Hearing loss due to excessive bone growth
Otosclerosis is a disease in which calcium is deposited on the ossicles in your middle ear. The result: you will hear less well.
Otosclerosis is a hearing disorder in which excessive bone growth occurs in the middle ear. This usually occurs on or near the auditory ossicle, or the stirrup. This bone growth can cause this ossicle to become completely stuck, so that sound vibrations are not properly transmitted to the middle ear. Heredity plays an important role in its development, but there are also environmental factors that can play a role. For example, a viral infection.
The majority of people with otosclerosis—about 70 percent—have it in both ears, but the condition can manifest in just one ear. If otosclerosis is not treated, the symptoms continue to increase.
1. What are the symptoms of otosclerosis?
Otosclerosis is not painful, but it is annoying. The main symptom of otosclerosis is hearing loss. Because the sound vibrations are transmitted less well, all sounds will sound softer. The maximum hearing loss – if the stirrup is stuck due to too much calcium deposits – is 50 to 60 dB, or fairly severe hearing loss. When the otosclerosis also affects the cochlea, sensorineural hearing loss can also occur. In that case, not only do sounds sound softer, but it also becomes increasingly difficult to understand people well, even when they speak louder. Other symptoms that can occur – but fortunately not everyone suffers from – are tinnitus (ringing in the ears), dizziness and balance problems.
2. How common is otosclerosis?
According to the ENT Association, otosclerosis occurs in approximately 0.3 to 0.4 percent of the white population. Non-whites get it significantly less often. The condition is twice as common in women as in men. Every year about 1000 to 1500 people report with otosclerosis complaints. Excessive bone growth can start at a young age, but the symptoms usually only show up in people between the ages of 20 and 40.
3. Can you also get otosclerosis in the inner ear?
Otosclerosis of the inner ear is uncommon, but it can be. The otosclerosis can be limited to the cochlea (cochlea), we then speak of cochlear otosclerosis. In that case, there is an inner ear problem, causing sensorineural hearing loss. There is nothing medical about this.
The second form is the mixed form, where the otosclerosis occurs in both the middle ear and the inner ear. The calcium deposits then almost always start in the middle ear, but continue in the inner ear. Mixed hearing loss, in which sounds are softer and people are more difficult to understand. Intervention in the middle ear is possible.
4. How is the diagnosis made?
Hearing impairment is of course not unique to otosclerosis, but it occurs in many hearing disorders, so it will first be necessary to find out which hearing disorder someone is struggling with. The ENT specialist will perform an external ear inspection and various hearing tests will be performed. The standard hearing test (audiometry) includes tone and speech tests and tests to see the mobility of the eardrum. In addition, the ossicular chain is examined. Sometimes a CT-scan place because it is easy to see whether there is calcium deposits at the stirrup. If, after these tests, the ENT doctor cannot say with 100 percent certainty whether it is otosclerosis, the choice can be made to confirm this via keyhole surgery, whereby the treatment can possibly be carried out immediately.
5. Is there treatment for otosclerosis?
Depending on the shape – only in the middle ear or also in the inner ear – something can be done about the effects of otosclerosis. The affected middle ear bone can be replaced by a plastic prosthesis, which restores the functioning of the middle ear. This is called a stapedectomy or stapedotomy. Often people are symptom-free after this, although nothing is done about the disease itself. It is possible that the otosclerosis will also occur after an operation in the inner ear. Nothing can be done about these complaints.
Surgery is not always chosen. In some cases one chooses to wait and see whether the bone proliferation comes to a spontaneous halt. This is especially the case when the complaints are not yet very serious. In the case of non-operation, the treatment consists of the fitting of a suitable hearing aid to compensate for the complaints as much as possible. Surgical intervention is not possible in any case with cochlear otosclerosis and a hearing aid is chosen as standard. If there is complete deafness, a cochlear implant be placed.
Some of the information in this article comes from the book 101 questions about tinnitus and other hearing problems of the National Hearing Foundation and Kosmos Publishers.
