What's the difference between a mini stroke and a regular stroke? We asked doctors.

By Claire Gillespie
September 02, 2020
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President Trump has denied suffering a series of mini strokes, using his Twitter platform to declare it “fake news.” But what are mini strokes exactly? And how does a mini stroke differ from a regular stroke

What are mini strokes?

Officially called a transient ischemic attack (TIA), a mini stroke happens when the blood supply to part of the brain is temporarily interrupted. Despite its transitory nature, a mini stroke is a serious condition—and often serves as a warning that a person is at risk for a more serious (and potentially debilitating) stroke. According to the National Institute of Neurological Disorders and Stroke, about one-third of people who have a mini stroke have an acute stroke at some time in the future. 

What are the warning signs?

Mini stroke symptoms are similar to those of stroke, but they don’t last as long. They can include numbness of weakness in the face, arm, or leg (especially on one side of the body), confusion or difficult talking or understanding speech, vision problems in one or both eyes, and loss of balance and coordination. Most mini stroke symptoms disappear within an hour, although they may last for up to 24 hours. 

“Stroke symptoms generally come on suddenly, and time is of the essence,” South Florida cardiologist Adam Splaver, MD, previously told Health. “The American Stroke Association has come up with a good acronym, FAST, which is a mnemonic for the typical symptoms of a stroke. ‘F’ stands for facial drooping; ‘A’ for arm or leg weakness; ‘S’ for speech problems; and ‘T’ for time to call 911. The last one is not a sign, but an important step to take.”

A study published in the British Journal of Surgery in 2016 found that 59% of 150 study participants who’d had a mini stroke didn’t know what was happening at the time. Because so many people don’t realize they’re having a stroke, being aware of the FAST acronym is crucial.  

What causes stroke? 

A mini stroke and acute stroke have the same causes. Many factors can cause a stroke, and doctors are continually learning about new ones. “Since strokes are due to an interruption of blood flow, there are different ways in which blood flow can be problematic,” Cen Zhang, MD, vascular neurologist at NYU Langone Health, tells Health. 

One cause is related to the arteries, which carry blood to the brain. “If arteries are weakened, for example due to buildup of plaque (atherosclerosis), trauma, or inflammation, then the vessels can become narrow over time and blood cannot flow to the brain,” explains Dr. Zhang. 

Another cause is related to the heart, which pumps blood to the brain. “Certain types of structural heart disease or abnormal heart rhythms can weaken the heart,” says Dr. Zhang. “As a result, clots can form inside the heart and travel to the brain, causing a stroke.”

The blood itself can also be a problem, if it is thicker than usual and forms clots spontaneously. “Some conditions in which blood is thicker than usual include cancer, certain blood disorders, pregnancy, and the use of estrogen-containing contraceptives,” says Dr. Zhang. “But in about 25% of cases, we do not know the cause of the stroke.” 

Your risk of having a stroke increases as you get older, says the American Stroke Association. Stroke is more common in Black people and women, and if your parent, grandparent, sister or brother has had a stroke—especially before reaching age 65—you may also be at greater risk.

Can you prevent stroke? 

“Stroke is scary for many people because it seems—and often is—an unpredictable and mysterious event,” Amy L. Doneen, medical director of the Heart Attack & Stroke Prevention Center in Spokane, Washington, previously told Health. “The good news is these events are preventable.” 

Treating underlying risk factors can prevent many strokes. According to the National Institute of Neurological Disorders and Stroke, the most important treatable factors linked to stroke and mini stroke are high blood pressure, cigarette smoking, heart disease, carotid artery disease, diabetes, and heavy alcohol use. Working with your doctor can help you with treatment and lifestyle changes to reduce these risk factors. 

Eating a balanced diet with lots of fruits and vegetables, exercising regularly, and maintaining a healthy weight are also good steps to take to lower your stroke risk. 

How is a mini stroke treated? 

Because it’s impossible to tell whether symptoms are from a mini stroke or an acute one, it should always be treated as an emergency. In other words, don’t wait to see if your symptoms go away. 

The National Institute of Neurological Disorders and Stroke says an evaluation within 60 minutes of the onset of symptoms is required to identify the cause of a mini stroke, then decide what treatment is suitable. In some cases, a doctor may recommend drug therapy or surgery to reduce the risk of stroke in people who have had a mini stroke. Antiplatelet agents like aspirin are also given to patients at risk for stroke. Aspirin isn’t recommended for people with atrial fibrillation (irregular beating of the heart), so they may be prescribed anticoagulants. 

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