otosclerosis Flashcards
What is otosclerosis?
A condition where there is remodelling of the small bones in the middle ear, leading to conductive hearing loss.
Oto- refers to the ears, and -sclerosis means hardening. It usually presents before the age of 40 years.
What factors contribute to the development of otosclerosis?
A combination of environmental and genetic factors.
The exact mechanism is not understood. It can be inherited in an autosomal dominant pattern, but no specific genetic mutations have been identified.
What is the primary function of the auditory ossicles?
To transmit sound vibrations from the tympanic membrane to the cochlea.
The auditory ossicles include the malleus, incus, and stapes.
What happens to the stapes in patients with otosclerosis?
The base of the stapes becomes stiff and fixed, preventing effective sound transmission.
This leads to conductive hearing loss.
What are the typical presentations of otosclerosis?
Unilateral or bilateral hearing loss and tinnitus in patients under 40 years.
It tends to affect lower-pitched sounds more than higher-pitched sounds.
What auditory phenomenon may patients with otosclerosis experience?
They may perceive their voice as being loud compared to the environment.
This is due to bone conduction of their voice.
What is the typical finding on otoscopy in otosclerosis?
Otoscopy is normal.
What does Weber’s test indicate in bilateral otosclerosis?
The sound will be heard equally in both ears.
If unilateral, the sound will be louder in the more affected ear.
What does Rinne’s test show in cases of otosclerosis?
Conductive hearing loss.
Air conduction is worse than bone conduction.
What is the initial investigation of choice for otosclerosis?
Audiometry.
will show a conductive hearing loss pattern.
What do tympanometry results typically show in otosclerosis?
Generally reduced admittance of sound.
What are the management options for otosclerosis?
Conservative (hearing aids) and surgical (stapedectomy or stapedotomy).
What is a stapedectomy?
Removal of the entire stapes bone and replacement with a prosthesis.
A prosthesis is added to transmit sound from the incus to the cochlea.
What is a stapedotomy?
Removal of part of the stapes bone while leaving the base attached.
A prosthesis is added to transmit sound from the incus to the cochlea.
True or False: Otosclerosis is more common in men than women.
False.
