Otosclerosis - Otosclerosis

Japanese: 耳硬化症 - じこうかしょう（英語表記）Otosclerosis

What is the disease?

Otosclerosis is Ossicles ( Knowledge ) This is a disease in which the stapes, which is located deepest in the ear and transmits vibrations to the inner ear, becomes less mobile. The space between the footplate of the stapes and the surrounding bones becomes less mobile. Conductive hearing loss ( Electricity ) As the condition progresses, Sensorineural hearing loss ( Kanonancho ) or Mixed hearing loss ( President of the ) It will be.

The disease is caused by genetic factors and is more common in Caucasians than Asians. It is slightly more common in women, and hearing loss can worsen during pregnancy.

How symptoms manifest

In many cases, the main symptom is bilateral progressive conductive hearing loss. In Japan, the age at which people become aware of hearing loss is around 30 years old, and the age at which people visit a hospital and receive a diagnosis is around 40 years old. eardrum ( Komaku ) If your hearing is normal, you may have otosclerosis.

Testing and diagnosis

Hearing tests usually reveal bilateral conductive hearing loss with greater loss in low frequencies.

In addition, tympanometry is used to measure the movement of the eardrum, and diagnosis is based on test findings such as the loss of the stapedius reflex. Although otosclerosis lesions are often not very clear on temporal bone targeted CT, this test is always performed because hearing loss can also be caused by fixation or underdevelopment of other ossicles.

Treatment methods

Hearing loss caused by otosclerosis is one of the few types of hearing loss where surgery can dramatically improve hearing. Because medical treatments are still under research, people who do not want to undergo surgery use hearing aids.

If the hearing loss is mild, surgery is not necessary. Air-bone gap ( Transportation ) Surgery is performed when the hearing loss exceeds 20-30 decibels. In cases of mixed hearing loss where sensorineural hearing loss has also occurred and the hearing loss is severe, surgery is performed to reduce the air-bone gap, and further treatment is performed using hearing aids. The effectiveness of wearing hearing aids can be significantly improved by surgery.

Stapes surgery is usually performed under general anesthesia. Various techniques have been developed to restore mobility to the fixed stapes footplate. These include removing the entire or part of the fixed footplate after removing the stapes superstructure, or drilling a small hole of 0.6 mm in the footplate and inserting a piston into it.

Recently, specialized microdrills and lasers have been developed, making surgery safer and more reliable.

Key points for examination

For patients with otosclerosis, stapes surgery can often improve hearing, but there is also the possibility of hearing loss due to inner ear disorders, so be sure to see a doctor who specializes in ear surgery.

Tetsuro Ikezono

Source: Houken “Sixth Edition Family Medicine Encyclopedia” Information about the Sixth Edition Family Medicine Encyclopedia

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