to move around to promote central compensation, where the brain uses vision and other senses to compensate for the loss of vestibular function.

• Loss of driving licence, if symptoms are sudden and disabling.¹⁴
• Quality of life can be severely affected in some people because of the unpredictable, and progressive nature of the condition.
• Anxiety and depression.

Usual disease course has 3 stages¹⁵:

• Early; predominantly vertigo attacks which are sudden and unpredictable. Hearing worsens and tinnitus increases. Returns to normal when attack is over.
• Middle; progressive lower pitch sensorineural hearing loss. Vertigo at its worst. Tinnitus also progresses. May have periods of remission of several months.
• Late-stage; progressively deteriorating hearing loss. General balance problems develop, especially in the dark, but vertigo lessens. Tinnitus is significant.