Meniere’s disease is a disorder that affects the inner part of the ear and causes balance and hearing problems. It is a chronic illness that affects approximately 1 in 1000 people, mostly between the ages of 40 and 60 years. Meniere’s disease affects the quality of life of its sufferers. The symptoms of Meniere’s disease include unexpected and sudden spells of dizziness and are usually the most distressing part of the illness. It can affect your ability to do daily activities and cause significant anxiety knowing that spells of dizziness can occur at any time. Hearing loss, or even the idea that your hearing may worsen, can cause emotional and social difficulties. Although there is no cure for Meniere’s disease, it can be managed.
The inner ear is made up of the organ of hearing (cochlea) and the organ of balance (semicircular canals). The inner ear is filled with a fluid called ‘endolymph’. Meniere’s disease occurs when too much endolymph builds up inside the inner ear, known as ‘endolymphatic hydrops’. In many cases, the cause of the fluid build-up is unknown.
The increased fluid pressure inside the organs of hearing and balance causes severe spells of dizziness (vertigo) as well as a hearing loss, a ringing or roaring sound (tinnitus), and a feeling of pressure (aural fullness) in the affected ear. Vertigo is specific dizziness that feels as though you or your surroundings are moving or spinning. The spells of vertigo, resulting from Meniere’s disease, last between 20 minutes to 24 hours. The time between spells can range from days to years.
Initially, hearing loss due to Meniere’s disease specifically affects your ability to hear low-pitched or bass sounds (low-frequency hearing loss). Hearing loss caused by problems with the cochlea (sensorineural hearing loss) normally affects your ability to hear high-pitched or treble sounds. Low-frequency sensorineural hearing loss is unusual and mainly typical of Meniere’s disease. The hearing loss can get worse and better (fluctuating hearing loss) which is also unusual for sensorineural hearing loss. It normally affects one ear (unilateral hearing loss), but in 50% of people, the other ear may eventually become affected. To summarise, especially in the early stages, Meniere’s disease is associated with fluctuating, unilateral, low frequency, sensorineural hearing loss.
Hearing loss and the stages of Meniere’s disease
In the early stages of Meniere’s disease, the main complaint is spells of vertigo. During the spell, you may experience aural fullness, hearing loss, and tinnitus. Often the spell will occur without warning, but sometimes aural fullness and tinnitus will occur beforehand. After the spell, your hearing may be reduced, specifically in the low frequencies. However, your hearing may return to normal between spells. Initially, you may not even notice the change in your hearing.
As Meniere’s disease progresses, in the middle stages, the spells of vertigo continue unpredictably. Hearing loss begins to affect the middle and high frequencies too. It may become permanent but fluctuate when a spell occurs.
In the later stages, the spells of vertigo occur less frequently or stop altogether. Hearing loss may worsen significantly at all frequencies and remain permanent.
Doctors normally make the diagnosis of Meniere’s disease based on your symptoms. In the early stages, all of the classic symptoms of Meniere’s disease may not be obvious, which can make it difficult to diagnose. Other disorders with similar symptoms may also need to be ruled out. For these reasons, it may take some time for doctors to come to a diagnosis.
As low-frequency sensorineural hearing loss is typical of Meniere’s disease, a hearing test is one of the most useful tests to confirm the diagnosis. Repeated tests would confirm the fluctuating hearing loss, which is also typical.
Other specialized tests that assess the functioning of the inner ear can be performed to help make a diagnosis, namely vestibular-evoked myogenic potential (VEMP) testing, electrocochleography (ECoG), caloric tests, or head impulse tests. Advancements in magnetic resonance imaging (MRI) have recently helped doctors diagnose Meniere’s disease by allowing them to better see the inner ear.
