STROKE

What is a stroke?
A stroke is damage to the brain due either to blockage in blood flow or to loss of blood from blood vessels in the brain. Blockage in blood flow or loss of blood causes the brain to lack oxygen and blood nutrients.
The brain requires a constant flow of blood to work properly. If the blood flow is disrupted, brain cells do not receive enough oxygen, resulting in cell death. The degree of damage that results from a stroke is dependent on where and how much blood flow to the brain is interrupted.
A stroke can be a symptom of a serious condition such as brain cancer.
A stroke is also called a cerebrovascular accident, cerebrovascular disease or CVA.
Categories of Strokes
There are two major categories of stroke: hemorrhagic and ischemic. Within the major categories are different kinds of strokes.
In ischemic strokes, there is a blockage of blood flow to the brain. About 80% of all strokes are ischemic. Ischemic strokes usually occur when a blood clot forms in a blood vessel in the brain or neck. Blood clots can also travel from other parts of the body, such as the heart, to the neck or brain and cause a stroke. A blood vessel that is extremely narrowed can also cause an ischemic stroke.
In hemorrhagic strokes a blood vessel in the brain is leaking or broken. These types of strokes accounts for approximately one out of five strokes. Hemorrhagic stroke is associated with a higher death rate than ischemic stroke. Hemorrhage can occur from a weak or thinned out area on the artery wall that balloons out over time, and then ruptures.
Kinds of Strokes
A stroke may also develop paralysis in one or both sides of the body.
How Does a Stroke Occur?
A stroke occurs when a blood vessel bringing oxygen and nutrients to the brain bursts or becomes blocked. Vessels can be blocked by blood clots or other particles. When blockage occurs, nerve cells in the part of the brain that is deprived of oxygen becomes dysfunctional. When the nerve cells become dysfunctional, the part of the body that is controlled by these cells is also unable to perform.
What Causes a Stroke?
Several different mechanisms may result in stroke: thrombus formation, embolus, and hemorrhage.
Thrombosis formation is an obstruction within an artery resulting from the gradual accumulation of plaque (atherosclerosis). If large enough, the obstructions may restrict or completely block blood flow through the artery. Blockage of arteries supplying the brain causes stroke if alternative routes are not available to deliver an adequate blood supply
Embolus is an obstruction of an artery due to material formed elsewhere in the body (such as the heart). The materials are usually generated in one part of the body and travels throughout the body until it becomes trapped in a blood vessel. The blood vessel then is unable to supply the brain with blood and nutrients.
Hemorrhage results from a rupture of a blood vessel located in the brain. Blood erupts at high pressure in the brain or in tissue surrounding the brain. Normal brain cells may be destroyed. The presence of blood often results in severe headache, lethargy, or coma.
Multiple Factors. Most strokes are associated with atherosclerosis, high blood pressure, oxygen damage or a combination of the three.
Medication. Some medications may increase the risk of developing a stroke. Vioxx, a medication used to treat arthritis was pulled off the market in September 2004 because it is linked to strokes and heart attacks.
What Does a Stroke Effect?
Stroke affects different people in different ways, depending on the type of stroke, the area of the brain affected and the extent of the brain injury. Brain injury from a stroke can affect the senses, motor activity, speech and the ability to understand speech, behavioral patterns, thought patterns, memory and emotions. Paralysis or weakness on one side of the body is common.
A stroke survivor may cry easily or experience sudden mood swings, often for no apparent reason. This is called emotional liability. Laughing uncontrollably also may occur but isn't as common as crying. Depression is common, as stroke survivors may feel less than "whole."
A stroke can also affect seeing, touching, moving and thinking, so a person's perception of everyday objects may be changed. Stroke survivors may not be able to recognize and understand familiar objects the way they did before. When vision is affected, objects may look closer or farther away than they really are, causing survivors to have spills at the table or collisions when walking.
Strokes may cause people to have problems understanding speech. They also may have trouble saying what they're thinking. This is called aphasia. Aphasia affects the ability to talk, listen, read and write. Aphasia is most common when a stroke weakens the body's right side.
A related problem is that a stroke can affect muscles used in talking (those in the tongue, palate and lips). Speech can be slowed, slurred or distorted, so stroke survivors can be hard to understand. This is called dysarthria and may require the help of a speech expert.
After a stroke, the individual often has difficulty thinking clearly. Planning and carrying out even simple activities may be hard. Stroke survivors may not know how to start a task, confuse the sequence of logical steps in tasks, or forget how to do tasks they've done many times before.
Signs of a Major Stroke
Some of the signs of major stroke are facial weakness, inability to talk, loss of bladder control, difficulty in breathing and swallowing, and paralysis or weakness, particularly on one side of the body.
Risks of developing a Stroke
Some of the most common risks of developing a stroke are:
A history of high blood pressure
heart disease
smoking
atherosclerosis
diabetes
migraine headaches
high levels of tryglycerides (a fatty substance in the blood)
use of birth control pills
Stroke Statistics, News, and Interesting Information
Can a Stroke be Treated?
Anyone who has a stroke needs immediate hospitalization, possibly including intensive care and life support. Unfortunately, there is no known cure for a stroke.