Post head injury, the patient had conductive deafness and on examination, tympanic membrane was normal and mobile with increased compliance on impedance. Likely diagnosis is:
**Core Concept**
Conductive deafness is a type of hearing loss that occurs due to a problem in the middle ear, affecting sound conduction to the inner ear. The middle ear consists of the tympanic membrane, ossicles, and the eustachian tube. Impedance audiometry measures the resistance to sound conduction in the middle ear.
**Why the Correct Answer is Right**
The increased compliance of the tympanic membrane suggests a problem with the ossicular chain, specifically the stapes bone, which is responsible for transmitting sound vibrations from the tympanic membrane to the inner ear. The stapes bone is connected to the oval window, which transmits sound vibrations to the inner ear. A defect in the stapes bone or its connection to the oval window can lead to a conductive hearing loss. The increased compliance of the tympanic membrane is due to the absence of the stapes bone, allowing the tympanic membrane to move more freely. This condition is known as otosclerosis, a type of middle ear otosclerosis.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specifically relate to the increased compliance of the tympanic membrane and the conductive hearing loss post head injury.
* **Option B:** This option is incorrect because it is a type of sensorineural hearing loss, which occurs due to a problem in the inner ear or the auditory nerve, not conductive hearing loss.
* **Option C:** This option is incorrect because it is a type of middle ear infection, which can cause conductive hearing loss, but it does not specifically relate to the increased compliance of the tympanic membrane.
**Clinical Pearl / High-Yield Fact**
Otosclerosis is a type of middle ear otosclerosis that can cause conductive hearing loss. It is often associated with a family history and can be diagnosed using impedance audiometry and tympanometry. The condition can be treated with stapedectomy, a surgical procedure that involves removing the affected stapes bone and replacing it with a prosthesis.
**Correct Answer: C. Ossicular discontinuity, likely due to otosclerosis.**