Which of the following vascular occlusion is the most common cause of hemiplegia?
**Core Concept**
The question requires knowledge of the causes of hemiplegia, which is a neurological condition characterized by weakness or paralysis of one side of the body. The underlying concept being tested is the relationship between vascular occlusion and its effects on the brain.
**Why the Correct Answer is Right**
The most common cause of hemiplegia is due to an occlusion of the middle cerebral artery (MCA), which is a major artery supplying blood to the brain. The MCA occlusion leads to a lack of oxygen and nutrients to the brain tissue, resulting in ischemic damage and subsequent neurological deficits, including hemiplegia. The MCA is responsible for supplying blood to the lateral surface of the hemisphere, including areas responsible for motor control.
**Why Each Wrong Option is Incorrect**
* **Option A:** Basilar artery occlusion is a cause of posterior circulation stroke, which typically presents with symptoms such as dysarthria, ataxia, and decreased level of consciousness, rather than hemiplegia.
* **Option B:** Posterior cerebral artery (PCA) occlusion is associated with symptoms such as visual field defects, memory loss, and decreased consciousness, rather than hemiplegia.
* **Option C:** Anterior cerebral artery (ACA) occlusion typically presents with symptoms such as weakness or paralysis of the lower limbs, rather than hemiplegia.
**Clinical Pearl / High-Yield Fact**
The "MCA syndrome" is characterized by contralateral hemiplegia, hemianesthesia, and homonymous hemianopia, and is a classic presentation of a stroke.
**Correct Answer: C. Anterior cerebral artery (ACA) occlusion is associated with weakness or paralysis of the lower limbs, rather than hemiplegia.