Meniere Disease

Overview

Meniere disease (MD) is an inner ear illness that causes hearing loss, tinnitus, and vertigo. In most situations, it progresses slowly and has a substantial influence on the affected individual's social functioning. The manifestation of MD might vary greatly amongst people.

Endolymphatic hydrops and increased fluid inside the inner ear organ are detected (or suspected) in all MD patients.

Meniere disease definition

Tinnitus, vertigo, and hearing loss are symptoms of Meniere illness, an inner ear ailment. This is assumed to be caused by the buildup of endolymphatic fluid in the cochlea and vestibular organ.

Probable Meniere disease can include the following clinical findings:

1. Two or more episodes of dizziness or vertigo lasting between 20 minutes and 24 hours
2. Aural symptoms (fullness, hearing, or tinnitus) in the afflicted ear that fluctuate
3. Another vestibular diagnosis explains the situation better.

Hearing loss is frequently intermittent, occurring mostly during vertigo spells. Loud noises might appear distorted and create pain. Hearing loss often affects lower frequencies first, although it frequently impacts higher tones as well over time. While hearing loss may fluctuate at first, it frequently becomes more permanent as the condition advances.

Epidemiology

Meniere illness has a frequency ranging from 3.5 per 100.000 to 513 per 100.000 and is more common in older, Caucasian, and female individuals.

The discovery of various comorbidities that are more common in Meniere illness patients gave birth to new views regarding the disease's etiology.

1. Migraine: Migraine is more common in Meniere disease patients, while there may be some overlap with basilar migraine misdiagnosed as Meniere illness.
2. Autoimmune diseases: Meniere illness is linked to a number of autoimmune disorders, including rheumatoid arthritis, systemic lupus erythematosus, and ankylosing spondylitis.
3. Genetic component: Meniere's disease is a multifactorial condition. Familial Meniere illness affects 10% of people of European descent. MD can be inherited in an autosomal dominant or autosomal recessive manner, although it can also be sporadic.

Etiology 

In individuals with Meniere illness, temporal bone studies indicated endolymphatic buildup in the cochlea and vestibular organ. Endolymphatic hydrops is associated with a hearing loss of more than 40 decibels, according to current studies. Vertigo may or may not be present. As a result, endolymphatic hydrops is not solely associated with Meniere illness, but can also be observed in cases of idiopathic sensorineural hearing loss.

The specific cause of Meniere illness is unknown. There are several ideas, but genetic and environmental variables both have a role. The connection to prevalent comorbidities is still a mystery.

Mechanism

The early origins of Ménière's illness are unknown, with a number of probable inflammatory reasons leading to endolymphatic hydrops (EH), a distension of the endolymphatic cavities in the inner ear. EH, in turn, is significantly linked to the development of MD, but not everyone with EH develops MD: "The association between endolymphatic hydrops and Meniere's disease is not a straightforward, perfect correlation."

Furthermore, in fully established MD, both the balancing system (vestibular system) and the hearing system (cochlea) of the inner ear are impaired, but in certain cases, EH only affects one of the two systems sufficiently to generate symptoms. The related subtypes of MD are vestibular MD, which causes dizziness, and cochlear MD, which causes hearing loss and tinnitus.

The mechanism of MD is not fully explained by EH, but fully developed EH may mechanically and chemically interfere with the sensory cells for balance and hearing, causing temporary dysfunction and even death of the sensory cells, resulting in the typical symptoms of MD - vertigo, hearing loss, and tinnitus.

Clinical presentation 

The physician will distinguish between vertigo of central, peripheral, and cardiovascular origin in the emergency room or in normal practice. Neurological symptoms or signs, sudden deafness, new kind or start of headache, or vertical/torsional/rotatory nystagmus are red flags indicating a central cause of vertigo.

If Meniere illness is suspected, the patient should be questioned regarding the nature of his or her vertigo, hearing loss, and previous episodes. The clinical investigation includes a thorough otologic history.

If Meniere illness is suspected, a comprehensive otologic examination, facial nerve testing, and nystagmus evaluation with Frenzel goggles, Rinne, and Weber tests should be performed.

• Rinne and Weber: Sensorineural hearing loss in Meniere's illness, whether acute or advanced.
• In the acute situation, Frenzel goggles may display horizontal nystagmus with a fast-beating component distant from the damaged vestibular organ.
• In contrast to other peripheral vestibular illnesses, head impulse testing (HIT) shows a limited sensitivity in Meniere disease.

