Otosclerosis

What is otosclerosis?

Otosclerosis is a condition that causes gradual hearing loss due to abnormal growth with the tiny bones in your middle ear.

What causes otosclerosis?

Tiny bones inside your ear, called ossicles, transmit vibrations to the inner ear. These vibrations are converted to signals that the brain picks up and translates into sounds.

If you have otosclerosis, one of these tiny bones (called the stapes) starts to grow abnormally. It fuses with the surrounding bone until it’s unable to move or transmit sounds to your inner ear, disrupting your brain’s ability to understand sounds.

Doctors aren’t sure why this happens. They think that factors like genetics, changing hormone levels in pregnancy, low fluoride levels, and complications from certain viruses, like measles, might play a part.

Who gets otosclerosis?

Symptoms of otosclerosis usually start in your 20s or 30s, but it can develop during childhood and the teenage years. Women are more commonly affected than men.

Otosclerosis symptoms

The main symptoms of otosclerosis are:

• Gradual hearing loss

• Speaking softly and feeling like you’re speaking loudly

• Difficulty hearing low, deep sounds

• Hearing better when there’s background noise

• Hearing buzzing or humming noises (tinnitus)

• Problems with balance and feeling dizzy

Hearing loss is the main symptom of otosclerosis, and one or both ears can be affected. It usually starts mild, getting gradually worse over time. The severity ranges from person to person, but it’s rare for otosclerosis to cause complete deafness.

Otosclerosis diagnosis

If you’re having trouble with your hearing, a doctor will start by looking at your medical history and asking about your symptoms. They’ll examine your ears and do some simple hearing tests, where you might listen to sounds through headphones and respond when you hear something.

The doctor will refer you to an ear, nose and throat (ENT) specialist or a hearing specialist if they think you have a hearing condition like otosclerosis.

The specialist will do more in-depth hearing tests. These might involve a small device called a tympanometer that can look at the movement of bone in your ear.

You may also have a CT scan to get a detailed picture of your ear and the extent of the otosclerosis.

Otosclerosis treatment

To start with, you may not need any treatment if your hearing loss is mild. As otosclerosis develops, the hearing loss can usually be treated successfully with hearing aids or surgery:

• Hearing aids – A small, discreet electronic device placed inside your ear. It helps increase the volume of the sound as it enters your ear, making sounds clearer and improving what you can hear. There are no risks to wearing hearing aids, and they are effective for many people

• Surgery – Surgical procedures for otosclerosis involve removing part of the stapes bone and inserting a plastic or metal implant into the ear. This helps the remaining bones to transmit sounds more effectively.

Long-term outlook

The progression of hearing loss is usually very gradual if you have otosclerosis.

Surgery is usually very successful, and around 80 to 90% of people who have surgery experience improved or restored hearing as a result. But it’s a delicate operation, and in rare cases, the surgery can fail, causing total deafness or other damage to the operated ear.

This small risk can make it difficult to decide whether or not to have surgery. Talk to your specialist about the procedure, the benefits and the risks, so you can be sure you’ve made the right decision for you.