An Overview of Otosclerosis

Otosclerosis is characterized by abnormal bone growth in the inner ear. The condition causes the stirrup-shaped hearing bone called the stapes to stiffen and become immobile, which can lead to hearing loss.

Causes of Otosclerosis

The cause of otosclerosis is unclear. There does appear to be a hereditary predisposition to the condition; however, there is some evidence indicating that it may be caused by a viral infection.

Otosclerosis affects approximately 18 percent of Caucasian females and 10 percent of Caucasian males. Of those affected, approximately 10 percent will have the condition to such a degree that they experience significant hearing loss. African-Americans, Asian-Americans, and Native Americans have a significantly lower incidence of otosclerosis than Caucasians. In women, the condition can develop or worsen during pregnancy. South Asians, such as Indian and Pakistani natives, have a higher incidence of this condition as well.

Diagnosing Otosclerosis

The diagnosis of otosclerosis typically involves a medical history and physical exam as well as hearing tests to rule out other conditions that can result in hearing loss. The most common tests used are an audiogram, tympanogram, acoustic reflexes, and a CT scan of the temporal bone.

Treatment Options

There are three treatment options for otosclerosis depending on the patient’s preference and level of hearing loss. A comprehensive evaluation by an ear specialist is necessary to determine which course of action is most appropriate in a particular situation.

• The first option is to do nothing. Otosclerosis is not a life-threatening condition, so treatment is not required for patients who are able to successfully adapt to the hearing loss. It is important to note that the condition is progressive, so the hearing loss will worsen with time. There is a limit to how bad the hearing will get.
• Hearing aids can provide a non-invasive treatment option depending on the individual patient’s preference, age, medical condition, and nature of the hearing loss.
• A surgical procedure known as a stapedectomy is highly successful in treating otosclerosis. The procedure involves removing the stapes with the help of a microscope and laser and replacing it with a prosthesis. The prosthesis connects to the anvil-shaped bone called the incus, which is located in the middle ear. The procedure takes less than an hour and is successful in restoring normal hearing in 90 to 95 percent of patients. About 1 in 300 (0.3%) of patients undergoing the procedure experience permanent hearing loss or persistent dizziness.