Continuing Education Activity

Meniere disease is an inner ear disorder characterized by tinnitus, vertigo, and hearing loss. This is thought to occur due to the accumulation of endolymphatic fluid in the cochlea and the vestibular organ. In most cases, it is slowly progressive and significantly impacts the social functioning of the individual affected. Hearing loss, tinnitus, and vertigo are all common symptomatic complaints with many potential causes, yet actual Meniere disease is quite rare and is fundamentally a diagnosis of exclusion. The current diagnostic criteria defined by the Barany society by Lopez-Escamez, et al. can help differentiate between probable and definite Meniere's disease. This activity reviews the evaluation and management of Meniere disease and explains the role of the interprofessional team in improving care for patients with this condition.

Objectives:

• Outline the epidemiology of Meniere disease.
• Identify the use of the Rinne and Weber test in the history and physical of patients with Meniere disease.
• Describe the audiometric tests used in the evaluation of Meniere disease.
• Review the importance of improving care coordination among the interprofessional team to enhance the delivery of care for patients affected by Meniere disease.

Introduction

Meniere disease (MD) is a disorder of the inner ear characterized by hearing loss, tinnitus, and vertigo. In most cases, it is slowly progressive and significantly impacts the social functioning of the individual affected.[1]

Hearing loss, tinnitus, and vertigo are all common symptomatic complaints with many potential causes, yet true Meniere disease is quite rare and is fundamentally a diagnosis of exclusion. The current diagnostic criteria defined by the Barany society by Lopez-Escamez, et al. can help differentiate between probable and definite Meniere's disease. 

Patients with a definite Meniere disease, according to the Barany Society, have:

1. Two or more spontaneous episodes of vertigo with each lasting 20 minutes to 12 hours

2. Audiometrically documented low- to medium-frequency sensorineural hearing loss in one ear, defining and locating to the affected ear on in at least one instance prior, during, or after one of the episodes of vertigo

3. Fluctuating aural symptoms (fullness, hearing, tinnitus) located in the affected ear

4. Not better accounted for by any other vestibular diagnosis

Probable Meniere disease can include the following clinical findings:

1. Two or more episodes of dizziness or vertigo, each lasting 20 minutes to 24 hours

2. Fluctuating aural symptoms (fullness, hearing, or tinnitus) in the affected ear

3. The condition is better explained by another vestibular diagnosis[2]

Etiology

Studies of the temporal bone revealed endolymphatic accumulation (hydrops) in the cochlea and the vestibular organ in patients with Meniere disease. Current research links endolymphatic hydrops to a hearing loss of >40dB. Vertigo may or may not be associated.[3] Therefore endolymphatic hydrops is not entirely specific to Meniere disease and can be found in cases of idiopathic sensorineural hearing loss. 

The exact etiology of Meniere disease remains unclear. Different theories exist, but genetic and environmental factors play a role.[4] The relation to common comorbidities remains elusive. 

Epidemiology

The prevalence of Meniere disease varies between 3.5 per 100.000 and 513 per 100.000 and occurs more often in older, white, female patients.[5][6][7]

Several comorbidities have been identified which occur in an increased fashion in patients with Meniere disease:

Migraine: Migraine occurs more often in patients diagnosed with Meniere disease, although there is likely significant overlap/misclassification of patients with basilar migraine wrongly diagnosed as having Meniere disease. There are theories regarding a vascular etiology for Meniere disease, but they remain unproven.[8]

Autoimmune diseases: Several autoimmune diseases are associated with Meniere disease, namely rheumatoid arthritis, systemic lupus erythematosus, and ankylosing spondylitis. IgE has been proposed as a contributory factor in some studies of middle ear samples in Meniere disease.[9][10]

Genetic component: Meniere disease is a polygenic disorder. Ten percent of cases in patients of European descent have familial Meniere disease. The condition may show autosomal dominant or recessive inheritance but is most commonly sporadic. Precise genetics in Meniere disease is an area of active research.[11]

Pathophysiology

The precise pathophysiology of Meniere disease is unknown. The most consistent histologic abnormality is endolymphatic hydrops, though not everyone with documented hydrops develops MD. Endolymphatic hydrops describes the expansion of the volume of the endolymphatic spaces and dilatation of Reissner's membrane. The exact pathophysiology of endolymphatic hydrops is likewise unknown, though the most common theories postulate an imbalance between the secretion and resorption of endolymph in the cochlea.[12]

History and Physical

In the emergency room or general practice, the physician must differentiate between vertigo of central, peripheral, and cardiovascular origin. According to Harcourt et al., signs and symptoms suggestive of a central origin of vertigo are additional neurological symptoms or signs, acute deafness, a new type or onset of headache, or vertical/torsional/rotatory nystagmus.[13]

A full otologic history is crucial to the clinical investigation for any hearing- or balance-related complaint. The patient should be questioned about the character of vertigo (with meticulous attention paid to differentiating true whirling vertigo complaints from more generalized imbalance or presyncopal sensations), hearing loss, and earlier episodes of these symptoms. Duration of episodes of vertigo and hearing loss should also be noted, likewise any positional triggers (vertigo when turning the head would suggest BPPV, for example, while lightheadedness upon standing suggests orthostatic hypotension). Family history of hearing and balance problems should also be elicited. 

A complete physical examination, including a comprehensive neurologic examination, is required. Cranial nerves should be examined to rule out any additional focal findings. Rinne and Weber tests can be used to crudely assess auditory nerve function, but formal audiology testing is warranted. Peripheral sensation should be documented in all extremities, and the gait should be examined. Cerebellar testing should be performed, and Romberg, Fukuda, and pronator drift tests also assessed. If there is a question of a positional component, then a Dix-Hallpike maneuver should be performed, ideally with Frenzel goggles to facilitate nystagmus identification, and orthostatic blood pressures should be documented.

