Stroke Overview
A stroke--also referred to as a brain attack or apoplexy--occurs when a part of the brain is injured by a disturbance to its blood supply.
There are two types of stroke. An ischemic stroke, or cerebral infarction, occurs when the flow of blood through an artery supplying part of the brain is suddenly interrupted, usually by a clot. A hemorrhagic stroke, or cerebral or subarachnoid hemorrhage, occurs when a blood vessel in the brain bursts, spilling blood into the substance of the brain or into the spaces surrounding brain cells.
The term "brain attack" is becoming increasingly common to describe this condition--and it makes sense. A person suffering a loss of blood flow to the heart is said to be having a heart attack, so a person with a loss of blood flow to the brain or sudden bleeding in the brain is having a "brain attack." Deprived of oxygen, nerve cells (neurons) in the affected area of the brain can't function and die within minutes. And when nerve cells can't function, the part of the body controlled by these cells can't function either. Although the healing process allows patients to improve after a stroke, some devastating effects of stroke are often permanent; dead brain cells aren't replaced.
Key Stats
1. Stroke, or brain attack, is the leading cause of serious disability in adults. Approximately 5.4 million Americans are living with the effects of stroke. About one-third have mild impairments, another third are moderately impaired and the remainder is severely impaired.
2. You can have a stroke at any age; it strikes all age groups. Ten percent of stroke victims are under 45. Women under age 45 are more likely to have a stroke than a heart attack.
3. Even though a stroke can occur at any age, the older you get, the greater your risk. For every decade after age 55, your risk of stroke doubles; two-thirds of all strokes occur in people over 65 years old. People over 65 also have a seven-fold greater risk of dying from stroke than the general population.
4. In 2002, 38.5 percent those who died from stroke were men and 61.5 percent were women.
5. There are two forms of stroke: ischemic (blockage of a blood vessel supplying the brain) and hemorrhagic (bleeding into or around the brain).
Risk Factors
The most important risk factors for stroke are hypertension, heart disease, diabetes and cigarette smoking. Other factors that increase your risk of having a stroke include heavy alcohol consumption, high blood-cholesterol levels, illicit drug use and genetic or congenital conditions (particularly vascular abnormalities).
Atrial fibrillation, a heart rhythm disturbance that causes the small chambers of the heart to beat irregularly, allowing blood clots to form, is another risk factor for stroke. It is particularly common in elderly people, in whom it is present in up to 10 percent. It may also occur in younger women, particularly in association with hyperthyroidism or Grave's disease.
You can have a stroke at any age. Ten percent of stroke victims are under 45. Women under age 45 are more likely to have a stroke than a heart attack. But the older you get, the greater your risk is for stroke. For every decade after age 55, your risk of stroke doubles; two-thirds of all strokes occur in people over 65 years old. People over 65 also have a seven-fold greater risk of dying from stroke than the general population.
Stroke seems to run in some families, particularly those in which family members have had heart attacks before age 50. These families have a tendency for premature atherosclerosis, or "hardening of the arteries," and may share a genetic predisposition for hypertension, elevated cholesterol or diabetes, all of which are risk factors for stroke. Of course, shared lifestyle habits of poor diet, lack of exercise and tendency to smoke or drink may also be a factor in a family history of stroke.
Symptoms
Awareness of stroke warning symptoms is the first step in diagnosis and management. You will most likely to be the one to initially diagnose if you are having a stroke. Symptoms vary, depending on the area of the brain that is involved, but they are nevertheless relatively easy to identify.
Primary symptoms include sudden, painless numbness or weakness, usually on one side of the body; sudden confusion or trouble speaking or understanding speech; sudden trouble seeing out of one or both eyes; sudden trouble walking; dizziness or loss of balance or coordination; or sudden severe headache with no known cause. Notice the one oft-repeated word: sudden. Onset is fast, and time is of the essence. Recognizing a stroke quickly means you get help sooner and possibly may be able to minimize the amount of damage the stroke will cause.
You may experience other, less-common symptoms, including sudden nausea, fever and vomiting. Sometimes, a stroke is accompanied by fainting, convulsions and/or coma. Stroke symptoms do not cause pain in the limbs, but hemorrhagic strokes are typically associated with sudden, severe, uncharacteristic headache.
