Cerebrovascular diseases (CBVD) are conditions that develop as a result of problems with the blood vessels inside the brain. Many people, as they get older, develop some cerebrovascular disease but this is mainly without symptoms and does not affect their lives. Some forms of cerebrovascular disease are more serious and need urgent treatment.
Types of CBVD
The most common types of symptomatic CBVD are:
- stroke - a medical condition where the blood supply to the brain is interrupted
- transient ischaemic attack (TIA)- a temporary fall in the blood supply to the brain, resulting in a lack of oxygen to the brain
- subarachnoid haemorrhage- an uncommon cause of stroke where blood leaks out of the brain's blood vessels
- vascular dementia - blood circulation problems result in parts of the brain not receiving enough blood and oxygen
The four types of CBVD are discussed in more detail below.
A stroke is a serious medical condition that occurs when the blood supply to the brain is disturbed or interrupted.
In order to function properly, the brain - like all organs - needs oxygen and nutrients that are provided by the blood. However, if the blood supply is restricted or stopped, brain cells will begin to die. This can lead to brain damage and possibly death.
An ischaemic stroke occurs when the blood supply to the brain is blocked as a result of a blood clot (where blood thickens and becomes solid). This is the most common cause of a stroke.
The main symptoms of a stroke can be remembered with the word FAST, which stands for Face-Arms-Speech-Time. Each of the symptoms is explained below.
- Face - the face may have fallen on one side, the person may not be able to smile, or their mouth or eye may have drooped.
- Arms - the person who has had a suspected stroke may not be able to raise both arms and keep them there due to arm weakness or numbness.
- Speech - they may have slurred speech.
- Time - it's time to dial 112 immediately if you see any of these signs or symptoms.
A stroke is a medical emergency. Prompt treatment is essential because the sooner a person receives treatment, the less damage is likely to occur.
A subarachnoid haemorrhage is a less common cause of stroke. It occurs when blood leaks from blood vessels onto the surface of the brain.
Like all strokes, a subarachnoid haemorrhage is a medical emergency that requires immediate treatment to prevent serious complications, brain damage and death.
Three quarters of all subarachnoid haemorrhages are the result of an aneurysm rupturing (bursting). An aneurysm is a bulge in a blood vessel that's caused by a weakness in the blood vessel wall.
Other causes of a subarachnoid haemorrhage include:
- severe head injury
- arteriovenous malformations - an uncommon type of birth defect that affects the normal formation of blood vessels
Transient ischaemic attack (TIA)
A transient ischaemic attack (TIA) or 'mini-stroke' is caused by a temporary fall in the blood supply to part of the brain, which results in a lack of oxygen to the brain.
This can cause symptoms that are similar to a stroke, although they don't last as long (stroke symptoms usually persist until treatment is provided). The symptoms of a TIA tend to last for a few minutes only.
However, having a TIA should be taken seriously because it's an early warning sign. There's around a one-in-five chance that people who have a TIA will experience a full stroke during the four weeks that follow the TIA.
If you or someone you know has had a TIA, contact your GP, local hospital or out-of-hours service immediately to arrange for a specialist assessment.
Dementia causes a range of related symptoms that are associated with an ongoing decline of the brain and its abilities. These include:
Vascular dementia is the second most common type of dementia after Alzheimer's disease. It's caused by brain damage that results from:
- a stroke
- a TIA
- a silent brain infarction - a type of mild stroke that doesn't cause any noticeable symptoms but still results in brain damage
Public health impact
CBVD is a leading cause of death in Ireland. It's estimated that 1 in every 10 deaths is due to a CBVD, usually a stroke.
In 2008 in Ireland, there were just over 2,000 deaths as a result of CBVD. Advancing age is an important risk factor for CBVD, but there's an increasing trend for these types of conditions to develop in middle aged adults.
For example, of the deaths resulting from CBVD in 2008 (mentioned above), almost 100 occurred in people who were under 55 years old.
Conditions that occur as a result of problems that develop with blood vessels in the brain are also the leading cause of long-term disability in Ireland
Cerebrovascular disease and stroke in children
Cerebrovascular diseases are much less common in children than they are in adults. However, stroke can affect children sometimes.
It's estimated that stroke is among the top 10 causes of childhood death.
The leading cause of childhood stroke is abnormalities in the blood vessels of the brain that cause bleeding in the brain. The classic warning signs of a stroke are the same in adults and children. See the 'FAST' set of symptoms, which are mentioned on this page.
Children may also experience additional symptoms including:
- a high temperature (fever) of 38ºC (100.4ºF) or above
- fits (seizures)
- nausea (feeling sick)
- vomiting (being sick)
- vision loss
Dial 112 immediately to request an ambulance if you think that your child has had a stroke.
An aneurysm is a blood-filled sac that forms in a weakened part of a blood vessel.
Arteries are blood vessels that carry blood from the heart to the rest of the body.
Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
Blood vessels are the tubes in which blood travels to and from parts of the body. The three main types of blood vessels are veins, arteries and capillaries.
The brain controls thought, memory and emotion. It sends messages to the body controlling movement, speech and senses.
Cholesterol is a fatty substance made by the body that lives in blood and tissue. It is used to make bile acid, hormones and vitamin D.
An embolism is the sudden blockage of a blood vessel, usually by a blood clot or air bubble.
A rupture is a break or tear in an organ or tissue.
Body tissue is made up of groups of cells that perform a specific job, such as protecting the body against infection, producing movement or storing fat.
