Lesion Patterns and Mechanism of Ischemia in Internal Carotid Artery Disease

Abstract
THE CLINICAL syndromes from extracranial internal carotid artery (ICA) occlusive disease result from 2 basic mechanisms—from embolism and from low flow due to inadequate collateral circulation distal to a hemodynamically significant stenosis or occlusion.1 Concurrently, regarding the topography of the ischemic stroke lesion in extracranial ICA disease, territorial and border-zone infarctions are the 2 major patterns. Although hemodynamic compromise due to low flow in the border-zone areas has usually been postulated to explain the infarcts in these regions,2,3 the actual cause of border-zone infarction is still controversial.