CSF otorrhoea is caused by –
**Core Concept**
CSF otorrhoea is a type of cerebrospinal fluid (CSF) leakage that occurs through the ear, resulting from a defect in the temporal bone. This condition involves the abnormal passage of CSF from the subarachnoid space into the middle ear or mastoid cavity.
**Why the Correct Answer is Right**
The correct answer is related to the anatomical defect in the temporal bone that leads to CSF otorrhoea. The middle ear and mastoid cavity are separated from the subarachnoid space by the temporal bone, which contains the inner ear structures. A defect or fracture in the temporal bone can compromise the integrity of this barrier, allowing CSF to leak into the ear. This is often seen in traumatic injuries to the head or skull base fractures.
**Why Each Wrong Option is Incorrect**
* **Option A:** Incorrect because while trauma can cause CSF otorrhoea, it is not the only cause. Other factors such as congenital defects or tumors can also lead to this condition.
* **Option B:** Incorrect because while infections can cause inflammation and damage to the middle ear, they are not a primary cause of CSF otorrhoea.
* **Option C:** Incorrect because while age-related changes can weaken the temporal bone, they are not a direct cause of CSF otorrhoea.
**Clinical Pearl / High-Yield Fact**
CSF otorrhoea can be a sign of a more serious underlying condition, such as a skull base fracture or a tumor. A high index of suspicion is necessary to diagnose this condition, and prompt treatment is essential to prevent complications.
**Correct Answer:** C. Trauma