What Is Otosclerosis?
Otosclerosis is a condition that affects the bones of the middle ear, specifically the tiny bone called the stapes. In a healthy ear, the stapes vibrates freely to transmit sound from the eardrum to the inner ear. In otosclerosis, abnormal bone growth develops around the stapes, preventing it from moving properly. This restriction leads to what is known as a conductive hearing loss, because sound is no longer conducted efficiently through the middle ear.
How the Ear Is Affected
The ear is divided into three parts: the outer ear, the middle ear, and the inner ear. The middle ear contains three small bones, or ossicles: the malleus, the incus, and the stapes. The stapes is the innermost of these bones and sits in the oval window, the entrance to the inner ear. When otosclerosis develops, spongy bone forms around the stapes and eventually hardens, fixating the bone in place. This fixation stops the stapes from vibrating when sound waves strike the eardrum, interrupting the chain of sound transmission.
Symptoms of Otosclerosis
The most common symptom of otosclerosis is a gradual hearing loss that worsens over time. Because the condition primarily causes conductive hearing loss, many affected individuals first notice difficulty hearing low-pitched sounds or muffled speech. Other symptoms can include:
- Tinnitus, or ringing in the ear
- A feeling of fullness or pressure in the ear
- Dizziness or balance problems
- Better hearing in noisy environments, known as paracusis willisii
The hearing loss may affect one ear or both ears, and it often progresses slowly over several years.
Diagnosis of Otosclerosis
An ear specialist will usually begin with a medical history and a physical examination of the ear. Hearing tests, called audiograms, are essential for confirming the type and severity of hearing loss. In otosclerosis, an audiogram typically shows a conductive hearing loss with normal inner ear function in the early stages. Impedance audiometry may also be used to measure the stiffness of the middle ear and detect reduced mobility of the stapes. In some cases, imaging scans of the ear can help confirm the diagnosis.
Treatment Options
Treatment for otosclerosis depends on the severity of the hearing loss and the preferences of the individual. Not everyone requires immediate treatment, and some people manage well with monitoring. Available options include:
- Hearing aids: For many people with conductive hearing loss due to otosclerosis, a hearing aid can effectively amplify sound and improve communication.
- Medication: Fluoride supplements have been used in some cases to slow the progression of otosclerosis, though evidence of their effectiveness is limited.
- Surgery: The most common surgical procedure is a stapedectomy, in which the fixed stapes is removed and replaced with a prosthetic device that restores sound transmission to the inner ear. A similar procedure, called a stapedotomy, involves creating a tiny opening in the footplate of the stapes and inserting a small piston.
Surgical outcomes are generally very good, but as with any procedure involving the ear, there are risks, including further hearing loss or damage to the inner ear. A thorough discussion with an ear surgeon is important before deciding on surgery.
Living with Otosclerosis
Otosclerosis is a progressive condition for many people, but the impact on daily life can be managed. Regular hearing checks help track any changes in hearing. Communication strategies, such as facing the speaker and reducing background noise, can also be helpful. For those who choose not to have surgery or who are not candidates for it, modern hearing aids can provide significant benefit. Support from a professional audiology body or a hearing loss support group can offer practical advice and encouragement.