A 58-year-old hypertensive smoker develops sudden vertigo, dysphagia, and hoarseness. Examination shows right Horner syndrome, loss of pain and temperature sensation over the right face and left limbs, right palatal weakness, and marked gait ataxia. Power is normal. Which vessel is most likely occluded?

• A Right anterior inferior cerebellar artery
• B Right superior cerebellar artery
• C Left vertebral artery at the origin
• D Right posterior inferior cerebellar artery ✓

Explanation

The combination of ipsilateral Horner syndrome, ipsilateral facial and contralateral trunk-limb pain-temperature loss, nucleus ambiguus signs (palatal weakness, hoarseness), vertigo and ataxia is the classic lateral medullary (Wallenberg) syndrome from PICA or distal vertebral artery occlusion. AICA occlusion causes ipsilateral facial paralysis and deafness from labyrinthine and CN VII/VIII involvement, which are absent here.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.