What is a transient ischemic attack?
A transient ischemic attack (TIA) happens when there is a temporary interruption in blood flow to the brain. Sometimes a TIA is called a mini-stroke.
TIA doesn’t cause permanent damage to the brain, but it is associated with a very high risk of having a major stroke in the future.
A TIA can occur when small pieces of debris (emboli), like blood clots, cholesterol deposits, or other foreign matter, travel through the blood and temporarily lodge in the small blood vessels in the brain.
When the debris interrupts the flow of blood to brain tissue, the tissue temporarily stops functioning until the debris dissolves.
What is the difference between a stroke and a transient ischemic attack?
TIAs are different from strokes in that they are brief and temporary.
Symptoms usually develop abruptly, can last a few minutes or hours, and go away in less than 24 hours. Blood flow is restored quickly enough so that brain tissue is not permanently damaged.
Most common symptoms
It is a common misconception that transient ischemic attacks aren’t dangerous. It is so crucial to talk to your doctor about symptoms or go to the emergency room if you think you are having a stroke, even if the symptoms disappear on their own. —Dr. Brian Walcott
The symptoms vary widely depending on the portion of the brain affected (any part of the brain can be affected). See your doctor immediately if you have any of these symptoms:
What causes a transient ischemic attack?
The emboli (debris) that get stuck in blood vessels and cause a TIA are commonly related to atherosclerosis. Atherosclerosis develops when plaque, which is a buildup of fatty deposits, forms inside the large arteries that travel to the brain.
Emboli can also originate from clots in the heart or from debris on heart valves. Certain abnormal heart rhythms, such as atrial fibrillation, are associated with a higher risk of blood clot formation and stroke.
Who is at risk?
A TIA means you are at an increased risk of having a future stroke, according to the National Institutes of Health.
Almost half of people who have had an ischemic stroke had at least one TIA some months before their stroke. But not all people who have TIAs will have a stroke.
TIAs are more likely to occur in people with:
- High blood pressure
- Certain types of heart disease
- People who smoke
- People who are of an advanced age
- Abnormal heart rhythm such as atrial fibrillation
- Blood clotting disorders
- Sickle cell disease
What happens after a TIA?
If you are having a TIA, it is common to be hospitalized so you can get a quick evaluation and needed tests.
The doctor will first check for other conditions that can mimic a TIA or stroke, including:
- Low blood sugar
- Low blood pressure
- Brain tumor
- Irregular heart rhythms
- Labyrinthitis (an inner ear disorder)
If you have recurring TIAs with symptoms that are always the same, it means you probably have a recurring blockage of the same artery. If the symptoms vary from one TIA to the next, emboli may be blocking different arteries each time.
While it doesn’t seem like it at first, TIA can sometimes be a very fortunate thing. By bringing attention to a major risk factor, like a severe blockage in an artery going to the brain, it is usually possible with treatment to avoid a major stroke in the future. —Dr. Walcott
You will be given several tests to determine the cause of the TIA. Common tests include examining the brain for signs of stroke with computer tomography (also known as a CT scan) and/or magnetic resonance imaging (MRI).
Further tests can be done to look for blockages in the arteries of the neck with CT, MRI, or ultrasound. Heart rhythms are analyzed with an EKG and the structure of the heart can be assessed with ultrasound (echocardiogram). Sometimes no obvious cause of the TIA is found.
Once the diagnosis of TIA is made, your doctor will focus on preventing a future stroke. They may give you blood thinning medications.
If there is a severe partial blockage in the arteries of the neck (the carotid artery), you may need a procedure to re-establish good blood flow in the vessel to prevent a stroke in the future. This can be done with surgery to remove the plaque blockage (carotid endarterectomy) or by implanting a stent (carotid artery stenting).
In general, the best prevention of TIA is to maintain a healthy lifestyle and focus on limiting risk factors.
- Quit smoking if you smoke.
- Control high blood pressure.
- Control blood sugar levels if you have diabetes.
- Get regular exercise (150 minutes a week).
- Lose weight if you’re overweight or maintain a healthy weight.
- Try to treat high cholesterol through diet, exercise, and medications.
- If you have specific risk factors such as a partial blockage of blood flow in your carotid artery or an abnormal heart rhythm, blood thinners or procedures may be necessary to prevent a TIA and stroke.