What Is a “Mini” Stroke?

A “mini” stroke may not cause permanent brain damage, but it’s a warning sign that you could be at risk for a debilitating—or deadly—stroke.

Approximately one in three American adults has experienced a symptom consistent with a “mini” stroke, sometimes called a transient ischemic attack (TIA). Yet, only three percent sought medical care, according to a 2017 study from the American Heart Association.

Ignoring these symptoms could have deadly consequences, says Dr. Mitchell Elkind, an attending neurologist on the stroke service at NewYork-Presbyterian/Columbia University Irving Medical Center. “A TIA is considered a warning sign for a stroke,” says Dr. Elkind. Once you’ve had a TIA, there’s a 10 percent chance you’ll suffer a full-blown stroke within the next three months. However, the greatest risk is in the first couple of days after a TIA, according to Dr. Elkind, who notes that five people out of 100 who’ve had a TIA are going to have a stroke within just two days. “The best way we’re going to prevent future problems is if a person acts quickly, so we can determine and treat the underlying cause.”

In time for World Stroke Day on Oct. 29th, Health Matters spoke with Dr. Elkind—who also serves as immediate past-president of the American Heart Association—about how to spot the warning signs of a TIA, how to respond if you or a loved one suffers one, and what you can do to help reduce the risk of having a stroke.

What is a TIA?
TIA stands for transient ischemic attack, sometimes known as a “mini” stroke. Most strokes are due to a blockage in a blood vessel that leads to an injury in the brain. A TIA is like a stroke that stopped before any permanent damage was done. This means there is a temporary cessation of blood flow causing dysfunction of the brain, but the blood flow is restored before there’s any permanent damage to the brain.

What’s the difference between a TIA and a full-blown stroke?
With a TIA, the symptoms are usually pretty short-lived. The person might have a drooping face and weakness of the arm on the same side of the body, but it will last only 5 to ten minutes, go away and the person will look and feel completely normal. With a full-blown stroke, the decrease in blood flow goes on for a longer period of time.

What we’ve learned, though, from more modern imaging techniques like MRI—which is sensitive to the earliest signs of a stroke—is that even people who have very brief spells, lasting just five or 10 minutes, do have evidence of permanent damage to the brain about half the time. So, these brief spells that we used to call TIAs are now actually referred to as strokes. The important thing is finding out what made this spell happen and what we can do to prevent the person from having a potentially large, disabling stroke.

If the symptoms resolve quickly, how does a person know they’ve suffered from a TIA and not something less dangerous?
A TIA is a transient event. Because the symptoms go away quickly, people are reassured and assume everything is okay. For that reason, people may attribute their symptoms to something else, like a migraine, a pinched nerve or an inner-ear issue that causes dizziness. When the symptoms are new or different from anything that you’ve experienced before, if they’re severe, or if they come on very suddenly, it’s important to get medical attention right away.

If you can’t come up with an obvious alternative explanation for your symptoms, then you should go to the emergency room and get it checked out because it can be the first sign of a more serious problem. Unfortunately, there’s no real way to know for sure unless you get it checked out.

Do we know what causes a TIA?
There are many different causes of a TIA, and the causes are essentially the same as those for stroke and heart disease. High blood pressure is the most important cause of strokes and TIAs. Heart diseases are also a common cause of stroke, especially heart rhythm disturbances like atrial fibrillation or an irregular heart rhythm. What happens in that situation is that the heart is not beating regularly, so instead of the blood flowing quickly through the heart, it can form little eddy pools inside the chambers of the heart. Those eddy pools can lead to the formation of blood clots. Those little blood clots can travel through the blood vessels, and when they get into a small enough blood vessel in the brain, they block it up and stop the blood flow, causing a stroke.

Another major cause is a narrowing in one of the arteries of the brain, particularly the carotid artery that comes up from the neck. This is the blood vessel that everybody can feel pulsing in their neck, carrying blood to the brain. A narrowing in a blood vessel is called a stenosis. With time and aging and certain risk factors, like high blood pressure and diabetes, the carotid and other vessels can narrow, and this leads to decreased blood flow to the brain. Sometimes it closes off completely and that can then lead to a stroke.

Who is most at risk for a TIA?
People who suffer from things like high blood pressure, diabetes, high cholesterol, smoking, sedentary lifestyle or inflammation are at risk. All of these conditions can gradually lead to damage to the heart or blood vessels over time.

