Ménière's disease(pronounced /meɪnˈjɛərz/) is a disorder of the inner earthat can affect hearingand balanceto a varying degree. It is characterized by episodes of vertigoand tinnitusand progressive hearing loss, usually in one ear. It is named after the French physician Prosper Ménière, who, in an article published in 1861, first reported that vertigowas caused by inner ear disorders. The condition affects people differently; it can range in intensity from being a mild annoyance to a chronic, lifelong disability.
Signs and symptoms
The symptoms of Ménière's are variable; not all sufferers experience the same symptoms. However, so-called "classic Ménière's" is considered to have the following four symptoms:
- Periodic episodes of rotary vertigoor dizziness.
- Fluctuating, progressive, unilateral (in one ear) or bilateral (in both ears) hearing loss, usually in lower frequencies.
- Unilateral or bilateral tinnitus.
- A sensation 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 rotational vertigo can be severe, incapacitating, and unpredictable and can last anywhere from minutes to hours, but no longer than 24 hours.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 sweatingsometimes accompany vertigo, but are symptoms of vertigo, and not of Ménière's.
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 without warning. Drop attacks are likely to occur later in the disease, but can occur at any time.Patients may also experience the feeling of being pushed or pulled. Some patients may find it impossible to get up for some time, until the attack passes or medication takes effect.
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.
There is an increased prevalence of migrainein patients with Ménière’s disease.As well, migraine leads to a greater susceptibility of developing Ménière’s disease. The distinction between migraine-associated vertigo and Ménière’s is that migraine-associated vertigo may last for more than 24 hours.
Ménière's disease is idiopathic, 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 is called "hydrops." The membranous labyrinth, a system of membranes in the ear, contains a fluid called endolymph. The membranes can become dilated like a balloon when pressure increases and drainage is blocked.This may be related to swelling of the endolymphatic sacor other tissues in the vestibular systemof the inner ear, which is responsible for the body's sense of balance. In some cases, the endolymphatic duct may be obstructed by scar tissue, or may be narrow from birth. In some cases there may be too much fluid secreted by the stria vascularis. The symptoms may occur in the presence of a middle ear infection, head traumaor an upper respiratory tract infection, or by using aspirin, smoking cigarettesor drinking alcohol. They may be further exacerbated by excessive consumption of saltin some patients. Some have pointed out that this "central hypothesis" of Ménière's is questionable, as many people without Ménière's have evidence of increased pressure in the inner ear, too.
It has also been proposed that Ménière's symptoms in many patients are caused by the deleterious effects of a herpes virus. Herpesviridaeare 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.
Ménière's symptoms can begin at any age, but typically begin between the ages of 30 and 60, and affects men slightly more than women. Hearing loss can affect both ears either simultaneously or with a variable interval between the first and the second ear.
Other possible conditions that may lead to Ménière's symptoms include syphilis, Cogan's syndrome, autoimmune diseaseof the inner ear, dysautonomia, perilymph fistula, multiple sclerosis, acoustic neuroma, and both hypo-and hyperthyroidism.
Doctors establish a diagnosis with complaints and medical history. However, a detailed otolaryngologicalexamination, audiometryand head MRIscan should be performed to exclude a tumourof the eighth cranial nerveor 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. Because Ménière's, by definition, is idiopathic, one no longer has Ménière's disease if the cause of the symptoms has been discovered.
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) 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:
- Fluctuating, progressive, sensorineural deafness.
- Episodic, characteristic definitive spells of vertigo lasting 20 minutes to 24 hours with no unconsciousness, vestibular nystagmusalways present.
- Usually tinnitus.
- 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:
- Certain - Definite disease with histopathological confirmation
- Definite - Requires two or more definitive episodes of vertigo with hearing loss plus tinnitus and/or aural fullness
- Probable - Only one definitive episode of vertigo and the other symptoms and signs
- Possible - Definitive vertigo with no associated hearing loss
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 per day.Patients are advised to avoid caffeine, alcohol and tobacco, all of which can aggravate symptoms of Ménière's. Patients are often prescribed a mild diuretic (sometimes vitamin B6). Many patients will have allergy testing done to see if they are candidates for allergy desensitization, as allergies have been shown to aggravate Ménière's symptoms.
Treatments aimed at lowering the pressure within the inner ear include antihistamines, anticholinergics, steroids, and diuretics.Devices that provide transtympanic micropressure pulses are now showing some promise and are becoming more widely used as treatments for Ménière's.
The antiherpes virus drug acyclovirhas 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 in 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.
Because Ménière's cannot be cured, treatments focus more on addressing symptoms.
Typical remedies to improve symptoms may include:
- Antihistamines considered antiemetics such as meclozineand dimenhydrinate
- Antiemeticdrugs such as trimethobenzamide.
- Antivertigo/antianxiety drugs such as betahistineand diazepam.
- Herbal remedies such as ginger root.
If symptoms do not improve with typical treatment, more permanent surgery is considered.Unfortunately, because the inner ear deals with both balance and hearing, few surgeries guarantee no hearing loss.
Nondestructive surgeries include those which do not actively remove any functionality, but rather aim to improve the way the ear works.
Surgery to decompress the endolymphatic sachas shown to be effective for temporary 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 placeboeffect, and that very little difference occurred in a 9-year followup, but could not deny the efficacy of the treatment.
Destructive surgeries are irreversible, and involve removing entire functionality of most, if not all, of the affected ear.
The inner ear itself can be surgically removed via labyrinthectomy. Hearing is always completely lost in the affected ear with this operation.Alternatively, a chemical labyrinthectomy, in which a drug (such as gentamicin) that "kills" the vestibular apparatus is injected into the middle ear can accomplish the same results while retaining hearing.
Alternatively, surgeons can cut the nerve to the balance portion of the inner ear in a vestibularneurectomy. Hearing is often mostly preserved, however the surgery involves cutting open into the lining of the brain, and a hospital stay of a few days for monitoring would be required.
Vertigo (and the associated nausea and vomiting) typically accompany the recovery from destructive surgeries as the brain learns to compensate.
Ménière's disease usually starts confined to one ear, but it often extends to involve both ears over time. The number of patients who end up with bilaterial Ménière's is debated, with ranges spanning from 17% to 75%.
Some Ménière's disease sufferers, in severe cases, may end up losing their jobs, and will be on disability until the disease burns out.However, a majority (60-80%) of sufferers will not need permanent disability and will recover with or without medical help.
Hearing loss usually fluctuates in the beginning stages and becomes more permanent in later stages, although hearing aidsand cochlear implantscan help remedy damage.Tinnitus can be unpredictable, but patients usually get used to it over time.
Ménière's disease, being unpredictable, has a variable prognosis. Attacks could come more frequently and more severely, less frequently and less severely, and anywhere in between. However, Ménière's is known to "burn out" when vestibular function has been destroyed to a stage where vertigo attacks cease.
Studies done on both right and left ear sufferers show that patients with their right ear affected 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.