Otosclerosis is a common cause of progressive deafness in young adults. Genetics (‘runs in the family’) or viral infections (e.g. measles), hormonal changes, effect of the auto-immune system may cause it, however the exact cause is not fully understood. In otosclerosis the bone round the base of the stapes thickens and finally fuses with the cochlear bone reducing normal sound transmission causing conductive deafness at the early stages, the cochlea and the nerve of hearing tend to remain unaffected till later. Both ears may be affected and tinnitus and balance problems may also be caused.
How is otosclerosis diagnosed?
- Person cannot hear well.
- Prefers to speak softly.
- Background noise is not irritating (only if inner ear/cochlea is intact).
- Similar hearing loss (flat) across pitches.
- Conductive loss (surgery to be considered).
- Accompanied by cochlear loss (surgery may not be the best solution)
- Healthy eardrum.
- Tympanometry and Acoustic Reflex tests are carried out.
Hearing Aid or Surgery
As hearing aids are reversible and can be taken out when the person wishes to, they are recommended to be used for otosclerosis. Indeed, they are usually more beneficial for otosclerosis than with nerve deafness. As hearing aids work well and are completely safe, many patients with otosclerosis decide not to undergo surgery.
However, surgery may improve hearing and/or stabilise otoslerosis, possibly protecting advancement to the inner ear. Stapedectomy is the removal of the stapes whereas a stapedotomy is more delicate and leaves part of the stapes intact. A prosthetic stapes (e.g metal or plastic) is then used.
Risks and Benefits
- Hearing – This operation produced good hearing in 85%, slight improvement in 10% and worsening in 5%. About 2% had severe hearing loss due to damage to the cochlea although there is still a risk of worse hearing after surgery. It is important for patients to prefer a surgeon who specialises in otosclerosis and ask them for their success rate.
- Balance – is common a few days after the operation.
- Taste – sometimes is the small nerve concerned with taste is affected as it runs just under the ear drum. This may cause metallic taste on the tongue 1-2 months after the operation.
- Others – with metallic prosthesis Magnetic Resonance Scan (MRI) of the head is contra-indicated whereas Computed Tomography (CT) scans are safe.
- Less than 1% of patients with successful stapedectomy may experience sudden hearing loss after many years. Age related hearing loss, however, affects everyone regardless but this is managed by hearing aids.
- 78% of people report improvement or elimination of tinnitus. 6% or less report worsening.
Second ear surgery
If something goes wrong with the first ear, it is still usually possible to hear with a hearing aid in the un-operated ear. The patient will decide, considering the risks.
- Try a hearing aid if you are unsure about surgery and you have slight hearing loss.
- Ask for a second medical opinion if you are not 100% happy about the advice you were given.
- Discuss the technique your doctor will use and his success rate. If your surgeon cannot tell you about his or her figures, you may want to seek advice elsewhere.
- Do not consider any surgery unless you have a clear idea of the risks and benefits.
- Only have the operation if you have completely understood and feel happy with all the above.