A 60-year-old man presents with right-sided tongue weakness that deviates the tongue to the right on protrusion, left hemiplegia, and loss of vibration and joint position sense on the left. Pain and temperature are preserved bilaterally. The artery most likely involved is:

• A Anterior spinal artery ✓
• B Posterior inferior cerebellar artery
• C Anterior inferior cerebellar artery
• D Paramedian branches of the basilar artery

Explanation

This is medial medullary syndrome, caused by occlusion of the anterior spinal artery or vertebral branches supplying the medial medulla. It affects three paramedian structures: the hypoglossal nerve fascicles (ipsilateral tongue LMN weakness), the pyramid (contralateral hemiplegia), and the medial lemniscus (contralateral loss of vibration and proprioception). Spinothalamic fibres lie laterally and are spared, explaining preserved pain and temperature. PICA territory is dorsolateral and gives Wallenberg syndrome instead.

Reference: Snell's Clinical Neuroanatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.