Ménière's Disease, What Is It?

Ménière's

Ménière's disease is a disorder of the inner ear that can affect hearing and balance to a varying degree. It is characterized by episodes of vertigo and tinnitus and 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 vertigo was 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.

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 vertigo or dizziness.Fluctuating, progressive, unilateral (in one ear) or bilateral (in both ears) hearing loss, usually in lower frequencies.

Other symptons

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 are 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 sweating sometimes accompany vertigo, but are symptoms of vertigo, and not of Ménière's.

Drop attacks

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.

In addition to hearing loss, sounds can appear tinny or distorted, and patients can experience unusual sensitivity to noises.

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.

Migraine

There is an increased prevalence of migraine in 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.

Cause

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 sac or other tissues in the vestibular system of 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 trauma, or an upper respiratory tract infection, or by using aspirin, smoking cigarettes, or drinking alcohol.

Excessive use of salt

They may be further exacerbated by excessive consumption of salt in some patients.It has also been proposed that Ménière's symptoms in many patients are 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.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 disease of the inner ear, dysautonomia, perilymph fistula, multiple sclerosis, acoustic neuroma, and both hypo- and hyperthyroidism.

Diagnosis

Doctors establish a diagnosis with complaints and medical history. However, a detailed otolaryngological examination, audiometric and head MRI scan should be performed to exclude a tumor of the eighth cranial nerve or superior canal dehiscence which would cause similar symptoms.

There is no definitive test for Ménière's, it is only diagnosed when all other causes have been ruled out. If any cause had been discovered, this would eliminate Ménière's disease, as by its very definition, as an exclusively idiopathic disease, it has no known causes.

Prevention

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 alcohol, caffeine, 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

Non invasive medical treatment is to control the vertigo, for example Serc, Stemetil, Stugeron (antivertigonous drugs) and Gentamycin. Low salt diets, vasodilation (hydralazine) and diuretics to alleviate the abnormal pressure in the scala media. Ménière's is not a curable disease, we can only treat the symptons.

Herpes virus

The antiherpes virus drug acyclovir 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 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 of 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.

Treatment

Because Ménière's cannot be cured, treatments focus more on addressing symptoms.

Symptoms

Typical remedies to improve symptoms may include:Antihistamines considered antiemetics such as meclozine and dimenhydrinateAntiemetic drugs such as trimethobenzamide.Antivertigo/antianxiety drugs such as betahistine and diazepam.Herbal remedies such as ginger root.

Coping

Sufferers tend to have high stress and anxiety due to the unpredictable nature of the disease.

Healthy ways to combat this stress can include aromatherapy, yoga, T'ai chi., and meditation.

Surgical Procedures

1.Drainage of the endolymphatic sack,(endolymphatic shunt) to reduce the pressure. Quite often this does not leave/preserve the hearing.

2.Destruction of all or part of the labyrinth (labrinthectomy). Ultrasonic techniques may allow the vestibular part only to be destroyed leaving the cochlea intact. Labrinthectomy will normally only be considered where the vertigo and/or tinnitus cannot be treated in any other way and have no serviceable hearing.

3.Vestibular nerve section,

Ménière's has in the past been considered to have a genetic component; this is now thought to be unlikely. Many different explanations have been offered for the cause of Ménière's and to this day there is still no definite cause.

Prognosis

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 bilateral 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 aids and cochlear implants can help remedy damage. Tinnitus can be unpredictable, but patients usually get used to it over time.

Unpredictable

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.

Reference;http://en.wikipedia.org/wiki/M%C3%A9ni%C3%A8re's_disease