Cerebrovascular disease and cardiovascular disease
Cerebrovascular disease (CBVD) is often confused with cardiovascular disease (CVD).
Cardiovascular disease is the term that's used to describe diseases affecting the heart or blood vessels – for example, coronary heart disease and peripheral arterial disease.
Cerebrovascular disease is also an example of cardiovascular disease which affects the blood vessels of the brain.
There are eight major risk factors for cerebrovascular diseases (CBVD). They are:
- high blood pressure (hypertension)
- high blood cholesterol
- lack of exercise
- being overweight and obese
- excessive alcohol consumption
Many of the risk factors for CBVD are linked, which means that if you have one, you're likely to have others as well.
The eight major risk factors for CBVD are described below.
High blood pressure
High blood pressure (hypertension) is one of the most significant risk factors for developing CVBD. This is because the increase in blood pressure damages the walls of the arteries in the brain, making it more likely that a blood clot will form or an artery will rupture (split open). Both of these can trigger a stroke.
If you have high blood pressure you're four times more likely to have a stroke than someone with healthy blood pressure.
Smoking is a major risk factor for developing CBVD because the toxins in tobacco can damage and narrow the blood vessels in the brain.
Smoking also causes high blood pressure.
It's estimated that a person who smokes 20 cigarettes a day is six times more likely to have a stroke than a non-smoker.
A diet that's high in saturated fat and salt can cause high blood pressure, high blood cholesterol levels and narrowing of the arteries, all of which are risk factors of CBVD.
High blood cholesterol
High blood cholesterol can cause your arteries to narrow and increase your risk of developing a blood clot.
Lack of exercise
People who don't exercise regularly usually have higher cholesterol levels, high blood pressure and high levels of stress. They're also more likely to be overweight or obese.
Being overweight or obese
Being overweight or obese increases your risk of developing diabetes and high blood pressure. Overweight and obese people also often have poor diets and don't exercise enough.
The high blood glucose (sugar) levels that are associated with type 1 diabetes or type 2 diabetes can damage the arteries. People with type 2 diabetes are also often overweight or obese.
Excessive alcohol consumption
Drinking excessive amounts of alcohol can increase your cholesterol and blood pressure levels.
Most of the factors that increase your risk of developing cerebrovascular disease (CBVD) are linked. This means that if you have one of these risk factors you'll probably have other risk factors as well.
For example, people who drink alcohol heavily usually have poor diets and are more likely to smoke.
Also, obese people are more likely to have diabetes, high cholesterol and high blood pressure (hypertension).
Addressing one risk factor, such as quitting smoking, will bring important health benefits. But to significantly reduce your risk of developing CBVD you need to look at your lifestyle as a whole. In particular, you need to consider:
- your weight
- your diet
- how much exercise and physical activity you do
- whether you need to stop smoking
- the amount of alcohol that you drink
An added advantage of making the lifestyle changes discussed above is that as well as reducing your risk of developing CBVD, your risk of developing other serious health conditions, such as heart disease, heart attack and cancer will also be reduced.
If you're overweight or obese, combining regular exercise and a calorie-controlled diet will enable you to lose weight (see below). Once you've reached your ideal weight you should aim to maintain it.
A low-fat, high-fibre diet that includes whole grains and at least five portions of fresh fruit and vegetables a day is recommended for a healthy heart.
Limit the amount of salt in your diet to no more than 6g (0.2oz or 1 teaspoon) a day. Too much salt will increase your blood pressure. Avoid eating foods that are high in saturated fat because this will increase your cholesterol level.
Foods that are high in saturated fat include:
- meat pies
- sausages and fatty cuts of meat
- ghee - a type of butter that is often used in Indian cooking
- hard cheese
- cakes and biscuits
- foods that contain coconut or palm oil
Eating some foods that are high in unsaturated fat can decrease your cholesterol level. These foods include:
- oily fish
- nuts and seeds
- sunflower oil
- olive oil
To maintain a good level of health the Department of Health recommend that you do a minimum of 30 minutes of vigorous exercise a day, five times a week.
The exercise that you do should be strenuous enough to leave your heart beating faster and you should feel slightly out of breath afterwards. Examples of activities that you could incorporate into your exercise programme include:
- brisk walking
- hill climbing
If you find it difficult to do 30 minutes of exercise a day, start at a level that you feel comfortable with. For example, you could do 5 to 10 minutes of light exercise a day before gradually increasing the duration and intensity as your fitness begins to improve.
If you have never exercised, or if it has been some time since you last exercised, visit your GP for a health check-up before starting a new exercise programme.
If you smoke, it's strongly recommended that you give up as soon as possible.
Your GP will be able to provide you with medication and advice to help you quit smoking.You can also call the National Smokers Quitline at 1850 201 203, or the HSE facebook page at www.facebook.com/hsequit.
If you drink alcohol, do not exceed the recommended weekly limits, which are:
- 21 standard drinks a week for men
- 14 standard drinks a week for women
A standard drink of alcohol is roughly equivalent to half a pint of normal-strength beer, a small glass of wine or a pub measure of spirits.
You should see your GP if you find it difficult to moderate your drinking. Counselling services and medication are available to help you reduce your alcohol intake.
If your risk of developing CBVD is thought to be particularly high, you may be prescribed medication to help reduce your risk.
Medications that are used to prevent CBVD include:
- statins, which are used to lower blood cholesterol levels
- anticoagulants (blood-thinning medication), such as warfarin or low-dose aspirin, which are used to prevent blood clots
- angiotensin-converting enzyme (ACE) inhibitors - these are used to treat high blood pressure.