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Stroke is the third leading cause of death and disability in the United States. However, with medical advances it's possible to reduce the debilitating consequences associated with stroke and even prevent one from occurring. Dr. John Cole, associate professor of neurology at the University of Maryland School of Medicine and clinical research scientist at the Baltimore VA Medical Center answers questions about signs and symptoms, decreasing your risk and when to seek treatment for a stroke as well as the medical advances in stroke prevention and treatment.
It's a sudden occlusion or blockage of a blood vessel that's feeding oxygen and glucose laden blood to the brain. The blockage doesn't allow the blood to pass, so the brain doesn't receive any oxygen. If the blockage persists for several minutes, brain cells start to die because they don't have the ability to store oxygen or glucose. Once brain cells die, they don't come back.
Unfortunately, they're very common. About 800,000 patients are diagnosed with having a stroke each year. About 200,000 are recurrent strokes, or patients who have already had one or more strokes.
What are the two types of stroke?
The two types are an ischemic stroke where the blockage comes from the heart or a blood vessel and travels to the brain. The other type of stroke is called a hemorrhagic stroke and that is when a blood vessel in the brain bursts.
What would cause a clot to go up into the brain?
There are many risk factors. What typically happens is people develop atherosclerosis which develops in the heart or vein. If a piece of that fat material that has collected in the vein breaks off, it can travel into the brain or cause a clot to form.
What are the symptoms of a stroke?
The most common symptoms are sudden numbness, weakness, vision and speech changes, problems with your balance or severe headache. The symptoms of a stroke tend to come on relatively quickly. You may be eating and all of a sudden you might not be able to move, feel or see. If you don't have any other explanation at that time, you need to ask yourself if it could be a stroke, and if so, go to the emergency room right away.
It's a transient ischemic attack. Essentially what will happen is somebody will have a blocked blood vessel which then causes the symptoms. The symptoms are manifested by not being able to do something such as see, feel, speak or hear. Then the blockage essentially goes away and the blood flow is restored. The main thing about TIA is that if you have one, you're much more likely to have a full blown stroke. TIAs are actually a warning shot. You have the symptoms, you get better. Even if you're back to normal, you need to go to the ER and let a physician sort it why you experienced the symptoms you did. If you have experienced a TIA, you're prone to have a full-blown stroke and you don't come back from that. There has been a change in thinking about stroke over the last couple of decades. It is an emergency, that's why neurologists call it a brain attack. They want people with these symptoms to get to a hospital right away.
How are strokes being managed differently now than in the past?
We're trying to get the public to view a stroke the same as a heart attack, hence brain attack. With a stroke, as with heart attack, you have little time to prevent the damage that can be done. If the brain cells are fully deprived of oxygen and glucose, they start dying immediately.
The medicine is stroke management is acute treatment with tissue plasminogen activator, or tPA, and we can give that to people within the 0-3 hour window from the time their symptoms start. Over the last year, we have learned that the window has expanded to up to four hours.
Some medical centers, including our own, can do more invasive procedures where they do a catheter procedure in the brain and put the tPA against the clot. In some cases, we even use a special device that allows us to grab the clot and pull it out. That's obviously a very risky and dangerous procedure, and not commonplace, but it is certainly an option.
There are time windows with both of these treatments. Really up to about 6-8 hours is the longest we could consider treatment after the onset of symptoms.
Is the difference between mild and severe strokes a result of how quickly the clot is dissolved?
If you can dissolve the clot and restore blood flow to the brain, there will be brain cells in various states, some are dead and some are stunned. If you get the blood flow back, the stunned brain cells will come back to life, so to speak, and start functioning again. With a stroke and the severity of it, it depends on how long the clot is there and whether you can reopen the blood vessel. It also depends on the size and if it's a large vessel blocked or a small one, but in some cases, you can have a very small stroke in one part of your brain and not notice, yet have the same size stroke in a different part of the brain and not be able to move.
How important is rehabilitation and when should it begin?
There's been a major paradigm shift in the way we do rehab over the last 15 or 20 years and even more recently. The way we look at it now is as soon as someone is stable medically we want them to start rehab. Numerous studies show that the sooner the individual starts rehab and the more consistent they are with it over the long haul, the better outcome they are going to have. Once they're stable medically, the cause of the stroke can be determined and risk for recurrence can be assessed. In the acute setting, we try to get patients started with rehab immediately.
After rehabilitation has been started, patients will begin to see rapid improvements. It will start to taper off and won't be as obvious two or three years down the line. However, if someone is very diligent practicing the things they can't do, they will continue to get better. I explain it to patients by likening it to weight lifting or playing the piano. You're not going to be very good at it when you first start, but if you keep working at it and you do it diligently for a year, I guarantee you'll be able do it much better. It's the same thing with stroke rehab. You're retraining your brain and people can absolutely improve several years after having a stroke.
Does the risk of stroke increase with age?
Every 10 years after age 55, it considerably increases. However, there has been some slowing of increasing risks in older age groups.
Interestingly over the last 10 years, there have been several studies that show increasing incidence in younger ages which we quantify as 45 or younger. We're attributing this shift to the obesity and diabetes epidemic America is experiencing.
What are the dangers associated with stroke?
Pretty much everything associated with heart attacks increases the risk of stroke. Definitely hypertension, diabetes, smoking and even abnormal heart rhythms can increase the chance of a person having a stroke. It also ties in with sleep apnea, which is a disorder where people stop breathing while they're sleeping. Interestingly, even very bad gum disease and tooth decay can contribute to a person's risk of having a stroke.
There's also evidence showing migraines in certain situations can cause a stroke, but those with the highest risk are those who have had a TIA.
The better you can control your blood pressure, cholesterol levels and blood sugar levels, the better chance you have of significantly reducing your risk for stroke. With every patient I see, I have a list that we will go through. I go through the list each visit until I can cross off every controllable risk factor.
Those are equally as important as controlling hypertension and diabetes. Easy ones that most people recognize are smoking, obesity, lack of physical activity and abusing alcohol. It's difficult to quit smoking, but it's an absolute risk factor for stroke. We're trying to get the message out that the more you smoke, the more you stroke. There are benefits with decreasing the amount of smoking that are obviously not as effective as quitting, but if you can cut back moderately you're making inroads and are that much closer to stopping which is the ultimate goal.
Is stroke genetic? If a family member has a stroke, are you at a higher risk?
There's definitely a genetic basis for stroke, there's also a genetic basis for most of the risks: hypertension, diabetes, high cholesterol. When you look at stroke, there's definitely genetic preponderance with factors like smoking in a family where the parents have had strokes. However, even if you take away the shared environment, there's still a definitive genetic risk and our group is working on indentifying and sorting out that risk.
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