STROKE

What is a stroke?

A stroke attacks the brain in a similar way to how a heart attack attacks the heart. For this reason it is sometimes known as a ‘brain attack’. Strokes occur when the blood supply to the brain is disrupted and is always classed as a medical emergency.  

A stroke comes in two forms:

• Ischaemic stroke: this is the most common type of stroke, which occurs when the bloody supply to the brain is blocked. This is usually caused by atherosclerosis, which causes deposits of fat to collect in the arteries and obstructs blood flow.
• Haemorrhagic stroke: is a stroke that occurs when a blood vessel located in the brain ruptures, causing blood to flow from the vessel into the brain. One of the causes of a haemorrhagic stroke is an aneurysm, which involves weak, fragile spots on the arteries ballooning and becoming susceptible to rupture.

Both ischaemic and haemorrhagic strokes cause damage to the brain. As brain cells are destroyed problems with movement, speech and memory may occur.

What is the definition of a mini-stroke?

A mini-stroke is also known as a transient ischaemic attack (TIA) and occurs when there is a temporary decrease in the amount of blood flowing to the brain. Some people experience symptoms of a stroke but others do not and numerous people are unaware that they have suffered a mini-stroke. A mini-stroke can last anywhere from a couple of minutes or more to a whole day and can be a pre-cursor to a full on stroke.

What signs should I look out for?

A stroke develops quickly and the sooner it is treated the better. If you notice somebody with the symptoms of a stroke, you should call the emergency services as soon as possible. Symptoms include:

• Sudden numbness in the face, arms or legs. This usually affects only one side of the body, so the face may droop to one side and the arms may fall to the side.
• Sudden problems with vision.
• Sudden confusion.
• Problems with speech.
• Sudden dizziness and difficulty walking.
• Loss of balance.
• Sudden headache.

How is a stroke diagnosed?

To begin with the doctor will talk to the patient about their symptoms and how and when they came on. They will then ask a few questions to determine whether or not the patient is able to think clearly. The doctor will also test the reflexes of the patient to ascertain if they have suffered any nerve damage.

The doctor will then most likely order a number of tests, which may include:

• Imaging tests: these obtain a clear image of the brain. These may include a CT (computerised tomography) scan and an MRI (magnetic resonance imaging) scan. These scans can help doctors to determine whether the stroke was a result of a haemorrhage or blockage.
• Electrical tests: tests such as an evoked response test and an EEG (electroencephalogram) may be carried out to check the electrical impulses in the brain. These tests can also check the sensory processes.
• Blood tests: tests such as the Doppler ultrasound test can highlight any changes or abnormalities relating to the flow of blood to the brain.

What effects does a stroke have?

The effects and outcomes of a stroke depend on a number of factors, including:

• The brain area affected by the stroke.
• The extent of the injury to the brain.
• The form or type of stroke.

Mild strokes can cause no damage to the brain, while severe strokes can cause serious, long-lasting damage and can even lead to death. Strokes can happen in different areas of the brain. There are four main areas of the brain, which are:

• The right hemisphere.
• The left hemisphere.
• The cerebellum.
• The brain stem.

If a stroke occurs in the left hand side of the brain, this is likely to cause the following problems:

• Speech and language difficulties: this includes trouble speaking and understanding others when they speak.
• Changes in behaviour: this may cause the individual to become more cautious and require help when making decisions.
• Problems with memory: this makes remembering things and learning new things very difficult.

If a stroke occurs in the right hand side of the brain, the following problems may result:

• Difficulty judging distance: this can increase the risk of falls.
• Impaired judgement: this may cause the individual to do something they would not normally do or shouldn’t do.
• Short-term memory loss: this causes problems with remembering things that happened in the recent past; the individual may remember events from 20 years ago but are unable to recall what they did yesterday.

If a stroke occurs in the cerebellum (the area of the brain in charge of coordination and balance) this may cause the following problems:

• Difficulty balancing.
• Dizziness, nausea and vomiting.
• Abnormal reflexes (usually in the face and upper body).

If a stroke occurs in the brain stem this is usually serious, as the brain stem is responsible for all the subconscious actions. These are the actions we do not need to consciously think about and involve activities such as breathing, hearing, moving our eyes, swallowing and speaking. Electrical impulses must travel along the brain stem to reach other parts of the body (the legs and arms, for example), so it is likely that a stroke which occurs in the brain stem will cause paralysis or partial loss of sensation affecting one side of the body.

It is common for a stroke to weaken the muscles, which can make even the most routine activities such as getting dressed or walking up the stairs difficult, and people who have had strokes often require help around the home. Physiotherapy can help to ease symptoms over the course of time.

Who is most at risk of a stroke?

