A "mini-stroke" or "transient ischemic attack" (TIA) occurs when there is a temporary drop in the blood supply to the brain; this can be caused by a variety of reasons, and deprives the brain of oxygen. The patient experiences stroke-like symptoms, although they don't last as long.
In other words, a TIA is like a stroke, produces similar symptoms, but only lasts a few minutes and causes no permanent damage.
It is estimated that up to 500,000 people in the United States experience a TIA each year.
Although symptoms fade away rapidly, most patients do not seek medical help. Between 10 and 15 percent of TIA patients have a full-blown stroke within 3 months. This is why recognizing the signs of a TIA and seeking medical attention is important.
Rapid evaluation and treatment of patients who experienced a mini-stroke, either in specially designed TIA clinics or the emergency room, can significantly reduce the risk of subsequent stroke.
Contents of this article:
Fast facts on transient ischemic attack (TIA)
Here are some key points about transient ischemic attack (TIA). More detail and supporting information is in the main article.
- A mini-stroke occurs when blood is temporarily cut off to regions of the brain
- Around 500,000 Americans have a stroke each year
- Rapid care is essential to minimize the medical implications of a stroke
- The object of TIA treatment is to prevent further occurrences
- One of the most common drugs used to prevent TIAs is warfarin, an anticoagulant medication
Symptoms of a TIA (mini-stroke)
The acronym FAST represents the signs and symptoms of stroke.
The signs and symptoms of a TIA are represented by the abbreviation FAST (Face, Arms, Speech, Time):
- Face - the face may fall on one side as some of the facial muscles become paralyzed. The patient's eye or mouth may droop, and they may be unable to smile properly.
- Arms - arm weakness or numbness might make it hard for the patient to either raise both arms, or to keep them raised.
- Speech - speech may be slurred and garbled.
- Time - if just one of these symptoms are present, it is time to dial emergency services.
Being able to identify the signs and symptoms present in FAST is especially important if you live with somebody in a high risk group, such as an elderly person, or an individual with hypertension (high blood pressure) or diabetes.
Other signs and symptoms of a TIA can include:
- Difficulty talking
- Difficulty understand what others are talking about
- Swallowing difficulties
- Very bad headache
- Paralysis, numbness, or weakness on one side of the body
- In severe cases, loss of consciousness
If you or somebody else has any of these signs and symptoms, medical attention should be sought immediately.
TIA symptoms are temporary and should disappear within 24 hours. They may last from a couple of minutes to 15 minutes. TIA sufferers experience varying symptoms, depending on which part of the brain is affected.
In some cases, a TIA may be a prelude to a full stroke, in which case permanent and possibly serious damage occurs. Prompt medical attention and treatment significantly reduces the risk of experiencing another TIA or stroke.
If you think that you, or somebody else is having a TIA, get medical attention immediately.
Causes of a TIA
- Disruption of blood supply to the brain: Two main blood vessels - the carotid arteries - supply blood to the brain. These arteries branch off into many smaller blood vessels. A TIA can occur if one of the smaller blood vessels becomes blocked, depriving that part of the brain of oxygen-rich blood.
- Atherosclerosis: Atherosclerosis causes arteries to narrow (stenosis). Fatty deposits (plaque) develop on the inner lining of blood vessels, causing them to become hardened, thickened, and less flexible - resulting in more difficulties with blood flow.
- Blood clots: A blood clot can disrupt the supply of oxygen-rich blood to parts of the brain Blood clots are usually caused by:
- Heart conditions - congestive heart muscle disease or atrial fibrillation
- Blood conditions - leukemia (blood cell cancer), sickle cell anemia, hyperlipidemia (high blood fat levels), polycythemia (very thick blood), or thrombocyemia (overproduction of blood platelets)
- Infections - phlebitis can cause blood clots
- Hemorrhage (internal bleeding): A minor brain hemorrhage (small amount of bleeding in the brain) can cause a TIA; however, this is rare.
Risk factors for TIA
Risk factors for TIA include ethnic origin, age, and family history.
There are some risk factors we can change, and others we cannot.
Risk factors we cannot change:
- A family history - people with a close relative who has had a stroke or TIA
- Age - people aged over 55 have a higher risk
- Sex - males have a slightly higher risk
- Ethnic origin - people of black African ancestry have a higher risk
Risk factors we can change:
- Hypertension - people with high blood pressure.
- Cardiovascular disease - people with cardiovascular diseases have a higher risk. This includes a heart defect, heart failure, or arrhythmia (abnormal heart rhythm).
- Carotid artery disease - this is when the blood vessels in the neck that lead to the brain are clogged.
- PAD (peripheral artery disease) - people whose blood vessels that carry blood to their arms and legs become clogged have a higher risk of stroke and TIA.
- Smoking - smoking increases the risk of various diseases and conditions, including TIA and stroke.
- Sedentary lifestyle - people who are physically inactive have a significantly higher risk.
- Diabetes - patients with diabetes are more likely to suffer from atherosclerosis (narrowing of the arteries due to a buildup of fatty deposits).
- Bad diet - people who consume too much bad quality fat and/or salt have a higher risk of stroke and TIA.
- Blood cholesterol levels - if blood cholesterol levels are high it increases the risk of TIA or stroke.
- Homocysteine levels - homocysteine is an amino acid produced by the body. It is usually a byproduct of consuming meat. Elevated levels of homocysteine in the blood can make the arteries thicken and scar, and more susceptible to clogs.
