Otosclerosis

One of the major contributors to hearing loss is otosclerosis. Otosclerosis is a condition that affects the stapes bone within the middle ear. Growths or lesions accumulate on the bone over a period of time. These abnormal growths – often soft and spongy in nature – keep the affected bone from vibrating correctly leading to hearing loss. Due to the gradual nature of the process, individuals suffering from otosclerosis may not become aware of the problem until it becomes severe enough to be noticed by themselves or others with whom they interact frequently.

The Hearing Process

Hearing begins when our outer ears pick up sound waves from the external environment and sends them to the middle ear. Here the ear drum begins to vibrate and – working together with three tiny bones – transmits the vibrations to the inner ear where they are converted to nerve impulses that end up in the brain. The brain recognises these impulses as sound. The common terms for the three bones of the middle ear -known collectively as the “ossicles” – are hammer, anvil, and stirrup. The correct medical terms are malleus, incus, and stapes. The inner ear holds the cochlea which is filled with fluid and hair cells. The vibrations received from the middle ear pass through the cochlear fluid and cause the hair cells to begin moving. It is this stimulation and movement that leads to the creation of the electrical nerve impulses that go to the brain. Different external sounds lead to different vibrations which stimulate different sections of the cochlea which results in the transmission of impulses that allow the brain to distinguish among a variety of sounds.

Otosclerosis And Hearing Loss

The abnormal growths or lesions resulting from otosclerosis most often affect the last bone in the middle ear – the stirrup or stapes. The growths affect the bone’s ability to vibrate, progressing to the point where the stapes gets stuck and won’t vibrate at all. This can have a serious impact on sound waves passing through to the inner ear. The change in both the number and the quality of the sound waves transmitted leads to the hearing loss. In rare cases, otosclerosis can impact the nerve fibres and cells within the inner ear.

Causes Of Otosclerosis

Researchers cannot point to a single cause with 100% accuracy but it appears genetics plays a major factor. Otosclerosis runs in families so if both of your parents have or had it you have about a 50% chance of developing it as well. Research also indicates a possible link between otosclerosis and hormonal changes occurring during pregnancy. Viral infections – like measles, influenza, and sinusitis – may also have links to otosclerosis.

Symptoms Of Otosclerosis

Hearing loss and tinnitus are the most common symptoms. Remember that the hearing loss can be gradual and take a long time before it becomes dysfunctional enough to be noticed. Tinnitus is most frequently thought of as “ringing in the ear”, but the sensations experienced may also include hissing, buzzing, or even roaring sounds.

Diagnosing and Treating Otosclerosis

Your doctor will typically refer a patient suffering from hearing loss to an otolaryngologist – an ear, nose, and throat specialist.  These specialists can determine if there are other causes of the hearing loss that could produce similar symptoms. Audiologists are usually involved in the diagnostic process as well. They have a variety of tests and procedures to evaluate the functioning of the middle and inner ear.

Once otosclerosis has been diagnosed there are two treatment options – surgery or hearing aids. The surgical procedure – called a stapedectomy – involves removing the stapes and replacing it with an artificial bone, frequently made of Teflon. In some cases the stapes is left in place and simply bypassed in favour of the implanted prosthetic or artificial device.

Hearing aids can be appropriate where the hearing loss resulting from ostosclerosis is less severe. A hearing aid acts as a sound amplifier. The audiologist who performed the diagnostic tests should be able to outline the types of hearing aids available and which would be most suitable to the needs of the person with the condition.

Research On Otosclerosis

Much of the current research emphasis is on identifying the genetic structure that might carry the disease from parent to child. In addition, laser surgery techniques applicable to stapedectomies are being improved. Researchers are also working on improving the artificial bones used in the process.

Additional Information

As with any medical issue, your doctor needs to be consulted. It is advisable to do some research before seeing medical practitioners so you can know what questions to ask them. University affiliated medical centres in your area can also be excellent sources of information.