Otosclerosis
Otosclerosis is an ear condition which affects the stapes (the smallest bone in the body). It causes progressive hearing loss, which means the hearing loss develops over time. It usually affects both ears (bilateral otosclerosis) but can affect one ear (unilateral otosclerosis).
Otosclerosis affects more girls than boys.
Otosclerosis usually develops in early adulthood. However, it can also occur in children and teenagers. This is sometimes called juvenile otosclerosis.
Otosclerosis is extremely rare in children under the age of 5. Most children with otosclerosis have already developed speech.
How otosclerosis affects the ear
In typical hearing, sound enters the ear through the ear canal and reaches the eardrum, causing the small bones of the middle ear (known as the ossicles) to vibrate. One of the ossicles is a tiny bone called the stapes. The stapes transmits these vibrations to the inner ear.
In otosclerosis, the stapes becomes fixed due to an overgrowth of bone in the middle ear. This can make it harder for sound vibrations to travel through the middle ear, causing conductive hearing loss.
Hearing loss can be mild at first. As the stapes becomes more stuck, it eventually stops moving completely, causing severe hearing loss.
In rare cases, the bone growth spreads into the inner ear, causing sensorineural hearing loss. It’s not known why this can happen.
Otosclerosis can cause tinnitus. Tinnitus UK provide support to people living with tinnitus.
Causes of otosclerosis
Otosclerosis can be genetic, which means it can be inherited. If your child has otosclerosis, there’s a chance that other people in your family also have the condition. Up to half of all cases of otosclerosis are thought to be genetic.
Some doctors believe that, in cases where there is no genetic cause, otosclerosis might also be linked to:
pregnancy
measles
small injuries to the bones in the ear
problems with the immune system
However, it’s still unclear whether these factors actually cause otosclerosis.
Treatment for otosclerosis
Children with otosclerosis are usually offered hearing aids. Because otosclerosis is progressive, children and young people will need regular hearing tests to make sure their hearing aids are suitable.
Otosclerosis can also be treated with an operation called a stapedectomy. A surgeon removes the affected stapes and replaces it with a tiny plastic or metal implant, known as a prosthetic. Stapedectomy surgeries are usually very successful for people with conductive hearing loss. If otosclerosis has spread to the inner ear, causing sensorineural hearing loss, then this cannot be reversed.
As with any surgery, there is a risk of complications, including increased hearing loss.
Some women with otosclerosis find their hearing loss progresses during pregnancy, potentially because of changes in hormone levels. It’s important that young people with otosclerosis continue to get their hearing tested regularly as they get older.
Full references for this webpage are available by emailing
informationteam@ndcs.org.uk