The term ischemic stroke is used to describe a variety of conditions in which blood flow to part or all of the brain is reduced, resulting in tissue damage. Although in some cases this may be a chronic condition, most strokes occur acutely. Research over the last four decades has resulted in a significant expansion of our knowledge and understanding of the molecular and cellular processes that underlie ischemia-induced cellular injury.
The goal of this review is to provide an overview of the underlying factors, such as the hemodynamic changes and molecular and cellular pathways, which are involved in stroke-related brain injury. A better understanding of these processes may help in the development of new therapies that are needed to treat this devastating disease.
The etiology and clinical classification of ischemic stroke subtypes is reviewed here briefly and discussed in greater detail separately. (See "Etiology, classification, and epidemiology of stroke", section on 'Brain ischemia' and "Clinical diagnosis of stroke subtypes".)
Acute ischemic stroke subtypes are often classified in clinical studies using a system developed by investigators of the TOAST trial, based upon the underlying cause (table 1) . Under this system, strokes are classified into the following categories:
●Large artery atherosclerosis