There are several ways to manage Meniere’s disease. Doctors may recommend that you change your diet by reducing salt, alcohol, and caffeine. If dietary changes don’t work, doctors may prescribe oral medications, namely Betahistine, which treats vertigo, and diuretics, which improve symptoms by reducing fluid pressure in the inner ear. They may prescribe an injection through the eardrum of steroids or, in very severe cases, Gentamicin (strong antibiotics) which stops vertigo by destroying the inner ear but which damages hearing. Doctors may suggest surgery to the inner ear to release pressure caused by the endolymph. If all else fails, when Meniere’s disease causes unbearable vertigo, doctors may consider surgery to remove the organ of balance or to cut the nerve of balance which also destroys hearing. To assist with balance problems, physical therapy may form part of treatment. Hearing aids may be also recommended to manage hearing loss.
Hearing aids: The challenges
A hearing aid is a small device that makes speech and the environment louder to overcome hearing loss. The most popular style of hearing aid, called a behind-the-ear hearing aid, sits behind the ear with a thin wire or tube that delivers amplified sound into the ear. The end of the wire or tube is held in place in the ear canal with an earmold or tip.
A hearing aid is programmed according to your specific hearing loss. It uses the results of your hearing test to work out what pitches must be made louder and by how much. With regards to the typical low-frequency hearing loss associated with Meniere’s disease; a hearing aid would be set to make low pitches louder only, and high pitches would not be amplified.
The biggest challenge in using a hearing aid if you have Meniere’s disease is that hearing levels fluctuate. If a hearing aid is set too loud, it can damage your hearing. If it is set too soft, you will not benefit from it. If it is not amplifying the correct pitches, the sound quality will be poor. With conventional hearing aids, you would need to see a hearing health professional often to set the hearing aid according to your fluctuating hearing levels.
Studies have shown that allowing people with Meniere’s disease to test their hearing and program their hearing aids at home has been successful in overcoming the challenge of using hearing aids with fluctuating hearing loss.
Setting a hearing aid for low-frequency hearing loss is another challenge. Sometimes, low-pitched sounds can cover up (mask) high-pitched sounds. High pitched sounds are important because they allow you to hear sounds such as ‘th’,‘s’, ‘f’, ‘k’, ‘t’, and ‘sh’ which give speech clarity. In other words, when low-frequency sounds are made louder by a hearing aid, you may not be able to hear high frequencies, and therefore speech, as clearly as you would without a hearing aid. Also, many environmental noises are lower in pitch, and making low frequencies louder may cause the hearing aid to sound noisy.
Selecting a suitable earmold or tip for a hearing aid is also challenging if you have a low-frequency hearing loss. Earmoulds or tips have holes (vents); the vent size is selected based on your hearing loss and affects the hearing aid’s sound quality. If the vent is too big, too much amplified sound may escape out of the ear canal and the sound may not be loud enough. If the vent is too small, too little sound may escape and it may sound too loud, as though your ear is blocked, or your voice is echoing (occlusion effect). With low-frequency hearing losses, smaller vents are recommended to keep the amplified low-frequency sounds from escaping out of the ear canal. This means that people with low-frequency hearing loss are at greater risk of the occlusion effect.
Another challenge worth mentioning is for people with late-stage Meniere’s disease who have very poor hearing. If hearing loss worsens to be severe or profound (complete hearing loss), you may not benefit from hearing aids. You may still struggle to understand words, even if speech is made loud enough with a hearing aid. Note that if you don’t benefit from a conventional hearing aid and only have a hearing loss in one ear, a CROS (contralateral routing of signal) hearing aid may be a good option. This device picks up sound on the side of the affected ear and transmits it wirelessly to a hearing aid on the better ear.
Hearing aids: The benefits
Fitting a hearing aid is challenging for people with Meniere’s disease, but not impossible. Hearing aid settings can be fine-tuned to correct sound quality issues. When set correctly, and when the correct earmold or tip is fitted, people with Meniere’s disease can have very positive experiences with hearing aids. While Meniere’s disease is no doubt a challenging illness, it can be managed, and improving your hearing can go a long way in improving your quality of life.