الفهرس 
Introduction & Aim of The WorkOnly 14 pages are availabe for public view
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Abstract
Cerebrovascular disease comprises a hetrogeneous group of that herald their presence by producing symptoms and SibYlIS from either ischemia or hemorrhage within the CNS (.Jose and Andre,1997). Stroke is the third leading cause of death, after cardiovascular ipisease and cancer, and a primary cause of long-term disability (.Jose and Andre,1997). Fisher (1995): said that the two main therapeutic avenues for stroke are improving perfusion of ischemic tissue and ameliorating the metabolic consequences of ischemic injury (neuroprotective therapy). Reduction of blood flow from a normal value of 56 ml/lOOg brain tissue/minute to about 20 ml/1OOg/minute is compensated for by increasing ,the extraction of oxygen from the blood cells. With a cerebral blood flow fof about 10-20 ml/IOOg /minute, anaerobic glycolysis is used for iproduction of adenosine triphosphate and so lactate accumulates. Below 10ml/1OOg/minute the ion pumps fail to maintain a normal distribution of k+ and Na+ ions between the intracellular and extracelluler compartments, resulting in massive release of K + into the extracelluler fluid and influx of ’calcium into the cells. This overload of calcium in the intracellular space is .essential for further pathophysiologic development with degradation of phospholipid, cell membrane destruction, and cell death.