A 64-year-old man develops sudden quadriplegia and loss of speech after severe neck pain. He is conscious, follows commands by blinking, and moves only his eyes vertically. Pupils are reactive. Which vessel is most likely involved?
- A Anterior spinal artery
- B Left middle cerebral artery
- C Basilar artery ✓
- D Right vertebral artery at PICA origin
Correct answer: C. Basilar artery
Explanation
Locked-in syndrome results from bilateral ventral pontine infarction due to basilar artery thrombosis, interrupting corticospinal and corticobulbar tracts while sparing the reticular activating system and the oculomotor pathways, leaving vertical eye movements intact. An anterior spinal artery stroke affects the cord below the face-sparing level and cannot produce this presentation with preserved consciousness.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.