Ischaemic stroke

Published by Bupa's Health Information Team, February 2010.

This factsheet is for people who have had an ischaemic stroke, or who would like more information about it.

A stroke happens when the blood supply to the brain is interrupted. In an ischaemic stroke, the blood supply is blocked by a blood clot or clump of fat. It’s the most common type of stroke.

About ischaemic stroke
Symptoms of ischaemic stroke
Complications of ischaemic stroke
Causes of ischaemic stroke
Diagnosis of ischaemic stroke
Treatment of ischaemic stroke
Prevention of ischaemic stroke

About ischaemic stroke

In an ischaemic stroke, parts of your brain are starved of oxygen and nutrients when blood vessels become blocked. This damages brain cells and they begin to die. There are two different ways that an ischaemic stroke can happen.

•    Arterial thrombosis. This is when a blood clot (thrombus) forms in a blood vessel supplying your brain and blocks the blood supply.  
•    Cerebral embolism. This is when a blood clot from somewhere else in your body (embolus) forms, travels to your brain and blocks the blood supply.

Your brain controls everything your body does, including your movements, speech, vision and emotions. Damage to your brain can affect any of these functions. After having an ischaemic stroke, about one in three people recover all or most of these functions.

Ischaemic strokes are most common in people over the age of 65, although they can happen at any age.

Symptoms of ischaemic stroke

Ischaemic stroke symptoms usually come on suddenly, within seconds or minutes. Less commonly, symptoms can come and go and get worse over several hours to a day or two.

A good way to recognise if someone has had a stroke is to use the face-arm-speech-time to call 999 test (abbreviated to FAST). This involves checking for any one of the three main symptoms of stroke – facial weakness, arm weakness or speech problems.

The exact symptoms of ischaemic stroke will depend on where in your brain the blood supply has been interrupted. For example, if a blood vessel that carries blood along the front of your neck to your brain becomes blocked you may have:
•    blindness in one eye
•    paralysis or weakness in one of your arms or legs, on one side of your body
•    problems with understanding people or finding words when talking

Or, if a blood vessel that carries blood along the back of your neck to your brain becomes blocked, you may have:
•    double vision
•    weakness on both sides of your body
•    dizziness and vertigo

If you notice that someone has any of these symptoms, you should call for emergency help straight away.

Complications of ischaemic stroke

Some ischaemic strokes may be mild and the effects only temporary, whereas others may be more severe and cause lasting damage. Complications of ischaemic stroke may include:
•    weakness or paralysis, usually on one side of your body
•    lack of awareness of one side of your body (usually the left side)
•    loss of sensation on one side of your body
•    difficulty swallowing
•    extreme tiredness and sleep problems
•    problems with speech, reading and writing
•    problems with vision - such as double vision, or partial blindness
•    memory and concentration difficulties
•    difficulty controlling your bladder and bowel movements (incontinence) or constipation
•    behavioural changes

Problems such as anxiety, depression and seizures (fits) can often improve as you recover.

If you’re unable to move because of stroke, you could be at risk of:

•    bed sores (pressure ulcers)
•    deep vein thrombosis (DVT)
•    pneumonia
•    contractures (altered position of your hands, feet, arms or legs because of muscle tightness)

Causes of ischaemic stroke

An ischaemic stroke happens when the flow of blood to your brain is interrupted either by a blood clot or clump of fat. The blockage may develop in one of the blood vessels in your brain (arterial thrombosis), or come from somewhere else in your body (cerebral embolus).

You’re at greater risk of getting a blood clot if your blood vessels have become narrowed and ‘furred up’ with fatty deposits – a process known as atherosclerosis. This often happens as people age. You can also develop atherosclerosis if you:
•    smoke
•    have uncontrolled high blood pressure
•    have high cholesterol
•    are overweight or obese
•    have diabetes
•    have a family history of stroke or heart disease

You're also at risk of ischaemic stroke if you have a type of abnormal heart beat (arrhythmia) called atrial fibrillation. In atrial fibrillation, your heart doesn't pump blood as efficiently and this can cause a blood clot to form in your heart.

The clot can then travel to your brain and cause a stroke. Regular, heavy drinking can put you at risk of developing an abnormal heart beat, as well as raise your blood pressure.

Diagnosis of ischaemic stroke

You will have a number of tests in hospital to try and find out what type of stroke you had and which part of your brain is affected. This will allow your doctor to plan your treatment.
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You will have your blood pressure measured and an electrocardiogram (ECG) to record the rhythm and electrical activity of your heart. You may then have blood tests to measure your cholesterol and blood sugar levels, and to check for clots. You will also have a brain scan (eg a CT or MRI) as soon as possible.
Later on, you may have some other tests on your heart and blood vessels to find out what caused your stroke. These may include tests for blood clotting abnormalities and an echocardiogram (a procedure that uses ultrasound to produce a moving real-time image of the inside of the heart).

Treatment of ischaemic stroke

When you go to hospital, you may be treated on a general ward or in a specialist stroke unit.

If you're unable to swallow, you will be given fluid through a drip in your arm to stop you becoming dehydrated. You will have a tube in your nose to give you all the nutrients you need. You may also be given oxygen through a face mask, if you need it, to help you breathe.

You will be helped to sit up and move around as soon as you’re able. If you're unable to move, you will be helped to regularly turn in your bed, to reduce your chance of getting bed sores and DVT.

Medicines

You may be prescribed the following medicines for ischaemic stroke.

•    Alteplase is a medicine used to break up blood clots and help restore the blood flow to your brain. It’s given through a drip in your arm within three hours of your symptoms starting. However, it may not be suitable for everyone.
•    Aspirin, clopidogrel and dipyridamole are all medicines used to reduce your risk of blood clots forming after a stroke. You may be given one of these medicines as a tablet or via a feeding tube placed in your nose. Aspirin can also be given as a suppository - a medicine that is inserted into the rectum (back passage). These medicines may also be used for the long-term prevention of strokes.
•    Warfarin and heparin are medicines which also prevent blood clots forming. They are mainly used to prevent strokes.
You may also be given some other medicines to control your blood pressure and to lower your cholesterol.

Surgery

Your doctor may advise that you have surgery. This may involve having an operation to remove the fatty deposits from an artery in your neck (carotid endarterectomy). It may help to reduce your risk of having another stroke. You will usually have the operation within two weeks of your stroke. However, it’s only suitable for some people.

Rehabilitation

After a stroke, you may need to relearn skills and abilities, or learn new skills and adapt to the damage a stroke has caused. This is known as stroke rehabilitation.
Stroke recovery can be difficult to predict. Most people will make most of their recovery in the early weeks and months following the stroke. However, recovery can continue after this time.
The stroke team at the hospital will work out a rehabilitation programme for you that will be designed around your particular needs. This will continue after you leave hospital. Your rehabilitation programme may involve physiotherapists, speech and language therapists, occupational therapists, ophthalmologists and psychologists, as well as doctors and nurses.