There is also a misconception about strokes and TIAs that they only affect older people. We have seen an increase in strokes in younger people as well. We think part of the reason for that is a change in the occurrence of risk factors in younger people. We know that there’s an obesity epidemic in the country, and there’s a lot of sedentary behavior. People aren’t getting enough activity and exercise. So, we’re seeing the occurrence of things like high blood pressure and diabetes in younger and younger people. Along with that come the complications, which include strokes and TIAs. So, at the public health and national level, that’s a major concern.

“There is also a misconception about strokes and TIAs that they only affect older people. We have seen an increase in strokes in younger people as well.”

— Dr. Elkind

How do you treat a TIA?
When somebody shows up in the emergency room with symptoms that may be consistent with a TIA or stroke, the first thing that will happen is that they will get a CAT scan or CT scan of the head. The main reason for doing that is to rule out bleeding in the brain or a hemorrhage. Strokes come in two major varieties. One is the blockage in the blood vessel. That’s what we call an ischemic stroke. The other is a hemorrhagic stroke which is due to bleeding from a blood vessel. Those are usually more severe, but rarely do people have the same kind of transient spells from a small hemorrhage. So, a CT scan is done to determine whether there’s been bleeding or something else in the head.

If there’s no evidence of bleeding and the symptoms are persisting, then the person may be a candidate for what we call thrombolytic therapy, or tPA, which is a medicine that can dissolve blood clots. They would need to get that within just a few hours after the stroke occurs to be effective. If this were a larger stroke and there were evidence of blockage in one of the large blood vessels in the brain, then the person might be taken for an interventional procedure—what we call a thrombectomy—which is the removal of a blood clot from that large blood vessel in the brain.

Headshot of Dr. Elkind

Dr. Mitchell Elkind

What kind of treatment do you offer if you don’t know the cause of the TIA or stroke?
Even after a thorough evaluation looking for heart problems and blood vessel problems and so forth, about a third of strokes are of undetermined cause. Most of those, we think, are due to a blood clot that came from the heart, but we haven’t been able to pin down the cardiac problem or the heart problem that caused the clot. The standard of care is to have the patient take aspirin to thin the blood, a cholesterol medicine or blood pressure medicine. About thirty percent of patients who suffer from an unexplained stroke will eventually have evidence of a heart rhythm disturbance like atrial fibrillation, but that means about seventy percent won’t. We’re doing a clinical trial right now called ARCADIA among people who have had an unexplained stroke to determine the best treatment for other underlying heart conditions that cause stroke. This will eventually allow us to more broadly screen people who have never had a stroke to see if they have similar underlying heart conditions and reduce their risk of having a stroke.

How can someone reduce their risk of having a stroke or TIA?
There are a lot of great ways to prevent having a stroke in the first place. Leading the pack is physical activity. The American Heart Association recommends 150 minutes, or 30 minutes for five days a week, of at least moderate intensity aerobic exercise. It could be riding a bike or jogging or playing tennis or things of that nature. If you have arthritis or other issues where you may not be able to engage in this level of activity, you could walk for half an hour a day. Whatever you can do to get up and get moving is going to be a great way to reduce the risk of a stroke.

Also, eating properly—I tell my patients to eat plenty of fruits and vegetables. Avoid concentrated sweets and processed foods. For protein, fish is good. Poultry is good, especially if you take off the skin, and limiting red meat ideally to no more than one time a week. People should drink water as much as possible. Seltzer is good, too. Avoid sugar-sweetened beverages. Even diet sodas and diet drinks may carry some risk with them. With regard to alcohol, we tell people no more than one drink a day for women and no more than two drinks a day for men.

I recommend getting your blood pressure checked, getting cholesterol levels checked and making sure that you’re not developing problems with blood sugar. And, of course, avoid smoking any tobacco products. We’ve seen the kinds of problems that vaping can cause to the lungs. And any tobacco products are potentially risky and should be avoided.

Mitchell Elkind, M.D, M.S, FAAN, FAHA, is an attending neurologist with NewYork-Presbyterian/Columbia University Irving Medical Center, a professor of neurology at Columbia University Vagelos College of Physicians and Surgeons, a professor of epidemiology at Columbia University Mailman School of Public Health, and immediate past-president of the American Heart Association. He is only the second neurologist to have been named president of the AHA. He is also a principal investigator of the ARCADIA trial, a joint Columbia University and Weill Cornell Medicine trial, funded by the National Institutes of Health, testing the hypothesis that the blood thinner apixaban will be more effective than aspirin in preventing second stroke among patients with unexplained stroke and atrial cardiopathy.

Additional Resources

  • Learn more about stroke services at NewYork-Presbyterian.