How to spot and respond to a "warning" stroke
A transient ischemic attack signals that a full stroke may be on the way. Get emergency care even if your symptoms fade quickly.
How to spot and respond to a "warning" stroke
Many people who have a first stroke received an earlier warning in the form of a transient ischemic attack (TIA), sometimes called a ministroke.
"TIAs typically bring on classic stroke symptoms, but because they are mild and brief, people tend to miss or dismiss them," says a stroke neurologist at a major Boston teaching hospital. "A TIA is your body flagging that you are at high risk of a full stroke - you need to listen."
Why TIAs happen
A TIA strikes when part of the brain gets too little oxygen-rich blood. Frequently the underlying problem is fatty plaque inside a neck artery such as the carotid, or in an artery within the brain. The plaque narrows the vessel and invites clots to form on top of it, choking healthy blood flow.
Another mechanism: a clot from the heart or carotid artery breaks loose and travels to the brain, briefly blocking a vessel there. A sudden fall in blood pressure can likewise cut flow through a narrowed artery enough to trigger a TIA.
Attacks last anywhere from 30 seconds to 20 minutes, with most running at least five. "Because TIAs pass quickly and leave no obvious lasting mark, it is easy to shrug them off," the neurologist notes. A TIA does not guarantee a future stroke - but it does mark you as high risk.
About one in five people with a suspected TIA will go on to have a full stroke within three months, according to a 2023 scientific statement from the American Heart Association. Danger peaks in the 48 hours after the first TIA.
Pinpointing the likely cause of a TIA early is the surest way to prevent a stroke. Since most TIAs involve a temporary clot in a narrowed brain artery, treatment usually opens with two antiplatelet drugs - aspirin and clopidogrel - or an anticoagulant to stop further clots forming.
Less often, a serious blockage in one of the two carotid arteries is to blame; that vessel needs opening through surgery or a procedure called endarterectomy.
Know the warning signs
TIAs can return with the same symptoms or different ones. The acronym BE-FAST helps people remember what to watch for. Most people notice one or more of these during an attack:
B: Balance. Balance trouble from a TIA can make standing difficult or send you toppling to one side.
E: Eyes. The commonest vision problem is losing sight in one or both eyes - often a dark grey curtain over part or all of the visual field. Blurred or double vision can also occur.
F: Face. One or both sides of the face may sag; typically the corner of the mouth pulls down and a normal smile is impossible.
A: Arm weakness. The most frequent symptom, usually on one side only, sometimes with numbness or tingling.
S: Speech difficulty. Slurred or garbled speech is most typical, though some people cannot find words or grasp what others say - and the trouble extends to writing and texting.
T: Time. Not a symptom but an instruction: call 911 or get straight to an emergency room, even if the symptoms lasted only a minute or two.