Close to its origin each posterior spinal artery gives off an ascending branch, which ends ipsilaterally near the fourth ventricle.

[3] Disruption of blood supply to this particular artery in the medulla would result in a number of sensory deficits.

If occlusion occurs above the level of sensory decussation, it would affect the proprioception, vibration, and two-point discrimination of the contralateral side of the body.

Particularly at the upper cervical spinal cord where the posterior spinal artery supplies some parts of the ventral column, lesion might extend to the anterolateral system and triggers the loss of pain and temperature sensation on the contralateral side of the body.

This article incorporates text in the public domain from page 579 of the 20th edition of Gray's Anatomy (1918) ocular group: central retinal