Posterior cord syndrome is most directly caused by stroke of which spinal artery?

• A. Anterior spinal artery
• B. Posterior spinal artery
• C. Superior posterior spinal artery
• D. Intercostal arteries

Answer: (B)

Posterior cord syndrome results from ischemia of the dorsal columns, which are fed primarily by the posterior spinal arteries. When these arteries are affected, vibration and proprioception (fine touch and position sense) below the lesion are lost, while motor function and pain/temperature sensation in the spinothalamic tract are often preserved. In contrast, the anterior spinal artery supplies the front of the cord (motor pathways and pain/temperature), so its occlusion causes anterior cord syndrome with weakness and loss of pain and temperature rather than dorsal-column deficits. Intercostal arteries provide segmental inflow but are not the direct source of the dorsal-column blood supply, and there isn’t a distinct superior posterior spinal artery recognized in standard anatomy. So, the stroke most directly causing posterior cord syndrome is in the posterior spinal arteries.