If you suddenly notice a strange but fleeting symptom – your arm or face suddenly feels weak or numb – you might be tempted to brush it off, especially if it’s short-lived.
However, if these strange, unexplained symptoms last longer than a few seconds, they can signal a transient ischemic attack, or TIA. A TIA, commonly known as ministroke, is caused by a temporary lack of blood in part of the brain. Most of the time, a blood clot is to blame and symptoms quickly resolve as your body’s natural anticoagulant properties restore blood flow. However, according to the American Stroke Association (ASA), these events should be labeled as warning strokes rather than mini-trokes.
“A TIA can herald a much more severe stroke,” says Dr. Christopher Anderson, director of acute stroke services at Harvard-affiliated Massachusetts General Hospital. If a blood clot blocking a cerebral artery doesn’t dissolve and stays in place for more than a few minutes, it can destroy brain cells by depriving them of oxygen and nutrients. Known as ischemic strokes, these strokes account for 87% of all strokes. Up to 17% of people with TIA will have a full ischemic stroke within the next 90 days, with the greatest risk in the first week.
What should you understand about TIAs?
A recent study found that women with short-lived sensory or visual symptoms were less likely to be diagnosed with TIA compared to men. One reason could be that migraines are more common in women. As a result, women with sensory or visual changes that may or may not occur with a migraine headache are more likely to have both women and doctors suspecting a TIA. “However, it’s important to consider a TIA in all people with these symptoms, regardless of their gender,” says Dr. Anderson.
Other short-lived TIA symptoms can be easily dismissed, says Dr. Anderson. “Sometimes people say, ‘This is funny, I can’t feel either side of my face’ and mutilate their words for a short time,” he says. People can drop objects (such as cookware) repeatedly but can return to normal functioning after a few minutes. Another classic TIA symptom is seeing a curtain, often referred to as a dark curtain, falling over one eye from top to bottom. This symptom is called amaurosis fugax (from the Greek) Amaurosiswhich means dark, and the Latin Fugaxwhich means fleeting).
FAST in detecting a stroke or a TIA
The ASA coined the mnemonic FAST to help people identify stroke symptoms. The first three letters that stand for F.Ace hanging, ONErm weakness and S.Peech difficulties account for about 75% of the symptoms that occur in a stroke. (The T stands for T.I’ll call 911.)
However, some neurologists suggest adding two extra letters: B for balance and E for eyes. Balance is difficult because imbalance can occur from a number of issues other than stroke, especially in the elderly, says Dr. Anderson. In a stroke, imbalance rarely occurs in isolation. They usually come along with other symptoms like weak legs or poor vision, he explains. Vision problems during a TIA or stroke can include reduced, blurred, or double vision.
The simpler FAST makes sense for a public health campaign. However, if you are at risk, knowing BE-FAST might be the most helpful as it may help you identify even more potential TIAs and strokes. High blood pressure is the number one cause of strokes. Other risk factors include smoking, diabetes, physical activity, and obesity. People with heart disease (such as coronary artery disease, atrial fibrillation, and heart failure) are at an above-average risk of stroke. Talk to your doctor about your risks for stroke or TIA and about healthy measures you can take to reduce the chances of having either one.