The most common site of cerebral infarction is in the territory of:
**Core Concept**
Cerebral infarction, also known as a stroke, occurs when there is a lack of blood flow to a specific area of the brain. This can lead to cell death and damage to the surrounding brain tissue. The brain's blood supply is divided into several territories, each supplied by a specific artery.
**Why the Correct Answer is Right**
The most common site of cerebral infarction is in the territory of the middle cerebral artery (MCA). This is because the MCA is the largest cerebral artery and supplies a significant portion of the brain, including the lateral surface of the hemisphere, the insula, and parts of the temporal and frontal lobes. The MCA is also more prone to occlusion due to its long course and tortuous path, which makes it more susceptible to atherosclerosis and thrombosis.
**Why Each Wrong Option is Incorrect**
* **Option A:** The anterior cerebral artery (ACA) supplies the medial surface of the hemisphere, including the corpus callosum and the anterior aspect of the frontal and parietal lobes. While infarctions in this territory can occur, they are less common than those in the MCA territory.
* **Option B:** The posterior cerebral artery (PCA) supplies the occipital lobe and parts of the temporal and thalamic regions. Infarctions in this territory are often associated with visual disturbances and are less common than those in the MCA territory.
* **Option C:** The vertebral and basilar arteries supply the brainstem, cerebellum, and parts of the posterior fossa. Infarctions in this territory are often associated with cranial nerve dysfunction, ataxia, and other brainstem symptoms.
**Clinical Pearl / High-Yield Fact**
The MCA territory is often referred to as the "lateral border zone" because it receives blood supply from both the MCA and the ACA. Infarctions in this territory can occur due to occlusion of either the MCA or the ACA, and are often associated with significant morbidity and mortality.
**Correct Answer:** C.