|Ménière's disease is a disorder of the inner ear that can affect hearing and balance. It is characterized by episodes of dizziness and tinnitus and progressive hearing loss, usually in one ear. It is caused by an increase in volume and pressure of the endolymph of the inner ear. It is named after the French physician Prosper Ménière, who first reported that vertigo was caused by inner ear disorders in an article published in 1861.
The symptoms of Ménière's are variable; not all sufferers experience the same symptoms. However, so-called "classic Ménière's" is considered to comprise the following four symptoms: periodic episodes of rotary vertigo (the abnormal sensation of movement) or dizziness; fluctuating, progressive, unilateral (in one ear) or bilateral (in both ears) hearing loss, often initially in the lower frequency ranges; unilateral or bilateral tinnitus (the perception of noises, often ringing, roaring, or whooshing), sometimes variable and asensation of fullness or pressure in one or both ears.
Ménière's often begins with one symptom, and gradually progresses. However, not all symptoms must be present for a doctor to make a diagnosis of the disease. Several symptoms at once is more conclusive than different symptoms at separate times.
Attacks of vertigo can be severe, incapacitating, and unpredictable. Some patients experience vertigo for hours or days, and this combines with an increase in volume of tinnitus and temporary, albeit significant, hearing loss. Hearing may improve after an attack, but often becomes progressively worse. Nausea, vomiting, and sweating sometimes accompany vertigo.
Some sufferers experience what are informally known as "drop attacks" — a sudden, severe attack of dizziness or vertigo that causes the sufferer, if not seated, to fall. Patients may also experience the feeling of being pushed or pulled (Pulsion). Some patients may find it impossible to get up for some time, until the attack passes or medication takes effect.
In addition to hearing loss, sounds can seem tinny or distorted, and patients can experience unusual sensitivity to noises (hyperacusis). Some sufferers also experience nystagmus, or uncontrollable rhythmical and jerky eye movements, usually in the horizontal plane, reflecting the essential role of non-visual balance in coordinating eye movements.
Studies done on both right and left ear sufferers show that patients with their right ear tend to do significantly worse in cognitive performance. General intelligence was not hindered, and it was concluded that declining performance was related to how long the patient had been suffering from the disease.
The exact cause of Ménière's disease is not known, but it is believed to be related to endolymphatic hydrops or excess fluid in the inner ear. It is thought that endolymphatic fluid bursts from its normal channels in the ear and flows into other areas causing damage. This may be related to swelling of the endolymphatic sac or other tissues in the vestibular system of the inner ear, which is responsible for the body's sense of balance. The symptoms may occur in the presence of a middle ear infection, head trauma or an upper respiratory tract infection, or by using aspirin, smoking cigarettes or drinking alcohol. They may be further exacerbated by excessive consumption of caffeine and salt in some patients.
It has also been proposed that Ménière's symptoms in some patients may be caused by the deleterious effects of a herpes virus. Herpesviridae are present in a majority of the population in a dormant state. It is suggested that the virus is reactivated when the immune system is depressed due to a stressor such as trauma, infection or surgery (under general anesthesia). Symptoms then develop as the virus degrades the structure of the inner ear.
Many disorders have symptoms similar to Ménière's. Doctors establish it with complaints and medical history. However, a detailed otolaryngological examination, audiometry and head magnetic resonance imaging (MRI) scan should be performed to exclude a tumour of the eighth cranial nerve (vestibulocochlear nerve) or superior canal dehiscence which would cause similar symptoms. Because there is no definitive test for Ménière's, it is only diagnosed when all other causes have been ruled out.
Ménière's typically begins between the ages of 30 and 60 and affects men slightly more than women.
Ménière's disease had been recognized prior to 1972, but it was still relatively vague and broad at the time. The American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium (AAO HNS CHE) made set criteria for diagnosing Ménière's, as well as defining two sub categories of Ménière's: cochlear (without vertigo) and vestibular (without deafness).
In 1972, the academy defined criteria for diagnosing Ménière's disease as:
1. Fluctuating, progressive, sensorineural deafness.
2. Episodic, characteristic definitive spells of vertigo lasting 20 minutes to 24 hours with no unconsciousness, vestibular nystagmus always present.
3. Usually tinnitus.
4. Attacks are characterized by periods of remission and exacerbation.
In 1985, this list changed to alter wording, such as changing "deafness" to "hearing loss associated with tinnitus, characteristically of low frequencies" and requiring more than one attack of vertigo to diagnose.
