Wallenberg syndrome involves which aery?
**Core Concept**
Wallenberg syndrome, also known as lateral medullary syndrome, is a neurologic disorder caused by a specific type of stroke that affects the lateral part of the medulla oblongata in the brainstem. This condition results from the occlusion of a critical artery that supplies blood to the medulla.
**Why the Correct Answer is Right**
The correct answer is related to the vertebral artery, which gives rise to the posterior inferior cerebellar arteries (PICA) and the basilar artery. However, the direct cause of Wallenberg syndrome is the occlusion of the posterior inferior cerebellar arteries (PICA) or the vertebral artery before it merges with the basilar artery. The vertebral arteries supply the medulla oblongata and the lateral part of the medulla is particularly sensitive to ischemia, resulting in Wallenberg syndrome.
**Why Each Wrong Option is Incorrect**
* **Option B:** The anterior inferior cerebellar artery (AICA) does not directly supply the medulla oblongata and is not primarily associated with Wallenberg syndrome.
* **Option C:** The middle cerebral artery (MCA) primarily supplies the lateral surface of the cerebral hemisphere and is not associated with Wallenberg syndrome.
* **Option D:** The basilar artery is formed by the fusion of the two vertebral arteries and supplies the brainstem, but it is not the direct cause of Wallenberg syndrome.
**Clinical Pearl / High-Yield Fact**
Wallenberg syndrome is typically characterized by a triad of symptoms: dysphagia (difficulty swallowing), hoarseness, and ipsilateral weakness of the face and limbs. The patient may also exhibit nystagmus, ataxia, and loss of pain and temperature sensation on the same side as the lesion.
**Correct Answer:** A.