What is otosclerosis? Causes, symptoms, preventions and treatments

What is Otosclerosis?

How can this middle ear condition cause hearing loss? 

Otosclerosis overview

Otosclerosis is a condition where abnormal bone growth in the middle ear impairs hearing. This growth typically affects the stapes bone, damaging its ability to transmit sound vibrations to the inner ear. It often leads to progressive hearing loss and can be treated with hearing aids or surgery.

In this article, we talk about understanding its pathophysiology, risk factors, and available treatments crucial for effective management and improved quality of life.

Otosclerosis and hearing loss

Otosclerosis is an ear condition within the middle ear caused by abnormal bone growth.  It results in hearing loss, commonly progressive, as the growth stops the small bone (known as the stapes) from vibrating.  This vibration allows us to hear.

When the name of this ear condition is broken down, “oto” means ear, and “sclerosis” means hardening.  Therefore, Otosclerosis means hardening of the ear.  This condition simply hinders sound transmission, leading to symptoms like hearing loss, tinnitus, dizziness, or a combination.

What is otosclerosis?

Otosclerosis is a condition that affects the small middle ear bone.  Usually, sound waves are converted into mechanical energy first inside the ear and then switch to electrical energy.  During this process the three small bones (ossicles) within your ear – malleus, incus, and stapes – vibrate. 

These tiny bones need to be able to move freely for you to hear properly.  When you have otosclerosis, the smallest of these, the stapes, hardens to the surrounding environment and cannot vibrate.  It’s similar to a roadblock, the energy just stops at that moment and is unable to make the journey to the inner ear causing loss of hearing.

Otosclerosis is a type of conductive hearing loss

As the ear loses this ability to transmit sound, people often complain of low-frequency hearing loss first.  This means that you may struggle with all those low-pitched sounds such as car engines and male voices.

Although otosclerosis is a form of conductive hearing loss, it is uncommonly discovered in patients who develop hearing loss, and quite difficult to know why the condition is contracted.  Therefore, it is a condition that is generally delayed, as in reality, most conductive hearing loss causes are middle ear fluid problems, perforated ear drum, and excessive ear wax. 

This is also why most people visit their GP, audiologist, or ENT department multiple times to receive a correct diagnosis, as often this condition can be misdiagnosed.

Who gets otosclerosis?

However, there are a few known risks linked to otosclerosis, which are pregnancy, genetics, race, gender, and age - particularly white women and young adults.

While a familial link is often associated with otosclerosis, it's not exclusive, as some individuals develop it without a family history. Typically emerging in people's late 20s or 30s, it can affect younger people too.

Otosclerosis is usually more prevalent in women, especially during pregnancy or menopause, as the condition's exacerbation may be linked to heightened oestrogen levels.  Concerned individuals should consult their doctor, who may recommend hearing tests to monitor any potential issues. 

Can you prevent otosclerosis?

There are no known preventions, like other causes of hearing loss, such as noise-induced hearing loss due to exposure to loud sounds that you can implement steps to reduce the risks.  There is also a lot more access to resources on the prevention and risk management of other hearing loss types. 

Top symptoms of otosclerosis

Some of the common symptoms of otosclerosis include:

Gradual hearing loss: A primary symptom of otosclerosis is a progressive hearing loss that develops over time, which can affect one or both ears.

Tinnitus: Some individuals with otosclerosis might experience ringing, buzzing, or other similar noises in their ears also known as tinnitus.

Dizziness or balance issues: Although less common, otosclerosis may bring dizziness or other balance issues.

Difficulty hearing low frequencies and noisy environments: People with otosclerosis may have particular difficulty hearing low-frequency sounds.  This means it can be hard to comprehend deeper voices or low-pitched sounds.

Those with otosclerosis often find it challenging to distinguish and understand sounds in noisy environments.  This ultimately leads to difficulty understanding conversations in crowded places such as coffee shops and live events.

Ear pressure or sensation of fullness in the ear: Some individuals may experience a sensation of pressure and/or fullness in the ear/ears.  This can even present itself without an apparent blockage.

Ear infections: While not a direct symptom of otosclerosis, some individuals with this condition might be more at risk of ear infections due to the changes in the middle ear.

Common treatments for otosclerosis

Treatment options for otosclerosis sufferers can include:

Hearing aids: In the early stages when hearing loss is mild, hearing aids can help improve and support hearing by amplifying sounds. They are often the first line of treatment for those with otosclerosis.

Sodium fluoride: This medication may help slow down the progression of otosclerosis in some cases. It works by inhibiting bone resorption and promoting new bone growth. However, its effectiveness can vary from person to person.

Surgery: Stapedectomy or stapedotomy is a surgical procedure often recommended for severe cases of otosclerosis. During these procedures, the surgeon bypasses the abnormal bone and replaces the stapes bone with a prosthetic device.

These surgeries can often restore hearing to a significant degree. However, they do carry some risks, such as hearing loss, tinnitus, and dizziness, and are generally considered for cases where hearing loss is significant and other treatment options have been ineffective.

Hearing rehabilitation therapy: For individuals who have undergone surgery or are using hearing aids, hearing rehabilitation therapy can be beneficial. This therapy helps individuals adjust to their improved or changed hearing abilities and learn strategies to communicate effectively.

Regular monitoring: Regular check-ups with an audiologist or an ear, nose, and throat (ENT) specialist are essential for monitoring the progression of otosclerosis and adjusting treatment as needed.

Seeking medical help with otosclerosis and the dangers of not

As mentioned earlier, otosclerosis is progressive and if left untreated it can worsen over time – limiting your ability to hear the sounds around you and reducing your quality of life.  Therefore, ignoring the signs is not the best strategy for your future hearing health.  If you are recognising some of the symptoms of otosclerosis, contact your GP for a diagnosis. 

If you are diagnosed with otosclerosis, your GP will be able to guide you through the next steps.  This is often a referral to your local ENT department or audiologist who will determine the best treatment for your level of hearing loss.  With various treatment options available, doing nothing is not one.

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