What is Ménière's disease?
Ménière's disease is a disease of the inner ear (cochlea and vestibular system) that classically causes the following three symptoms: vertigo (the sensation of spinning), tinnitus (ringing in the ear) and hearing loss – usually a low frequency sensorineural hearing loss. All three usually have to be present to make a diagnosis of Ménière's disease.
What causes it?
There are many theories, but the cause is still largely unknown. What is known is that an excess of fluid within the inner ear occurs, which causes swelling and disruption of the delicate structures within it. In this way, it can be like having ‘glaucoma in the inner ear’. With the excess fluid and swelling come the symptoms. Then, as the swelling settles and the inner ear structures heal, the symptoms abate until another attack occurs.
What is a typical attack of Ménière's disease like?
Typically, one first feels a fullness in the affected ear, followed by tinnitus and hearing loss. These symptoms usually herald the onset of a spell of vertigo, which typically lasts from 20 minutes to 6 hours. Following the episode, one may feel imbalanced for several days, even without the vertigo. The hearing loss slowly recovers after the attack, but with time, may become permanent.
Many patients can tell when they are going to get an attack of Ménière's disease. The amount of attacks one gets in a year will vary from individual to individual. People with Ménière's disease may also find that they are sensitive to changes in the weather.
Who gets it?
It is more common in females and usually starts in the 30s and 40s. It usually occurs in one ear but 30 to 50% of sufferers will develop it in both ears within 3 years of the first episode.
How is it diagnosed?
The diagnosis of Ménière's disease is usually made by an ENT surgeon and is based on the symptoms of vertigo attacks lasting 20 minutes to several hours, tinnitus and hearing loss, the three occuring together. An examination of the ear is usually normal. There are no tests that can definitively diagnose Ménière's disease, but a hearing test can often show evidence of hearing loss, though this may be normal if performed in between episodes when the patient is not having symptoms, or if performed early on in the disease. Balance tests may show a weakness in the vestibular system of the affected ear. An MRI scan of the ear may be performed to rule out any other causes of the symptoms.
How is it treated?
There are many options for treating Ménière's disease. Usually, it is treated in a step-wise manner, starting with dietary control and medications. Surgery is usually reserved for those cases where medications no longer control symptoms or prevent attacks.
Patients are usually advised to practice a low-salt diet. This is because excess salt is thought to cause a retention of fluid in the inner ear. Many patients with Ménière's disease report an onset of symptoms after a very salty meal. Monosodium glutamate (MSG), used in various types of fast food (especially Chinese food), should also be avoided. Always read the labels of food that you buy. Caffeine and alcohol are also thought to be triggers of Ménière's disease.
Medications used in the treatment of Ménière's disease include diuretics (‘water pills’). It is thought that this may help increase the excretion of water and salts from the inner ear and therefore prevent attacks by preventing a build-up of fluid. The main diuretic used in bendrofluazide. Betahistine is also commonly used. This is an antihistamine and is thought to work by increasing the blood supply to the inner ear. Both bendrofluazide and betahistine are used to prevent attacks from occurring (prophylactic therapy). During an actual attack of Ménière's disease, medications such as prochlorperazine (also called stemetil) or cyclizine are useful in the short term for controlling vertigo (symptomatic therapy). They should not be used long term as a means of prevention.
Some patients may respond to a Meniett device. This machine is a low-pressure pulse generator that help the excess fluid in the inner ear to flow, thereby reducing the pressure and swelling. Doctors usually prescribe 3 Meniett treatments per day, 5 minutes each time for Ménière’s disease. A grommet (ventilation tube) must first be inserted across the ear drum before the Meniett device can be used. More information about the Meniett device can be read here.
If the above therapies do not work, medications can sometimes be injected into the ear to have a more direct effect. This is known as intratympanic therapy and can be performed in the clinic under a local anaesthetic. A steroid injection is typically tried first. This is usually effective after the first injection, but can take up to three injections, each 2 weeks apart. If this does not help, then gentamicin is tried. Gentamicin has a much higher success rate that steroids and can result in a cure. It does this by chemically destroying the vestibular system. There is a 15 to 35% risk of the hearing being affected as well, however, and some people are more susceptible to this than others. Most people will respond to gentamicin within three injections.
In all cases, any troublesome hearing loss is best managed with a hearing aid.
What surgical procedures are there for Ménière's disease?
Most patients (>90%) can hope to achieve good control of their symptoms using the non-surgical methods described above. In the small percentage of patients who do not respond to these measures, surgery is an option. The surgery that is best suited for the patient will be decided by the surgeon on an individual basis. All of these procedures are performed under a general anesthetic. They are as follows:
Endolymphatic sac decompression
The endolymphatic sac supplies the fluid of the inner ear in health, and is thought to be overactive in Ménière's disease. This operation therefore aims to decompress the sac, thereby releasing the fluid pressure and swelling within the inner ear. A shunt may also be placed in the sac to drain excess fluid into the mastoid bone. The success rate of this is about 85%. The main advantage of this surgery is the ability to preserve hearing in the affected ear.
The labyrinth is another name for the vestibular system. In this operation, the vestibular system is exposed and surgically destroyed so that it can no longer send abnormal signals to the brain and cause vertigo. The success rate is about 85%, but results in total hearing loss.
Vestibular nerve section
In this operation, the nerve that carries signals from the vestibular system to the brain, the vestibular nerve, is exposed and cut so that no further abnormal signals can be transmitted. This surgery is usually carried out by a neurotologist or a neurosurgeon. It has a success rate of 90% and hearing can be preserved in over 95% of cases, but the surgery carries other risks, such as facial weakness (3%) and a leak of brain fluid into the ear (6%).
Can I drive if I have Ménière's disease?
A diagnosis of Ménière's disease is reportable to the DVLA. The DVLA states that patients with Ménière's disease must stop driving, but will be permitted to do so once again once good symptomatic control is achieved. More information about Ménière’s disease and driving can be found at the Ménière’s Society website here.
Further information, support and current research for people suffering with Ménière’s disease can be found at the Ménière’s Society website: http://www.menieres.org.uk