Published: Feb. 15, 2010
Updated: Feb. 15, 2010
Otosclerosis is an abnormal growth of bone in the middle ear that causes hearing loss.
The loss is genetically transmitted, although expression of the disease can vary greatly so it is often seen in people who do not have a known family history of this type of hearing loss.
It usually presents in middle age, can affect one or both ears, and is most often initially a conductive type of hearing loss; sensorineural hearing loss can develop, usually later in the disease process. Tinnitus (or ringing in the ear) may also be present.
The bone growth most commonly affects the movement of the smallest ear bone -- the stapes (or stirrup). The bone becomes fixed, and unable to vibrate so that sound is not transmitted normally to the inner ear.
Diagnosis is based on a thorough audiological assessment and medical evaluation. The diagnosis may be suspected, but cannot be confirmed before the time of surgery, when direct visualization of the problem confirms the diagnosis.
Treatment may involve either hearing aid use or surgery. Medication such as oral fluoride may help to control the hearing loss, but definitive clinical research studies have not been performed. The surgical procedure to treat otosclerosis is called a stapedotomy.
In this procedure, a tiny incision is made inside the ear canal, and the eardrum opened. The middle ear is explored and if the diagnosis of otosclerosis is confirmed, the stapes bone is removed and replaced with a prosthesis, allowing the middle ear bones to move freely with sound.
Surgery may be done using a variety of instruments, including a laser.