What are the other Names for this Condition? (Also known as/Synonyms)

• Otospongiosis

What is Otosclerosis? (Definition/Background Information)

• Otosclerosis is a very common ear condition. The term Otosclerosis is derived from Greek words ‘oto’ for ear and  ‘sclero’ for hard
• Otosclerosis is the abnormal growth of bone causing sclerosis (hardening of tissue) in the middle ear. As the bone grows, it affects other parts of the ear, interfering with the transmission of sounds, which results in a hearing loss
• Sclerosis occurs in the temporal bone (located at the side and base) of the skull. Multiple areas of sclerosis can be seen on a temporal bone
• There are three bones in the middle ear, called malleus, incus, and stapes. These bones are connected to each other and help in the transmission of sound waves. When the footplate of the stapes bone becomes fixed to the cochlea (auditory portion that has the hearing nerve) due to sclerosis, it results in conductive type of hearing loss
• Otosclerosis commonly affects young and middle-aged adults. There are no clear causes why the condition occurs, but there are evidences linked to viral infections and hormonal changes
• The signs and symptoms of Otosclerosis may include hearing loss and paracusis (ability to hear well against a noisy background)
• The treatment of the ear condition depends upon the severity of hearing loss and may include the use of hearing aids and surgery for severe hearing loss
• Otosclerosis can result in a complete deafness, if the condition remains untreated. Some hearing abilities can be improved with surgery , though it cannot completely cure the condition

Who gets Otosclerosis? (Age and Sex Distribution)

• Otosclerosis is most common during early to mid-adulthood stage. It is often found among young adults. The incidence of the condition is around 1 in 200
• Otosclerosis is found more among women (than men) and Caucasians
• The disorder is less common in people of Japanese and South American origin and very rare in African-American population

What are the Risk Factors for Otosclerosis? (Predisposing Factors)

Research has shown that Otosclerosis may be hereditary and passed down from family members.

• A positive family history increases the risk

Note: It has been researched that individuals, who have one parent with Otosclerosis, have a 25% chance of developing the disorder; whereas, if both parents have otosclerosis, the risk is much higher at 50%, or more.

• Individuals with Paget’s disease have similar areas of sclerosis, but the two conditions are not related to each other

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Otosclerosis? (Etiology)

• The exact cause and mechanism of development of Otosclerosis is largely unknown
• However, there are evidences linking it to viral infections and hormonal changes (such as during pregnancy). There is still a lot of debate among researchers on how hormonal changes might play a role
• Otosclerosis is observed to run in families. The pattern of inheritance is not clear. Sometimes, the condition is noticed to skip generations. Even in a family, one sibling may have Otosclerosis, while the others are not affected. Some researches indicate that the condition is probably autosomal dominant

What are the Signs and Symptoms of Otosclerosis?

The common signs and symptoms associated with Otosclerosis include:

• Hearing loss: Usually the hearing loss is very gradual
• Initially, the individual may be unable to hear low frequency sounds such as whispers
• Dizziness, difficulty of balance
• Tinnitus: A sensation of ringing or buzzing in the ear
• Paracusis: Ability to hear well even in a noisy background (a noisy bar or busy street)
• The hearing abilities seem to be better in louder environments than in quieter ones

How is Otosclerosis Diagnosed?

A diagnosis of Otosclerosis may require:

• Complete evaluation of medical history along with a thorough physical exam
• Otoscopic examination by the physician may be the first step towards a diagnosis of the condition. On looking into the ear canal, the tympanic membrane may appear normal. There is generally no fluid accumulation, such as associated with an infection. A pink spot representing the blood vessels may be visible, which the medical professionals refer to as a Schwartze sign
• Hearing conduction studies conducted by an audiologist such as an audiogram and a tympanogram
• CT scan of the head to rule-out other possible causes of hearing loss

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Otosclerosis?

A few complications associated with Otosclerosis include:

• Complete deafness
• Damage to the hearing nerve
• Funny taste in the mouth, due to damage of the nerve responsible for taste

How is Otosclerosis Treated?

The treatment of Otosclerosis depends upon the severity of hearing loss.

• The use of hearing aids can help improve one’s hearing capacity
• Oral treatment with fluorides, such as sodium fluoride, may help in slowing the progression of deafness
• In case of severe hearing loss, a surgery called stapedectomy may be performed. In this procedure, a part of the stapes bone is removed and replaced with a prosthesis

How can Otosclerosis be Prevented?

• Currently, there are no specific methods or guidelines to prevent Otosclerosis, since it is thought to be a genetic condition
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

What is the Prognosis of Otosclerosis? (Outcomes/Resolutions)

• Otosclerosis is a hearing disorder that slowly progresses and gets worse if treatment is lacking
• Some hearing abilities can be improved with surgery, though it cannot completely cure the condition. There may be pain and dizziness after the surgery, though it usually subsides within a few weeks.

Additional and Relevant Useful Information for Otosclerosis:

It was once believed that Otosclerosis got worse during pregnancy, but current research has failed to prove or substantiate this hypothesis.