Transient ischaemic attacks [TIAs for short] are a kind of mini stroke. The symptoms may be like a stroke, but they get better very quickly [in less than an hour].

Common symptoms include brief attacks of weakness, clumsiness, numbness or pins and needles of the face, arm or leg in 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 temporary loss of vision in one eye; this feels more like a curtain coming down and is called Amaurosis Fugax.

These attacks usually last for a few minutes or hours and are always better within a day. More severe attacks that last longer are called strokes and although they improve, often they leave some degree of disability.

The symptoms depend on which vessel to the brain or eye is blocked and so which part of the brain is starved of blood.

The annual incidence of stroke in the western population is 200 per 100,000 population; the numbers  increase dramatically  in males after the age of 75, and the incidence reaches 1400 cases over 100,000  population. The annual incidence of stroke in people with greater than 70% stenosis of the main artery that supplies the brain [carotid] is 3-5% per year.

3. Are there any other causes?

There are several illnesses which may seem very much like TIAs. These include migraine, epileptic fits or seizures, a low blood sugar, faints and changes in heart rhythm. TIAs do not usually cause blackouts, fainting or loss of consciousness. These other illnesses need different treatment and it is important that people with TIAs are seen by a specialist [neurologist or vascular surgeon] to find out the cause of the trouble [or at least exclude the presence of carotid territory TIA].

5. What tests are required?

If your specialist thinks that your symptoms are a cause of concern, then a series of tests will be arranged. These usually include blood tests for high cholesterol and diabetes and a heart tracing [ECG]. If there is a possibility that the TIAs were caused by a narrowing of a blood vessel in your neck [carotid artery], then a painless ultrasound scan of the neck will check on this. If the ultrasound confirms that there is a significant narrowing, then often a special x-ray of the artery [arteriography] will be required.

6. What about treatment?

Your treatment depends on the results of the examination and tests. If you smoke, you should stop completely. High blood pressure should be controlled and high cholesterol or high sugar levels in your 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 heaving a stroke or heart attack by 25%. The dose of aspirin is small [150mg per day] and does not usually cause indigestion. Only rarely a stronger drug to thin your blood [warfarin] may be prescribed.

If the ultrasound scan suggests that the carotid arteries in your neck are narrowed, then an operation to correct this narrowing may be necessary. This is called carotid endarterectomy. Further tests may be arranged before the operation, including an arteriogram and a scan of the brain [CT scan].

Carotid Endarterectomy

1. What is the problem?

Every day hundreds of people have a stroke [CVA] or warning signs of a stroke [mini-stroke or TIA]. Such patients are at higher risk of having another, perhaps major stroke. Although the annual incidence of stroke in the whole population is 2 per thousand, it rises to 1.5% for men after the age of 70 and reaches 10-25% in people who had had TIAs.

All patients with an increased risk of stroke should be given medical treatment [aspirin] and advice to reduce this risk. This includes treatment of high blood pressure, diabetes, high fat levels in the blood, heart disease and abstinence from smoking.

However, in many cases surgical treatment is far more effective as preventative treatment compared to the medical one. In such cases there is a significant narrowing of the artery in the neck [carotid arteries] that supplies blood to the brain. It is important to realise that the left side of the brain looks after the right arm and leg and the right side of the brain looks after the left arm and leg, For this reason, the patient often thinks that the “wrong” side is being operated upon when in fact it is the correct side!

Although there are no cut-off points in life, at present we know that the presence of a greater than 60% [on ultrasound] or 70% [on angiography] narrowing in the carotid artery makes the chances of suffering a major stroke in the future much higher than in a person without such a degree of narrowing.  The risk of stroke in such cases is about 26% at 18months in patients who have the best medical treatment. The same is true for smaller narrowings when there is an ulcer or soft clot within the artery. We also know that performing an operation called carotid endarterectomy [to correct the narrowing] will reduce the chances of stroke and / or death by six to ten times in symptomatic patients compared with tablets [3.5% compared to 26%]. For patients who have a significant narrowing [60%] but have had no symptoms, the annual risk of stroke is 3%, while it falls to 1% per year after surgery.

2. Before the operation

Please bring with you all the medications that you currently take.

Surgery involves admission to the hospital for two days and will usually be carried out on the day after admission.

Before the operation you will be seen by the anaesthetist who will examine you and by a member of the surgical team who will explain anything that you are not sure about. Your nurse will also explain the ward routines and will answer any questions that you may have. You will have a number of preoperative tests, including blood tests, a cardiogram and a chest x-ray [if they were not done during the pre-admission clinic a week earlier. You may also be asked to have a repeat ultrasound scan on your neck.

You will be asked to eat or drink absolutely nothing for 6 hours before the operation but you should have your medications till midnight before the day of surgery. You will be started injections of heparin which will continue throughout your stay in hospital, in order to stop clots forming in the veins of your legs.

3. The operation

Once you’ve been anaesthetised, a cut is made in the skin of the neck over the carotid artery. The artery is exposed and then temporarily clamped off and opened to core out the diseased lining. It is then closed and blood flow through it is restored. A dissolvable stitch is used to close the skin and a drainage tube is placed which will be taken out the next day.

4. After the operation

When you wake up you will find that your arm is connected to one or two plastic tubes to provide you with fluids and to monitor your blood pressure. You will usually be returned to a high dependency unit [HDU, ICU] so that we can keep a special eye on you for 4 hours. After this you will be returned to your own ward.

You will be allowed to drink after you have woken completely from the anaesthetic. The operation itself is not particularly painful, although you may need some painkillers, which will be given to you if required. On the following day after surgery you will be allowed to get out of bed and to eat normally and go home. If after a week any part of the skin stitch comes to the surface it may be removed with a pair of tweezers. If it will not pull through, cut it flush with the skin with the scissors.