A stroke is where the brain is deprived of blood for a period of time. When this happens brain cells do not get the oxygen they need to function and can start to die off, resulting in the loss of senses controlled by the brain cells that have died.
This often manifests as loss of memory and/or muscle control, with some sufferers of stroke experiencing only mild symptoms such as temporary weakness in a limb, while others having much more serious issues such as paralysis on one side or losing the ability to speak, or feed or dress themselves, or death.
Causes of stroke
A number of things can cause stroke. Strokes are classified into two types - haemorrhagic and ischaemic. Haemorrhagic strokes are caused either by a brain aneurysm bursting or a leak from a weakened blood vessel, whereas ischaemic strokes are caused by a blockage in the artery supplying blood to the brain.
These blockages can form either elsewhere in the body and travel up to the brain (called an 'embolic' stroke) or can form in an artery supplying the brain (called a 'thrombotic' stroke). Haemorrhagic strokes are less common (around 15% of all strokes) but are more serious and cause more deaths (around 40% of all stroke deaths).
In Australia one in every six people will have a stroke and stroke is one of the biggest causes of death, however there are things you can do to minimise the possibility of suffering a stroke.
Stroke Risk Factors
There are a number or risk factors for stroke. These are:
- Drinking alcohol (6+ units per day)
- Being physically inactive
- Being overweight or obese
- Not having a healthy diet (i.e. having a diet high in fat and cholesterol and low in fruit and vegetables)
- High blood pressure (often a result of the above)
- Age (risk of stroke increases with age)
- Being a man (stroke is more common in men than women)
- Genetic predisposition (having a family history of stroke)
- Transient Ischaemic Attack or 'TIA' (these are in fact 'mini strokes' where blood flow is very temporarily obstructed_
- Atrial Fibrillation (a form of irregular heartbeat)
- Fibromuscular Displasia or “FMD' (this is where blood vessels in the body become twisted and restrict blood flow)
Minimising any of the lifestyle risks listed above will reduce any chances of suffering a stroke. Where someone has been identified as being at high risk of stroke and/or has had a TIA, other approaches may be suitable, including...
- Medication to lower blood pressure
- Medication to lower cholesterol (statins)
- Medication to prevent blood clotting
- Surgery - either removal of plaque from the carotid arteries that supply blood to the front section of the brain (this procedure is called a 'carotid endarterectomy' or 'carotid revascularisation endarterectomy') or a procedure to open narrowed arteries called 'carotid stenting'
Symptoms of Cerebrovascular Disease
The symptoms of a stroke vary, depending on the location of the embolus or clot that cuts off blood flow in your brain. They usually involve a loss of motor and sensory abilities in the arms and legs. Often only one side of your body is affected: the side opposite the location of the clot or embolus. You may also experience slurred speech and drooping of one side of the face.
While symptoms of a stroke may heal over time, some deficits may be permanent. It is also important to remember that even a first stroke can be fatal. Of those who survive a stroke, half will suffer another stroke.
TIA (Transient Ischemic Attack)
Symptoms of a TIA include a short-term numbness or paralysis of an arm, leg, or both on one side of the body. These symptoms are caused by a small clot or embolus to the brain that blocks blood flow. By definition, any motor or sensory loss caused by a TIA will resolve in 24 hours or less. Common temporary symptoms include difficulty speaking or understanding others, loss or blurring of vision in one eye, and loss of strength or numbness in an arm or leg. Usually these symptoms resolve in less than 10 to 20 minutes, and almost always within one hour. Even if all the symptoms resolve, call 000 to be evaluated immediately.
This occurs when an embolus or clot travels to the ophthalmic artery and blocks blood flow there. This causes temporary loss of vision in the affected eye. The blindness usually begins in one quadrant of the eye and progresses until all vision is lost. Vision is restored in the same pattern.
Lear more about stroke prevention: