A 58-year-old hypertensive man develops sudden vertigo, dysphagia, and hoarseness. Examination shows loss of pain and temperature sensation over the left face and right limbs, left ptosis with anhidrosis, left limb ataxia, and intact motor power. Which artery is most likely occluded?

• A Anterior spinal artery
• B Anterior inferior cerebellar artery
• C Posterior inferior cerebellar artery ✓
• D Superior cerebellar artery

Explanation

This is lateral medullary (Wallenberg) syndrome, classically due to posterior inferior cerebellar artery or vertebral artery occlusion. The crossed sensory findings (ipsilateral facial and contralateral truncal pain-temperature loss) reflect involvement of the spinal trigeminal nucleus and lateral spinothalamic tract, with ipsilateral Horner syndrome from descending sympathetic fibres and nucleus ambiguus signs causing dysphagia and hoarseness. The anterior spinal artery produces medial medullary syndrome with contralateral hemiparesis, which this patient does not have.

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

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Written and medically reviewed by the StethoPrep medical team.