In the UK there are at least 100,000 strokes every year – that’s one stroke every five minutes. It’s one of the leading causes of severe disability and kills almost 40,000 people annually, making it the fourth biggest cause of death in the UK and the second globally. What’s more, one in four stroke survivors will go on to have another stroke.
The age group most at risk are the over 55s, but everyone has some risk, even children, so it’s important to know the symptoms. Limiting the damage from a stroke is vital to recovery. If you think you may have had a stroke, call an ambulance and get to hospital straight away. Thrombolytic (clot-busting) treatment has to be given within three hours of the first symptoms for it to be effective. Recognising the signs of stroke and acting quickly so that the person can get to hospital within the vital three-hour window results in a greater chance of recovery as well as reduced likelihood of permanent disability and lesser need for extensive rehabilitation.
What are the main causes of stroke?
A stroke happens when there is a blood clot or bleed in the brain, which damages or kills brain cells in the affected area.
The majority (85%) of strokes are ischaemic strokes, which happen when a blood clot develops in one of your arteries and then travels to your brain, where it blocks an artery.
This can happen if you have atherosclerosis, a condition that happens when the walls of your arteries harden and become furred up with fatty material known as atheroma. Thick areas of atheroma can trigger blood clots to form, which are carried along in the blood stream. If the blood clot blocks an artery in your heart, this can cause a heart attack.
Haemorrhagic strokes are caused when, instead of an artery in your brain being blocked, it becomes weakened, bursts, and causes bleeding in your brain, which affects the brain tissue in the area. The term for this is intracerebral haemorrhage, and it can mean that the cells in the area may be damaged or may die.
A mini stroke, or a transient ischaemic attack (TIA), is caused by a temporary interruption in blood flow.
Strokes with an unknown cause are referred to as cryptogenic.
What happens when you have a stroke?
During a stroke, a person typically loses almost 2 million nerve cells per minute. Stroke is the leading cause of severe adult disability.
The effects that a stroke has on your brain and body are governed by the location of the blood clot, and its severity.
Some blood clots cause strokes that may not cause too much damage – for instance a stroke may only affect one of your hands.
At the other end of the scale some strokes can be so severe that they may leave you partially paralysed.
If the stroke is severe, and medical help isn’t available quickly enough, a stroke can cause death.
The signs of a stroke are; facial weakness, arm or leg weakness, speech problems, loss of sight or blurred vision.
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Can you prevent a stroke?
You can’t entirely prevent a stroke but there are steps you can take to reduce your risk.
Reducing blood pressure and giving up smoking are the keys. High blood pressure can be lowered by cutting salt intake by a third, to the recommended daily maximum of 6g; this would prevent one-fifth of strokes.
Very moderate drinking has a protective effect, but a Scottish study over 20 years showed that people who drank more than five units a day were twice as likely to die from a stroke than teetotallers.
Diet is boringly important. Cruciferous vegetables (cauliflower, cabbage, broccoli and Brussels sprouts) are particularly protective because they contain high levels of antioxidant vitamins, as are richly coloured fruit and veg such as blackcurrants, oranges and green and red peppers. Even eating one additional portion of fruit or veg a day can lower your stroke risk by 6%. Fibre is important too, in a large European study of 400,000 people higher fibre intake decreased risk by 23%.
These simple lifestyle changes may help prevent a stroke happening:
- Don’t smoke. Smoking doubles your risk of stroke and causes damage to your arteries.
- Drink sensibly. Too much alcohol raises your blood pressure, which increases your risk of stroke.
- Eat sensibly. Don’t have too much saturated fat as it helps fur up your arteries, putting you at greater risk of stroke.
- Keep salt to a minimum as it raises blood pressure.
- Watch your weight. Being overweight increases your risk of high blood pressure, heart disease and diabetes, which increase your risk of stroke
- Have your blood pressure checked every year – more often if it is high (you can buy inexpensive blood pressure monitors to use at home). Bringing high blood pressure down is one of the best ways to reduce your risk of having a stroke.
- If you have diabetes, try to keep your blood sugar levels down to normal levels if you can.
- Have your cholesterol level checked. If it is high talk to your doctor about having treatment to reduce your cholesterol.
- Making sure that you take any medicines you’ve been prescribed for medical conditions, and seeing your GP if you feel that you need further help with them.
Stroke and high blood pressure
A stroke is rather like a heart attack, because the damage happens when a blood clot blocks blood travelling along an artery (or vein). The difference is that the blockage – the trigger for a stroke - happens in your brain rather than your heart.
High blood pressure causes damage to the artery walls, and these lead to the brain as well as the heart and elsewhere in the body. When a blood clot blocks an artery in your heart, it causes a heart attack. When a blood clot blocks an artery in your brain, and stops the blood supply, it causes a stroke.
