The polar (tuberothalamic) artery supplies the anterior pole of the thalamus (anterior nuclei and a portion of the anterior region of the dorsomedial nucleus) and is the only thalamic artery to branch of the PCOM, and therefore the only that can be involved in an anterior circulation stroke. 

The following ( Paramedian/thalamic-subthalamic artery, Thalamogeniculate/inferolateral artery, Posterior choroidal artery) are blood supply to the thalamus from the posterior circulation (PCA).