Diagnosis

All patients with Meniere illness must have an audiometric assessment. The condition is characterized by fluctuating low frequency unilateral sensorineural hearing loss. Hearing loss can spread to all frequencies. Tinnitus is a frequent and ipsilateral condition.

To rule out retrocochlear disease, all patients with one-sided hearing loss should have magnetic resonance imaging (MRI). A BERA (brainstem evoked response audiometry) is adequate in some countries. Imaging is not required in the acute situation, although it may be performed within a few weeks after the beginning of symptoms. Endolymphatic hydrops in the afflicted organs may be detected immediately using high-resolution MRI imaging. More study is being conducted to see whether this is clinically useful.

Vestibular (caloric) function tests may reveal a considerably under-functioning afflicted organ in 42% to 74% of cases and a complete loss of function in 6% to 11% of cases.

Balance tests

Balance tests are used to evaluate the function of your inner ear. Meniere's disease patients have a diminished balancing response in one of their ears. Electronystagmography is the most often used balancing test to diagnose Meniere's illness (ENG).

Electrodes will be implanted around your eyes to detect eye movement throughout this exam. This is done because the inner ear's balancing reaction generates eye movements.

Hot and cold water will be pumped into your ear during this test. The water activates your balancing function. Your unintentional eye movements will be recorded. Any anomalies might suggest an inner ear condition.

Rotary chair testing is becoming less popular. It will reveal your doctor if your condition is caused by an ear or a brain problem. It is used in addition to ENG testing since ENG findings might be inaccurate if you have ear damage or wax in one of your ear canals. During this test, your eye movements are meticulously recorded as the chair moves.

Vestibular evoked myogenic potential (VEMP) testing assesses the inner ear vestibule's sound sensitivity. And posturography testing can help you figure out which element of your balance system isn't working properly. While wearing a safety harness and standing barefoot, you will respond to numerous balancing problems.

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

1. Two or more episodes of vertigo, each lasting 20 minutes to 12 hours
2. Audiometrically verified low- to medium-frequency sensorineural hearing loss in one ear, identifying and locating the afflicted ear on at least one occasion pre, during, or after one of the vertigo episodes
3. Variable aural symptoms (fullness, hearing, tinnitus) in the afflicted ear
4. No other vestibular diagnosis can account for it.

Probable Meniere disease can include the following clinical findings:

1. Two or more episodes of dizziness or vertigo lasting between 20 minutes and 24 hours
2. Aural symptoms (fullness, hearing, or tinnitus) in the afflicted ear that fluctuate
3. Another vestibular diagnosis explains the situation better.

Management

Once other conditions have been ruled out and MD has been diagnosed, the family physician is in a good position to begin conservative therapy. MD treatment is tailored to the patient's symptom management and aims to reduce the frequency, length, and intensity of vertigo events.

While tailored MD treatment is effective in reducing vertigo symptoms, there is currently no medicine available to stop or reduce the course of hearing loss. We recognize that MD treatment varies from center to center. The method shown below is one that we endorse and believe to be effective in managing patients with MD while limiting risk.

Conservative therapy: 

Counseling to relieve stress and lifestyle adjustments such as dietary changes to limit caffeine and alcohol use are advised. Restricting salt and monosodium glutamate consumption has been linked to less vertigo episodes by physically lowering pressures in the hydropic ear.

Adults in Canada should not consume more than 2300 mg of salt per day. Betahistine is suggested by doctors and has been proved to help with vertigo, but only when taken on a regular and preventative basis. Anecdotally, diuretics such as hydrochlorothiazide and triamterene have been proposed to decrease hearing loss by lowering fluid pressures in the hydropic ear, although proof of their usefulness is lacking.

The administration of oral prednisone for a short period of time can lower the severity of vestibular symptoms by reducing inflammation and immunological responses that impact the vestibular nucleus. However, due to the significant systemic hazards, such treatment is not usually suggested in MD. To reduce vestibular sensations during acute bouts, benzodiazepines might be used sparingly.

Nonablative therapies:

Intratympanic steroids can be used to manage vertigo episodes in a subset of individuals whose symptoms are not successfully controlled by conservative therapy. These are commonly delivered in the clinic by OHNS under local anesthetic. Studies back up its value in this regard, with possible explanations including general reduced inflammation and immunological reactions.

This surgery is linked with a low incidence of chronic TM perforation. Commercial local overpressure devices have been launched in recent years, although proof of their efficacy in treating MD symptoms is inadequate.