Most people associate stokes with older people, but they can affect people of all ages. However, the risk of suffering a stroke increases with age and it is uncommon for young people to have a stroke. Two thirds of stroke cases affect people over the age of 65. Strokes may also run in families and the risk of suffering a stroke is higher if you have close relatives who have had a stroke. People of all ethnicities can have problems with strokes. However, strokes are more common among people with Caribbean, South Asian and African heritage. This is largely due to risk factors, such as diabetes and high blood pressure, being more common among these populations.

Major risk factors for a stroke include:

• High blood pressure.
• Smoking.
• Heart disease.
• Obesity and being overweight.
• Atrial fibrillation (an irregular heart rhythm).

Hormonal changes in the body (such as those experienced during pregnancy and the menopause) can also increase the risk of a stroke.

How do I stop a stroke?

Doctors and experts believe that around 80 percent of strokes are avoidable. Some risk factors, including ethnicity, age and family history, cannot be controlled, but there are many things you can change or do to reduce your risk of having a stroke. These include:

• Keeping an eye on your blood pressure: a person’s blood pressure is likely to increase if the heart is required to work harder to pump blood around the body. Most people who suffer with high blood pressure do not have any symptoms, so you may not know that you suffer with high blood pressure. This makes it especially important to get your blood pressure measured and checked on a regular basis. Your blood pressure is usually checked when you have a routine health check.

• Quit smoking: smoking increases blood pressure, which is a major risk factor for strokes and causes damage to almost every organ and system in the body. Giving up smoking will reduce your risk of having a stroke, as well as decreasing the risk of heart disease and other medical conditions. There are various methods and treatments that can be used to help you quit, including nicotine patches and artificial cigarettes.

• Have a test for diabetes: diabetes increases the risk of strokes, but often does not cause any symptoms for a long time. It is important to get yourself checked for this reason, especially if you notice that you are thirsty and need to go to the toilet more frequently.

• Maintain a healthy, stable weight: obesity is linked to a host of health problems and you should try to maintain a healthy weight. If you are overweight your doctor will be able to offer advice to help you lose weight. The best way to lose weight is to eat a healthy, balanced diet and do exercise on a regular basis.

• Get triglyceride and cholesterol levels checked: cholesterol is a substance found naturally in the body. However, if there an elevated level of cholesterol in the body it can start to collect in the arteries and this makes it difficult for blood to flow freely. If the blood supply to the brain is blocked this will result in a stroke. Triglycerides are a type of fat and higher levels of triglyceride increases the risk of a stroke. There are often no symptoms of high triglyceride and cholesterol levels, so regular testing is important. If your levels are too high your doctor will be able to advise you on lowering the levels.

• Control drinking: drinking alcohol on a regular basis increases the risk of strokes, so ensure you stick to the recommended daily guidelines of 2 units for women and 3 units for men.

• Coping with stress: it would help to find effective methods for coping with stress, such as massage, exercise and breathing exercises.

Should I take aspirin daily to reduce the risk of a stroke?

Aspirin may be advisable for some people who have a high risk of having a stroke. However, it can have damaging side-effects so you should always check with your doctor before you start taking regular doses of aspirin. If your doctor does advise you to take aspirin, make sure you follow the dosage guidelines carefully.

Does taking the contraceptive pill increase the risk of having a stroke?

Taking the contraceptive pill should not increase the risk of a stroke in healthy, young women. It may not be advisable for older women, women with a higher blood pressure than normal, women with diabetes and women who are smokers. If you have any concerns about taking the pill you should consult to your doctor.

How is a stroke treated?

Strokes that result from blood clots are usually treated with clot-busting medication; an example is TPA (tissue plasminogen activator). It is imperative that TPA is administered within three hours of the onset of the stroke, though tests must first be conducted. It is therefore vital for patients who have had a stroke to be admitted to hospital as soon as possible.

Other medications can be administered to treat and prevent strokes. They include antiplatelet agents (such as aspirin) and anticoagulants (such as warfarin) to prevent the body’s clotting process. These medications may be prescribed for people who have a high risk of having a stroke, such as patients who have atrial fibrillation.

Surgery can sometimes be administered to treat or stop strokes from occurring, by removing fatty deposits from the arteries. A carotid endarterectomy is a procedure carried out to remove fat deposits from the carotid artery (found in the neck). In the case of a haemorrhagic stroke, surgery may be carried out to attach a clip to the base of an aneurysm or remove blood vessels that are abnormal.

Stroke rehabilitation

Rehabilitation is an extremely important aspect of the treatment process. The effects and outcomes of a stroke can affect an individual’s ability to carry out everyday activities and they may be required to modify the way they live. They may also require help around the house and possible 24-hour care.

This is intended to promote independence and although it cannot reverse the outcomes of a stroke it can help to make life more manageable. Rehabilitation aims to build your physical and mental strength. Services may include:

• Physiotherapy: to strengthen your muscles, improve balance, movement, coordination and increase flexibility.
• Speech therapy: to improve your speech.
• Occupational therapy: to help with commonplace activities and promote independence.