 Otosclerosis on the rise in India
 Otosclerosis affects about 1 or 2 of 100 people in India. It usually first develops between the ages of 15 and 35, but sometimes develops in younger children. Women are affected twice as often as men. Pregnancy is not a cause but may make the condition worse, so symptoms are commonly first noticed during pregnancy.
Otosclerosis is a condition of the middle ear which mainly affects the tiny stapes bone.
It causes gradual hearing
loss. The treatment for this include hearing aids and surgery.
This disease is specially common in the southern state of Tamil Nadu and also in the eastern and north-eastern part of the country like Orissa and West Bengal and also in Bangladesh. This is one of the most important causes of
hearing loss and can be corrected easily with a simple surgery.
Otosclerosis is a condition that affects the stapes, one of the tiny bony ossicles in the middle ear. To have normal hearing, the ossicles need to be able to move freely in response to sound waves. What happens is that abnormal bone material grows in and around the stapes. The foot of the stapes, where it attaches to the cochlea, is usually where the condition starts. In time, more and more of the stapes becomes affected. The abnormal bone reduces the movement of the stapes, which reduces the amount of sound that is transferred to the cochlea. The laying down of the abnormal bone is very gradual. However, eventually the stapes becomes 'fixed' which causes severe hearing loss.
In most cases, only the stapes is affected. Sometimes the disease also affects the bony shell of the cochlea. Both ears are usually affected but sometimes only one. The cause of otosclerosis is not known. Bone is continually being broken down and remodelled. It seems that the remodelling process of the stapes becomes faulty. New bone is not made properly and abnormal bone forms. However, the reason why this occurs just in the stapes and sometimes the cochlea is not clear.
Hereditary (genetic) factors are important. About 2 in 3 people with otosclerosis have other family members who also have this condition. It is also thought that fluoride possibly has something to do with it. The number of cases in the UK went down after fluoride was routinely added to drinking water. Also, a virus may play a part. It may be that people with otosclerosis inherit a genetic tendency to develop the condition, but it may need a virus infection to 'trigger' the disease process.
The hearing loss may remain mild but, commonly, it gradually becomes worse. It most commonly affects both ears, but not always. In some people the hearing loss stays mild for a number of years before getting worse. In others the hearing loss quickly becomes worse. Without treatment, in time the affected ears often become totally deaf.
Other symptoms:
In addition to hearing loss:
Tinnitus occurs in about 4 in 5 cases. Tinnitus is an abnormal noise which you hear but it does not come from outside the ear. Noises heard include ringing, whistles, roaring and machine-type noises.
Paracusis is common. This means you tend to hear better when there is a lot of background noise. For example, when talking to someone in a pub or cafe that is full of other people.
Vertigo (dizziness and balance problems) develops in about 1 in 4 cases. This occurs when the balance mechanism in the cochlea (the semi-circular canals) is affected.
At first, when the hearing loss is mild, one may not need any treatment. As the disease progresses and hearing loss becomes worse, hearing aids can make a big difference. However, when the hearing loss is severe, hearing aids will not be of much help.
An operation can be done to replace the stapes with an artificial plastic bone. In most cases this operation is successful and restores hearing. However, it is a very delicate operation. Some people decide to stick with hearing aids until the hearing becomes so bad that the hearing aids are not very helpful. Other people opt for surgery earlier so as not to depend on hearing aids.
The surgery to treat otosclerosis is called Stapedectomy. This is a very simple operation done completely through the ear with no external cuts or scars. The affected patients get back completely normal hearing and, therefore, surgery should be considered the first option in treatment of these patients.
Dr Ravi Ramalingam
ENT Surgeon and Managing Director,
KKR ENT Hospital.
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