What Is Otosclerosis?
Otosclerosis is a condition that results in impaired hearing. There is irregular bone growth or remodeling happening in the small bone in the middle ear. These tiny bones in the middle ear transmit the sound vibrations reaching the middle ear to the inner ear. So, when there is remodeling of bone growth happening around these, it interferes with the effective transmission of sound vibrations. Hence the patients will have impaired hearing. This condition will have conductive hearing loss as the conduction of sound vibration is affected. Otosclerosis usually does not cause complete deafness; it results in mild to moderate deafness only.
What Causes Otosclerosis?
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The ear is divided into three parts, the external ear, the middle ear, and the inner ear. The sound travels from the external through the ear canal to the middle ear. In the middle ear, there are three small bones called ossicles; they are the malleus (hammer), incus (anvil), and stapes (stirrup).
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When the stapes bone moves, it disturbs the fluid in the inner ear, and the hair cells of the inner ear get stimulated. The hair cells convert the sound vibrations into electrical signals, which are then sent to the brain via nerves.
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When the stapes bone is fused with the surrounding tissue, the sound vibration cannot be effectively transmitted to the inner ear. As a result, the sound is not transmitted effectively.
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The exact cause of otosclerosis is unknown. But it is seen to be affecting women more than men and especially during pregnancy, which may mean that change in hormone levels may be a reason.
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The other reason could be an underlying genetic cause. This condition seems to run in families as the faulty gene is transferred to generations.
What Are the Symptoms of Otosclerosis?
Mostly the symptoms are seen in patients in their 20s and 30s. One or both ears can be affected. The commonly seen symptoms are otosclerosis patients are:
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Hearing loss which is worsened over time.
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Difficulty in hearing low and deep sounds and whispers.
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Hear better in noisy surroundings.
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Speaking in a modulated voice as they hear their own voices too loud.
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Tinnitus (constant ringing or buzzing sound experienced in one or both ears).
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Dizziness.
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Vertigo (a sensation that the environment around is spinning).
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Balance problems.
Who Does Otosclerosis Affect?
Otosclerosis affects young adults more than old people. Even though it affects males and females, females are seen as more affected than males. It is also observed that there is a sudden onset of otosclerosis seen during pregnancy time.
How Is Otosclerosis Diagnosed?
Otosclerosis is diagnosed by an ear, nose, and throat (ENT) specialist. The specialist will rule out the presence of other diseases first. A detailed history is taken, and a physical examination. The following tests could be advised: an audiogram, which is a graph that shows the audible threshold for standardized frequencies as measured by audiometry, and a tympanogram, which is a test done to know how well the eardrum (tympanum) works. Also, a CT scan could be advised so as to see the bones and tissues inside the ear in great detail.
How Is Otosclerosis Treated?
The treatment of the otosclerosis condition depends upon the age and severity of the disease. In mild cases, the patient might only need assistance with hearing aids, which can greatly improve impaired hearing. If the patient has very mild hearing loss, then even a hearing aid might not be needed. In moderate to severe cases, surgery might be the treatment advised. In advanced cases of otosclerosis, surgery alone might not be useful in such patients; a cochlear implant might be needed. Also, some medicines, such as sodium, fluorides, and bisphosphonates, have been shown to limit the worsening of otosclerosis.
1. Hearing Aids
Hearing aids are electronic devices that will amplify the sound entering the ear so that one can hear things more clearly. This device can help overcome hearing loss due to fixed stapes by increasing the sound volume. The modern devices are so small that they can even be placed inside the ear and are not obvious. The advantage of using this device is that, unlike surgery, it does not carry any complications.
2. Surgery
- The surgery done in otosclerosis conditions is called stapedectomy or stapedotomy. Surgery is ideally performed under local anesthesia (where the patient is awake and only the particular area is numbed before the surgery) as this provides on-table confirmation of the diagnosis and simultaneously, helps evaluate successful prosthesis placement.
- In this procedure, an incision is made inside the ear canal or above or in front of the ear to get access to the bones inside the ear. The bone is approached through the incision, and the part of the stapes is removed, known as stapedotomy, or the stapes bone is removed, known as stapedectomy, and is replaced with a prosthetic device or implant. This prosthetic device will allow the bone of the middle ear to move again, and the conduction of sound vibration can happen, correcting the conductive hearing loss.
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Pain is minimal following the surgery. Some patients may experience dizziness for some days post-surgery, which will get resolved on its own. Also, altered or loss of taste is complained of following surgery by some patients for weeks or months and will revert back to normal after some time.
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In rare instances, there are risks of injuring the eardrum or causing additional hearing loss, which needs to be discussed with the doctor.
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Post-surgery, an ear pack is placed in the ear canal because of which the improvement in hearing after the surgery might not be evident, which will be resolved by removing the ear pack.
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In case of hearing loss in both ears, the surgeon will operate on the ear most affected. Surgery is not done on both ears at the same time. The other ear will be operated on six months after the first surgery.
What Are the Complications Associated With Otosclerosis Treatment?
As surgery always has some complications associated with it, the treatment for otosclerosis, which is stapedectomy, also has a risk of complications. 80-90 % of the patients undergoing this treatment have produced expected results, but in some cases, it may not be successful. In rare instances, it is seen that the hearing has worsened post-surgery. So it is important to talk to your healthcare provider prior to the treatment to know the possible risks and complications associated with the treatment.
Conclusion
Otosclerosis is a condition that affects the middle ear. The stapes bone is the affected one, which is remodeling of bone growth happening in the stapes. This will affect the stapes’ ability to conduct the sound waves. Either one or both ears might be affected. The patient presents with impaired hearing also, and the patient can complain of other symptoms such as vertigo, tinnitus, and dizziness. The treatment will be either a hearing aid or surgery, depending on the severity of the disease. Even though the condition cannot be cured completely, intervention by the doctor will help to improve the symptoms. Hence seek medical advice as soon as the patient complains of any similar symptoms.
