Cerebral vascular accident
It is defined as damage to the brain caused by a disruption of the blood supply to a part of the brain. This disruption of blood supply can be caused by a blood clot, or by a ruptured artery. The symptoms of a cerebral vascular accident depend on the part of the brain affected. CVA are mostly related to heart function because they are often associated with conditions affecting the heart. CVA is also referred to as a Stroke. stroke occurs all of sudden affecting the blood vessels of the brain. Stroke is the third leading cause of death in the United States and the second leading cause of death in the world. It is called a Temporary Ischemic Attack (TIA) when the symptoms are temporary (less than 24 hours), and stroke when the loss of brain function is permanent.
This “brain attack” occurs when there is not enough blood reaching the brain. A disturbance in blood flow may be due to one of two main causes:
1) there is blockage due to an arterial clot or fatty deposit and vessel rupture.
2) When there is a malfunction in blood flow, cellular death or infarction occurs
In case if stroke is left untreated , more cells in the brain die due to oxygen and nutrient starvation. Therefore, cellular death in the brain can be localized or systemic. A stroke is a medical emergency . If there is any symptom of stroke occurs the patient should be taken immediately to a medical facility for diagnosis and treatment.
Types of Strokes
There are two major types, ischemic stroke and hemorrhagic strokes.
Ischemic strokes involve arterial or vessel blockage. The following are two types of ischemic strokes:
Cerebral Embolism – This type of stroke is one of the most common . The carotid arteries serve as the major blood vessel that travels blood to the brain. A stroke will occur if any smaller branch is occluded, thereby blocking the passage of blood. This may occur if cholesterol, a clot, or other material deposited in a vessel – usually within the carotid artery – breaks off into a smaller vessel where it becomes lodged between the vessel walls. A traveling clot or piece of debris traveling from any where in the body to the brain is called an embolus. When blood supply is cut off from the brain, there is a very serious risk of brain damage or death.
- Cerebral Thrombosis – The carotid artery in the neck and the cerebral artery in the brain can also succumb to a blood clot or atherosclerosis. When it occurs , the occlusion is called a thrombus, a stationary blockage of the artery that cuts off blood passage. TIA, transient ischemic attacks, which may cause stroke-related symptoms last just a short time.
- Intracerebral Hemorrhage – When a vessel inside the brain ruptures, it spills blood into the surrounding area. The effect of vessel rupture occurs in two-folds; the spilled blood irritates brain tissue causing inflammation and swelling and the broken vessel cuts continuous blood flow to the rest of the brain. The main Causes of this type of stroke include drug and alcohol abuse as well as hypertension. Hypertension, or high blood pressure, puts excess pressure in the brain’s blood vessels thereby causing the walls to weaken. The risk for this stroke increases with age . This is frequently seen in young women and is congenital in nature.
- Subarachnoid Hemorrhage – An aneurysm is a weakened part of a vessel wall that may become so thin that it causes a bulge in the wall. If the aneurysms breaks or bursts, a subarachnoid hemorrrhage will occur. This is a rupture, or trauma causing rupture in a certain area between coverings.
Article publié pour la première fois le 06/01/2012