What is a Stroke?
A stroke - also known as a cerebrovascular accident, is defined as the result of an acute deprivation of blood to part of the brain by the narrowing or thrombosis of an artery. This causes damage to, or death of, brain cells which are starved of oxygen. Alternatively it may be a result of physical damage to the brain caused by bleeding or a haemorrhage. Where the blood supply to part of the brain is interrupted for more than 24 hours – a stroke has occurred.
Strokes usually occur suddenly, and are unique to the individual, each one affecting a person in different ways, as different parts of the brain control different parts of the body. The main areas which may be affected are speaking, memory, swallowing and moving.
The first sign of a stroke may be a sudden severe headache, and may be quickly be accompanied by a loss of function in some other parts of the body. This may manifest itself in the form of:-
- weakness or paralysis down one side of the body
- numbness in the arms or legs
- loss of vision on one side
- weakness in the facial muscles & droop in the mouth
- slurred speech or speech difficult to understand
- involuntary turning of the eyes to one side
- difficulty swallowing
- loss of muscle coordination or balance
- Epileptic fit
- sudden onset of mental confusion
Different Types of Stroke
The most common form of Stroke is known as an Ischaemic Stroke. This is when a blood clot blocks one of the arteries carrying blood to the brain, and accounts for approximately 80% of all strokes.
Other types of Stroke are :-
This is when a blood vessel bursts inside the brain and causes a bleed (haemorrhage) into the surrounding brain tissue.
This is when a blood clot (also known as a thrombus) forms in an artery that supplies blood to the brain. This disrupts the flow of blood to the brain, which in turn leads to brain cell damage due to lack of oxygen.
This is a condition where a blood clot that has formed in a different part of the body, through the circulation, eventually reaches the brain and becomes lodged in the brain similar to the thrombosis. Once inside the brain, it causes the same oxygen starvation to the affected brain cells.
Transient Ischaemic Attack
Alternatively known as a TIA or ‘mini-stroke’, this is a short-term stroke that lasts for less than 24 hours. The oxygen supply to the brain is quickly restored and symptoms disappear. A transient stroke needs prompt medical attention because it indicates a serious risk of a major stroke.
Causes of Stroke
High blood pressure
High blood pressure causes increased pressure on the walls of the arteries. If the arterial walls are already brittle and hardened this makes them more likely to rupture and cause a cerebral haemorrhage.
Smokers have double the risk of stroke as non-smokers, due to the chemicals found in cigarettes which cause narrowing and hardening of the arteries.
Arrythmia or Irregular heart beat (atrial fibrillation)
Although Arrythmia is fairly common in old age, it increases the risk of stroke by causing blood clots to form in the heart. Blood clots can be prevented from forming by taking drugs such as Warfarin, a medicine that makes the blood less likely to clot. Warfarin treatment requires careful monitoring with regular blood checks and is a very effective way to reduce the risk of stroke.
Diabetes affects 1 in 20 older people and can increase the risk of having a stroke. Good control of diabetes is important and requires attention to diet, regular urine tests or blood tests and probably some medication.
Excessive alcohol consumption increases the risk of a stroke. The UK recommended safe limits for alcohol consumption are 21 units each week for women and 28 units each week for men. One unit of alcohol is equivalent to a measure of spirits, a 125ml glass of wine or half a pint of beer. People who drink more than this run a higher risk of stroke, liver disease and dementia.
Excessive Dietary Fat
Blood vessels that are clogged with fatty deposits (also known as Atheroma) make a blockage more likely.
If you suspect that someone has had a stroke, there is a quick and simple test that you can do to determine whether or not to seek emergency medical attention and call 911. This is known as the FAST test and is conducted as follows :-
Face-arm-speech test (FAST)
Facial weakness: can the person smile? Has the mouth or eye drooped?
Arm weakness: can the person raise both arms?
Speech problems: can the person speak clearly and understand you?
Test – If any of these indicators are present, you should immediately call 911 or take the person to hospital or an ER facility.
People who have had a severe stroke may lose consciousness. Unfortunately, the likelihood of such patients making a good recovery is poor. Those who do recover often have a severe impairment of normal function. Smaller haemorrhages often result in less brain damage and possibly no loss of consciousness with only signs of functional loss to the nervous system.
Medicines cannot cure a stroke once it has happened, and drug treatment has only a limited role to play in the management of a person after a stroke.
This is Usually carried out at hospital or ER center. A brain scan will be carried out to determine the type of stroke and hence the most appropriate form of treatment. If a blood clot is diagnosed as the cause, ‘clot busting’ medication may be used to dissolve the clot, but this must be given within three hours of the stroke. Anti-clotting medication such as aspirin may also be given to stop the stroke from getting worse.
Anti-clotting medication is not given in strokes caused by haemorrhaging because it will make the bleeding worse.
Other Stroke treatments include:-
- tests on key functions like swallowing and movement
- checks on oxygen, glucose and blood pressure levels
- if swallowing is affected, fluids are given into a vein (intravenously) to avoid food going into the lungs.
Recovering from a stroke
More than half the people affected by cerebral haemorrhage lose consciousness early into the affliction, and in the most severe cases never regain it and die within a short time – perhaps a matter of a few days or even hours. Smaller haemorrhages often result in less brain damage and possibly no loss of consciousness.
Cerebral thrombosis or a minor embolism may produce symptoms similar to, but less severe than cerebral haemorrhage and in these cases recovery is more common.
In the first few days after a stroke, treatment provided by health professionals tends to focus on hydration and proper nourishment.
The next phase of treatment is recovery through rehabilitation. This involves a team of health professionals, including physiotherapists, speech therapists, occupational therapists, nurses and doctors.
If a stroke is caused by a blood clot, then taking a low-dose aspirin once a day may help make the blood less sticky and less likely to cause clots.
Maintaining an active lifestyle is important during the recovery period as this has been shown to produce longer term improvements in mobility.