Extradural haemorrhage is due to
**Core Concept**
Extradural haemorrhage (EDH) is a type of traumatic brain injury characterized by bleeding into the space between the dura mater and the inner surface of the skull. This condition is often caused by a head injury, leading to damage to the middle meningeal artery, which is located in this space.
**Why the Correct Answer is Right**
The correct answer is related to the anatomy and blood supply of the brain. The middle meningeal artery is a branch of the maxillary artery, which is part of the external carotid artery system. When this artery is damaged due to a head injury, it can lead to bleeding into the extradural space. This bleeding can cause increased intracranial pressure, displacement of the brain, and potentially life-threatening complications.
**Why Each Wrong Option is Incorrect**
**Option A:** Cerebral edema is not the primary cause of extradural haemorrhage, although it can be a complication of the condition.
**Option B:** Subarachnoid hemorrhage occurs in a different location, between the arachnoid mater and the pia mater, and is often caused by an aneurysm or arteriovenous malformation.
**Option C:** Epidural hematoma is a term sometimes used interchangeably with extradural hemorrhage, but it is not the most specific or preferred term.
**Clinical Pearl / High-Yield Fact**
In the context of extradural hemorrhage, the classic "lucid interval" refers to the period of time after the initial head injury during which the patient appears to be recovering, only to then deteriorate rapidly due to increasing intracranial pressure.
**Correct Answer: C. Trauma to the middle meningeal artery.**