Otosclerosis
otosclerosis /oto·scle·ro·sis/ (-sklĕ-ro´sis) a condition in which otospongiosis may cause bony ankylosis of the stapes, resulting in conductive hearing loss.otosclerot´ic
otosclerosis
otosclerosis (ō´tōskl
rō´sis),
otosclerosis
Definition
Otosclerosis is an excessive growth in the bones of the middle ear which interferes with the transmission of sound.
Description
The middle ear consists of the eardrum and a chamber which contains three bones called the hammer, the anvil, and the stirrup (or stapes). Sound waves passing through the ear cause the ear drum to vibrate. This vibration is transmitted to the inner ear by the three bones. In the inner ear, the vibrations are changed into impulses which are carried by the nerves, to the brain. If excessive bone growth interferes with the stapes ability to vibrate and transmit sound waves, hearing loss will result.
Otosclerosis is classified as a conductive disorder because it involves the bones of the ear, which conduct the sound to the nerve. If a person has hearing loss classified as neural, the nerve conducting the impulses to the brain is involved.
Otosclerosis is a common hereditary condition. About 10% of the caucasion population has some form of otosclerosis, however, it is rare among other ethnic backgrounds. Women are more likely than men to suffer from otosclerosis. It is the most common cause of conductive hearing loss between the ages of 15-50, but if the bony growth affects only the hammer or anvil, there are no symptoms and the condition goes undetected. Disease affecting the stapes is also associated with progressive hearing loss.
Causes and symptoms
Otosclerosis is hereditary. Acquired illness and accidents have no relationship to its development.
The primary symptom of otosclerosis is loss of hearing. In addition, many people experience tinnitus (noice originating inside the ear). The amount of tinnitus is not necessarily related to the kind or severity of hearing loss.
Diagnosis
Hearing loss due to otosclerosis is usually first noticed in the late teens or early twenties. Hearing loss usually occurs in the low frequencies first, followed by high frequencies, then middle frequencies. Extensive hearing tests will confirm the diagnosis.
Treatment
People with otosclerosis often benefit from a properly fitted hearing aid.
The surgical replacement of the stapes has become a common procedure to improve conductive hearing problems. During this operation, called a stapedectomy, the stapes is removed and replaced with an artificial device. The operation is performed under local anesthesia and is usually an outpatient procedure. Surgery is done on only one ear at a time, with a one year wait between procedures. The degree of hearing improvement reaches its maximum about four months after the surgery. Over 80% of these procedures successfully improve or restore hearing.
Prognosis
People with otosclerosis almost never become totally deaf, and will usually be able to hear with a hearing aid or with surgery plus a hearing aid. In older people, the tendency for additional hearing loss is diminished due to the hardening of the bones.
Prevention
Otosclerosis cannot be prevented.
Key terms
Tinnitus — Tinnitus is noise originating in the ear, not in the environment. The noise can range from faint ringing to roaring.
Resources
Organizations
American Tinnitus Association. P.O. Box 5, Portland, OR 97207. (503) 248-9985. 〈tinnitus@ata.org〉.
National Association of the Deaf. 814 Thayer Ave., Silver Spring, MD, 20910. (301) 587-1788. 〈http://nad.policy.net〉.
NIDCD Hereditary Hearing Impairment Resource Registry. c/o Boys Town National Research Hospital. 555 N. 30th St., Omaha NE 68131. (800) 320-1171.
Self Help for Hard of Hearing People, Inc. 7800 Wisconsin Ave., Bethesda, MD 20814. (301) 657-2248. http://www.shhh.org.
otosclerosis /oto·scle·ro·sis/ (-sklĕ-ro´sis) a condition in which otospongiosis may cause bony ankylosis of the stapes, resulting in conductive hearing loss.otosclerot´ic
o·to·scle·ro·sis (  t-skl -r s s)n. A formation of spongy bone about the stapes and the oval window of the ear, causing progressive deafness. |
otosclerosis
[ō′tōsklərō′sis]
Etymology: Gk, ous + skleros, hard, osis, condition
a hereditary condition of unknown cause in which irregular ossification occurs in the ossicles of the middle ear, especially of the stapes, causing hearing loss. It is usually first noticed between 11 and 30 years of age. Women are affected twice as often as men. The condition may worsen during pregnancy. Stapedectomy or stapedotomy is usually successful in restoring hearing.
otosclerosis (ō´tōskl
rō´sis),n a disorder of the middle ear that generally results in hardening and fusion of the ossicles of the ear, with resultant immobilization so that sound waves cannot be conducted along their paths.
otosclerosis
the formation of spongy bone in the capsule of the labyrinth of the ear, often causing the auditory ossicles to become fixed and less able to pass on vibrations when sound enters the ear. May be an inherited condition in humans.
otosclerosis
ENT Abnormal growth of bone in inner ear, blocking normal function of ear bones with gradual loss of hearing Clinical Slow, progressive; hearing may be better in noisy environments, tinnitus Diagnosis Ear examination may exclude
other causes of hearing loss; audiometry/audiology may determine extent of hearing loss; CT, MRI, PET of head
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