Pathophysiology of Stroke

Stroke can be defined as having a neurological deficit of sudden onset and lasts 24 hours as a result of cerebrovascular disease. In general, brain blood vessel disorders or stroke is a cerebral circulatory disorders. Is a focal neurologic disorder that can arise secondary to a pathological process in the cerebral blood vessels, such as thrombosis, embolus, rupture of the vessel wall or basic vascular diseases, such as atherosclerosis, arteritis, trauma, aneurysm and developmental abnormalities.
(Suzanne C. Smeltzer, 2002, p 2131)

1. Thrombosis (thrombo-occlusive disease) is the most frequent cause of stroke. Cerebral arteriosclerosis and cerebral circulation slowdown is the main cause of cerebral thrombosis, which is a common cause of stroke. Signs of cerebral thrombosis varies. Onset of the headache is not common. Some patients experience dizziness, seizures, and cognitive changes or some other common onset. In general, cerebral thrombosis did not occur suddenly, and temporary loss of speech, hemiplegia or paresthesias in half body weight may precede the onset of paralysis in a few hours or days.

Thrombosis occurs usually has something to do with the local damage blood vessel walls due to atherosclerosis. The process of atherosclerosis is characterized by fatty plaque in the intima layer of the artery. Cerebral artery intima part becomes thin and stringy, whereas muscle cells disappeared. Lamina interna elastika torn and frayed, so the vessel lumen partially filled by the sclerotic material. Plaques tend to form at branching or curved places. Thrombi were also associated with these special places. Blood vessels that have a risk in an increasingly rare sequence is as follows: internal carotid artery, vertebral and basilar part of the bottom. Intima loss will make connective tissue exposed. Platelets stick to the exposed surface so that the surface of the blood vessel walls become rough. Platelets will let go of the enzyme, adenosine diphosphate mechanisms that initiate coagulation. Fibrinotrombosit stopper can be detached and form emboli, or it can remain in place and eventually all that will be clogged artery perfectly.

2. Embolism: Cerebral embolism including the second of the main causes of stroke. Embolism patients are usually younger than patients with thrombosis. Most sereberi emboli originating from a thrombus in the heart, so the real problem faced is the embodiment of heart disease. Although less common, embolus may also originate from atheromatous plaques karotikus sinus or internal carotid artery. Each part of the brain can suffer embolism, but usually embolus embolus will clog the narrow passages .. the most frequently affected artery embolus sereberi is sereberi media, especially the top.

3. Cerebral hemorrhage: cerebral hemorrhage including third leading cause of all cases of cerebral vascular disorders, and a tenth of all cases of the disease. Intracranial hemorrhage is usually caused by the rupture of cerebral arteries. Extravasation of blood occurs in the brain and / or subarachnoid, so which is located on the nearby tissue to be displaced and depressed. Blood is very irritating to the brain tissue, resulting in vasospasm in arteries around the bleeding. These spasms can spread throughout the brain and the circle wilisi hemisper. Blood clot that initially resemble soft red jam will eventually dissolve and shrink. In the light of histological brain located around the clot can swell and undergo necrosis. Because enzymes work will occur liquefaction process, thus forming a cavity. After several months of all necrotic tissue will be replaced by astrocytes and new capillaries to form the fabric around the cavity earlier. Finally cavities filled by fibers experiencing astroglia proliferation. Subarachnoid hemorrhage is often associated with rupture of an aneurysm. Most aneurysms of the circle of wilisi. Hypertension or bleeding disorders facilitate the possibility of rupture. Often there is more than one aneurysm.

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