Ménière Disease

An inner ear disorder characterised by recurrent spontaneous vertigo, fluctuating sensorineural hearing loss, tinnitus and aural fullness, associated pathologically with endolymphatic hydrops.

Pathophysiology

Distension of the endolymphatic compartment, most marked in the cochlear duct and saccule, arises from an imbalance between endolymph production and absorption by the endolymphatic sac. The traditional explanation for attacks is rupture of Reissner membrane with potassium rich endolymph entering the perilymphatic space, depolarising and then blocking hair cell and neural function, followed by healing and restoration. This model does not explain all features, and current thinking also implicates altered sac function, immune mechanisms, vascular factors and ion transport abnormality. Endolymphatic hydrops is found in patients without symptoms and is best regarded as a marker rather than the complete explanation.

Diagnostic criteria

Definite Ménière disease requires:

• Two or more spontaneous episodes of vertigo, each lasting 20 minutes to 12 hours.
• Audiometrically documented low to mid frequency sensorineural hearing loss in the affected ear on at least one occasion before, during or after an episode.
• Fluctuating aural symptoms, that is hearing, tinnitus or fullness, in the affected ear.
• Not better accounted for by another diagnosis.

Probable disease requires episodic vestibular symptoms of 20 minutes to 24 hours with fluctuating aural symptoms, without documented audiometric confirmation.

Natural history

• Bilateral involvement develops in 25 to 40 percent over 10 to 20 years.
• Vertigo attacks typically decline in frequency over years and often burn out, while hearing loss progresses and becomes fixed, typically plateauing at 50 to 60 dB with poor discrimination.
• Tumarkin otolithic crisis, a sudden drop attack without loss of consciousness caused by abrupt otolithic stimulation, occurs in 5 to 10 percent, causes injury, and is an indication for aggressive treatment.

Associations: migraine, which coexists in a substantial proportion and complicates diagnosis; autoimmune disease; and a family history in around 10 percent.

The attack

• Aural fullness and increasing tinnitus often precede vertigo by minutes to hours, giving a warning.
• Sudden rotational vertigo lasting 20 minutes to several hours, rarely beyond 12 hours, with severe nausea, vomiting and prostration.
• Horizontal torsional nystagmus, which changes direction during the attack from irritative to paralytic.
• Fluctuating hearing loss, typically low frequency and worse during the attack.
• Distortion of sound, diplacusis and intolerance of loud sound.
• Profound fatigue for hours to days afterwards.
• Between attacks the patient may be entirely normal early in the disease, and progressively less so as hearing loss becomes fixed.

Later disease

• Persistent hearing loss with a flat or peaked audiogram and poor discrimination.
• Persistent tinnitus and unsteadiness rather than discrete vertigo.
• Tumarkin drop attacks.

Red flags requiring exclusion of another diagnosis

• Vertigo lasting seconds, which suggests benign paroxysmal positional vertigo.
• Vertigo lasting days, which suggests vestibular neuritis or labyrinthitis.
• Headache, photophobia, phonophobia and visual aura, which suggest vestibular migraine.
• Progressive unilateral hearing loss without fluctuation, which requires exclusion of vestibular schwannoma.
• Pressure or sound induced vertigo with autophony, which suggests superior canal dehiscence.
• Neurological signs, which require imaging for central pathology.

• Detailed history focusing on attack duration, which is the most discriminating single feature.
• Serial pure tone audiometry, ideally including an audiogram during or shortly after an attack, showing the characteristic low to mid frequency sensorineural loss that fluctuates. A single normal audiogram does not exclude the diagnosis.
• Speech audiometry with word recognition, which deteriorates as the disease progresses.
• Tympanometry to exclude middle ear disease.
• Glycerol test, in which osmotic dehydration produces a threshold improvement, which is now infrequently used.
• Electrocochleography with a raised summating potential to action potential ratio, generally above 0.4, supporting hydrops but with limited sensitivity.
• Vestibular evoked myogenic potentials: cervical potentials are often absent or have raised thresholds in the affected ear, reflecting saccular hydrops.
• Caloric testing showing unilateral vestibular hypofunction in around half of patients.
• Video head impulse testing, which is frequently normal early in the disease, giving a characteristic dissociation between abnormal calorics and normal head impulse gain that helps distinguish Ménière disease from vestibular neuritis.
• Magnetic resonance imaging of the internal auditory meati with gadolinium in every patient to exclude vestibular schwannoma, demyelination and other central pathology.
• Delayed intravenous or intratympanic gadolinium enhanced magnetic resonance imaging with high resolution sequences can now demonstrate endolymphatic hydrops directly, and is available in specialist centres.
• Laboratory tests where an alternative or contributory diagnosis is suspected: syphilis serology, autoimmune screen, thyroid function, and glucose.

Management has three separate goals: aborting the acute attack, preventing further attacks, and preserving hearing and function. Treatment is escalated stepwise, and destructive procedures are reserved for those who fail everything less invasive.

