Transient Ischemic Attack

A transient ischemic attack (TIA), sometimes called a mini-stroke, is a sudden, short-lived neurological condition. It is caused by a small, temporary blockage in one of the blood vessels that carries blood to the brain.

Common transient ischemic attack signs and symptoms include temporary loss of vision, slurred speech and weakness of the face, arm or legs. The attack itself usually passes within a few minutes, and symptoms generally clear within an hour of them first appearing. 1

The swift recovery time of a transient ischemic attack is what differentiates it from an ischemic stroke. In an ischemic stroke, the blockage tends to last for more than a few minutes and can cause long-term damage to the brain. 2 This is why a transient ischemic attack is often referred to as a mini-stroke.

Although a TIA does not usually cause permanent damage to the brain, in some cases it can be a warning sign that a full-blown stroke may occur in the near future. 3 Treatment often aims to prevent further attacks or strokes through medication, lifestyle changes and, in certain cases, surgery. People, who suspect that they may have had a transient ischemic attack, should treat it as a medical emergency and immediately discuss their symptoms with a doctor.

The symptoms of a transient ischemic attack tend to arrive and leave quickly. Symptoms usually peak within the first minute of their appearance and then disappear within an hour. Common signs of a transient ischemic attack or mini-stroke include: 1 4 5 6

• Weakness or paralysis of the face, arm or leg, usually on one side of the body
• Loss of vision
• Slurred speech, also known as dysarthria
• Difficulty finding words, also known as dysphasia
• Loss of balance
• Impaired memory
• Confusion
• Behavioral changes
• Headache

However it should be noted that these symptoms are usually different from person to person, and a person may not experience all of these symptoms. This is because a blood vessel blockage can affect different parts of the brain, and different parts of the brain control different parts of the body. 1

Although transient ischemic attack symptoms typically disappear within an hour and leave no lasting neurological damage, an attack signifies a greater risk of a stroke happening in the future. The American Stroke Association estimates that around a third of people who experience a transient ischemic attack go on to suffer a more severe stroke within a year. 3 Strokes can result in long-lasting damage and, in the most serious cases, even death, so it is important to always consult a doctor if a transient ischemic attack is suspected.

Good to know: The initial symptoms of a TIA can be identical to that of an ischemic stroke. It is crucial to visit a doctor without delay, even if symptoms appear to have passed.

A TIA is most often caused by a small, temporary blockage in an artery that carries oxygenated blood to the brain. This blockage causes a part of the brain to be temporarily without oxygen, resulting in the symptoms of a transient ischemic attack.

The blockage is usually a blood clot that becomes lodged in the artery. Blood clots typically develop when tiny particles in the blood, known as platelets, stick to fatty deposits called plaques. 1

The cause of a transient ischemic attack is identical to the cause of an ischemic stroke. However, in a transient ischemic attack, the blood clot tends to break up quickly, and the affected part of the brain is only without oxygen for a few minutes at most. 5

A transient ischemic attack can affect anyone, but there are a number of risk factors that may increase the risk of an attack occurring.

The following risk factors for a TIA or mini-stroke cannot be modified, but it is still important to know what they are in order to assess overall risk: 5 7 8 9

• Age. Being older than 55 years of age. Although TIAs are more common among the elderly, they can occur at any age
• Genetics. Having a family history of transient ischemic attacks or strokes
• Gender. Being male. Men are slightly more likely to have a transient ischemic attack than women
• Ethnicity. Being of a certain ethnic background. Transient ischemic attacks are more likely to affect African-American people, and are more likely to affect Hispanic people at a younger age than those of non-Hispanic background

Transient ischemic attacks are also more likely to occur in people with certain medical conditions, including: 4 5 7 8 9

• High blood pressure, known as hypertension
• Diabetes
• Obesity
• Heart disease
• Abnormal heart rhythm, known as atrial fibrillation
• High cholesterol
• Sickle cell disease
• Carotid artery disease (CAD) and peripheral vascular disease (PVD)
• High levels of fats or lipids in the blood, known as dyslipidemia
• Predisposition to the formation of blood clots, known as thrombophilia or hypercoagulability
• Inflammation of the blood vessels, known as vasculitis

In addition to the above, there are a number of controllable lifestyle factors associated with an increased risk of transient ischemic attack: 4 5 7 8 9 10 11

• Smoking. Cigarette smoking can raise blood pressure and increase the risk of blood clots forming
• Diet. High-salt, high-fat, high-calorie foods may increase the risk of TIA
• Excess alcohol. The U.S. Department of Health and Human Services defines moderate alcohol consumption as no more than one alcoholic drink a day for women or two drinks a day for men. High alcohol consumption can be linked to high blood pressure, diabetes and weight gain
• Lack of exercise. Physical inactivity can lead to high blood pressure, high cholesterol and weight gain
• Birth control pills. Oral contraceptive pills have been linked to an increased risk of ischemic strokes, although the risk is very low

Good to know: Having one or more of the above risk factors will not automatically result in a transient ischemic attack occurring. However, because the possibility of an attack directly increases with these risk factors, many treatment methods center around minimizing the risk factors that can be controlled, such as exercise, diet and smoking.

As symptoms of a transient ischemic attack usually resolve within an hour, diagnosis is often made retrospectively. 4 Even if symptoms appear to have passed, it is crucial to visit the doctor for a prompt, proper diagnosis.

