Meniere disease

Meniere disease (endolymph hydrops) is a disorder of the inner ear caused by impaired endolymph resorption. The exact etiology of endolymph malabsorption is unknown but viral infections, autoimmunity, and allergies are thought to play a role. Meniere disease most commonly manifests in adults between 40–50 years of age. Clinical manifestations include recurrent episodes of peripheral vertigo, fluctuating unilateral sensorineural hearing loss (SNHL), and unilateral tinnitus (referred to as the Meniere triad); horizontal nystagmus or horizontal rotatory nystagmus may also be present. The episodes fluctuate in severity, typically lasting from 20 minutes to 12 hours. The diagnosis is based on characteristic clinical features and low to mid-frequency SNHL on audiometry. Treatment is symptomatic. Vestibular suppressants (e.g., benzodiazepines and first-generation antihistamines) may be used during acute vertigo attacks. Lifestyle modifications (e.g., avoidance of allergens, low-sodium diet) and vestibular rehabilitation therapy can help minimize the risk of recurrence. Diuretics should be considered in patients with frequent attacks. Interventional therapy (e.g., chemical vestibular ablation with intratympanic gentamicin, intratympanic steroids) or surgical vestibular ablation (e.g., labyrinthectomy, vestibular neurectomy) is reserved for patients with intractable symptoms that significantly impact their quality of life.

See also “Vertigo,”

• Sex: ♀ ≥ ♂ ^[1]
• Onset: 20–60 years of age
• Peak incidence: : 40–50 years
• Prevalence: : 50–200 in 100,000 individuals in the US

Epidemiological data refers to the US, unless otherwise specified.

• Idiopathic
• Several etiologies have been proposed, including:
  • Viral infections ^[2]
  • Autoimmune disease
    • Inner ear autoimmune disease
    • Systemic autoimmune disease ^[2]
  • Allergies ^[1]

All patients with Meniere disease have impaired endolymph resorption that results in endolymph hydrops. However, not all patients with endolymphatic hydrops have symptoms of Meniere disease. The cause of impaired resorption is unknown. There are currently two main theories about why some patients develop symptoms:

• Endolymph hydrops: accumulation of fluid in the endolymphatic sac.
• Rupture theory: fluid accumulation in the endolymphatic sac → tear in the Reissner membrane → increased perilymphatic potassium → depolarization of the afferent acoustic nerve fibers → symptom onset
• Compression theory: impaired endolymph resorption → compression of the semicircular canals → symptom onset

The endolymph is rich in potassium and perilymph is rich in sodium. In Meniere disease, the concentration of potassium in the perilymph increases.

Meniere disease characteristically manifests as recurrent episodes of acute, unilateral symptoms that last from minutes to hours. ^[1]

Meniere triad ^[1]

• Peripheral vertigo
• Tinnitus
• Asymmetric fluctuating sensorineural hearing loss (SNHL)
  • Low to mid-frequency hearing loss that progressively worsens with each episode
  • May progress to deafness over several years
  • Tuning fork tests ^[3]
    • Weber test: lateralization to the healthy ear
    • Rinne test: bilaterally positive

Additional symptoms

• Spontaneous horizontal or horizontal rotatory nystagmus ^[4][5][6]
  • Seen in some patients during an acute episode of Meniere disease
  • The direction of nystagmus is variable and can change . ^[5]
  • Can be supressed by visual fixation ^[7]
• Nausea and vomiting
• Ear fullness

Triggers

• Definitive triggers of Meniere disease are not known to exist ^[8]

Progression

• Episodes fluctuate in severity and typically last from 20 minutes to 12 hours
• Periods of remission between attacks vary from months to years.
• In 10–25% of patients, the disease becomes bilateral. ^[1]

Lermoyez syndrome ^[4]

• A variant of Meniere disease in which hearing improves during or immediately after the episode of vertigo
• Thought to be caused by the movement of endolymph from the cochlea towards the semicircular canals, which results in:
  • A reduction in the endolymphatic hydrops in the cochlea → improved hearing
  • An increase in the endolymphatic hydrops in the semicircular canals → vertigo

Drop attacks (Tumarkin otolithic crisis) ^[4]

• An uncommon feature that may occur in advanced­ Meniere disease, characterized by suddenly falling to the ground without warning
• There is no loss of consciousness.
• Falls may have severe to life-threatening adverse consequences (e.g., TBI, hip fractures).
• Difficult to treat but may resolve spontaneously

Meniere disease is diagnosed based on the characteristic clinical features and demonstrable low- to mid-frequency SNHL on audiometry. Specialized tests (e.g., vestibular function testing, electrocochleography) are reserved for patients with atypical symptoms or before attempting ablative therapies. Neuroimaging should be considered if central vertigo is suspected. See also “Approach to vertigo” for patients with undifferentiated acute vestibular syndrome. ^[1]

Diagnostic criteria for Meniere disease ^[1]

• Definite Meniere disease: must include all of the following criteria
  • ≥ 2 spontaneous attacks of vertigo, each lasting 20 min to 12 hrs
  • Low to mid-frequency sensorineural hearing loss in the affected ear on audiometry
  • Fluctuating aural symptoms in the affected ear (hearing loss, tinnitus, or ear fullness)
  • Other suspected causes of vertigo excluded
• Probable Meniere disease: Patients that meet all of the above criteria but do not demonstrable hearing loss on audiometry.

