Prevalence of watershed infarction and its relation to intracranial stenosis in patients with acute ischemic stroke

Abstract

Watershed (WS) infarction is a type of ischemic stroke which can be defined as infarction in a region of the brain where the distributions of nutrient arteries meet, or overlap; in these areas, tissue perfusion is most compromised when blood flow is decreased (Stedman's Medical Dictionary, 2006), watershed infarction has two types; cortical watershed (CWS) and internal watershed (IWS) (Bogousslavsky, 1986). The most important and specific risk factor for WSI is hemodynamic impairment. Several factors lead to decrease perfusion pressure such as (severe hypotension due to blood loss, shock, heart failure…); local causes (extra cranial or intracranial stenosis) play the major role in the pathogenesis of WSI. Intracranial stenosis is a narrowing of the arteries inside the brain similar to carotid stenosis in the neck (Ringer et al., 2005).