Dr Cathy Stephenson: Strokes - 18 May
What is a stroke?
A stroke is simply a brain "attack" (also known as a cerebrovascular attack or CVA) where the blood supply to a part of the brain is interrupted. Without blood supply, brain cells can be permanently damaged. Because the brain controls everything the body does, this damage will affect certain bodily functions, depending where in the brain the damage is. For example, a stroke might affect speech, swallowing, limb movement, strength or even how we think and feel. The effects are sudden and immediate. They may be devastating.
There are 2 main types of stroke:
1.Ischaemic stroke - by far the most common (>80%). This is caused by a blockage in the arteries carrying blood to the brain. This can be a result of either hardening/ narrowing of the arteries in the brain due to fatty plaques, or an embolus (a clot from the heart or one of the large blood vessels, which breaks off and travels to the brain);
2.Haemorrhagic stroke - bleeding into the brain when a blood vessel bursts. This may be caused when a blood vessel within the brain bursts (intracerebral haemorrhage), or when an aneurysm on the surface of the brain bursts (subarachnoid haemorrhage).
A mini-stroke (transient ischaemic attack or TIA) happens when the blood supply to the brain is interrupted only temporarily. The symptoms can be identical to a stroke, but will disappear completely within 24 hours. These "mini-strokes" are clear warnings that a severe stroke might follow.
How common is it?
According to the Stroke Foundation, 21 New Zealanders will have a stroke every day - that's nearly 8000 a year. It is the 3rd biggest killer in NZ (> 2000 each year) and is the leading cause of adult disability. It is largely preventable.
Who is at risk?
Stroke can affect anyone at any age. Nearly 2000 stroke victims in NZ each year will be under 65 years old, including approximately 40 children.
The main risk factors are:
Ethnicity (Maori and Pacific Islands communities more at risk)
High blood pressure
How to recognise the signs.
Common initial signs might include:
Numbness, weakness or paralysis on one side of the face or body;
Slurred or garbled speech;
Blurred vision or loss of sight;
Giddiness, unsteadiness or confusion;
If you are concerned, follow the FAST test:
F - is there drooping of the face, eg can they smile, is their mouth or eye drooping?
A - arm weakness, eg can they lift both their arms?
S - speech problems, eg can they speak clearly and understand you?
T - time! If any of the above symptoms are present, it is essential to get help immediately. Dial 111 straight away.
Support and treatment.
All patients who have had a stroke should receive:
Urgent assessment and admission to hospital if appropriate
Care in a specialised stroke unit, by a team of health professionals with expertise in stroke and rehabilitation
Thorough assessments of their swallowing and speech
CT scan within the first 48 hours to make a definite diagnosis
Aspirin within the first 48 hours (unless contraindicated)
Management of all risk factors
Information, support and advice for themselves, their whanau and caregivers
Assessment for ongoing support and rehabilitation needs
The same treatment should apply to anyone who has had a "mini-stroke" or TIA (although with slightly less urgency) - this will vastly reduce the likelihood of a severe stroke in the future.
How to prevent a stroke
1. Get your blood pressure checked, and treated if it is high
2. Stop smoking
3. Exercise regularly
4. Limit alcohol and eat a healthy diet
5. Control your weight
6. Get a diabetes check
7. Ask your Dr to test for atrial fibrillation (an irregular heart rhythm that greatly increases the risk of stroke when untreated)
8. If you are at high risk, talk to your Dr about starting aspirin or another anti-clotting medication to lower your risk