When hearing loss occurs, you may hear more clearly in noisy places. Be alert to otosclerosis!

Author: Li Yongxin, Chief Physician, Beijing Tongren Hospital, Capital Medical University

Member of the Otolaryngology and Head and Neck Surgery Branch of the Chinese Medical Association

Reviewer: Liu Yuhe, Chief Physician, Beijing Friendship Hospital, Capital Medical University

Vice Chairman of the Science Popularization Branch of the Chinese Medical Association

In life, you may encounter a strange phenomenon: some people cannot hear the other person clearly in a quiet environment, but they can hear clearly in a noisy vegetable market. This is abnormal. You should be alert to a disease, which is otosclerosis.

1. What is otosclerosis?

Otosclerosis is a disease of unknown cause. The compact bone wrapped in the labyrinth of the inner ear undergoes spongy degeneration, replacing the original normal bone. Later, this new bone re-ossifies and hardens. Clinically, it is called otosclerosis. According to the site of onset, it can be divided into vestibular window type, cochlear type and mixed type, among which the vestibular window type is the most common. At present, the pathogenesis of otosclerosis is still unclear.

Figure 1 Original copyright image, no permission to reprint

Otosclerosis usually occurs in both ears. It may occur in one ear first or in both ears at the same time.

Otosclerosis is more common in women than in men, and the high-risk age group is generally around 20-40 years old. The incidence rate of women increases during menstruation and lactation, and it is speculated that the onset may be related to changes in female hormone levels.

There are no early symptoms of otosclerosis, but as the disease progresses, you may find that your hearing is slightly reduced, and sometimes there is tinnitus. In addition, your hearing is poor in a quiet environment, but it feels good in a noisy environment.

Why do patients with otosclerosis hear more clearly in noisy environments? This phenomenon is called Willis's parahearing. In a noisy environment, people around them will involuntarily raise their voices to cover the background noise. However, patients with otosclerosis are not significantly disturbed by the noise environment, so they feel that they can hear more clearly.

25%-80% of patients with otosclerosis will experience tinnitus of varying nature and degree. The tinnitus caused by otosclerosis is mostly low-pitched, like a low roaring sound.

If the lesions in patients with otosclerosis affect the vestibular nerve, vertigo may also occur.

2. Will otosclerosis eventually lead to total deafness?

The location of the sclerosis lesions in otosclerosis is different, the nature of the hearing loss is different, the degree of disease progression is different, and the degree of deafness is also different.

In the early stage of vestibular window otosclerosis, the ossicles may be affected and the hearing loss is mild. As the lesion continues to worsen, the activity of the stapes and the conduction of the ossicular chain are restricted, and the hearing loss will also worsen. If the lesion is limited to the stapes, after the stapes is fixed, the hearing loss is mainly conductive hearing loss.

If the sclerosis occurs around the cochlea, the lesion will invade the cochlea, which is clinically called cochlear otosclerosis. The hair cells in the cochlea are the device for sensing sound, and damage to the cochlea can directly lead to sensorineural deafness.

If both the cochlea and the stapes base are affected, it is clinically called mixed otosclerosis.

Figure 2 Original copyright image, no permission to reprint

As the disease progresses and the lesions expand, the deafness will also worsen, and in the later stages it may even lead to complete deafness.

Therefore, if you find that you have hearing loss, you should go to the hospital for examination in time. The doctor can basically diagnose whether it is otosclerosis by asking about your medical history, checking the audiogram, and doing a CT scan.

3. How to treat otosclerosis?

Drug treatment has been the research direction of scientists in recent years. Although some studies have shown that sodium fluoride can be used for patients with otosclerosis, there is no clear large-sample clinical research evidence to support its effectiveness and safety.

There are two treatment methods: non-surgical treatment and surgical treatment.

Non-surgical treatment can improve hearing by wearing hearing aids. In addition to hearing aids, there are also some bone conduction hearing aids that can be surgically implanted or non-surgically glued behind the ear. There are even some devices that can be placed on the molars to improve hearing.

Surgical treatment involves reconstruction of the ossicular chain, shaking the stapes, or removing or drilling the stapes base, and then placing an artificial ossicle to replace the original fixed stapes.

Most patients with otosclerosis suffer from the disease in both ears. If a patient has undergone surgery on one ear, he or she can try wearing a hearing aid on the other ear. By comparing the differences between hearing aids and ossicular chain reconstruction surgery, they can determine which treatment method is more suitable for them.

Ossicular chain reconstruction can improve the hearing of patients with otosclerosis, but it is difficult to achieve natural hearing levels, so you need to have a reasonable expectation of the surgery. For example, some people's hearing can only be improved by 30 decibels, and some people's hearing can only be improved by 10 decibels. Currently, stapes surgeons around the world cannot accurately quantify how much hearing can be improved by surgery.

If the lesion is relatively large and the cochlea and stapes are affected, resulting in severe hearing loss, there is little point in performing ossicular chain reconstruction surgery. If the hearing loss worsens further and the ossicular chain surgery and hearing aids cannot meet the hearing needs, you can consider implanting a cochlear implant to improve hearing.