different_types_of_strokesSuffering from a stroke can easily be a life-changing experience, if it is not fatal. Even a mild, transient ischemic stroke (TIA) can cause problems. A person who suffers a stroke can have paralysis in any part of the body. At times the paralysis may reverse over a period of time, but often, if the brain is completely dead at a particular place and is unable to create new neural pathways, the paralysis can be permanent. While stroke patients may recover a great deal of mobility with the right physical therapy and medication, there are times when no recovery is possible. So you should be aware of stroke risks, because it can occur at any time and without any apparent symptoms or early warnings of an impending attack.

Different kinds of stroke

Stroke is caused by blood clots in the brain or in an artery where the pathway to the brain is blocked. There are two kinds of clots that can cause strokes: Hemorrhagic clots that cause bleeding and swelling in the brain and non-hemorrhagic clots that block the free flow of oxygenated blood. In either case, the brain is deprived of oxygen and parts of it may die out. Of the two, hemorrhagic clots are more serious in that they may need the patient to be stabilized and operated to remove excess blood from the brain or other surgical methods depending on the source of the stroke in an emergency situation. Apart from bleeding cloths, hemorrhagic strokes can also occur if an artery that supplies blood to the brain ruptures and results in internal bleeding. Hemorrhages can be of different types and occur in various parts of the brain, affecting functions of different parts of the body.

Non-hemorrhagic clots result in ischemic stroke and can either occur if an artery that directly supplies blood to the brain is blocked by a clot or a clot that occurs in a different part of the body forms an embolus and travels to the brain. However, non-hemorrhagic clots have a different treatment option. If the patient makes it to the hospital fast enough, the doctor can inject a medicine that will bust the clot and the patients quickly revert to normal. Subsequent medical treatment with drugs may be required on a long term basis.

You should be aware of many risk factors

There are usually known risk factors that predispose a person towards a stroke. High blood pressure, diabetes and high cholesterol levels are known to cause plaque in the arteries and this causes narrowing of the arteries and increases the risk of blood clots that can break free and travel. Other risk factors include arteriovenous malformation (AVM) that can be present even at birth. Gene defects can also result in greater risk of stroke.

Some people, who may not have other risk factors, may suffer from atrial fibrillation: this results in irregular electrical signals in the heart’s upper chambers that cause the muscles to contract very rapidly, without rest and cause the blood flow to be erratic. A person with atrial fibrillation is at much greater risk of stroke, even if the person is otherwise healthy.

Clot busting drugs

Clot busting drugs are used at the treatment of choice for non-hemorrhagic strokes. The TPA (tissue plasminogen activator like Aletplase) is a double-edge sword. On the one hand, it can successfully bust the clot before it causes permanent brain damage. On the other hand, it may have an even more serious side-effect – that of causing bleeding the brain that can complicate the person’s condition. A patient who can take a TPA has to meet strict standards to qualify for the treatment.

Another problem is that it is very difficult for the doctor to assess whether a blood clot that causes a stroke is a new blood clot or an old blood clot. Unfortunately most stroke busting drugs work only on new blood clots; they do not work on old blood clots that may have formed in the heart and travelled to the brain over a period of time. Older blood clots are difficult to dissolve and that is why the drug may not work.

A new drug is currently under research that is better and more effective. While the TPA drugs are chemicals, plasmin that is a natural enzyme, when loaded into a liposome and sent to the blood clot via IV may work faster and better. The liposome is targeted therapy, in that it is burst with an ultrasound pulse when it at the site. It also reduces the risk of concurrent bleeding which is a negative for traditional clot busting therapy. However, this therapy has still to go into clinical trials and may take another five years to do so.

Time is of the essence

Research has shown that early treatment of stroke increases the chances of success. A study published in the journal, Circulation Cardiovascular Quality Outcomes, and led by Dr. Deepak Bhatt of Brigham and Women’s Hospital in Boston analyzed data of more than a million patients in the U.S. from 1,700 hospitals. The study showed that the use of stroke busting drugs has exponentially increased over the past decade from 43 percent to 77 percent

In another study, published in Stroke lead researcher Dr. Daniel Strbian, an associate professor of neurology at Helsinki University Central Hospital in Finland, studied data on 6,800 patients in Europe over a time frame of 14 years. They found that patients who received the stroke busting drug within 90 minutes of experiencing the stroke recovered faster and with little or no impact or disability than those who received the therapy within the stipulated time frame of 4.5 hours.

For this study the subjects were divided according to the severity of the stroke. While minor stroke patients recovered almost completely, which they may have done even without the clot buster, those in the middle category benefited the most from the stroke busting therapy. However, patients who suffered from severe stroke did not benefit much from early therapy as they had other concurrent problems like extensive arterial blockages.

New therapy, quicker treatment and, above all, greater awareness among people regarding reducing their risk factors and taking the appropriate treatment for them as also recognizing stroke symptoms can lead to better chances of success and recovery.

Journal of the American Medical Association

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