The Spectrum of a Brain Attack: From Tia to Stroke

Brain attacks, or strokes, are the third leading cause of death in the U.S. They can also result in devastating permanent consequences, including paralysis and an inability to talk or understand speech. The range and duration of problems related to brain attacks can be quite variable.

Though their spectrum of severity is quite wide, brain attacks are all due to the same end cause -- too little oxygen to the brain. The duration of low oxygen to the brain determines the end result. If the brain is deprived of oxygen for too long, permanent brain damage occurs.

Blood carries oxygen to the brain. In almost all cases of brain attacks, low oxygen to the brain is a result of poor blood flow. Poor blood flow to the brain can occur for different reasons. The most common reason is blocked or clogged arteries that supply the brain with blood. This is usually due to cholesterol plaque build up, called atherosclerosis, which develops over many years.

The heart can be another cause of low blood flow to the brain. If the heart is not pumping hard enough for any reason, blood does not circulate well to the brain. For example, certain irregular heartbeats or heart failure can result in a brain attack. In addition, blood clots or clumps of other non-liquid material in the blood can float up into the arteries in the brain and cause blockage.

Regardless of the cause, the end result is that the brain does not get enough oxygen. The mildest form of a brain attack is called a transient ischemic attack (TIA). A TIA is a reversible state of low oxygen to the brain, which causes symptoms that go away in less than 24 hours. The symptoms of a TIA are the same as the symptoms of a full stroke, but they go away quickly. Most of the time, a TIA lasts only 5 to 20 minutes.

The common symptoms of TIA and stroke include:

If people experience these symptoms, they should go immediately to the nearest hospital emergency room. Even if the symptoms go away, they should never be ignored. People who have a TIA have a very high likelihood of having a stroke in the near future. Treatments are available for people who have a TIA to markedly reduce their risk of stroke in the future. These treatments include drug therapy, such as aspirin and cholesterol-lowering drugs, and possibly surgery to clear out any blockage in the arteries leading to the brain.

The main difference between a TIA and a stroke is how long the symptoms last. With a TIA, the symptoms go away and the brain is generally not permanently damaged. With a stroke, the symptoms do not go away for more than a few days and the brain is permanently damaged. There is even a middle stage that sometimes occurs in which the symptoms go away over the course of a few days, but last longer than 24 hours.

It is important to note that those with a stroke may regain quite a bit of function several weeks or months later if the body learns to adjust to the brain damage. Intense rehabilitation is often given to maximize recovery.

When a person sees a doctor while they are having active symptoms, the doctor may not be able to tell right away whether the person is having a TIA or a stroke. Many different X-ray tests may be ordered, such as a CAT scan of the brain. This and other X-ray tests help to look for evidence of a stroke, problems with the heart or blockage of the arteries in the neck. Which tests are ordered depends on the individual patient.

If you or someone you love experience symptoms of a brain attack, go to the nearest hospital emergency room immediately. There are new treatments available, such as drugs to bust up any clots in the brain, which may even "cure" a stroke if it is caught early enough. Even if the symptoms go away after a few minutes, prompt evaluation is needed.

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