Subjective audiometry ^[1]

• Indications
  • All patients with suspected Meniere disease
  • Before and after ablative therapy
• Modalities and characteristic findings: Subjective audiometry should always be performed in both ears.
  • Pure-tone audiometry: low- to mid-frequency sensorineural hearing loss (SNHL), with > 15 dB difference between the two ears
  • Speech audiometry (with word recognition score): a difference of > 15% in word recognition score between the two ears

Asymmetric fluctuating hearing loss is a characteristic feature of Meniere disease. Subjective audiometry may be normal at the time of testing because the attacks of Meniere disease are episodic. ^[1]

Additional evaluation

Vestibular function tests and electrophysiologic testing ^[1]

Not routinely recommended

• Indications
  • Atypical symptoms
  • Identifying the affected ear
  • Before vestibular ablative procedures.
• Modalities and supportive findings
  • Vestibular function tests: decreased vestibular function in the affected ear ^[9]
  • Electrocochleography: measures the summating potential (SP) generated by cochlear hair cells and the action potential (AP) of the cochlear nerve in response to acoustic stimulation
    • Supportive findings: elevated SP/AP ratio
  • Normal vestibular function testing or electrocochleography does not rule out Meniere disease.

Imaging ^[1][10]

Imaging studies are not routinely indicated in patients with suspected Meniere disease.

• Indications
  • To rule out differential diagnosis in patients with atypical symptoms (e.g., sudden SNHL, nonfluctuating SNHL)
  • Before ablative therapies
• Preferred modality: MRI internal auditory canal and posterior fossa (without and with IV contrast)
• Supportive findings: endolymphatic space distention (endolymphatic hydrops) in the cochlea and vestibule ^[10][11]

• See “Causes of vertigo” for other etiologies of vertigo.
  • Causes of peripheral vertigo: e.g., meniere disease, vestibular neuritis
  • Causes of central vertigo: e.g., cerebellar stroke, vestibular migraine, multiple sclerosis ^[13]
• See “Differential diagnoses of vertigo” for other conditions that mimic vertigo: e.g., anxiety or panic disorder, postural hypotension, medication side effects
• Traumatic endolymphatic hydrops (due to e.g., head trauma, barotrauma)
• Otosclerosis
• Otosyphilis ^[14][15]

Always consider vestibular migraine as a differential diagnosis of Meniere disease.

The differential diagnoses listed here are not exhaustive.

There is currently no definitive cure for Meniere disease. Treatment is directed toward symptomatic management and prevention of recurrence. Interventional therapy or surgery is reserved for patients with intractable symptoms that significantly hinder their quality of life. ^[1]

Acute therapy ^[1]

See “Management of peripheral vertigo” for more information and dosages.

• Consider short-term symptomatic pharmacotherapy with vestibular suppressants (e.g, first-generation antihistamines, benzodiazepines, antiemetics).
• Consider movement restriction.

Vestibular suppressants are the treatment of choice for an acute vertigo attack in Meniere disease.

Chronic use of vestibular suppressants is contraindicated because of their potential to inhibit central compensation, which could elicit gait and postural instability.

Recurrence prevention ^[1]

• Lifestyle modifications ^[1][16]
  • Stress reduction
  • Low-sodium diet (1500–2300 mg per day)
  • Identification and avoidance of dietary and environmental triggers (e.g., caffeine, alcohol, nicotine, and stress).
• Vestibular rehabilitation and physical therapy
  • Indications: chronic imbalance , incomplete central vestibular compensation after ablative therapy
  • Options: vestibular habituation exercises (e.g., Cawthorne-Cooksey exercises) and physical exercises that increase stability and help with balance and walking
• Other:
  • Allergen testing, avoidance, and treatment ^[1]
  • Patients should be educated about avoiding known triggers and the natural course of the disease, including recurrence and worsening of SNHL with each attack.

Maintenance therapy ^[1]

Patients with frequently recurring episodes of Meniere disease may be considered for chronic pharmacotherapy.

• Diuretics ^[1]
  • Thiazide diuretics; (with or without a potassium-sparing diuretic) are commonly used (e.g., hydrochlorothiazide; , hydrochlorothiazide/triamterene ).
  • Carbonic anhydrase inhibitor (e.g., acetazolamide ) ^[17]
• Other agents: : systemic steroids, antivirals, benzodiazepines, betahistine ^[18][19]
• Monitoring and duration
  • Patients should be monitored frequently for:
    • Symptomatic improvement
    • Drug intolerance and side effects (e.g., measurement of BMP in patients on diuretics)
  • Medications can be tapered off once symptoms subside.
  • Duration of therapy has not been established.

Interventional therapy ^[1]

• Chemical ablation with intratympanic gentamicin (injection of gentamicin into the middle ear through the tympanic membrane)
  • First-line for patients with unilateral Meniere disease with recurrent or intractable symptoms unresponsive to pharmacological therapy
  • Usually well-tolerated
  • Greatly reduces vertigo attacks and improves vertigo symptoms ^[1]
• Intratympanic steroid therapy (injection of methylprednisolone or dexamethasone into the middle ear through the tympanic membrane)

Positive pressure pulse generator devices (e.g., Meniett device) are no longer recommended for Meniere disease.

Surgical intervention ^[1]

• Labyrinthectomy (Hearing-sacrificing surgery): destruction and removal of the labyrinth through the mastoid
• Vestibular neurectomy (Hearing preservation surgery): selective transection of the vestibular nerve within the middle cranial fossa via a craniotomy
• Endolymph drainage procedures (e.g., sacculotomy , cochleosacculotomy , endolymph sac decompression ): No longer recommended as they are of doubtful clinical benefit ^[1][20]