Stroke

stroke

Strokes come suddenly and without warning - hence the name - and can cause weakness, paralysis or even death. However, rehabilitation can help survivors overcome any resulting disability.

A stroke is a failure in the blood supply to the brain, caused either by internal bleeding (cerebral haemorrhage) or by a blocked blood vessel (cerebral infarction). Either of these leads to shortage of oxygen and nutrients and a shut-down of brain activity in the affected area.

The person involved often has little or no warning before he is struck down with partial or total weakness or paralysis down one side of the body (hemiplegia). This may be accompanied by loss of speech (aphasia) or other problems of the higher brain functions. Much more rarely, strokes occur away from the parts of the brain that control movement, so there is no paralysis.
A COMMON DISORDER
The effects of a stroke usually reach a maximum within minutes, though sometimes it may take a few hours. In the following weeks, there is usually an improvement as other brain cells take over the functions of those destroyed.

Strokes are one of the most common causes of death in the Western world, and about a quarter of all physically handicapped people in developed countries have been disabled by strokes. Strokes are particularly common among the elderly, but they can affect people of all ages.
HIGH BLOOD PRESSURE
Recent medical research has, with some success, focused on the prevention of strokes by identifying and treating those most at risk. This means largely those suffering from hypertension (high blood pressure), which has come to be seen as a major factor in disease of the blood vessels.
BLOCKAGES
If a cerebral artery is so blocked that blood cannot get through, the cells it supplies with oxygen and nutrients quickly die. Fortunately, in the brain there are many cross-connections between neighbouring blood vessels, so the area of damage is generally restricted.

Arteries get blocked either as a result of a disease within the artery itself - a cerebral thrombosis - or by a free-floating blood clot which passes through the blood supply to the brain and gets stuck. This is called a cerebral embolism.

A cerebral thrombosis may be caused by inflammation, perhaps as a result of an infection, but more usually when fatty deposits accumulate on the artery walls. This condition, which is known as atherosclerosis, also affects the blood vessels of the heart, and is a major cause of heart attacks.

Another link between strokes and heart problems are embolisms, often caused by heart disease. Although some arise from disorders in the main arteries of the neck, most embolisms (blood clots) form on the valves or on the damaged inside walls of the heart, or in the upper chambers of the heart when it is not beating effectively, before breaking off and entering the blood stream.
BURST VESSELS
The other cause of strokes is a burst blood vessel, which releases a rush of blood under pressure into the brain, severely damaging nerve fibres. The most common cause is an aneurysm, a weak spot in the artery wall, which may be there since birth or the result of a traumatic injury, such as whiplash or a blow to the head. Aneurysms may rupture under the influence of higher than normal blood pressure.

High blood pressure also tends to produce weak places in the smaller arteries within the brain.

Some people are much more likely to have strokes than others. Diabetics, smokers, people with heart disease and/or high blood pressure, and those with a high level of cholesterol in their blood are particularly at risk. In addition, strokes seem to run in families, although this is difficult to prove as they are so common anyway.

Being in a high risk group means preventative measures can be taken to reduce the chances of a stroke. Such action means that the number of strokes is going down in countries such as the USA. Much of this is due to better treatment of high blood pressure. The main problem is that most people who have hypertension do not suffer from it. They feel well and may need some convincing about modifying their diet or behaviour or agreeing to take drugs on a daily basis.
PREVENTATIVE MEASURES
After minor strokes, from which a complete recovery has been made, it's important to stop another, more serious attack. Sometimes there is a surgical option, dealing with the large blood vessels in the neck. These may have developed roughened linings from which pieces fly off to become emboli.

Small daily doses of aspirin can help to prevent strokes. Relatively small amounts of the drug interfere with the clotting ability of the blood; not enough to cause problems, but enough to stop some clots forming in the blood vessels. Other, more specialized anti-coagulant drugs are used to prevent strokes when one of the heart conditions known to cause them is identified.
TREATING STROKES
Initial hospital treatment for a stroke concentrates on damage limitation. Blood pressure is reduced, using drugs if necessary. Occasionally, blood clots can be surgically removed, but they are usually in inaccessible areas of the brain.

The main care of people who have had strokes is in the hands of nursing staff and various therapists who help in the often necessarily slow recovery period. Nursing is important to prevent bed sores and chest troubles, both of which can seriously impair recovery.
THERAPY
Physiotherapists work to maximize the amount of feeling and function that gradually returns to affected areas. At first, they make sure that the unused limbs remain supple. When the patient is up and about - as early as possible, as prolonged periods in bed can be dangerous - physiotherapists concentrate on overcoming abnormal reflexes.

Speech therapists help those suffering from speech difficulties, while occupational therapists try to prepare stroke victims for a return to as normal a life as possible, given whatever disabilities other therapies have not managed to eliminate. Therapists generally continue to work with patients once they have left hospital. An important part of their work is to support and guide the victims' families to make sure they are not so over-protective as to slow recovery.
OUTLOOK
Although strokes can be fatal, the majority of victims recover to some degree. With therapy, at least half progress to a point where they can look after themselves, while the remainder may have to depend on people to look after them at home.

Continue reading here: Symptom: Fatigue

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