Transient Ischaemic Attack (TIA)

What is a Transient Ischaemic Attack?

Transient Ischaemic Attacks (TIAs) are a kind of mini-stroke. The symptoms may be very like a stroke but they get better very quickly. Common symptoms include attacks of:

• Weakness
• Clumsiness
• Numbness or pins and needles in the face, arm or leg on one side of the body
• Temporary slurring of speech or difficulty in finding words can also occur
• The eye can also be affected resulting in loss of vision in one eye. This is called Amaurosis Fugax.

These attacks may only last for a few minutes or hours and are usually better within a day.

What causes TIAs?

TIAs and strokes are caused by narrowing and blockages of the blood vessels that supply the brain. This is due to the hardening of the arteries (atherosclerosis) which may be caused by smoking, high blood pressure, high cholesterol levels and diabetes.

In TIAs the blockage is temporary and quickly clears itself. The symptoms depend on which blood vessel to the brain or eye is blocked and so which is starved of blood.

However, there are several illnesses that may seem very much like TIAs. These include:

• Migraine
• Epileptic fits or seizures
• Low blood sugar
• Changes in heart rhythm

TIAs do not usually cause “blackouts”, fainting or loss of consciousness. These other illnesses need different treatments and it is important that people with TIA symptoms are seen by a specialist to find out the cause of the trouble.

Why are TIAs important?

Although TIAs may be frightening they do not cause any permanent damage. However, a person who has had a TIA has a higher risk of suffering a stroke. The risk of having a stroke in the first year after a TIA is about 10% and about 5% each year after this.

It is important that TIAs are investigated so that any underlying cause can be corrected to try to prevent a stroke in the future.

What tests are required?

If your specialist thinks that your symptoms are a cause for concern, a series of tests will be arranged. These usually include blood tests for high cholesterol and diabetes, and a heart tracing (ECG). Sometimes TIAs are due to the narrowing of a blood vessel in the neck (carotid artery). A painless ultrasound scan of the neck will check on this.

What about treatment?

Your treatment depends on the results of your examination and tests.

• If you smoke you should stop completely.
• High blood pressure, high cholesterol or high sugar levels in the blood can often be helped by a healthier diet, although drugs may also be needed.
• Aspirin may also be prescribed to make the blood less sticky. This reduces the risk of having a stroke or heart attack by about 25%. The dose of aspirin is small and does not usually cause indigestion.
• If the ultrasound scan suggests that the carotid arteries in the neck are narrowed, then an operation to correct the narrowing may be necessary. This is called a carotid endarterectomy. In selected patients, stenting of the narrowed carotid artery can be performed.

Further test may be arranged before the operation including an x-ray of the arteries (arteriogram) and a scan of the brain (CT scan).