What is Otosclerosis?

Otosclerosis is a middle ear disease that doesn't cause pain but leads to hearing loss and tinnitus in affected individuals. While not a serious disease, untreated otosclerosis can cause significant social problems due to associated hearing loss.

Otosclerosis most often occurs after age 30. It's very rare in young people and extremely rare in childhood, and is also uncommon after age 60. It's more prevalent in women.

Otosclerosis is prevalent in populations around the Mediterranean basin. The reason for this geographic concentration is unknown. Otosclerosis is less common in the Far East and sub-Saharan Africa.

There are several types of otosclerosis:

• Stapedial otosclerosis: blockage of the stapes without cochlear involvement;
• Mixed otosclerosis: stapes blockage with cochlear involvement;
• Cochlear otosclerosis: deafness due to a cochlear lesion;

What are the symptoms of otosclerosis?

Hearing Loss

Hearing loss, the most common symptom, can manifest as bilateral (both ears) or unilateral (one ear) deafness.

Tinnitus

Tinnitus involves various bothersome noises that are often intractable and don't disappear after surgery. Their origin is unknown, and science hasn't yet identified the causes or a solution.

Vertigo or Instability

This symptom is also not yet fully understood scientifically. Vertigo is an unpleasant sensation of imbalance that can cause nausea. However, such symptoms are rare.

How is otosclerosis diagnosed?

Otosclerosis is diagnosed by an otolaryngologist through:

• Symptom assessment (hearing loss and possibly tinnitus and vertigo) and family history;
• Otoscopy (examination of the external auditory canal and tympanic membrane);
• Audiometry, which assesses the degree of deafness in one or both ears. Audiometry also determines the type of deafness (conductive, mixed, or sensorineural);
• Impedance testing with stapedial reflex study: This examines the mobility of the tympano-ossicular system and the presence or absence of the stapedial reflex (stapes mobility) to further confirm the diagnosis;
• Speech audiometry: Assesses hearing quality (as opposed to audiometry, which measures the quantity of hearing loss);
• Vestibular examination (rarely necessary) to study vertigo or instability if present;
• Radiological examination (non-contrast CT scan) is rarely indicated, only in rare cases of sensorineural hearing loss with evidence of cochlear involvement;

How is otosclerosis treated?

Otosclerosis treatment can be surgical or prosthetic. Surgery is generally recommended when the chances of hearing recovery are high, particularly with conductive hearing loss and a low perceptive component. In unilateral otosclerosis, surgery is often delayed until the healthy ear compensates for the affected ear's deficit. Hearing aids are a valid alternative for those who cannot or choose not to have surgery.

The primary treatment for stapedial otosclerosis is surgery. This surgery is performed under local anesthesia, without external incision, through the ear canal, leaving no scars.

The ear with the poorest hearing is operated on first using stapedotomy. The other ear is not operated on for 10-12 months to allow for stabilization of the first surgery's results.

Even with mixed otosclerosis, surgery (stapedotomy) is the best option. Hearing recovery is partial due to the unrecoverable cochlear lesion, but residual hearing improvement may allow for satisfactory hearing aid use.

In cochlear otosclerosis, surgery is contraindicated, but hearing aids can improve hearing. In rare cases of advanced cochlear otosclerosis (ossified cochlea) where hearing aids are ineffective, a cochlear implant may restore hearing.

Risks and Complications of Stapedotomy Surgery for Otosclerosis

The greatest risks of stapedotomy surgery concern hearing preservation. Most patients regain full hearing, but in a few cases, recovery is partial. Very rarely, hearing is not recovered, or may worsen or be lost.

Other risks of stapedotomy surgery include:

• Tympanic membrane perforation (usually repairable during surgery);
• Postoperative infection (requiring antibiotic therapy);
• Rare cases of transient facial nerve palsy (resolving with anti-inflammatory treatment);
• Even rarer cases of permanent facial nerve palsy;

Postoperative Follow-up and Check-ups

Patients usually leave the hospital the same day or the next morning. Post-stapedotomy, a week of antibiotic therapy is followed. Follow-up occurs approximately 30 days post-surgery and includes:

• Tonal audiometry to check hearing recovery;
• Speech audiometry to assess hearing quality;

Ear wetting (showers, etc.) is only permitted after the first follow-up visit.

Further check-ups occur at 6 months and 1 year. Surgery on the second ear can be planned after one year.