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Cerebrovascular disease or Stroke or cerebrovascular accident is a vascular disease of the cerebral circulation. Arteries supplying oxygen to the brain are affected resulting in one of a number of cerebrovascular diseases.〔 Most commonly this is a stroke or mini-stroke and sometimes can be a hemorrhagic stroke.〔 Any of these can result in vascular dementia. Hypertension (high blood pressure) is the most important contributing cause because it damages the blood vessel lining exposing collagen where platelets aggregate to initiate a repair. If maintained hypertension can change the structure of blood vessels ( narrow, deformed). Blood pressure affects blood flow in narrowed vessels causing ischemic stroke, a rise in blood pressure can cause tearing of vessels leading to intracranial hemorrhage.〔 A stroke usually presents with an abrupt onset of a neurologic deficit, attributable to a focal vascular lesion. The neurologic symptoms manifest within seconds because neurons lack glycogen, so energy failure is rapid. == Subtypes of Stroke== *Transient ischemic attack (TIA). This is a condition in which the blood flow is quickly restored and the brain tissue can fully recover and the symptoms are only transient, leaving no sequelae. In order to diagnose this entity ''all neurologic signs and symptoms must have been resolved within 24 h without evidence of brain infarction on brain imaging.'' *Ischemic stroke,the most common, usually caused by thrombosis of the cerebral vessels themselves or by emboli from a proximal arterial source or the heart, that completely blocks a brain blood vessel. The neurologic signs and symptoms must last longer than 24 hours or the brain infarction is demonstrated, mainly by imaging techniques. *Subarachnoid haemorrhage where blood leaks out of blood vessels directly into or around the brain. The neurologic symptoms are produced by the blood mass effect on neural structures, from the toxic effects of blood on the brain tissue, or by the increasing of intracranial pressure. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「cerebrovascular disease」の詳細全文を読む スポンサード リンク
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