- Bodyweight - obese people have a significantly higher risk.
- Alcohol - people who drink large quantities of alcohol regularly.
- Illegal drugs - some illegal drugs, such as cocaine, can raise the risk of stroke or TIA if taken often enough.
Diagnosis of TIA
Anybody who has signs and symptoms of a TIA should seek medical attention immediately. As TIAs do not last very long, it is most likely the patient will have no symptoms by the time they get to see the doctor. Try to bring someone who witnessed the event with you, so that they may share what symptoms they may have noticed.
The doctor may need to carry out a neurological examination, even if symptoms have gone. This will include some simple tasks to check skills, such as memory and coordination.
While being examined, the patient will be asked questions regarding symptoms, such as how long they lasted, what they were like, and how they affected the patient. This will help the doctor discard any other conditions that may have similar symptoms.
If the doctor believes the patient might have had a TIA they will be referred to a neurologist for further testing.
The specialist may order a number of tests designed to identify the underlying factors that may have caused the TIA.
- Blood tests
A number of tests may be necessary to fully understand the neurological causes of the TIA.
- Electrocardiogram (ECG) - records the electrical activity and rhythms of the heart.
- Echocardiogram - an ultrasound scan that checks the pumping action of the patient's heart.
- Chest X-ray - this helps the doctor rule out other conditions.
- CT scan - creates a 3D image that can show aneurysms, bleeding, or abnormal vessels within the brain.
- MRI scan - generates a 3D view of the brain. An MRI can often give a more detailed view of the brain than a CT scan, and can help the doctor identify any brain damage.
- Ultrasound - a wand waved over the carotid arteries in the neck can provide a picture that indicates any narrowing or clotting.
Treatment options for TIAs
The doctor may prescribe medication which lowers the risk of a blood clot, or recommend surgery or an angioplasty; this will depend on the cause of the TIA.
The type of medication prescribed will depend on what caused the TIA, how severe it was, and what part of the brain was affected.
- Anti-platelet drugs - these make platelets in the blood less likely to stick together.
- Aspirin and dipyridamole - make the platelets less sticky and lower the risk of undesirable blood clots. Some doctors may prescribe Aggrenox - this drug contains both aspirin and dipyridamole, another anti-platelet medication. Some doctors may recommend ticlopidine (Ticlid).
Side effects of aspirin can include:
- Ringing of ears
- Stomach irritation and bleeding
- Clopidogrel - the doctor may prescribe clopidogrel (Plavix) if the patient experienced severe side effects from taking aspirin, had a further TIA despite taking aspirin, or has arterial disease. Side effects of clopidogrel may include:
- Abdominal pain
- Anticoagulants - examples of anticoagulants are warfarin (Coumadin) and heparin. Warfarin can be used long-term, while heparin is used short-term. The most serious undesirable side effect of warfarin is bleeding. Any patient on warfarin who has any of the following symptoms should tell their doctor immediately:
- Blood in urine
- Blood in feces (either specs of blood, or feces are black)
- Severe bruising
- Nosebleeds that persist for more than ten minutes
- Blood in vomit
- Coughing up blood
- Unexplained headaches
- Bleeding from the vagina
- Heavy or increased bleeding during menstruation
- Medications for hypertension - hypertension needs to be controlled as it is an important risk factor for stroke and TIA. There are many different types of antihypertensive drugs. If the patient is unfit and overweight hypertension can often be brought down by losing weight, doing exercise, getting at least 7 hours good quality sleep every night, and eating a well-balanced healthy diet.
- Cholesterol medication - high blood cholesterol levels significantly increase a patient's risk of stroke and TIA. As with hypertension, losing weight, following a well-balanced diet, doing regular exercise, and sleeping at least 7 hours every night can help bring cholesterol levels back to normal. Sometimes medications are necessary and the patient may be prescribed a statin, which helps reduce the production of cholesterol.
Surgery - Carotid endarterectomy
Smoking is a significant risk factor in strokes.
This operation involves removing part of the lining of the damaged carotid artery, as well as any blockage that has accumulated in the artery.
This operation is not suitable for patients whose arteries are nearly completely blocked. Even some patients with partial blockage may not be suitable for this procedure because of the risk of stroke during the operation.
Prevention of TIAs or mini-strokes
The measures below can help you reduce your risks of having a mini-stroke (TIA), stroke, or a recurrent TIA:
- Give up smoking - the moment you stop smoking your risk of stroke, TIA, and many other conditions and diseases goes down significantly, and continues dropping each month.
- Diet - follow a well-balanced diet, with plenty of fruit and vegetables, whole grains, fish, poultry, and very lean meat. Avoid all junk foods and foods with bad fats, such as saturated and trans fats.
- Salt (sodium) intake - individuals prone to high blood pressure should avoid salty foods and not add salt to cooking.
- Physical exercise - exercise moderately for at least 30 minutes five times a week. Check with your doctor whether you can do this.
- Sensible alcohol consumption - either don't drink alcohol at all, or stay within the daily recommended limits.
- Body weight - bring body weight down to normal and risk will be decreased.
- Illegal drugs - many illegal drugs, such as cocaine, significantly raise your risk of stroke and TIA.
- Diabetes - good diabetes control, i.e. following diabetes treatment properly, greatly reduces the risk of stroke and TIA.
- Sleep - get at least 7 hours good quality, continuous sleep every day.