Otosclerosis is a condition producing hearing loss due to impaired movement of the stapes bone of hearing by fixation from abnormal adjacent bony overgrowth. The stapes (one of the three little bones of hearing, malleus, incus and stapes) is unable to vibrate or transmit acoustic energy to the inner ear (containing the nerve endings).
Although the underlying cause of this abnormal bony formation is unknown, recent information suggests that the measles virus interacting with collagen disorders may contribute to the development of otosclerosis. Genetic predisposition (autosomal dominant genetic pattern) to otosclerosis has been observed although this seems to be less so as society becomes more heterogeneous (mixed). There are some communities, such as in India in which the incidence of otosclerosis is very prevalent. In the United States, the lowered incidence of otosclerosis may be partly due to the mixing of genetic pool and measles vaccine.
How is the hearing loss managed?
Conductive hearing loss is treated with amplification with a hearing aid or surgery. Amplification with a hearing aid is very successful because the inner ear (nerve) function is usually normal. Sometimes the abnormal bone metabolism may affect the sensorineural (nerve) function in the cochlear, which can reduce hearing.
Frequently patients do not want to resort to hearing aids when successful surgery, called stapedectomy (total or partial removal of stapes) or stapdotomy (partial removal of stapes with small hole in stapes footplate), can improve hearing in otosclerosis. Otological microsurgery replaces the immobile stapes bone with a mobile prosthesis- usually made of stainless steel/platinum and/or teflon which is not rejected by the body. In properly selected cases, the hearing improvement can reach complete or near complete elimination of the conductive hearing loss in 96% of the operative cases in the hands of experienced ear (otologist) surgeons. Three percent may have no change an up to 1% may have loss of hearing including inner ear nerve dysfunction which would not be aidable with a hearing aid. Dizziness may occur following stapedectomy; it is usually transient (that is, a few days).
If there is a mixed hearing loss, that is an accumulative hearing loss from conductive (stapes fixation) and sensorineural (nerve) deficit, successful surgery will resolve only the conductive component. A hearing aid still may be required for the sensorineural hearing loss if it is symptomatic.
How long is the surgery and how long will I be out of work?
The surgery takes about 1 hour. It can be performed with local or general anesthesia. The patient is usually then discharged from the hospital the same day of surgery. Patients are advised not to incur the risk of barotrauma (flying, scuba diving, weight lifting, and heavy exertion) for 2 weeks after surgery.
Post operative management
Patients will be seen in the office one week after surgery for behind the ear lobe(from where a very small piece of tissue was taken for sealing off the prosthesis in the stapes footplate) suture removal and removal of ear canal packing. Usually antibiotics are prescribed for 10 days following surgery. The operated ear canal should be kept dry for 10 days following surgery. During shower or bathing, a cotton plug with Vaseline may be placed in the outer part of the ear to protect it from water.
An audiogram (hearing test) will be obtained at six weeks after surgery, at which time the hearing should be significantly improved.
Are there any non surgical treatments for Otosclerosis?
Some believe that otosclerosis is the end result of abnormal active softening the bone surrounding the inner ear: a process called otospongiosis (oto-ear spongiosis- softening). This softening of bone may be moderated by dietary supplement with mineral fluoride and calcium in a preparation called Florical. A multiple vitamin containing Vitamin D needs to be taken daily to assure adequate absorption of calcium. Biphosphonates such as Didronel (Etidronate Diaxodium), used for osteoporosis, has been utilized by some to regulate bone metabolism in the medical management of otospongiosis.
There is considerable controversy concerning the efficacies of these medical therapies in affecting the course and symptoms of otospongiosis/otosclerosis. Generally these medications have minimal side affects but people find that continued medical regimen bothersome-especially if the results of these therapies are uncertain. It should be noted that early data is suggesting that biphosphonate treatment may be effective to reduce the irritative effects of otosclerosis/otospongiosis biochemical activity to the inner ear. Your otologist may recommend such therapy depending on your individual situation.
For more information on Otosclerosis and Stapedectomy/Stapedotomy, please go to:New York Ear Surgeon - Otosclerosis and Stapedectomy - Dr. Paul Hammerschlag