The National Stroke Association defines a stroke as “a sudden disruption of the blood supply to a part of the brain, which, in turn, disrupts the body function controlled by that brain area.” In short, you might call a stroke a “ heart attack” that occurs in the brain.
There are technically four different types of strokes, but all of them have the same basic description: a blood clot or clogged artery prevents blood from continuing through the brain. The areas on the other side of this “medical dam” cannot receive the nutrient-rich blood they need to function. The result? Like a lawn that isn't watered in the heat of summer, the brain cells dry up and die.
The “Laps” a Stroke Swims
This is what happens when someone experiences a stroke. An artery wall in the brain or neck becomes clogged, and blood can't get past the clog. As a result, the brain cells beyond the clog literally die from the lack of oxygen-rich blood. When those cells die, the person loses whatever function those brain cells controlled.
Because we know that certain areas of the brain control certain functions, we can predict the effects of a stroke based on the location of the blockage. If the blockage occurs near the front of the brain, it can affect such things as organization skills, memory, communication, and problem solving. If it occurs lower down, near the brainstem, it can cause unconsciousness and an inability to breathe, swallow, or control elimination.
If the stroke happens in the brain itself, it is called thrombosis. If a blood clot in another part of the body (either the neck or the heart) breaks away from that artery wall and travels up to the brain, the stroke that occurs is called embolic.
In addition, which side (hemisphere) of the brain the stroke occurs on determines its side effects and which body functions are affected. (See Why Head Injuries Are So Dangerous for a full explanation of the right and left hemispheres of the brain.) If the blockage occurs anywhere on the right side of the brain, it can result in the following conditions:
- Paralysis or weakness on the left side of the body
- Extreme emotional highs and lows
- Excessive talking
- An inability to perform routine tasks such as brushing the teeth or buttoning a shirt
If the stroke occurs anywhere on the left side of the brain, it can produce the following results:
The right and left sides of the brain are referred to as hemispheres. The right side controls more of a person's emotions, creativity, and abstract thinking. The left hemisphere controls more of the language skills, logic, perception, and organization.
- Paralysis or weakness on the right side of the body
- An inability to understand language
- Trouble speaking
- Memory problems
- Decreased attention span
Although a stroke, or an infarction as it is officially called, can occur in younger people, it is usually the result of the build-up over the years that clogs, narrows, and decreases the resilience of arteries leading to the brain.
Like heart attacks, the risk factors that may lead to stroke include such unhealthy lifestyle choices as cigarette smoking, obesity, and uncontrolled high blood pressure, combined with factors that we can't do anything about, such as family medical history, individual medical history, and diabetes.