Transient Ischemic Attack
A person who suddenly experiences muscle weakness, difficulty walking, and coordination problems—all of which are symptoms of stroke—may be having what is called a transient ischemic attack (TIA). TIA (sometimes called a mini stroke) is a medical emergency has the same cause and symptoms as a stroke. But a key difference is that transient ischemic attack symptoms completely fade after a short period of time, without causing any lasting brain damage. It also serves as a warning sign of possible future strokes.
Many people who have a transient ischemic attack have strokes shortly thereafter—typically within a couple of days, although they may happen any time during the first three months after a transient ischemic attack.
Transient ischemic attacks are diagnosed most frequently in people aged 55 and older. They are more common in men than women.
What is a transient ischemic attack?
A transient ischemic attack is a brief occurrence during which blood flow to the brain is temporarily cut off, usually by a blood clot, but sometimes by a narrowed carotid artery. This causes stroke-like symptoms for a brief time, until the blood clot breaks apart or dissolves. Once blood flow to the brain is restored, the symptoms of the transient ischemic attack resolve, and no permanent brain damage occurs.
In healthy people, blood flows freely throughout the body, reaching the brain and other sites without incident. When someone has risk factors for transient ischemic attack, including high blood pressure, diabetes, and high cholesterol levels, their blood vessels may be narrowed, and blood clots are more likely to develop. If a blood clot lodges in a narrowed carotid artery, blocking blood flow to the brain, the person may experience the stroke-like symptoms of a transient ischemic attack.
It may be difficult to distinguish between a transient ischemic attack and a stroke, so it’s crucial to treat a transient ischemic attack like a medical emergency. Additionally, seeing a doctor quickly may help to reduce stroke risk after a transient ischemic attack.
What causes transient ischemic attack?
Transient ischemic attacks are often caused by blood clots that block the flow of blood to the brain. A blood clot may form within the brain, or a clot may travel to the brain from another location. Having narrowed arteries within the brain or leading to the brain may make it more likely for a blockage to occur. Damaged vessels that supply blood to the brain may also increase the risk of a transient ischemic attack.
People are more likely to have blood clots or narrowed blood vessels if they have:
What are the symptoms of transient ischemic attack?
People who experience a transient ischemic attack may have symptoms that mimic stroke symptoms, including:
- Muscle weakness, often on one side of the body
- Difficulty walking
- Coordination problems
- Memory loss
- Difficulty reading or writing
- Difficulty communicating thoughts to others
- Difficulty understanding other people’s thoughts
- Difficulty swallowing
- Vision changes, including vision loss
- Changes to hearing
- Feeling sleepy or less alert
- A tingling feeling on half of the body
- Loss of bladder or bowel control
What are the risk factors for transient ischemic attack?
People who are at increased risk of transient ischemic attack include those who have:
- Heart disease
- Metabolic syndrome
- Chronic kidney disease
- High blood pressure
- High cholesterol levels
- A sedentary lifestyle
- Poor blood circulation in the feet and legs
- A personal history of transient ischemic attack or stroke
- A family history of stroke
- A personal history of heart attack, blood clots, or irregular heartbeat (Afib)
- A personal history of preeclampsia during pregnancy
- Sleep apnea
- Rheumatoid arthritis
People who smoke, consume high levels of alcohol, or use illegal substances are also at increased risk.
How is transient ischemic attack diagnosed?
It’s possible to diagnose a transient ischemic attack based on your symptoms and medical history, but tests are often ordered to confirm the diagnosis. That’s why it is important for a person who is suspected of having a transient ischemic attack to seek immediate medical attention.
The doctor will ask if you have diabetes, high blood pressure, high cholesterol levels, kidney disease, or sleep apnea—and about a personal and family history of stroke or transient ischemic attacks. Additionally, you’ll be asked about the symptoms that occurred during the transient ischemic attack.
During a physical exam, doctors may look for lingering symptoms of the transient ischemic attack, and they may perform a neurological exam to check muscle tone and nerve function. They will listen to your heartbeat and may also place their stethoscope on the carotid artery to see if they can hear sounds demonstrating abnormal blood flow. The noises associated with a narrowed or blocked carotid artery—an indication of transient ischemic attack—sound different than healthy blood flow through that artery.
Doctors may also order tests, such as:
- MRI or CT scan, to examine the brain. If transient ischemic symptoms have resolved, they may not see the type of brain changes that would be present after a stroke.
- Ultrasound, to identify any blockages or see if the carotid arteries in the neck have narrowed.
- Angiogram, to examine blood flow within the brain, which may identify a blocked blood vessel.
- Electrocardiogram or other tests, to check for an irregular heartbeat.
How is transient ischemic attack treated?
Because transient ischemic attack can resolve on its own, there is no specific treatment for it; however, going to the emergency department as soon as possible is essential, because it may help to reduce the risk of an impending stroke. To ensure immediate medical attention, calling 911 is recommended, rather than driving or being driven to the hospital by a friend or family member.
To lower the risk of future stroke, doctors may prescribe medicine, such as:
- Blood thinners, to reduce the risk of blood clots
- Cholesterol-lowering medications, which may help to unclog arteries
- Medication to reduce blood pressure levels, which helps to lower stroke risk
- A variety of medications to control diabetes, which is a risk factor for stroke
Additionally, doctors may recommend lifestyle changes, such as:
- Eating a healthy diet
- Getting at least 30 minutes of physical activity daily
- Maintaining a healthy weight
- Quitting smoking
- Reducing alcohol intake
- Avoiding illegal substances
- Seeking treatment for sleep apnea
Some people may need minimally invasive surgical intervention to lower their risk of stroke after a transient ischemic attack. If a carotid artery is found to be narrowed, doctors may place a stent within the artery to widen it. In other cases, they may remove a blockage from the artery during a procedure called endarterectomy.
What is the outlook for people who have a transient ischemic attack?
Closely adhering to medical advice after a transient ischemic attack—including managing risk factors—will help people reduce their risk of stroke.
People who don’t seek medical attention for a transient ischemic attack—often because their symptoms disappeared quickly—are at high risk for a stroke within days or months of the initial attack.