What is a transient ischemic attack?
Transient ischemic attacks (TIAs) are a type of mini-stroke. The symptoms may be very similar to a stroke, but they get better very quickly. Common symptoms are attacks of:
- Numbness, or pins and needles on the face, arm, or leg on one side of the body
- There may also be temporary problems with speech or difficulty finding words
- The eye can also be affected, resulting in loss of vision in one eye. This is called amaurosis fugax.
- These attacks can only last a few minutes or hours and are usually better within a day.
What causes TIAs?
TIAs and strokes are caused by narrowing and blocking of the blood vessels that supply the brain. This is due to hardening of the arteries (atherosclerosis) that can be caused by smoking, high blood pressure, high cholesterol, and diabetes.
In TIAs, the blockage is temporary and quickly clears on its own. Symptoms depend on which blood vessel to the brain or eye is blocked and which is blood-deficient. Are there other causes? There are several diseases that can be very similar to TIAs. These include:
- Epileptic fits or seizures
- Low blood sugar
- Changes in heart rhythm
- TIAs usually do not cause “blackouts,” fainting, or unconsciousness. These other diseases require different treatments, and it is important that people with TIA symptoms be evaluated by a specialist to determine the cause of the problem.
Why are TIAs important?
While TIAs can be scary, they don’t cause permanent harm. However, a person who has had a TIA is at a higher risk of having a stroke. The risk of stroke in the first year after a TIA is around 10% and around 5% every year thereafter.
It is important that TIAs are investigated so that any underlying causes can be addressed in an attempt to prevent stroke in the future.
What tests are required?
If your specialist thinks your symptoms are cause for concern, a series of tests will be done. This usually includes blood tests for high cholesterol and diabetes, and a heart tracker (EKG). Sometimes TIAs are due to a narrowing of a blood vessel in the throat (carotid artery). A painless ultrasound of the neck will check this.
What about the treatment?
Your treatment will depend on the results of your exam and tests.
If you smoke you should stop completely.
High blood pressure, high cholesterol, or high levels of sugar in the blood can often be helped by a healthier diet, although medication may also be needed.
Aspirin can also be prescribed to make the blood less sticky. This reduces the risk of a stroke or heart attack by about 25%. The aspirin dose is small and does not usually cause indigestion. If the ultrasound scan suggests that the carotid arteries are narrowed, surgery to correct the narrowing may be needed. This is called a carotid endarterectomy.
Another test can be arranged before surgery, including an x-ray of the arteries (arteriogram) and a scan of the brain (CT scan).