Otosclerosis (from oto, meaning "of the ear," and sclerosis, meaning "abnormal hardening of body tissue.") is a disease of the bones of the middle and inner ear. The ossicles (bones) become knitted together into an immovable mass, and do not transmit sound as well as when they are healthy and more flexible. Why this happens is still unclear, but scientists think it could be related to a previous measles infection, stress fractures to the bony tissue surrounding the inner ear, or immune disorders. Otosclerosis also tends to run in families. Hearing loss usually begins between the ages of 10 and 30. When otosclerosis involves the small bones of the middle ear hearing loss can be corrected both by a hearing aid as well as a surgical procedure called stapedectomy. When otosclerosis significantly involves the bone which surrounds the inner ear then stapedectomy is not effective.
Otosclerosis is diagnosed by health care providers who specialize in hearing. These include an otolaryngologist (commonly called an ENT, because they are doctors who specialize in diseases of the ears, nose, throat, and neck), an otologist (a doctor who specializes in diseases of the ears), or an audiologist (a health care professional trained to identify, measure, and treat hearing disorders). The first step in a diagnosis is to rule out other diseases or health problems that can cause the same symptoms as otosclerosis. Next steps include hearing tests that measure hearing sensitivity (audiogram) and middle-ear sound conduction (tympanogram). Sometimes, imaging tests—such as a CT scan—are also used to diagnose otosclerosis.
Otosclerosis may slowly get worse. The condition may not need to be treated until you have more serious hearing problems.
Currently, there is no effective drug treatment for otosclerosis. Medications such as fluoride, calcium, or vitamin D may help to slow the hearing loss. However, the benefits of these treatments have not yet been proven.
A hearing aid may be used to treat the hearing loss. This will not cure or prevent hearing loss from getting worse, but it may help with symptoms.
Surgery is often required. Surgery to remove the affected part of the ear (stapes) and replace it with a prosthesis can cure conductive hearing loss. A total replacement is called a stapedectomy. Sometimes only part of the stapes is removed and a small hole is made in the bottom of it. This is called a stapedotomy. Sometimes a laser is used to help with the surgery. Some hearing loss may persist after stapedectomy. It is important to discuss any surgical procedure with an ear specialist to understand potential risks and limitations of the operation.