Meniere's disease
At the time of the American Civil War a French physician named Prosper Meniere described several symptoms that were new and different. He described individuals who experienced symptoms of vertigo, hearing loss, tinnitus and aural fullness. Meniere examined their ears after their deaths and found blood in the inner ear. He suspected that this was the cause of their symptoms. While Meniere described the effects of leukemia on the inner ear, today we associate his name with the same symptoms caused by an unknown source. Meniere's disease may cause any or all of these systems over a longer period of time.
What is the problem?
The current theory is that Meniere's disease is caused by an imbalance in the fluid pressure between different compartments of the inner ear. The compartment containing endolymph is the center of the inner ear. The endolymphatic compartment is believed to build up excess pressure and cause swelling. Because the inner ear is entirely encapsulated in bone, there is no place for the swelling to go. As a result of this it causes damage to the small hair cells in the inner ear. This can also result in tears in the membranes. Fluids then are chemically mixed together effectively "short-circuiting" the inner ear. Each time these abnormalities occur, a patient experiences severe symptoms of an attack. Once the pressure has been released, the membrane begins to heal and the fluid chemistry returns to normal. When this is completed, the patient is relieved of the symptoms. It is important to remember that this is all theory supported by some research in this area.
What causes the fluid build up?
No one knows for certain why these fluid abnormalities occur. It is thought that sodium intake in the diet plays a role. Some individuals have recommended that by minimizing salt intake that the attacks of Meniere's disease can be made less severe and less frequent. Most Americans consume considerably more than the recommended three grams of sodium per day that the American Heart Association recommends as a safe quantity. Other factors seem to influence the disease as well. Meniere's disease can run in families, and attacks occur more frequently in individuals with a family history of the disease. Stress can play a role in creating a situation where attacks occur more frequently.
What is the course of this disease?
Some patients have very few attacks and seem to heal quickly, while the disease can incapacitate others. Most of the individuals with this disease will have long periods when they are symptom free or have minimal attacks. Approximately one-third of the individuals will have more frequent attacks and may experience symptoms over a number of years. The disease can continue for an unpredictable period of time but will finally "burnout." The process of burning out means that the symptoms of vertigo will tend to occur less frequently and in some individuals this process is associated with a higher level of unpredictability. Attacks are usually associated with an aura that the attack is coming. This warning feeling tends to disappear when the disease burns out. At the same time, hearing will have a tendency to become worse, ultimately ending in deafness in the affected ear. In individuals who have a more debilitating course, they may be unable to drive an automobile or work. Individuals where balance is critical to their safety at work should not be doing this type of work when they have this disorder.
Medical treatment
Medical treatment of Meniere's disease is based upon decreasing the amount of fluid in the inner ear. Using a low salt diet and taking a diuretic accomplish this. The use of diuretics reduce total body sodium and it may take some time to see their effects. In addition to a low sodium diet and a diuretic some physicians recommend the use vestibular suppressants. These suppressants can be from a number of different families including antihistamines, Benzodiazepines, and central nervous system agents. These medications primarily change the brain chemistry to prevent the brain from interpreting the abnormal signals from the disease can inner ear.
Surgical treatment
Surgical treatment is considered only if medical treatment has failed and the patient is suffering from incapacitating symptoms. Every effort should be made to try conservative treatment before reaching a surgical decision. There are several different surgical and semi-surgical approaches. There is an excellent chance of preventing attacks with one of the more conservative operations. However, the more serious procedures result in a higher chance of success.
Endolymphatic sac
This surgery is designed to both preserve hearing and improve balance problems. An incision is made directly behind the ear and some bone is removed over the natural drainage point from the inner ear. This procedure will minimize the symptoms of dizziness. Over time, the surgery tends to have reduced effectiveness. There is approximately a 50 -- 60 percent chance of controlling the attacks of dizziness. A small number of people may actually have worsening dizziness, hearing loss, and even potentially facial paralysis. Complications from the procedure are rare. Most individuals have the operation in the morning, and go home on the same day. Occasionally individuals have an impact of dizziness immediately following the surgery. This does not mean that the procedure has failed, it can indicate that the procedure will be successful but at a later time.
Labyrinthectomy
There are many ways to reduce balance function from the inner ear. One way is to inject an antibiotic solution into the middle ear space. These injections can be carried out with an antibiotic called Gentamicin. Anywhere between one and 15 injections are necessary to reduce the abnormal stimulations coming from the diseased ear. The injections may be repeated a number of times a year or may be repeated years following the initial injections. Gentamicin is toxic to all the cells in the inner ear and will probably result in some hearing loss. Most of the time the hearing loss is insignificant. Approximately one-third of the patients who take this medication experience increasing tinnitus. High-pitched frequencies may experience higher levels of hearing loss.
Another approach is to use a surgical procedure that will remove the inner ear. Immediately following the operation patients will experience increased levels of dizziness for several days and potentially several weeks. There are individuals who take months to fully recover. The operation will result in hearing loss in the operated ear. Following a labyrinthectomy, dizziness control is very high. As many as 90 percent of individuals who undergo the operation will experience resolution or significant improvement in their symptoms of dizziness. Long-term results tend to be lower because it is possible to develop the disease in the opposite ear.
Vestibular nerve section
This surgery is designed to preserve hearing and completely eliminate balance function like a labyrinthectomy. An incision is made further behind the ear and into the skin of the neck. The operation creates an opening into the covering of the brain. This opening provides a surgeon with exposure to the hearing and balance nerves. The two nerve branches are separated and only the balance nerve is cut. There is a small chance of total deafness and a chance of hearing loss following the procedure. There is a small chance of weakness or paralysis of the face. The operation has an excellent chance to improve balance control while giving the patient an opportunity to preserve hearing function. Those individuals who undergo the operation also accept a small risk of central nervous system injury.
Additional treatments
One option for Meniere's disease patients is physical therapy. The treatment with vestibular rehabilitation can be quite helpful. Although exercise cannot cure Meniere's disease, this treatment gives patients the ability to manage their symptoms better. Specific exercises are designed to 1) decrease dizziness, 2) increase balance function and 3) increase general activity and strength. The exercise programs retrain the brain to use other functions beside the inner ear to establish balance and re-establish balance when positions and conditions change.
Autoimmune mechanisms
Some individuals may have Meniere’s disease as a result of an immune related process. This was suggested first about 20 years ago. While most doctors agree that this disorder exists there are debates about how best to diagnose and treat it. Many doctors believe that the use of steroids, given either orally or by injection into the ear, is the best way to diagnose and treat this condition. Once the diagnosis of autoimmune Meniere’s disease is made, other drugs may be used for treatment. These drugs include methotrexate and immuran. These are serious drugs with serious side effects.
Support groups
There is a support group in the metropolitan area and they can be very helpful to some individuals. It is important to note that most individuals with long-standing problems tend to need a support group, but it may not be the best source of information for less severely incapacitated patients.