Finally in 1995, the list was again altered to allow for degrees of the disease:
1. Certain - Definite disease with histopathological confirmation
2. Definite - Requires two or more definitive episodes of vertigo with hearing loss plus tinnitus and/or aural fullness
3. Probable - Only one definitive episode of vertigo and the other symptoms and signs
4. Possible - Definitive vertigo with no associated hearing loss
Initial treatment is aimed at both dealing with immediate symptoms and preventing recurrence of symptoms, and so will vary from patient to patient. Doctors may recommend vestibular training, methods for dealing with tinnitus, stress reduction, hearing aids to deal with hearing loss, and medication to alleviate nausea and symptoms of vertigo.
Several environmental and dietary changes are thought to reduce the frequency or severity of symptom outbreaks. Most patients are advised to adopt a low-sodium diet, typically one to two grams (1000-2000mg) at first, but diets as low as 400mg are not uncommon. Patients are advised to avoid caffeine, alcohol and tobacco, all of which can aggravate symptoms of Ménière's. Some recommend avoiding Aspartame. Patients are often prescribed a mild diuretic (sometimes vitamin B6). Many patients will have allergy testing done to see if they are candidate for allergy desensitization as allergies have been shown to aggravate Ménière's symptoms.
Many patients consider fluorescent lighting to be a trigger for symptoms. The plausibility of this can be explained by how important a part vision plays in the overall mechanism of human balance.
Women may experience increased symptoms during pregnancy or shortly before menstruation, probably due to increased fluid retention.
Some doctors recommend Lipoflavonoids.
Treatments aimed at lowering the pressure within the inner ear include antihistamines, anticholinergics, steroids, and diuretics. Devices that provide transtympanic micropressure pulses (such as the Meniett) are now showing some promise and is becoming more widely used as a treatment for Ménière's. The Meniett, specifically, is proven to be a safe method for reducing vertigo frequency for a majority of users.
The anti-herpes virus drug Aciclovir has also been used with some success to treat Ménière's Disease. The likelihood of the effectiveness of the treatment was found to decrease with increasing duration of the disease probably because viral suppression does not reverse damage. Morphological changes to the inner ear of Ménière's sufferers have also been found which it was considered likely to have resulted from attack by a herpes simplex virus. It was considered possible that long term treatment with acyclovir (greater than six months) would be required to produce an appreciable effect on symptoms. Herpes viruses have the ability to remain dormant in nerve cells by a process known as HHV Latency Associated Transcript. Continued administration of the drug should prevent reactivation of the virus and allow for the possibility of an improvement in symptoms. Another consideration is that different strains of a herpes virus can have different characteristics which may result in differences in the precise effects of the virus. Further confirmation that acyclovir can have a positive effect on Ménière's symptoms has been reported.
Surgery may be recommended if medical management does not control vertigo. Permanent surgical destruction of the balance part of the affected ear can be performed for severe cases if only one ear is affected. This can be achieved through chemical labyrinthectomy, in which a drug (such as gentamicin) that "kills" the vestibular apparatus is injected into the middle ear. Alternatively, surgeons can cut the nerve to the balance portion of the inner ear in a vestibular neurectomy, or the inner ear itself can be surgically removed (labyrinthectomy). These treatments eliminate vertigo, but because they are destructive, they are a last resort. Typically balance returns to normal after these procedures (albeit a balance system only using the unaffected side) but hearing loss may continue to progress.
Surgery to decompress the endolymphatic sac has shown to be effective for temporarily relief from symptoms. Most patients see a decrease in vertigo occurrence, while their hearing may be unaffected. This treatment, however, does not address the long-term course of vertigo in Ménière's disease. Danish studies even link this surgery to a very strong placebo effect, and that very little difference occured in a 9-year followup, but could not deny the efficacy of the treatment.
Progression of Ménière's is unpredictable: symptoms may worsen, disappear altogether, or remain the same.
Sufferers whose Ménière's began with one or two of the classic symptoms may develop others with time. Attacks of vertigo can become worse and more frequent over time, resulting in loss of employment, loss of the ability to drive, and inability to travel. Some patients become largely housebound. Hearing loss can become more profound and may become permanent. Some patients become deaf in the affected ear. Tinnitus can also worsen over time. Some patients with unilateral symptoms, as many as fifty percent by some estimates, will develop symptoms in both ears. Some of these will become totally deaf.
Yet the disease may end spontaneously and never repeat again. Some sufferers find that after eight to ten years their vertigo attacks gradually become less frequent and less severe; in some patients they disappear completely. In some patients, symptoms of tinnitus will also disappear, and hearing will stabilize (though usually with some permanent loss).