The diagnosis of a transient ischemic attack often begins with questions about the symptoms experienced and a physical examination. This may include: 1 4 12 13

• Tests for the existence of known risk factors such as high blood pressure
• Neurological tasks to test coordination, strength and understanding
• Eye examination to detect any blockage in the blood vessels at the back of the eye
• Audial examination of the neck using a stethoscope, to detect a murmuring sound in the arteries known as a bruit

Referral to a specialist doctor or neurosurgeon might be made for further tests to take place. Such tests may include: 1 4 12 13

• Neuroimaging tests, such as a CT scan or MRI scan to generate a 3D image of the brain
• Blood tests to check for clotting, diabetes and and cholesterol levels among others
• Vascular ultrasound, which uses non-invasive sound waves to detect abnormalities in the arteries and veins
• Echocardiogram, which also uses non-invasive sound waves to scan the heart and nearby blood vessels
• Electrocardiogram (ECG), which uses small electrodes to monitor the heart’s rhythm and electrical activity

Diagnostic procedures will vary from person to person, depending on their individual circumstances and medical history. However, the aims of these procedures are: 1

• To confirm the diagnosis of a transient ischemic attack, rather than a stroke
• To determine which underlying medical factors may have caused the attack
• To identify and prevent factors which may increase the risk of a mini-stroke or stroke happening in the future

Once a transient ischemic attack diagnosis has been made, treatment methods usually aim to reduce both the short and long-term risk of another attack taking place by addressing any associated medical issues. 14

Prescription drugs are typically used to reduce the possibility of blood clots forming. Precise medications will depend on the affected person’s own circumstances, but doctors may prescribe: 1 4 12 15

• Antiplatelet drugs such as aspirin or clopidogrel. These reduce the stickiness of platelets in the blood, therefore reducing the risk of blood clots forming
• Anticoagulant drugs such as warfarin, dabigatran or rivaroxaban. These work by blocking the production of certain proteins that cause blood clotting
• Medication for other risk factors such as statins to treat high cholesterol, or antihypertensives to treat high blood pressure

Certain risk factors for transient ischemic attacks can be reduced through simple lifestyle alterations, such as: 10 12 16

• Stopping smoking, as cigarettes can raise blood pressure, damage the arteries and increase the risk of blood clots forming
• Eating more fresh fruit and vegetables as part of a low-fat, low-salt, balanced diet
• Reducing alcohol intake. The U.S. Department of Health and Human Services recommends a maximum of one alcoholic drink a day for women or two drinks a day for men
• Exercising more often. Around 30 minutes of moderate physical exercise a day can lower blood pressure and cholesterol
• Control of other existing medical conditions such as high cholesterol, high blood pressure, atrial fibrillation and diabetes

In some cases, a surgical procedure called a carotid endarterectomy may be suggested. This is only recommended for certain people who have a severe narrowing of the carotid artery in the neck. 17

Narrowing of the carotid artery is typically due to fatty deposits, known as atheroma or plaque, building up in the arterial walls and restricting blood flow to the brain. A carotid endarterectomy involves opening up the affected artery and removing the buildup of plaque. The procedure usually takes between one and two hours and is done under anesthetic. 18

Although a TIA typically lasts only a few minutes and causes no permanent damage, it can be a warning sign that the affected person may suffer a more severe ischemic stroke in the near future. Ischemic strokes can result in a number of complications, and therefore transient ischemic attacks also require urgent medical attention.

Q: What is the difference between a transient ischemic attack and a stroke?
A: A transient ischemic attack is often referred to as a mini-stroke, because it shares many of the same causes, symptoms and risk factors as an ischemic stroke. However, the outcomes can be very different.

Both are caused by a blockage in the bloodstream, resulting in restricted oxygen flow to the brain. In a transient ischemic attack, the blockage usually dissolves, and the symptoms clear within an hour. However, in an ischemic stroke the blockage remains long enough to cause significant damage to the brain, long-term disability and may possibly even be fatal.

A transient ischemic attack can be a warning sign that an ischemic stroke may happen in the near future. Therefore, both should be classed as medical emergencies and receive urgent medical attention.

Good to know: There is another type of stroke, called a hemorrhagic stroke. Hemorrhagic strokes and ischemic strokes share some of the same symptoms but have completely different causes and treatments. A hemorrhagic stroke is usually caused by a bleed in the brain. 19

Q: What are the signs of a transient ischemic attack?
A: Signs of a transient ischemic attack can vary depending on which part of the brain is affected, but the most common symptoms include:

• Weakness or paralysis of the face, arm or leg
• Problems seeing properly, or other visual disturbances
• Speech difficulties
• Loss of balance

Q: How long does a transient ischemic attack last?
A: Transient ischemic attack symptoms usually clear within a few minutes. Although the recovery time appears to be quick, urgent medical attention should still be sought, even if the symptoms have passed.

Q: Is it necessary to see a doctor after a transient ischemic attack?
A: Yes. Transient ischemic attacks are classed as medical emergencies, and urgent medical intervention is required.

Q: Are there long-term effects of a transient ischemic attack?
A: Transient ischemic attacks on their own do not usually cause any long-term damage or long-term disability. However, they can be a warning sign that the affected person may suffer a more severe stroke in the future, or that the person may have another underlying condition, like a heart problem, which is why it still requires urgent medical attention.

Transient ischemic attacks may also be referred to as:

• TIAs
• Mini-strokes
• With the slight spelling variation of transient ischaemic attacks