High blood pressure – particularly uncontrolled high blood pressure – is one of the main causes behind the incidence of stroke in the UK. This is because high blood pressure can damage the blood vessels in your brain, and make them narrower. This can make it more difficult for blood to get through, and makes it more likely that a blood vessel might become blocked, or might even burst.
If this happens, it means that oxygen and energy-carrying blood may not be able to reach parts of the brain. Eventually, the brain cells that have been starved of oxygen can die. When this happens, you have had a stroke.
Stroke and genetics
There are some conditions that we know increase our risk of having a stroke – atrial fibrillation (where your heart beats erratically), and high blood pressure for instance, but the health of your siblings could also be relevant. Research shows that if one of your brothers or sisters had a stroke you could be 60% more likely to have one as well.
While the specific symptoms of a stroke can vary from one person to another, depending on which part of the brain has been affected, it can be difficult to remember them all.
These are some of the symptoms that you may experience.
- Feeling unsteady, or dizzy
- Numbness or paralysis on one side of the body
- Sudden, blurred vision
- Difficulties with balancing and co-ordination, as well as with speech, eyesight and the ability to smile – their face may also look twisted, and they may be drooling.
- They may have a severe headache and may be confused.
- In more severe cases the person may become unconscious.
To help identify a stroke use FAST, the Face-Arm-Speech Test. These three checks will help you recognise if someone has had a stroke or mini-stroke (transient ischaemic attack – TIA).
- F Facial weakness: Can the person smile? Has their mouth or an eye drooped?
- A Arm weakness: Can the person raise both arms?
- S Speech problems: Can the person speak clearly and understand what you say?
- T Time: If you see any one of these three signs, it’s TIME to call 999.
If you see any of these signs, call 999 immediately.
What is the treatment for stroke?
Having a stroke can be life changing, even life threatening, so it is vital that you get to hospital as quickly as possible. Even though minor strokes – TIAs – may only cause minor symptoms, they may be an early warning sign of a more serious stroke.
The treatment you have in hospital will depend on which type of stroke you have.
Treatment for ischaemic stroke
Ischaemic stroke is the type of stroke cause by a blood clot that prevents blood reaching your brain. This type of stroke is treated with a number of different medicines.
One method involves injecting you with alteplase, a medicine that dissolves blood clots. By doing this it means that blood can reach your brain again. Your doctor may refer to this as ‘clot-busting’ or with its medical term, thrombolysis.
Before you have this treatment you’ll have a computer tomography brain scan (also known as a CT scan). This is to check whether you have had an ischaemic stroke, caused by a clot or a bleed. If you have, the thrombolysis treatment can go ahead. If you have had a bleed you will have a different type of treatment. A CT scan can also show doctors the part of the brain that has been affected.
There is a time limit on treatment with alteplase. It needs to be carried out as soon as possible after you have a stroke. Once four and a half hours have passed since your stroke, it may not have much effect, so this tends to be the cut-off point for this treatment, (although in some cases it can be extended for an hour or so).
According to the Stroke Foundation only about 15% of people who go to hospital because of a stroke can have thrombolysis treatment. Some of the reasons for this are because their stroke has been cause by a bleed rather than a clot; they have had a stroke or other head injury in the last three months, or did not get to the hospital in time for thrombolysis.
In some cases, where the stroke has been caused by a blood clot blocking a large artery in the brain, doctors my carry out a thrombectomy. This involves having a catheter inserted into an artery in your body, which is fed through your arteries to the site of the blood clot in your brain. The clot is then removed, using either suction, or a tiny device that is passed through the catheter. Depending on the circumstances you will be given either a local or general anaesthetic before this procedure begins.
Treatment for a haemorrhagic stroke
A haemorrhagic stroke is when one of the arteries in your brain bursts, and blood escapes, into your brain. This is an intracerebral haemorrhage. In some cases you may have bleeding onto the surface of your brain. Or you may have bleeding between the fluid-filled layers between the membrane layers. In this case your doctors will say that you have had a subarachnoid haemorrhage.
These types of strokes happen less often than ischaemic strokes, but can cause more damage to your brain.
There are a number of factors that can cause this type of stroke. They include having high blood pressure, which also causes most ischaemic strokes, and having an aneurysm. This is when part of the wall of an artery becomes very thin, and bursts.
Having high blood pressure is one risk factor for having an aneurysm. You may have been prescribed an anticoagulant drug, to stop your blood clotting and so reducing your risk of stroke. However, this can put you at risk of bleeding, so you need to have your health and the drug’s effects, checked regularly.
Where stroke is concerned, it is vital to have your blood pressure checked regularly. If your doctor thinks that you are at risk they will advise you on the steps you can take to reduce your risk, and review your medication.
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