APA Dictionary of Psychology

a condition in which brain tissue is deprived of an adequate blood supply and thus lacks oxygen and nutrients. It is usually marked by loss of normal function of the affected area and may be accompanied by cerebral edema. A brief interruption in blood supply—a transient ischemic attack (TIA)—usually causes no serious damage. An interruption lasting more than several minutes may result in cerebral infarction. See cerebrovascular accident; stroke.