What is otosclerosis?
Our ears contain three tiny bones, called the ossicles, that sit in the middle ear behind the eardrum. They’re a very important part of how we hear, and it’s important that they can move freely in order to pass on the vibrations from the eardrum to the inner ear. Then they can be translated into electrical signals and sent on to the brain where we then interpret them as sounds.
Otosclerosis happens when one of these bones, called the stapes, has an abnormal amount of growth around it, which prevents it from moving properly. Without its movement, the sound waves cannot move to the inner ear, which causes hearing loss.
Eventually, the growth around the stapes can stop it from moving altogether, which could result in quite a severe hearing loss.
The main symptom of otosclerosis is hearing loss, which can happen in one or both ears. However, as it is a gradual hearing loss, people may not notice a change in their hearing until much later in life.
Unlike other types of hearing loss, you might actually find that your hearing is much better in crowded or noisy environments to begin with. This is because it affects how deep or low-pitched sounds are heard. So when people are speaking louder, it becomes easier to hear, rather than getting lost in background noise.
Some people also find that they speak more quietly, as it can sound as if your voice is louder to you.
Other symptoms can include:
Difficulty hearing whispers or low-pitched sounds
Tinnitus (ringing in the ears)
Dizziness or problems with your balance
Causes of otosclerosis
It isn’t fully clear why otosclerosis happens, but many cases tend to run in families.
It’s a lot more common in women than in men, and there is also a link between worsening symptoms of otosclerosis and pregnancy.
Otosclerosis is typically diagnosed by an audiologist or an ear, nose, and throat (ENT) specialist who will carry out some checks to test your hearing, your ear health, and to rule out other potential causes of hearing loss.
This might involve a full hearing test, called an audiogram, or using a tuning fork to check your hearing. They might also check the health of your eardrum using a test called a tympanogram to see how mobile the eardrum is.
Sometimes it may be necessary to have a CT scan in order to get a good look at the structures within the ear.
Hearing aids for otosclerosis
Hearing aids may offer a less invasive and quick improvement to hearing as they work by amplifying the sounds entering your ear. An audiologist will identify the kind of situations where your hearing could be improved and will be able to recommend the right hearing aid for you.
Surgery is also an option to treat otosclerosis. The procedure is known as a stapedotomy or stapedectomy and involves removing some of the enlarged bone and putting in a metal or plastic implant to help the bones work as normal.
Prognosis for otosclerosis
Otosclerosis tends to get worse over time, as the bone becomes less mobile. So if it is left untreated, it is likely that your hearing will gradually get worse, but it is rare to have a complete hearing loss from it.
Treatment is typically very successful, and most people find that their hearing has improved by wearing hearing aids or having surgery.
Most cases of otosclerosis will only affect the stapes bone in the middle ear, but sometimes it can spread into the inner ear and affect the cochlea. This is the snail-like structure that creates the electrical signals needed to send on to the brain.
This hearing loss from cochlear otosclerosis is worse than otosclerosis and unfortunately can’t be treated with surgery.
The exact cause of otosclerosis is not fully understood yet, but it is thought to be genetic. So you’re more likely to develop otosclerosis if someone in your family has it.
Otosclerosis is most common in people in their 20s or 30s, although it is more common in women.
Surgical treatment for otosclerosis is known as a stapedotomy or stapedectomy, which involves removing part of the stapes bone and replacing it with a metal or plastic implant to help the other bones to properly pass on sound waves to the inner ear.
Otosclerosis rarely leads to complete hearing loss – but it can be quite a severe hearing loss if it is left untreated, or if it affects the cochlea in the inner ear.