Question

A 30 year old male patient presented with history of dizziness, vertigo, diplopia, dysphagia, weakness on the right side of the body, along with Horner's syndrome on the same side. Loss of pain and temperature sensations on the left side was noted. The patient also has loss of memory. Which artery is most likely involved in the condition described above?

• A. Anterior inferior cerebellar
• B. Posterior inferior cerebellar
• C. Middle cerebral
• D. Superior cerebellar

Hint:

Ipsilateral Horner's plus contralateral pain and temperature loss points to lateral medullary syndrome.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
This vignette is describing a brainstem stroke. The trick is separating which signs sit on the same side as the lesion and which sit on the opposite side.

Step 2: Key Formula or Approach:
Same side (ipsilateral) signs come from structures that have not crossed yet, like cranial nerve nuclei and descending sympathetic fibers. Opposite side (contralateral) signs come from tracts that already crossed lower down, like the spinothalamic tract.

Step 3: Detailed Explanation:
Horner's syndrome on the right and the cerebellar type features on the right are ipsilateral, so the lesion sits on the right side of the brainstem.
Loss of pain and temperature on the left is contralateral, matching a spinothalamic tract that crossed lower down and is now travelling up on the right side, so it gets caught by the same right sided lesion.
Dysphagia adds nucleus ambiguus involvement, again on the right.
This full package, ipsilateral Horner's, ipsilateral bulbar signs like dysphagia, contralateral pain and temperature loss, is the textbook description of Wallenberg syndrome from an infarct of the lateral medulla.
The lateral medulla is fed by the posterior inferior cerebellar artery, so blockage there is the cause. AICA would add facial weakness and deafness from pontine involvement, the middle cerebral artery gives cortical signs like hemiparesis and aphasia, and the superior cerebellar artery gives a different cerebellar pattern, none of which fit this exact combination.

Step 4: Final Answer:
The artery most likely involved is the posterior inferior cerebellar artery, producing Wallenberg (lateral medullary) syndrome. \[ \boxed{\text{Posterior inferior cerebellar artery}} \]