A 53 year-old man developed the acute onset of tetraplegia. On exam, he had paralysis of the tongue and flaccid weakness of all four extremities. Sensation to pinpick was lost below the neck but vibration was relatively intact.

(Left) Axial T2-weighted image of the lower medulla; (Middle) Axial T2-weighted image of the mid-cervical spine; (Right) Sagittal T2-weighted image of the upper cervical spine and lower brainstem. On the left image, note the infarct in the medial medulla. On the middle image, not the infarct within the spinal cord, sparing the posterior columns. On the right image, not the intramedullary lesion from C5-6 up through the medial medulla. This is a complete anterior spinal artery stroke (ASA). The ASA arises from the intracranial vertebral artery where is supplies the medial medulla. It then descends on the anterior surface of the cord supplying the anterior two-thirds of the spinal cord. Radicular arteries throughout the spinal also anastomose with the ASA. Complete infarctions result in a complete cord syndrome with the exception of the posterior columns (hence, the sparing of vibration) which are supplied by the posterior spinal arteries. 

Revised 05/19/06.
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