What is Otosclerosis?
Otosclerosis is a disorder of part of the inner ear bone called the "otic capsule." It occurs in approximately 6% of the population. In some people with otosclerosis, abnormally growing otosclerotic bone spreads across the base of the stapes bone (the smallest bone in the human body). This reduces the ability of the of the stapes to vibrate and to transmit sound from the outside world through into the inner ear. Often with progression of the disorder, "inner ear" hearing loss will occur also.
Sometimes there may be a strong family history of Otosclerosis or hearing loss. For half of people affected by otosclerosis, there is no previous family history of otosclerosis at all.
One current theory is that an inherited tendency to develop this disorder is activated by the measles virus,(often earlier in life) leading to development of symptoms in some. Several genes contributing to otosclerosis have now been identified.
How may it affect me?
Otosclerosis causes hearing loss. Usually the hearing loss is called "conductive" because the stapes hearing bone becomes stiffer and fails to "conduct" normal sound through to the inner ear.
The disorder gets worse at times of hormonal change and is a little more common in women. Thus at puberty and during pregnancy symptoms become worse. Often after many years of this condition, inner ear hearing loss may occur also. Inner ear hearing loss is generally not correctable by surgery , whereas conductive hearing loss often is correctable by surgery.
Some experience tinnitus (ringing or a rushing sound in the ear), and a small number of people may experience dizziness
What can be done about it?
Unfortunately there is no known cure for Otosclerosis as yet. In recent times it was thought that fluoride therapy may be very promising in reducing inner ear hearing loss associated with otosclerosis, but it appears now in most cases that fluoride is ineffective, and may have some unwelcome side effects. Most of the treatment that can be offered relates management of the hearing loss. The most frequent management options include (1) Hearing Aids (2) Surgery.
1) Hearing Aids are ideally suited to the treatment of Otosclerosis. They can be very effective and produce good quality sound. There are many excellent and cosmetically acceptable hearing aids these days, and technology continues to rapidly improve in this area. There is no risk with hearing aid use, although there are a few downsides, including cost and the inability to wear the aids during water exposure, in some physical activities and in sleep.
2) Stapedectomy/Stapedotomy Surgery: Usually results in a dramatic improvement in hearing. The operation is performed under local anaesthetic with sedation. This means that you would be drowsy although able to chat while the operation was being done. Alternatively, this may be done under a general anaesthetic.
Local anaesthetic is inserted into the ear. The ear drum is gently lifted and the hearing bones in the middle ear carefully inspected. The movement of the stapes hearing bone is checked. A tiny hole 0.6 mm in diameter is drilled through the base of the stapes bone (the footplate) into the inner ear. A platinum/teflon or teflon piston is then inserted through the micro perforation and the rest of the stapes hearing bone is removed. The ear drum is then returned to its normal position. Ointment and a light dressing are inserted into the ear canal
An overnight stay is required. Physical exercise is not recommended for one month after surgery. After this, all activities can resume.
Scuba diving and bungy jumping should not ever be attempted after this procedure, because of the large pressure changes involved which could affect the inner ear, and subsequently the hearing.
Most people who have hearing loss with otosclerosis, even those who have had surgery, will eventually will need hearing aids . It may be helpful to think of stapedectomy surgery as deferring the need for hearing aids-sometimes by 10-20 years.
Are there Complications of Stapedectomy Surgery?
Fortunately in experienced hands, complications are few. However they do include:
- Failure of the surgery to produce the desired result. The risk of this is between 5-10 %. This could result in a fleeing of blockage of the ear and /or ringing in the ear.
- Permanent and total or partial hearing loss in the ear: The risk of this is approximately 1-3%.
- Reduction or loss of taste sensation along the border of the tongue. This is a not uncommon event which can occur temporarily for some weeks or even months, after the surgery.
- Dizziness - most people experience some mild dizziness or unsteadiness for up to a week or so following the surgery.
- Tinnitus - ringing in the ear is an unusual complication of successful surgery but may occur in 1-3%.
If you would like further information about your own hearing condition please contact my office for an individual consultation.