A 72-year-old man develops flaccid paraplegia with bilateral loss of pain and temperature sensation below the umbilicus immediately after thoracoabdominal aortic surgery. Vibration and joint position sense in the legs remain intact. The compromised vessel most commonly arises from which segment of the aorta?
- A Right side, between T5 and T8
- B Left side, between T9 and T12 ✓
- C Left side, between C8 and T2
- D Midline origin at the L1 level
Correct answer: B. Left side, between T9 and T12
Explanation
This is anterior spinal artery syndrome of the lower thoracic cord. The great radicular artery of Adamkiewicz reinforces the anterior spinal artery and classically arises from a left posterior intercostal artery between the T9 and T12 segments in about 75 percent of people. Its compromise devascularises the anterior two thirds of the cord, sparing the posterior columns supplied by paired posterior spinal arteries. This explains the preserved vibration and proprioception alongside bilateral motor and spinothalamic loss.
Reference: Gray's Anatomy, 42nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.