Stroke Facts

Read these stroke facts ...

A stroke or brain attack is a medical emergency. It occurs when a blood clot blocks an artery or a blood vessel breaks, disrupting blood flow to an area of the brain.  When either of these things happens, brain cells begin to die and brain damage occurs.

Depending on the area of the brain involved and the extent of brain cell death, the specific body functions such as speech, movement or memory may be affected.

Here are the basic stroke facts:

• Stroke is the third leading cause of death in the United States. 
• It is a leading cause of serious long-term disability.
• Every 45 seconds someone in America has a stroke. 
• Fewer than one in five Americans can identify even one stroke symptom. 
• The southeastern United States has the highest stroke mortality rates in the country.
• About 700,000 strokes occur in the United States each year. About 500,000 of these are first or new strokes. About 200,000 occur in people who have already had a stroke before.
• Nearly three quarters of all strokes occur in people over the age of 65. The risk of having a stroke more than doubles each decade after the age of 55.
• High blood pressure is the leading risk factor for stroke. High blood pressure affects two thirds of African-Americans.
• Atrial fibrillation is another risk factor for stroke. About 15% of all people who have stroke have AF.
• Women over age 30 who smoke and take high-estrogen oral contraceptives increase their risk of stroke 22 times.

A stroke can be devastating, so it is very important to minimize the risk. Understanding these stroke facts is a first step.

Causes of stroke

The blockage of an artery in the brain by a clot leading to deprivation of blood and oxygen is the most common cause of a stroke.

An ischemic stroke is caused when a clot or a piece of atherosclerotic plaque (cholesterol and calcium deposits on the wall of the artery) blocks a blood vessel in the brain cutting off the blood flow. The blood clot may form elsewhere in the body and travel through the blood stream to the brain.

Strokes caused by a break in the wall of a blood vessel in the brain are called hemorrhagic strokes. There are two types of hemorrhagic stroke:

• Subarachnoid hemorrhage in which bleeding occurs under the thin, delicate membrane surrounding the brain, and
• Intracerebral hemorrhage in which bleeding occurs within the brain itself. It deprives blood and oxygen to parts of the brain.

All the above causes of stroke lead to deprivation of oxygen to the brain tissue and its resultant death.
 
Vasculitis and migraine headache are rare causes of stroke.

Features of stroke

When brain cells are deprived of oxygen, they fail to perform their usual tasks. The symptoms that follow a stroke depend on the area of the brain that has been affected and the amount of brain tissue damage.

Small strokes may not cause any symptoms, but can still damage brain tissue. These strokes that do not cause symptoms are referred to as silent strokes. It is imperative to note the time you experienced your first stroke symptoms. If you have experienced any of these symptoms, you may have had a TIA or mini-stroke. It occurs when the blood supply to the brain is briefly interrupted.

Effects of stroke

The brain is an incredibly complex organ, and each area within the brain has responsibility for a particular function or ability. If a stroke occurs and blood flow fails to reach the region that controls a body function, there occurs disability in that particular body part. The specific abilities that will be lost or affected by stroke depend on the extent of the brain damage and most importantly where in the brain the stroke occurred: the right hemisphere (or half), the left hemisphere, the cerebellum or the brain stem.

Stroke produces both short and long term effects. Short-term effects disappear with time as any swelling in the brain goes down and the damaged cells surrounding the dead brain cells are repaired. Long-term effects are caused by the death of brain tissue. They don't go away, but they can often be modified with rehabilitation.

Around a third of strokes are fatal ...

For more stroke facts ...

There are many good reference websites available for more information on stroke. We have compiled a list of stroke information websites.