Rinne and Weber: Will show sensorineural hearing loss in acute Meniere disease or advanced disease, but this will depend on the degree of hearing loss. For this reason, a formal audiology evaluation is required.

Frenzel goggles: May show horizontal nystagmus with a fast-beating component away from the affected vestibular organ in the acute setting.

Dix-Hallpike maneuver: A test for BPPV wherein the patient's head is rotated to one side, and the neck hyperextended. The patient is then taken rapidly from a seated to supine position with the eyes open, and the eyes are examined for rotational nystagmus +/- the development of vertiginous symptoms. This is then repeated with the head turned to the contralateral side. If positive, this is diagnostic of BPPV.

Head impulse testing (HIT): In contrast to other peripheral vestibular disorders, this test has a low sensitivity in Meniere disease.[14]

Evaluation

Audiometric evaluation is mandatory in all patients with Meniere disease. Fluctuating low frequency unilateral sensorineural hearing loss is characteristic of the disease. The hearing loss can progress to all frequencies. Tinnitus is common and ipsilateral.[15]

All patients with one-sided hearing loss should undergo magnetic resonance imaging (MRI) to rule out retrocochlear pathology. In some countries, a BERA (brainstem evoked response audiometry) is sufficient. There is no need to perform imaging in the acute setting, but it may be done within a few weeks after the onset of symptoms. High-resolution MRI imaging may directly show endolymphatic hydrops in the affected organs. More research is underway to show if this is of clinical use.[16][17]

Vestibular (caloric) function testing may show a significantly under-functioning affected organ in 42% to 74% and a complete loss of function in 6% to 11%.[18]

Treatment / Management

Different treatment options for Meniere disease exist with substantial variability between countries. None of the treatment options cure the disease. As many treatments significantly impact the functioning of surrounding structures, one should start with non-invasive approaches with the fewest possible side effects and proceed to more invasive steps.

1. Sodium restriction diet: Low-level evidence suggests that restricting sodium intake may help to prevent Meniere attacks.[13]
2. Thiazide diuretics: Form the mainstay of medical treatment in many centers. Evidence suggests they reduce the frequency and severity of symptomatic episodes but do not appear to prevent hearing loss.[19]
3. Betahistine: Substantial disagreement exists in the medical community about the use of betahistine. A Cochrane review found low-level evidence to support the use of betahistine with substantial variability between studies.[20] 
4. Intratympanic steroid injections: May reduce the number of vertigo attacks in patients with Meniere disease while preserving auditory function.[21]
5. Intratympanic gentamycin injections: Gentamycin has strong ablative properties towards vestibular cells. Side effects are sensorineural hearing loss because of a certain amount of toxicity toward cochlear cells.[22] 
6. Vestibular nerve section or labyrinthectomy: Nerve section is a therapeutic option in patients who failed the conservative treatment options, and labyrinthectomy when surgical options failed. Labyrinthectomy leads to complete hearing loss on the affected side.[18]

Differential Diagnosis

Basilar migraine: Associated with vertigo but without aural symptoms

Vestibular neuronitis: Associated with vertigo lasting for several days, no aural symptoms

Benign paroxysmal positional vertigo: Associated with vertigo related to head movements, lasting seconds to minutes, no aural symptoms

Medications (e.g., aminoglycosides and loop diuretics)

Central vertigo: causes include stroke, multiple sclerosis, seizure disorder, others

Peripheral vertigo of non-otogenic origin: Commonly seen in elderly patients with peripheral neuropathy and deconditioning

Orthostatic hypotension: Not true vertigo, but patients may describe themselves as "dizzy" 

Neoplasm: vestibular schwannoma, meningioma, malignancy

Infectious causes: meningitis, syphilis, HIV cerebritis, others

Prognosis

According to Perrez-Garrigues, et al., the number of episodes of vertigo is higher in the first years of the disease and decreases in later years regardless of treatment; most patients reach a "steady-state phase free of vertigo," but often with significant hearing loss as a result.[23]

As with vertigo, loss of hearing is highest in the early years of the disease and stabilizes in later years. Usually, there is no recovery from hearing loss. Patients with Meniere disease in one ear are at higher risk of developing it in the contralateral ear; one systematic review reports bilateral involvement of the vestibular organ in up to 47% of patients over 20 years.[24][25][26]

Complications

In later stages of the pathology, patients may experience sudden unexpected loss of muscle tone (drops) without loss of consciousness, termed crises of Tumarkin.[27]

Patients with Meniere disease report significantly impaired quality of life compared to healthy individuals, and the prevalence of anxiety and depression is significantly higher in MD patients compared to the general population.[28][29]

Consultations

Refer patients with signs suggestive of Meniere disease for otolaryngologic consultation and formal audiometric evaluation.

Deterrence and Patient Education

Suspect Meniere disease if the patient experiences loss of hearing in one ear with attacks of vertigo which last from several minutes to several hours, and tinnitus. These patients should undergo an urgent evaluation to exclude potentially life-threatening conditions, facilitate a final diagnosis, and begin treatment.

Pearls and Other Issues

Meniere disease is rare and should only be diagnosed via specific criteria after excluding other causes of symptoms.

Vertigo, tinnitus, and hearing loss are extremely common and can be caused by serious or life-threatening pathology.

Enhancing Healthcare Team Outcomes

The evaluation of patients with vertigo is complex. Patients often require medical attention from neurologists, otolaryngologists, internal medicine, audiologists, and nursing staff, all functioning as an interprofessional medical team. The Bárány Society published the current classification of Meniere disease. It is essential to base the diagnosis of Meniere disease on the criteria published and mentioned in this article to warrant a uniform diagnosis, especially in the presence of different international approaches to diagnosing patients with vertigo.