Otosclerosis is a conductive type of hearing loss involving the middle ear. The cause of hearing loss is related to abnormal bone growth of the ossicles, a group of three bones important to the function of conduction and amplification of sound waves from the outer ear to the inner ear.
Symptoms of Otosclerosis
The most common symptom related to otosclerosis is loss of hearing. The loss may be gradual and may begin with inability to hear low-pitched sounds or whispers. Another common occurrence is to have an easier time hearing when background noise is present. Tinnitus or dizziness may also occur with otosclerosis.
Diagnosis of Otosclerosis
An audiogram and tympanogram can be used by an audiologist or otologist to determine the degree of hearing sensitivity and conductivity. A CT scan can give a definitive diagnosis of otosclerosis by showing the level of bone overgrowth which would differentiate this disorder from other causes of hearing loss.
Treatment of Otosclerosis
Treatment of otosclerosis can either be supportive(treats symptoms) or curative. Supportive therapies include:
- hearing aid – amplification of sound may help reduce the level of hearing loss
- calcium, fluoride, and vitamin D may have some effect in reducing hearing loss, however the research is poorly supported and not well recommended for supportive therapy
- While there is no guarantee for a cure in surgical procedures, stapedectomy or stapedotomy may cure the disorder or help decrease the symptoms. In rare cases, the procedure may worsen the symptoms, so a otolaryngologist should be consulted on the risks versus benefits of these surgical procedures.
Risk Factors of Otosclerosis
Research surrounds causes of otosclerosis, however, genetics do play a role in the inheritance of this disorder. Another cause without clear understanding is that hormones involved in pregnancy may lead to this disorder as well. Other risk factors also without a clear rationale include:
- middle-aged women
- viral infections (such as measles)
Medline Plus. Otosclerosis. Accessed: March 25, 2009 from http://www.nlm.nih.gov/medlineplus/ency/article/001036.htm
National Institute on Deafness and Other Communication Disorders. Otosclerosis. Accessed March 25, 2009 from http://www.nidcd.nih.gov/health/hearing/otosclerosis.asp