article/1916852 Ischemic stroke "Ischemic Stroke: Practice Essentials, Background, Anatomy" "Ischemic Stroke: Practice Essentials, Background, Anatomy" "Ischemic Stroke: Practice Essentials, Background, Anatomy" http://emedicine.medscape.com/article/1916852-overview emedicine.medscape.com Ischemic stroke http://emedicine.medscape.com/article/1916852-overview