Otosclerosis

What is Otosclerosis?

Otosclerosis, also known as Otospongiosis, is a medical condition that results from the abnormal remodeling of the bones within the middle ear that are responsible for the transmission of sound vibrations and essential for hearing. This usually affects the stapes bone resulting in a fixed bone that is unable to vibrate and transmit the sounds to the inner ear. It is more common in middle-aged adults and is more common in women.

Is Otosclerosis condition a medical emergency?

Otosclerosis is not a medical emergency.

Causes

The exact cause of otosclerosis is not fully understood, but the condition development of the condition is influenced by both genetic and environmental factors. In otospongiosis, there is resorption of normal bone tissue that makes up the three tiny bones in the middle ear and it is replaced with spongy or sclerotic bone tissue, which progressively becomes denser as the disease progresses. Among the three bones in the middles ear, the stapes bone is more commonly affected and results in conductive hearing loss as it can no longer vibrate to carry the incoming sound vibrations to the inner ear. Immune mediators are believed to play an important role in abnormal bone development.
Some factors that can result in otosclerosis include:

• Measles infection
• Stress fractures
• Immune disorders

Risk factors

Factors that increase the risk of otosclerosis include:

• Gender – more common in women
• Age – more common in the third decade of life
• Race – more common in Caucasians
• Family history of Otosclerosis

Symptoms & signs

The signs and symptoms of otosclerosis include:

• Gradual loss of hearing starts in one ear and eventually affects both ears
• Dizziness
• Loss of balance
• Tinnitus

Investigations

Some investigations that are advised for the evaluation of otosclerosis include:

• Laboratory tests:
  • CBP & ESR
• Imaging tests:
  • CT scan of the head – to evaluate the temporal bone
• Otoscopy
• Tuning fork testing
• Audiometry including impedance audiometry

Diagnosis

A diagnosis of otosclerosis is established based on medical history, clinical evaluation, and results of the investigations done.

Treatment

The treatment of otosclerosis depends on the severity of the condition, and surgical interventions are required for its definitive management.

Medical management

There are currently no medications that can treat or manage otosclerosis. The following may sometimes be used:

• Fluoride supplementation – For postoperative management of obliterative and labyrinthine otosclerosis

Interventional including surgery and indications for surgery

Surgical interventions for the management of otospongiosis are required when the air-bone gap is more than 20dB and include the following:

• Stapedectomy – Procedure involves replacing the stape bone with a prosthesis.

Role of Diet/ Exercise/ Lifestyle changes/ Preventive measures

Some measures that are advised for the management of hearing loss in otospongiosis include the use of hearing aids.

Complications

Some complications of otosclerosis include:

• Progressive hearing loss
• Loss of balance and vertigo
• Complications from surgery
• Perforation of eardrum
• Infection
• Bleeding
• Facial nerve injury and facial palsy
• Failure or displacement of the prosthesis
• Necrosis of incus bone
• Abscess or granuloma formation

Prognosis

The prognosis for otosclerosis which is a slowly progressing disease is generally good when diagnosed early and managed well. Surgical interventions are successful in restoring hearing in a majority of cases and the success rate of stapedectomy in the management of otospongiosis is around 85-90%.

When to contact the doctor or hospital? / How to identify the emergency or complications?

It is advisable to seek medical attention if there is hearing loss that is gradually getting worse along with symptoms of dizziness or vertigo.

Indications for hospitalization if required

Brief hospitalization will be required for the management of otosclerosis when surgical interventions are advised.

Suggested clinical specialist/ Department to consult for this condition

• Otorhinolaryngologist (ENT)