Stroke Causes

Poll

You have had a stroke. Hopefully, you went to the hospital when you developed your symptoms of weakness, numbness, altered speech or visual impairment. Your hospital care enabled you to limit the damaging effects of the loss of circulation to a portion of your brain. You've made it through the acute phase of stroke management. Now what?

You will want to obtain the best achievable outcome from the impairments you already have. If you have "motor" impairments (weakness or clumsiness) you can rest assured that randomized, controlled trials -- the gold-standard method for determining a treatment's effectiveness -- have shown that physical therapy can improve your level of functioning. If you have speech impairment, then speech therapy might be beneficial, though this has never been proved by means of randomized, controlled trials.

While it is important to focus on rehabilitation following a stroke, there are also other issues to attend to. As a survivor of a stroke you are at increased risk for another.

Researchers at the Mount Sinai School of Medicine and Columbia University in New York studied 655 people who suffered first ischemic strokes. (Ischemic strokes are due to plugged blood vessels and not bleeds, and comprise 85-90% of all strokes.) Publishing their results in a March 2006 issue of the journal "Neurology," the investigators found that in the first five years following the stroke there was an 18% likelihood of another. Over the same time period the research subjects also had a 5% likelihood of a heart attack.

Can you improve your odds? Absolutely! The process of using information from the first stroke to help prevent another is called "secondary stroke prevention." The idea is that if there is something that can and should be done to reduce one's risk, now is the time to do it. There is no point in waiting for yet another attack to occur before getting started.

A blue-ribbon panel from the American Stroke Association and American Heart Association reviewed the state of knowledge concerning secondary stroke prevention for patients with ischemic strokes and published their results in a March 2006 issue of the journal "Circulation." They found that use of blood-pressure-lowering medications has a powerful effect in reducing the risk of a second stroke -- ranging from 24-43% in better studies -- and this benefit might even extend to patients who have normal blood pressure to start with.

If you have diabetes, then it is especially important to control high blood pressure. Using a medication from the groups of drugs known as "angiotensin converting enzyme inhibitors" (ACEIs) and "angiotensin receptor blockers" (ARBs) will not only help control blood pressure, but will additionally help protect the kidneys. If you have diabetes, then it is also important to consider use of cholesterol-lowering medication, especially from the class of drugs known as "statins." Statins can additionally benefit people without diabetes and even those without elevated cholesterol levels. Of course, in diabetes it is also important to keep the blood-sugar levels as close to normal as is humanly possible.

Quitting smoking is also pivotal in preventing another stroke, and it is never too late in the game to benefit from this difficult but important change. Consumption of more than two standard drinks of alcohol per day also increases the risk of stroke and should be avoided. If you are obese, then it is in your best interests to lose weight through a combination of calorie reduction and sensible exercise.

The carotid arteries are a pair of pulsating blood vessels in the front of the neck that carry blood to much of the brain. If your hospital studies showed that a carotid artery is 70-99% narrowed (severe stenosis) and your recent stroke was downstream from this blood vessel, then you are much less likely to have another stroke if you have a surgical clean-out (endarterectomy) by an experienced surgeon whose complication rate is less than 6%. If you have severe narrowing, but because of some medical or surgical problem the surgery is considered too risky, then insertion of a stent into the narrowed artery can serve as a substitute for endarterectomy.

If the carotid artery on the same side of the stroke is 50-69% narrowed (moderate stenosis), then an endarterectomy can be considered, but the benefit of surgery in these circumstances is much less clear-cut. If the narrowing is less than 50% (mild stenosis), then you are better off leaving the artery alone.

The above recommendations are based on studies in people with atherosclerosis (hardening of the arteries) which is the most common cause of strokes and, for that matter, heart attacks. But not every stroke is caused by atherosclerosis. That's why medical testing is important in stroke patients -- so that treatment can be tailored to individual circumstances.

What about blood-thinners? If you have atrial fibrillation (a specific pattern of irregular heartbeats) then you are at particular risk to have a stroke due to a blood clot being thrown into the circulation from the heart. In this case warfarin (Coumadin) is the blood-thinner of choice. If for some reason the warfarin cannot be tolerated or is considered too risky, then aspirin is a second-best choice.

If your stroke was due to atherosclerosis, then studies support the use of an "anti-platelet" drug. Platelets are the building blocks from which blood clots are made, and anti-platelet drugs interfere with the ability of the platelets to clump together to form a clot. Antiplatelet drugs of first choice include aspirin by itself, aspirin in combination with extended-release dipyridamole (Aggrenox), and clopidogrel (Plavix).

It's important to realize that patients who address every risk factor for a second stroke are likely to have the best outcome and the lowest chances of another attack. Handling some risk factors and not others is better than doing nothing at all, but in fighting off a second stroke, you want to use every weapon in your arsenal.

(C) 2006 by Gary Cordingley

Gary Cordingley, MD, PhD, is a clinical neurologist, teacher and researcher who works in Athens, Ohio. For more health-related articles see his websites at: http://www.cordingleyneurology.com and http://www.neurologyarticles.com