Otosclerosis is the abnormal growth of bone in the middle ear. This growth prevents structures of the ear from functioning properly and can cause hearing loss. The blocked structures are unable to vibrate in response to sound waves and therefore the ear does not function properly, causing partial or complete hearing loss. Otosclerosis is the most common cause of middle ear hearing loss in young adults and may affect one or both ears.

Causes of Otosclerosis

The exact cause of otosclerosis is unknown although it is believed to be hereditary. Otosclerosis may be brought on by hormonal changes during pregnancy and is more common in families with a history of hearing loss. While not fully proven, there is also a theory that otosclerosis may be related to viral infections such as measles.

Symptoms of Otosclerosis

Gradual hearing loss is the major symptom of otosclerosis. Some people with otosclerosis may also experience:

  • Dizziness
  • Balance problems
  • Ringing or buzzing in the ears,also known as tinnitus

Diagnosis of Otosclerosis

A onotolaryngologist can diagnose otosclerosis through a physical examination of the ear and by performing the following diagnostic tests:

  • Audiogram to measure hearing sensitivity
  • Tympanogram to measure middle ear function

A temporal-bone CT scan may also be performed to help distinguish otosclerosis from other causes of hearing loss.

Treatment of Otosclerosis

Mild hearing loss due to otosclerosis can be treated with a hearing aid, which helps to amplify sound. However, a hearing aid is only a symptomatic treatment and will not prevent hearing loss from progressing. Since the bone most frequently affected by otosclerosis is the last of the three small bones of the ear, called the stapes, otosclerosis is often treated with a surgical procedure called a stapedectomy. During this surgery, the damaged stapes is replaced with a prosthetic device that will vibrate and allow sound waves to travel through the ear.

If left untreated, otosclerosis may progress to complete deafness. A doctor will create a customized treatment plan for each individual patient's condition.

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