Cerebrovascular accident, also known as brain attack, or stroke is a sudden neurological deficit characterized by loss of motor control, altered sensation, cognitive or language impairment, and disequilibrium or coma. This occurs when blood flow to a part of the brain is suddenly stopped and oxygen cannot supply this part. This lack of oxygen may damage or kill the brain cells. Death of a part of the brain may lead to loss of certain body functions controlled by that affected part.
Brain attack may be caused by a piece of fatty plaque that is gradually formed in a blood vessel. This plaque formation is also known as a thrombus which may may clot an artery or blood vessel. Blockage of this artery resulting to stroke is called thrombotic stroke. If this plaque dislodged in the blood vessel, it may travel inside the artery causing blockage to smaller arteries. This type of stroke is called an embolic stroke. Another cause is a torn artery in the brain, causing blood to spill out. This is called a cerebral hemorrhage or hemorrhagic stroke. It often results from high blood pressure.
The possibility of suffering a stroke can be markedly decreased if risk factors are controlled. The most important risk factor is high blood pressure. A blood pressure that is persistently high, roughly greater than 140/90 mmHg, increases the risk of having stroke in proportion to the degree by which the blood pressure is elevated. Controlling blood pressure in the normal range decreases the chances of a stroke. Another important factor is cigarette smoking. The cigarettes cause the carotid arteries to develop severe atherosclerosis, which can lead to their closure and block the blood flow to the brain. Atherosclerosis in general is the build up of fatty substance deposits, cholesterol, cellular waste products and other substances forming in the inner lining of the artery.This buildup is called atherosclerotic plaque. It usually affects large and medium-sized arteries. Some hardening of arteries often occurs when people grow older. Cessation of cigarette smoking reverses risk to that of non-smokers within 5 years after quitting. Another risk factor for developing a stroke is diabetes mellitus. Diabetes causes increase viscosity in the blood promoting high blood pressure. Good control of blood sugar is important in decreasing the risk of having stroke in diabetic patients. Lastly, an elevated level of blood cholesterol is also a risk factor for a stroke due to the eventual blockage of blood vessels. Medications and a low cholesterol diet can help normalize an elevated blood cholesterol level.
