What is a stroke?
A stroke occurs when the blood supply to
the brain is interrupted, depriving the brain of oxygen. As a result, some of
the brain cells die and others are damaged. This means that the area of the
body normally controlled by the damaged part of the brain will not be able to
A stroke is also known as a
What causes a stroke?
The majority of strokes are caused by a
sudden blockage in the blood vessels (arteries) supplying the brain, by a blood
clot (thrombus). This is called an ischaemic stroke. The clot may actually form
in an artery supplying blood to the brain. Clots can also form elsewhere in the
body and then travel via the blood vessels to the brain, where they lodge in an
artery and cut off the blood supply. This form of clot is called an embolism.
Various factors can increase risk of a
clot developing – these include high blood pressure and a condition called
atherosclerosis – which causes hardening and narrowing of the arteries.
Some strokes are caused by the sudden
bursting (haemorrhaging) of an artery in the brain, leading to bleeding inside
the brain. This type of stroke is much less common.
What is a mini-stroke (TIA)?
A “mini-stroke” or transient ischaemic
attack (TIA) is a brief loss of blood supply to the brain, causing the person
affected to experience brief symptoms of stroke (see below). The blood supply
is quickly restored and symptoms of the stroke completely disappear – normally within
A TIA doesn’t usually cause any permanent brain
damage or disability; however it is a warning sign that you may be at serious
risk of a major stroke, so you must seek medical attention if you think you have
had a TIA.
What are the symptoms of stroke?
Different parts of the brain control
different functions in the body, such as speaking, memory, swallowing and
moving. The symptoms of a stroke therefore depend on which part of the brain is
affected and the extent of the damage. Some of the following effects may be
- Sudden paralysis, numbness or weakness of the
face, arm or leg, especially on one side of the body
- Sudden confusion, trouble speaking or
- Sudden trouble seeing in one or both
- Sudden trouble walking, dizziness, loss of
balance or coordination
- Sudden, severe headache with no known cause
If you, or someone else is having a
stroke, it is important to get emergency medical treatment as soon as possible,
as the sooner treatment is given, the less risk there will be of long-term
damage. If symptoms of a stroke seem to be occurring, contact your doctor or
phone for an ambulance immediately.
Who is at risk of having a stroke?
The following factors can increase the
risk of a stroke:
- Increasing age
- Male gender
- Family history of stroke
- Excessive alcohol consumption
- High blood pressure (hypertension)
- High cholesterol
- Irregular heart beat (atrial fibrillation)
— this is quite common in older people, and increases the risk of stroke by
causing blood clots to form in the heart.
- Smoking — smoking doubles the risk of
Can I prevent stroke?
Some factors – such as age and family
history cannot be changed. However, you can greatly reduce your risk of having
a stroke by making some lifestyle changes – such as giving up smoking, losing
any excess weight, getting regular physical exercise, keeping alcohol intake to
within recommended limits, eating more fruit and vegetables and eating less
salt and fatty foods.
It is also important to get regular blood
pressure checks and treatment if necessary for high blood pressure.
How is stroke diagnosed?
A doctor will carry out a physical
examination to check your symptoms, such as co-ordination, memory, speech and
thinking. Other tests, such as a CT or MRI scan may be carried out to obtain
images of your brain, in order to see which areas have been affected and the
extent of the damage.
How is a stroke treated?
If your stroke has been caused by a clot,
you may be given a drug to break down the clot and reduce the damage to your
brain. However, this drug is only suitable for certain patients, and is only
useful if given within 3 hours of the stroke occurring.
You may also be given drugs to prevent the
blood from clotting and to ‘thin’ the blood. An common example of this type of
drug is aspirin. If you have high blood pressure or high cholesterol, you will
also be given drugs to control these conditions, and reduce your risk of
another stroke occurring.
Once you have begun to recover from your
stroke, the main focus of your treatment will be on rehabilitation. The aim of
rehabilitation is to resolve any speech problems and restore any lost movement
or sensation you may have. Participating in a good rehabilitation programme can
greatly help you recover from a stroke.
A rehabilitation programme will be specifically
designed for you, depending on your individual needs – and may involve
physiotherapists, speech therapists, occupational therapists, nurses and
What is the outlook?
While there is currently no known cure for
a stroke, about half of all people recover completely from their first stroke
through an effective rehabilitation programme. Unfortunately, many people who
have had a stroke may suffer some permanent damage and require some level of
assistance. However, in many cases other parts of the brain compensate for the
damaged area and rehabilitation can help to restore much of the lost movement
or sensation. The rate of recovery is different for every person.
There are various support groups in
Ireland that offer services and support for people with stroke, including: