Ménière’s disease is an idiopathic inner ear disorder characterized by endolymphatic hydrops. It manifests as recurrent episodes of rotational vertigo, fluctuating sensorineural hearing loss, tinnitus, and/or aural fullness. This condition was first described in 1861 by French physician Prosper Ménière.
Epidemiology
The reported incidence of Ménière’s disease varies widely, ranging from 7.5 to 157 per 100,000 individuals. The age of onset ranges from 4 to 90 years, with a higher prevalence among young and middle-aged adults. The peak age of onset is between 40 and 60 years. The male-to-female ratio is approximately 1:1 to 1:1.3. While the disease commonly affects one ear, bilateral involvement can occur with disease progression.
Etiology
The primary mechanism of Ménière's disease involves an imbalance between the production and absorption of endolymph, although the exact mechanisms remain unclear.
Mechanical Obstruction of Endolymphatic Ducts and Impaired Endolymph Absorption
Narrowing or blockage in any part of the endolymphatic flow system, such as congenital narrowing, hypoplasia of the endolymphatic sac, or inflammatory fibrotic changes, may result in mechanical obstruction or impaired endolymph absorption. These are major causes of endolymphatic hydrops.
Immune Reaction Hypothesis
Antigens entering the inner ear through various mechanisms, or those endogenously generated within it, can stimulate immune-active cells clustered around blood vessels, endolymphatic ducts, and the endolymphatic sac to produce antibodies. The antigen-antibody reaction increases the permeability of capillaries in the inner ear, leading to fluid infiltration into the membranous labyrinth. Additionally, hypersecretion by structures such as the stria vascularis, and disrupted absorption in the endolymphatic sac due to antigen-antibody complex deposition, may also contribute to endolymphatic hydrops.
Inner Ear Ischemia Hypothesis
Dysregulation of autonomic nervous functions and vasospasm in small inner ear vessels could lead to microcirculatory disturbances in the inner ear and endolymphatic sac. Consequent tissue hypoxia, metabolic disruption, changes in the physicochemical properties of endolymph, increased osmotic pressure, and fluid infiltration from the perilymph and blood may result in endolymphatic hydrops.
Other Theories
These include the endolymphatic sac dysfunction hypothesis, viral infection hypothesis, and genetic predisposition hypothesis.
Pathology
The fundamental pathological feature is the dilation of the membranous labyrinth due to endolymphatic hydrops. The scala media and saccule are more prominently affected compared to the utricle and ampulla. The semicircular ducts and the endolymphatic sac do not exhibit dilation. The dilated cochlear duct pushes Reissner's membrane towards the scala vestibuli, in severe cases nearly contacting the bony wall, obstructing perilymphatic flow. Hyperplasia of the Reissner's membrane epithelial cells may also occur.
The dilated saccule may fill the vestibule, extending laterally to the stapes footplate and posteriorly compressing the utricle, causing its torsion and displacement. Utricular enlargement can induce similar changes in the ampulla. Extremely elevated endolymphatic pressure may cause rupture of Reissner's membrane, mixing endolymph and perilymph. Although the endolymphatic sac itself does not dilate, its epithelial folds may become flattened or disappear due to chronic compression, with the epithelial cells transitioning from columnar or cuboidal shapes to a flattened form. Some cells may detach entirely, while subepithelial fibrotic thickening and capillary reduction may also occur.
Chronic hydrops, particularly in cases of recurrent or unresolved membranous labyrinth rupture, may result in the degeneration of structures such as the stria vascularis, tectorial membrane, cochlear hair cells and their supporting cells, afferent nerve fibers, and spiral ganglion cells. Vestibular sensory organs, however, are typically less affected than the cochlea. The mixing of endolymph and perilymph disrupts ionic equilibrium and biochemical homeostasis, serving as a pathophysiological basis for clinical manifestations of Ménière’s disease. Additionally, the morphological expansion and deformation of the membranous labyrinth are implicated in the disease mechanism.
Clinical Features
Ménière’s disease is characterized by typical symptoms including recurring attacks of vertigo, fluctuating and progressive hearing loss, tinnitus, and aural fullness.
Vertigo
Episodes typically present as sudden rotational vertigo. Patients may experience a sensation of themselves or their surroundings spinning in a specific direction, or feelings of swaying, rising, falling, or floating. Vertigo is often accompanied by autonomic symptoms such as nausea, vomiting, pallor, cold sweats, bradycardia, and hypotension. These symptoms tend to worsen when the patient opens their eyes or moves their head, and improve when the eyes are closed, and the patient remains at rest. Episodes of vertigo occur with preserved consciousness, lasting between 20 minutes and several hours, usually resolving within 2–3 hours. Episodes lasting longer than 24 hours are rare. During the remission period, patients may feel imbalance or unsteadiness, which can persist for several days. Vertigo frequently recurs, with increasing frequency and duration over time and shortening intervals between episodes.
Hearing Loss
Hearing loss may not be noticeable in the early stages of the disease and tends to become evident after multiple episodes. It is often unilateral, worsens during attacks, and improves during remission, showing a fluctuating pattern. Hearing loss tends to deteriorate with increasing episodes but rarely progresses to total deafness. Patients may experience unpleasant sensitivity to loud high-frequency sounds. Occasionally, the patient perceives the same pure tone as different in pitch or timbre in each ear, a phenomenon clinically referred to as diplacusis.
Tinnitus
Tinnitus often precedes vertigo attacks. In the early stages, it presents as a persistent low-frequency hum or the sound of flowing water, which later transforms into high-frequency buzzing, whistling, or siren-like sounds. Tinnitus tends to intensify during vertigo episodes and diminish during remission, although it rarely disappears completely.
Aural Fullness
During episodes, the affected ear or the head may feel full, heavy, or under pressure. At times, there may be a burning pain around the affected ear.
Examinations
Otoscopy
The tympanic membrane appears normal. Tympanometry shows a normal curve, and Eustachian tube function is intact.
Vestibular Function Tests
During attacks, spontaneous nystagmus with rhythmic and varied intensity may be observed, or recorded through electronystagmography. This nystagmus typically starts toward the affected side and later shifts to the unaffected side, exhibiting horizontal or rotatory-horizontal traits. Positional nystagmus may also occur. During recovery, nystagmus may shift back to the affected side. Abnormal results are often found in static and dynamic balance tests. In the remission phase, spontaneous nystagmus and results from various provocation tests may appear normal. After multiple episodes, the vestibular function of the affected ear may deteriorate or be lost. Caloric testing may show directional preponderance. If the stapes footplate adheres to the expanded saccule, changes in external ear canal pressure may induce vertigo and nystagmus, known as a positive Hennebert’s sign.
Audiology Tests
Results commonly indicate sensorineural hearing loss. Long-term sufferers may exhibit more profound sensorineural damage. Early pure-tone audiograms often display a rising or peaked configuration (loss at low and high frequencies with a peak around 2 kHz), whereas later stages may show a flat or descending pattern. Suprathreshold tests may reveal recruitment phenomena, and tone decay tests are typically normal. Electrocochleography findings may include an increase in the -SP (summating potential), a widened SP-AP (action potential) complex, and an elevated -SP/AP ratio (-SP/AP > 0.4). The amplitude-intensity function of the AP may present an abnormally steep curve. In long-term cases, the mean speech recognition score may decrease, while the mean hearing threshold increases.
Dehydration Test
This method evaluates changes in auditory function by reducing excessive endolymph to assist in diagnosis. Glycerol testing is commonly used: a fasting dose of 1.2–1.5 g/kg of glycerol mixed with an equal volume of saline or juice is administered. Pure-tone audiometry is performed before administration and every hour for 3 hours afterward. An increase in the average hearing threshold (as defined by diagnostic criteria) of 15 dB or more, or a 16% or greater improvement in speech recognition rate, is considered positive. While this test often yields positive results for Ménière’s disease patients, it may be negative during remission, dehydration treatment, or for patients with mild or severe but nonfluctuating hearing loss. A decrease in the -SP amplitude on the electrocochleogram or the reappearance of otoacoustic emissions after glycerol administration is considered objective evidence of a positive result.
Temporal Bone CT
CT occasionally reveals poor aeration around the vestibular aqueduct or a narrowed or absent endolymphatic duct.
Membranous Labyrinth MRI
Some patients may show thinning of the endolymphatic duct. By administering gadolinium contrast agents through various methods (systemically, via tympanic injection, or through the Eustachian tube) and combining this with MRI imaging, visualization of the membranous labyrinth is possible. Comparative analysis of endolymphatic and perilymphatic spaces can help assess the degree of endolymphatic hydrops.
Diagnosis
The diagnosis of Ménière’s disease relies primarily on a detailed medical history, comprehensive examinations, and careful differential diagnosis. A positive glycerol test may assist in confirming the condition.
Diagnostic Criteria for Clinical Diagnosis:
- Recurring episodes of rotational vertigo occurring two or more times, each lasting between 20 minutes and 12 hours.
- Audiological evidence of low- to mid-frequency sensorineural hearing loss in the affected ear at least once during the course of the disease.
- Fluctuating hearing loss, tinnitus, and/or aural fullness in the affected ear.
- Exclusion of other causes of vertigo, such as vestibular migraine, sudden sensorineural hearing loss, benign paroxysmal positional vertigo, labyrinthitis, vestibular neuritis, vestibular paroxysmia, drug-induced vertigo, posterior circulation ischemia, intracranial masses, and secondary endolymphatic hydrops.
Clinical Staging
Staging is based on the worst pure-tone average threshold (0.5 kHz, 1.0 kHz, and 2.0 kHz) observed during the last six months in the remission phase. Staging provides insights into treatment choices and prognosis. In bilateral Ménière’s disease, each ear's clinical stage is determined individually.
- Stage I: Pure-tone threshold ≤ 25 dB HL
- Stage II: Pure-tone threshold 26–40 dB HL
- Stage III: Pure-tone threshold 41–70 dB HL
- Stage IV: Pure-tone threshold > 70 dB HL
Diagnostic Criteria for Suspected Cases:
- Two or more episodes of vertigo, each lasting between 20 minutes and 24 hours.
- Fluctuating hearing loss, tinnitus, and/or aural fullness in the affected ear.
- Exclusion of other causes of vertigo, such as vestibular migraine, sudden sensorineural hearing loss, benign paroxysmal positional vertigo, labyrinthitis, vestibular neuritis, vestibular paroxysmia, drug-induced vertigo, posterior circulation ischemia, intracranial masses, and secondary endolymphatic hydrops.
Differential Diagnosis
Benign Paroxysmal Positional Vertigo (BPPV)
BPPV is the most common peripheral vestibular disorder. It presents as short episodes of vertigo and nystagmus triggered by changes in head position relative to gravity. The absence of cochlear symptoms distinguishes BPPV from Ménière’s disease. Positional testing is the primary method for diagnosis.
Vestibular Neuritis
This condition is believed to result from viral infections. It is characterized by sudden vertigo, spontaneous nystagmus toward the unaffected side, nausea, and vomiting. Vestibular function is reduced without hearing loss or tinnitus. Symptoms gradually resolve over days, but positional vertigo may persist for months. Recurrence is rare. The absence of cochlear symptoms differentiates it from Ménière’s disease.
Ototoxic Vestibulopathy
This condition is associated with a history of exposure to ototoxic drugs. Symptoms include a slowly progressive onset of vertigo of mild to moderate intensity, which may persist for an extended period and may improve gradually due to compensation. Hearing loss and tinnitus are common.
Labyrinthitis
This condition often has a history of suppurative otitis media or middle ear surgery, aiding differentiating diagnosis.
Sudden Sensorineural Hearing Loss
Approximately half of these cases are accompanied by vertigo, though recurring episodes are rare. Hearing loss is abrupt and severe, without fluctuation.
Ramsay Hunt Syndrome
This condition may involve mild vertigo, tinnitus, and hearing impairment. The presence of herpes zoster lesions on the auricle or surrounding skin and facial paralysis supports differentiation from Ménière’s disease.
Cogan’s Syndrome
This condition features vertigo, bilateral tinnitus, and hearing loss, in conjunction with non-syphilitic interstitial keratitis and vasculitis. Glucocorticoid treatment exhibits good efficacy, allowing for distinction.
Delayed Endolymphatic Hydrops
This condition presents with unilateral or bilateral hearing loss initially, followed by episodic vertigo occurring one or several years later. The causes may include head trauma, labyrinthitis, mastoiditis, otitis media, or even diphtheria.
Perilymph Fistula
Either spontaneous or secondary (e.g., post-surgical or post-traumatic) perilymphatic fistula at the round or oval window may manifest as fluctuating hearing loss accompanied by vertigo and balance disturbances. Suspected cases may require surgical exploration of the round and oval window membranes for confirmation and repair.
Head Trauma
Vestibular symptoms may follow head trauma, including cervical injuries, central nervous system trauma, and peripheral vestibular injuries. For example, transverse fractures of the temporal bone commonly cause severe vertigo, spontaneous nystagmus, tinnitus, hearing loss, and facial paralysis, which may gradually improve after 2–3 weeks, leaving residual positional nystagmus or positional vertigo.
Acoustic Neuroma
The details can be seen in the section on acoustic neuroma.
Superior Semicircular Canal Dehiscence Syndrome
Vertigo triggered by loud sounds or changes in external ear canal pressure is characteristic of this syndrome. High-resolution CT imaging aids in differentiation from Ménière’s disease.
Treatment
Given that the cause and pathogenesis of Ménière’s disease remain unclear, treatment often focuses on comprehensive medical therapy or surgical options aimed at regulating autonomic nervous system function, improving microcirculation in the inner ear, and reducing endolymphatic hydrops.
General Treatment
During acute episodes, bed rest is recommended. A high-protein, high-vitamin, low-fat, and low-sodium diet is encouraged. Once symptoms subside, gradual resumption of activities is advised. The role of psychological and mental health support is significant, particularly for patients with long-term illness, frequent episodes, or associated neurasthenia. Clear explanations and emotional support can help alleviate mental stress.
Medication Therapy
Symptomatic Medications
Vestibular depressants such as diazepam, diphenhydramine, and dimenhydrinate are commonly used, but only during acute episodes.
Anticholinergics, including scopolamine and anisodamine, are effective.
Vasodilators and calcium channel blockers such as cinnarizine, flunarizine, betahistine, and nimodipine are frequently prescribed.
Diuretics and osmotic agents, such as chlorthalidone and 70% isosorbide dinitrate, are helpful. Drugs like ethacrynic acid and furosemide are avoided due to ototoxicity.
Intratympanic Medication
Drugs administered via tympanic injection can penetrate the inner ear through the round window membrane. Gentamicin and dexamethasone are commonly used. The former induces chemical labyrinthectomy, while the latter is associated with immunomodulation of the inner ear.
Middle Ear Pressure Therapy
Low-pressure pulse therapy is frequently adopted for symptom management.
Surgical Therapy
Patients with frequent and severe vertigo attacks, unresponsive to long-term conservative treatment, or worsening tinnitus and hearing loss may undergo surgical intervention. Various surgical techniques are available, with a preference for less destructive procedures that preserve hearing.
Hearing Preservation Surgery
These procedures are classified based on whether vestibular function is preserved or not:
- Vestibular Function-Preserving Surgery: This includes endolymphatic sac surgery and semicircular canal plugging.
- Vestibular Function-Destroying Surgery: This includes chemical labyrinthectomy and vestibular nerve section via various approaches.
Non-Hearing Preservation Surgery
For late-stage or severely hearing-impaired Ménière’s disease patients, labyrinthectomy may be considered.
Vestibular and Hearing Rehabilitation
Vestibular Rehabilitation Training
This applies to Ménière’s disease patients with stable, non-fluctuating vestibular dysfunction. It can alleviate dizziness, improve balance, and enhance quality of life. Rehabilitation methods include general vestibular rehabilitation, individualized therapy, and balance training based on virtual reality technologies.
Hearing Rehabilitation
For stage III and IV Ménière’s disease patients with stable conditions, hearing aids or cochlear implants may be considered, depending on the severity of hearing loss.