Otosclerosis is a disorder caused by abnormal growth of spongy bone tissue at the junction of the inner ear and middle ear, resulting in gradual hearing loss. The overgrowth of bone impedes and, in the majority of cases, eventually immobilizes the stapes, one of the three tiny bones in the middle ear that mechanically conduct sound waves into the inner ear.
This condition results in what is known as conductive hearing loss. In some cases, however, excess bone growth may eventually spread to the inner ear, impairing function of the inner ear (sensorineural hearing loss), which is far more difficult to treat than conductive hearing loss.
Otosclerosis may occur in one ear alone, but most often it affects both, either simultaneously or in succession. In general, hearing loss progresses gradually over a period of 10 to 15 years, usually leading to total deafness. Partial or total hearing can be restored, however, with a surgical procedure called a stapedotomy. Otosclerosis is fairly common, affecting one out of every 200 people, usually between the ages of 15 and 30 and is especially prevalent among whites. Incidence is twice as high in women as in men.
What Causes Otosclerosis?
- Otosclerosis appears to be an inherited disorder; many of those who develop it report a family history of hearing loss.
- Pregnancy may trigger the onset of symptoms or accelerate the rate of hearing loss in those with active otosclerosis.
Symptoms of Otosclerosis
- Gradual and progressive hearing loss
- Difficulty with balance
- Ringing or noises in the ears (tinnitus)
- A tendency to speak softly
- Improved ability to perceive spoken words in environments with background noise. (The opposite is true with many other types of hearing loss, including that which commonly occurs with age.)
There is no known way to prevent otosclerosis. Fluoride therapy may limit the progression of otosclerosis in the inner ear.
- Diagnosis is suspected in patients who have a blood relative with known otosclerosis or early hearing loss.
- Hearing tests will be performed to determine the type and degree of hearing loss. If the doctor suspects otosclerosis, especially if a patient has a family history of the disorder, more specialized hearing tests will be conducted.
- CT scan produces images of the ear and head
- The Rinne test compares perception of sounds transmitted by air conduction to those transmitted by bone conduction through the mastoid.
- The Weber's test can detect unilateral (one-sided) conductive hearing loss and unilateral sensorineural hearing loss.
How to Treat Otosclerosis
- Stapedotomy (surgical removal of a portion of the stapes bone and replacement with an artificial prosthesis) is the only method to restore functional hearing. The procedure is often highly successful, significantly improving hearing in the majority of cases. Because there is a slight risk that the surgery will result in total deafness in the operated ear, stapedotomy is usually performed on one ear at a time.
- Hearing aids can be very effective for people with otosclerosis when stapedotomy is not possible. Also, a hearing aid may be required to augment hearing after stapedotomy.
When to Call a Doctor
- Contact an otolaryngologist (ear, nose and throat specialist) or ask your regular family practitioner to recommend one if you experience any degree of hearing loss.
- If you have had stapedotomy surgery for otosclerosis and you experience any sign of postoperative infection (pain, dizziness or fever), call a doctor immediately.
Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference
Simeon Margolis, M.D., Ph.D., Medical Editor
Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50
Updated by Remedy Health Media