Acute attack

• Reassurance, lying still in a darkened room.
• Prochlorperazine 12.5 mg intramuscularly, or 5 to 10 mg orally three times daily, or 3 mg buccally twice daily. Watch for acute dystonic reactions, particularly in young patients.
• Cyclizine 50 mg orally, intramuscularly or intravenously three times daily.
• Promethazine 25 mg orally or intramuscularly.
• Ondansetron 4 to 8 mg for vomiting, noting QT prolongation.
• Diazepam 2 to 5 mg orally or intravenously for severe attacks, used sparingly.
• Intravenous fluids with 0.9 percent sodium chloride where vomiting prevents oral intake.
• Limit vestibular sedatives to the attack itself, since prolonged use impairs central compensation.

Maintenance, first line

• Dietary sodium restriction to approximately 1.5 to 2 g of sodium daily, with an emphasis on avoiding large sodium loads and on consistency of intake across the day rather than absolute restriction.
• Reduce caffeine, alcohol and nicotine. Avoid monosodium glutamate.
• Adequate hydration and regular meal and sleep patterns.
• Stress reduction, since stress is a widely reported trigger.
• Betahistine 16 mg three times daily, increased to 24 mg twice daily or up to 48 mg three times daily in refractory cases. Evidence from placebo controlled trials is inconsistent, with a large trial showing no benefit over placebo, but it is widely used, well tolerated and reasonable to trial. Contraindicated in phaeochromocytoma; caution in asthma and peptic ulcer disease.
• Thiazide diuretic: hydrochlorothiazide 25 mg daily, or hydrochlorothiazide 25 mg with amiloride 2.5 mg daily to limit potassium loss, or acetazolamide 250 mg twice daily. Monitor urea, electrolytes and creatinine at 2 weeks and periodically thereafter, and warn about postural hypotension and photosensitivity.
• Treat coexisting migraine vigorously, since a substantial proportion of apparent Ménière disease has a migrainous component that responds to migraine prophylaxis.

Second line, intratympanic therapy

• Intratympanic dexamethasone 24 mg/mL or methylprednisolone 40 mg/mL, given as a course of injections at intervals of 1 to 2 weeks, repeated as required. It controls vertigo in a substantial proportion without hearing risk, and is the preferred second line agent where hearing is useful.
• Intratympanic gentamicin, using a low dose titration protocol of 26.7 to 40 mg/mL, typically 0.5 mL instilled with the patient supine and head turned for 30 minutes, given once and repeated at 4 week intervals only if vertigo persists. It achieves vertigo control in 80 to 90 percent through selective chemical ablation of vestibular hair cells, particularly type I cells.
• The hearing risk with gentamicin is real, with significant sensorineural loss in roughly 10 to 25 percent depending on protocol. Titration dosing with a minimum 4 week interval and endpoint of vertigo control or the appearance of unsteadiness minimises this. Do not use fixed multiple dose schedules.
• Gentamicin is contraindicated in bilateral disease and in an only hearing ear, and must be used with great caution where the contralateral vestibular function is impaired, since bilateral vestibular loss with oscillopsia is a devastating outcome.

Positive pressure therapy

Low pressure pulse generators delivering pressure through a ventilation tube have not shown benefit over placebo in controlled trials and are not recommended as standard therapy.

Surgery, hearing preserving

• Endolymphatic sac decompression or shunt: low morbidity, no hearing risk, vertigo control reported in 60 to 80 percent, though placebo controlled evidence is contested. Reasonable in patients with useful hearing who have failed medical therapy.
• Vestibular nerve section through a retrosigmoid or middle fossa approach: vertigo control in 90 to 95 percent with hearing preservation in most, but it is a craniotomy with the associated risks of cerebrospinal fluid leak, headache, meningitis and facial nerve injury. Reserved for patients with serviceable hearing and intractable vertigo who have failed less invasive options.

Surgery, destructive

• Labyrinthectomy: transmastoid removal of the vestibular neuroepithelium, giving vertigo control in over 95 percent at the cost of total loss of hearing in that ear. Indicated only when hearing is already non serviceable, in a patient with normal contralateral function who can compensate centrally.
• Not to be performed in bilateral disease or where contralateral function is impaired.
• Vestibular rehabilitation afterwards is essential, and compensation is slower in the elderly.

Rehabilitation and support

• Vestibular rehabilitation for interictal unsteadiness and after ablative treatment. It does not prevent attacks.
• Hearing aids for the fluctuating loss, accepting that fluctuation makes fitting difficult and that programmable multiple memory devices help.
• Cochlear implantation for profound loss, which also frequently improves tinnitus.
• Tinnitus management with sound therapy and cognitive behavioural approaches.
• Counselling on driving, working at height, swimming and operating machinery, since sudden attacks are hazardous. Advise patients to inform the licensing authority where required.
• Psychological support and treatment of the anxiety and depression that commonly accompany unpredictable disabling attacks.

Follow up

Serial audiometry at least every 6 to 12 months, review of attack frequency using a diary, and reassessment of the contralateral ear, since bilateral disease changes management fundamentally and rules out destructive treatment.