Ablative therapies: 

Intratympanic gentamicin, vestibular neurectomy, and labyrinthectomy are examples of alternative therapy. Although these therapies are beyond the focus of this article, they are often curative but are seldom required since MD is adequately managed in the majority of patients with the medications outlined above.

Driving restrictions: 

Most MD patients can continue to drive if they have enough warning before an episode. The treating physician must assess this in each individual situation. Patients suffering from Tumarkin otolithic crises, also known as abrupt drop attacks, are an exception. This category of patients requires the treating physician to suspend their driver's licenses through the provincial ministry of transportation. After the patient has been free of drop attacks for at least 6 months, the license should be reinstated.

Surgery

Surgery may be recommended if symptoms do not improve with standard care. One possibility is surgery to decompress the endolymphatic sac. According to a 2015 systematic review, three techniques of decompression have been used: simple decompression, insertion of a shunt, and sac ectomy. It discovered some evidence that all three techniques were effective for decreasing dizziness, but the degree of evidence was poor since studies were not blinded and no placebo controls were utilized.

Another 2015 analysis discovered that shunts used in these operations are frequently moved or misplaced upon autopsy, and suggested their usage only in situations when the problem is uncontrolled and affecting both ears. According to a 2014 comprehensive analysis, EL sac decompression was helpful in treating vertigo in at least 75% of persons in the short term (>1 year of follow-up) and long term (>24 months)

Eustachian tube dysfunction affects around 30% of patients with MD. While a 2005 assessment indicated preliminary evidence of benefit from tympanostomy tubes for improving disease-related unsteadiness, a 2014 review concluded that their usage is not justified.

Destructive procedures are irreversible and include the removal of much, if not all, of the functioning of the damaged ear; as of 2013, essentially little evidence exists to determine if these surgeries are successful. The inner ear can be surgically removed by labyrinthectomy, however hearing in the afflicted ear is always lost with this procedure.

In a vestibular neurectomy, the surgeon can also sever the nerve to the balancing component of the inner ear. Hearing is frequently retained; nevertheless, the procedure entails cutting up the lining of the brain, necessitating a few days in the hospital for monitoring.

Differential Diagnosis

Unlike the most prevalent type of peripheral vertigo, benign paroxysmal positional vertigo, MD bouts continue longer and are not repeatable by particular head motions. Similarly, dizziness without the appearance of spinning caused by fast changes in vertical head height is most likely caused by orthostatic hypotension, which is usually caused by dehydration or cardiogenic reasons.

Vestibular migraines (VM) might seem remarkably identical to MD, although individuals with VM usually have a migraine history. VM vertigo bouts may not be temporally connected with headaches, with vertigo start occurring years later with headache-free intervals in between.

Vertigo bouts in Vestibular migraines can last anywhere from minutes to days and may include visual auras or allodynia. Viral infections of the inner ear, such as vestibular neuronitis and viral labyrinthitis, can cause vertigo for days to weeks. Hearing loss is another symptom of viral labyrinthitis. Ramsay Hunt syndrome, caused by varicella zoster virus reactivation inside the vestibular ganglion, is another viral illness that commonly manifests as vertigo and facial nerve paralysis.

Superior canal dehiscence syndrome can cause vertigo for a few seconds at a time, as well as hyperacusis, in which patients perceive exaggerated noises of body motions. Acoustic neuroma (vestibular schwannoma) patients do not generally present with symptoms comparable to MD. It should, however, be considered in any patient who has asymmetric SNHL.

The presence of motor weakness, neuropathic discomfort, and sexual dysfunction distinguishes multiple sclerosis from MD. Furthermore, symptoms of MD can overlap with symptoms of cerebrovascular illness, although the latter is distinguished by symptoms of visual abnormalities, diplopia, peripheral weakness, and headaches.

Conclusion 

Ménière disease is a rare cause of vertigo and dizziness. Patients, on the other hand, readily offer the standard traits during history taking. Migraine-related dizziness and vertigo is a typical mimicker of MD that can also be handled initially by the family physician, with a referral to neurology or neurotology considered.

Because peripheral vestibular diseases are infrequent causes of dizziness and patient-reported vertigo, distinguishing genuine vertigo from other causes of dizziness is the first step in treating patients with dizziness or vertigo. MD is treated using conservative, nonablative, and occasionally ablative treatments.

Dietary changes and betahistine are the first steps in conservative treatment, which can be started by the family doctor. All individuals suspected of having MD should be referred to an otolaryngologist. With customized care, the majority of MD patients achieve satisfactory symptom control.