Otosclerosis causes abnormal bone to form and accumulate in the bones of the ear. The abnormal bone interferes with the transmission of sound from the middle ear to the inner ear.
In otosclerosis, the area most commonly affected is around the stapes (one of three bones that connect the eardrum with the the inner ear). As a result, the stapes cannot move easily, and progressive hearing loss results.
Otosclerosis tends to run in families, and half of all cases are inherited. Children have a 25% chance of developing otosclerosis if one parent has it and a 50% chance if both parents have it.
Symptoms of Otosclerosis
Only about 10% of people with otosclerosis develop hearing loss. Hearing loss usually becomes apparent during late adolescence or early adulthood. Rarely, hearing loss develops by age 7 or 8.
Typically, otosclerosis develops in one ear, although more than half of people develop symptoms in both ears. Hearing loss is the most common symptom. Loss may be gradual. In many people, the first sign of otosclerosis is a problem hearing low-pitched sounds or whispers. Some people with otosclerosis also have tinnitus (ringing or buzzing in the ear) and very rarely dizziness.
Diagnosis of Otosclerosis
Otosclerosis is usually diagnosed by a specialist in hearing disorders. Audiologic tests (such as tympanometry) help doctors identify the cause of hearing loss and determine what other testing may be needed. Sometimes computed tomography (CT) is done.
Treatment of Otosclerosis
A hearing aid usually improves hearing, but some people may prefer surgery. Stapedectomy can be done to remove some or all of the stapes and to replace it with an artificial part (prosthesis). However, with this procedure, worsening hearing loss and balance problems are possible risks.
