What Is a Transient Ischemic Attack (TIA)?
Most people have heard of strokes, medically known as cerebral vascular accidents (CVAs), but not as many know what a transient ischemic attack (TIA) is. A TIA is often called a mini-stroke or a warning stroke. A mini-stroke has the same symptoms as a stroke, but they go away on their own within a few minutes to an hour. Although, they can last for up to 24 hours. TIAs are serious even though symptoms are transient, or temporary.
For many people, a TIA is a warning sign that a more serious stroke may occur. Every year, about half a million adults in the United States experience at least one TIA, almost as many as the 800,000 adults who have full strokes.
TIAs and strokes have the same causes. The most common type of stroke is an ischemic (ĭ-skee-mik) stroke: A clot or other substance blocks blood flow to the brain, depriving brain tissue of vital oxygen and nutrients. Most TIAs have the same cause, except unlike strokes, the blockage that causes a TIA moves or dissolves on its own before any permanent brain damage. Blood flow returns and the symptoms go away.
Ischemic strokes and TIAs are caused most often by atherosclerosis. This is a condition in which plaque—fatty deposits from cholesterol—has built up along the artery walls. The plaque can grow to block the artery, or a piece of plaque can break away and cause a blockage elsewhere along the artery, such as a smaller blood vessel in the brain.
According to statistics, about one-third of U.S. adults who have any type of stroke had at least one TIA beforehand, usually within a year. Up to 40% of people who had ischemic strokes had at least one earlier TIA. In addition, strokes that follow TIAs are often more severe than they are for people who do not have TIAs.
Other TIA causes include:
- Spasms in the arterial wall that temporarily blocking blood flow
- Too little oxygen in the blood transported to the brain, caused by such conditions as carbon monoxide poisoning, anemia, or leukemia.
Just like strokes, TIAs can affect anyone, although some people are at higher risk for TIA than others. For example, if you have a close family member who has had a stroke or TIA, you may be at higher risk.
Other risk factors include:
Being a man. More men have TIAs than women.
Being older than 55 years
Being African American or Hispanic
Having sickle cell disease
Smoking including prior smoking habit
Using recreational/illicit drugs
Heavy alcohol consumption
Consuming high-fat, high-salt diet
Using certain types of oral contraceptives or hormone replacement therapy
The only difference between stroke vs. TIA symptoms is with TIAs the symptoms disappear, sometimes as quickly as they appear.
The most common signs of a TIA are sudden onset of:
Difficulty speaking or understanding what is said
Visual disturbances, such as double vision or blindness
Lack of balance or inability to walk
TIAs are a medical emergency.
If you experience any TIA symptoms, this must be treated like a medical emergency even if the symptoms quickly disappear. Call 911 or have someone bring you to the closest emergency room. Don’t drive yourself in case you have another attack while you are behind the wheel. Once you arrive, explain your symptoms, how long they lasted, and if you have experienced anything like this before. Also, mention if you have any TIA risk factors (such as family history, hypertension, etc.).
In order to diagnose if you had a TIA, the ER staff will ask you what happened and about your medical history. A doctor will perform a physical examination and order tests to check for other conditions, such as migraines, diabetes, seizures or tumors, that may have caused the symptoms.
Tests could include:
Angiography to look for narrowed or blocked vessels in the brain or leading to the brain
Blood tests to check for high cholesterol, diabetes, and other possible conditions
Carotid ultrasound to measure blood flow to the brain
CT scan (computed tomography) or MRI (magnetic resonance imaging) to examine the brain for damage. Injecting a dye into the bloodstream during a brain MRI is a powerful and noninvasive way to diagnose poor blood flow to the brain. This procedure is magnetic resonance angiography (MRA).
EKG (electrocardiogram, or ECG) and other heart tests to evaluate heart health and function
Once your doctor has diagnosed a TIA, treatment is related to the probable cause. The first step is to reduce your risk factors, such as high blood pressure, uncontrolled diabetes, even being overweight. By reducing your risk factors, you lessen your chances of having another TIA—or possibly a stroke. There are several TIA treatments but the most common ones include:
Antiplatelet medications to reduce the risk of a clot forming in your blood vessels
Anticoagulants, also known as blood thinners, to help prevent blood clots through a different mechanism than antiplatelet drugs
Thrombolytic therapy with the ‘clot-busting’ drug alteplase (Activase) to dissolve the clot in the blood vessel
Surgery, if your carotid artery is too narrow due to fatty plaque deposits
Don’t ignore signs of a TIA. It’s true the symptoms will go away and you’ll recover quickly, but the TIA could be a warning of something much more serious to come. By recognizing the signs and symptoms of a TIA and getting treatment, you help decrease your chances of having a severe stroke. Likewise, if you have had a stroke, you are at higher risk for TIAs. If this happens, call 911 immediately. It could mean your treatment is no longer effective and you need a new treatment plan.