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Ménière's
Disease
What is Ménière's disease?
Ménière's disease is an abnormality of the inner ear
causing a host of symptoms, including vertigo or severe dizziness,
tinnitus or a roaring sound in the ears, fluctuating hearing loss,
and the sensation of pressure or pain in the affected ear. The
disorder usually affects only one ear and is a common cause of
hearing loss. Named after French physician Prosper Ménière
who first described the syndrome in 1861, Ménière's
disease is now also referred to as endolymphatic hydrops.
What causes Ménière's disease?
The symptoms
of Ménière's disease are associated with a change
in fluid volume within a portion of the inner ear known as the
labyrinth. The labyrinth has two parts: the bony labyrinth and
the membranous labyrinth. The membranous labyrinth, which is
encased by bone, is necessary for hearing and balance and is
filled with a fluid called endolymph. When your head moves,
endolymph moves, causing nerve receptors in the membranous labyrinth
to send signals to the brain about the body's motion. An increase
in endolymph, however, can cause the membranous labyrinth to
balloon or dilate, a condition known as endolymphatic hydrops.
Many
experts on Ménière's disease think that a rupture of the membranous
labyrinth allows the endolymph to mix with perilymph, another inner
ear fluid that occupies the space between the membranous labyrinth and
the bony inner ear. This mixing, scientists believe, can cause the symptoms
of Ménière's disease. Scientists are investigating several
possible causes of the disease, including environmental factors, such
as noise pollution and viral infections, as well as biological factors.
What are the symptoms of Ménière's disease?
The symptoms
of Ménière's disease occur suddenly and can arise
daily or as infrequently as once a year. Vertigo, often the
most debilitating symptom of Ménière's disease, forces
the sufferer to lie down. Vertigo attacks can lead to severe
nausea, vomiting, and sweating and often come with little or
no warning.
Some
individuals with Ménière's disease have attacks that start
with tinnitus, a loss of hearing, or a full feeling or pressure in the
affected ear. It is important to remember that all of these symptoms
are unpredictable. Typically, the attack is characterized by a combination
of vertigo, tinnitus and hearing loss lasting several hours. But people
experience these discomforts at varying frequencies, durations, and
intensities. Some may feel slight vertigo a few times a year. Others
may be occasionally disturbed by intense, uncontrollable tinnitus while
sleeping. And other Ménière's disease sufferers may notice
a hearing loss and feel unsteady all day long for prolonged periods.
Other occasional symptoms of Ménière's disease include headaches,
abdominal discomfort and diarrhea. A person's hearing tends to recover
between attacks but over time becomes worse.
How is Ménière's disease treated?
There is
no cure for Ménière's disease. Medical and behavioral
therapy, however, are often helpful in managing its symptoms.
Although many operations have been developed to reverse the
disease process, their value has been difficult to establish.
And, unfortunately, all operations on the ear carry a risk of
hearing loss.
The
most commonly performed surgical treatment for Ménière's disease
is the insertion of a shunt, a tiny silicone tube that is positioned
in the inner ear to drain off excess fluid.
In another more reliable
operation, a vestibular neurectomy, the vestibular nerve which serves
balance is severed so that it no longer sends distorted messages to
the brain. But the balance nerve is very close to the hearing and facial
nerves. Thus, the risk of affecting a patient's hearing or facial muscle
control increases with this type of surgical treatment. Also, older
patients often have difficulty recovering from this type of surgery.
A labyrinthectomy, the removal
of the membranous labyrinth, is an irreversible procedure that is often
successful in eliminating the dizziness associated with Ménière's
disease. This procedure, however, results in a total loss of hearing
in the operated ear—an important consideration since the second
ear may one day be affected. Also, labyrinthectomies themselves may
result in other balance problems.
Some physicians recommend
a change of diet to help control Ménière's symptoms. Eliminating
caffeine, alcohol and salt may relieve the frequency and intensity of
attacks in some people. Eliminating tobacco use and reducing stress
levels may lessen the severity of the symptoms. And medications that
either control allergies, reduce fluid retention or improve blood circulation
in the inner ear may also help.
How is Ménière's disease diagnosed?
Scientists estimate
that there are 3 to 5 million people in the United States with Ménière's
disease, with nearly 100,000 new cases diagnosed each year. Proper diagnosis
of Ménière's disease entails several procedures, including
a medical-history interview and a physical examination by a physician;
hearing and balance tests; and medical imaging with magnetic resonance
imaging (MRI). Accurate measurement and characterization of hearing
loss are of critical importance in the diagnosis of Ménière's
disease.
Through the use of several
types of hearing tests, physicians can characterize hearing loss as
being sensory, arising from the inner ear, or neural arising from the
hearing nerve. An auditory brain stem response, which measures electrical
activity in the hearing nerve and brain stem, is useful in differentiating
between these two types of hearing loss. And under certain circumstances,
electrocochleography, recording the electrical activity of the inner
ear in response to sound, helps confirm the diagnosis.
To test the vestibular or
balance system, physicians irrigate the ears with warm and cool water.
This flooding of the ears, known as caloric testing, results in nystagmus,
rapid eye movements that can help a physician analyze a balance disorder.
And because tumor growth can produce symptoms similar to Ménière's
disease, magnetic resonance imaging is a useful test to determine whether
a tumor is causing the patients vertigo and hearing loss.
What research is being done?
Scientists are investigating
environmental and biological factors that may cause Ménière's
disease or induce an attack. They are also studying how fluid composition
and movement in the labyrinth affect hearing and balance. And by studying
hair cells in the inner ear, which are responsible for proper hearing
and balance, scientists are learning how the ear converts the mechanical
energy of sound waves and motion into nerve impulses. Insights into
the mechanisms of Ménière's disease will enable scientists
to develop preventive strategies and more effective treatment.
Where
can I get additional information?
The NIDCD currently
supports research on Ménière's disease in medical centers
and universities throughout the nation. For more information about Ménière's
disease, you can contact:
1998
Updated April 1999 |
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