In a typical anterior circulation ischemic stroke, an embolus, either from the heart or an unstable atheroma, lodges in the distal internal carotid artery where it bifurcates to form the anterior and middle cerebral arteries.
Blood flow to the affected anterior cerebral artery is maintained via the anterior communicating artery. However, blood flow to the middle cerebral artery now is supplied only by small end-to-end anastomoses between middle cerebral artery branches on the one hand, and anterior and posterior cerebral artery branches on the other.
Copyright 2000