Image Based Question-66112

• It is characterized by abnormal removal of mature dense otic capsule bone by osteoclasts, and replacement with the woven bone of greater thickness, cellularity, and vascularity.
  • Mainly affects Stapes.
    • Begins in ‘fossula antefenestrum.’
  • Autosomal dominant
  • Common in females.
  • 50% of patients of otosclerosis have positive family history.
  • Age = most common between 20-30 years and is rare before 10 and after 40 years.
  • Deafness is increased by pregnancy, menopause, trauma and major operations.

Symptoms of otosclerosis

• Hearing loss :- Bilateral conductive deafness which is painless and progressive with insidious onset. In cochlear otosclerosis sensorineural hearing loss also occurs along with conductive deafness.
• Paracusis willissii :- An otosclerotic patient hears better in noisy than quiet surroundings.
• Tinnitus :- More common in cochlear otosclerosis.
• Speech :- Monotonous, well modulated soft speech.
• Vertigo :- is uncommon.

Signs in otosclerosis

• Tympanic membrane is quite normal and mobile.
• In 10% of cases flamingo – pink blush is seen through the tympanic membrane called as Schwartz sign. Various tests show conductive hearing loss.
• Stapes footplate—Shows a rice grain / biscuit type appearance
• Blue mantles are seen histopathologically.

Tuning fork tests in otosclerosis

• As otosclerotic patients have conductive deafness, the tuning fork tests results will be as follows :‑
  • Rinnes :- Negative
  • Webers :- Lateralized to the ear with greater conductive loss.
  • Absolute bone conduction (ABC) :- Normal (can be decreased in cochlear otosclerosis).
  • Gelles test :- No change in the hearing through bone conduction when air pressure of ear canal is increased by Siegle’s speculum.

Audiometry in otosclerosis

1. Pure tone audiometry

• Shows loss of air conduction, more for lower frequencies with characteristic rising pattern.
• Bone conduction is normal. However in some cases, there is a dip in bone conduction curve which is maximum at 2000 Hz (2 KHz) and is called the Carhart’s notch.

2. Impedance audiometry

i) Tympanometry

• Patient with early disease may show type A tympanogram (because middle ear areation is not affected) Progressive stapes fixation results in classical As type tympanogram.

ii) Acoustic (stapedial reflex)

• It is one of the earliest sign of otosclerosis and precedes the development of airbone gap. In early stage, diphasic on-off pattern is seen in which there is a brief increase in compliance at the onset and at the termination, stimulus occurs. This is pathognomonic of otosclerosis. In later stage the reflex is absent.

Treatment

• Conservative approach/Hearing aid
• Medical : Sodium Fluoride supplementation has met with variable response
• Surgery : total stapedectomy, partial stapedectomy, and stapedotomy