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
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.
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.
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
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
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.
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.
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.
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.
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.
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