Overview of strokes Neurological Disorders?
THE word “stroke”-literally a striking down-has frightening overtones for most people. A stroke can be very serious, even fatal. But it can also be quite mild. A “little stroke” does not necessarily shorten a person’s life and may impair his faculties only temporarily. It most certainly should not be looked upon as the end of a man’s productive life.
Overview of Strokes Neurological Disorder
Strokes, which doctors term cerebrovascular accidents, or apoplexy, have advanced from seventh to third place among the natural causes of death, and are now behind only heart disease and cancer. Hundreds of thousands of people are killed by strokes each year, and many more suffer non-fatal strokes. Yet strokes receive less attention than many maladies that affect fewer persons.
Often called apoplexy, a stroke occurs when the blood supply to the brain, or to some portion of it, is cut off. To perform its vital functions the brain needs an enormous quantity of oxygen- twenty per cent of the total amount consumed by the body. It gets this oxygen directly from the blood-stream. More than a pint and a half of blood must be circulated through the brain every minute. If brain cells are denied their quota of oxygen for even five minutes, they die. Once killed, they cannot grow back. Though this damage is irreparable, the brain’s ability to perform all functions is often recovered. The area affected may be large or small.
A stroke usually takes place in the cerebrum, that part of the brain where nerve centres controlling sight, hearing, speech and bodily movements are located. These zones of nerve cells are on the surface of the cerebrum, and nerve fibres run from them deep into the brain and on down the spinal cord, carrying impulses between the zones and the parts of the body they affect. If a blockage stops blood flow to one of these control zones, or to nerve fibres leading from the zones, then the activity controlled by the zone will be impaired.
For example, if the nerve centre controlling speech is damaged, the ability of the zone to co- ordinate ideas and words and to send correct signals through the nerve to tongue and vocal cords is affected. The victim will find his ability to speak impaired.
Overview of strokes Neurological Disorders?
There are at least four ways in which a stroke can take place:
1. Clotting. In atherosclerosis, fatty substances like cholesterol accumulate on the walls of the blood vessels, narrowing the space through which the blood can pass. (Atherosclerosis is the most serious form of hardening of the arteries.)As the blood flow slows down, it may begin to stagnate. Tiny “platelets”-specks of chemical “dust” in the blood-stream-may begin to cluster on rough spots caused by atherosclerosis. Thus coagulation may form the core of a clot, or thrombus, which blocks the further flow of blood and produces a condition known as thrombosis.
Sometimes the artery seems to be closed by a nervous spasm. Occasionally the spasm relaxes or the brain manages to establish some circulation round the obstruction. When this happens, many of the impaired brain abilities return and much of the paralysis disappears. Another form of clotting is called embolism. After surgery and under some other conditions, a blood clot, or em bolus, may break away in the body and be carried through arteries to the brain, where it blocks a blood vessel. Em bolus is from the Greek word meaning “a plug.” When strokes occur in young persons, a cerebral embolism is usually responsible.
Overview of strokes Neurological Disorders? Step by step
Once lodged in the brain, little can be done about an em-bolus. But administration of one of the “anticoagulant” drugs may prevent the formation of additional embolism or the growth of the one already present. Anticoagulants also slow coagulation of the blood and prevent formation of embolism during surgery.
2. Haemorrhage. A brain artery may rupture. The blood escapes, damaging the surrounding tissue. Since the brain floats in cerebral- spinal fluid and is encased by unyielding bone, much bleeding may also cause serious pressure on the brain. Cerebral haemorrhage usually detectable by blood in the spinal fluid—is harder to recover from than any other type of stroke.
If the haemorrhage is massive, death may come swiftly. But most haemorrhages are small. There may be only a slow leakage of blood, only a few tiny arteries and capillaries broken down. The damage may not, therefore, be enough to cause the patient to lose consciousness. Some clots resulting from cerebral haemorrhage may be re- moved by surgery. Where the clot has not hardened, the surgeon may drill a small hole in the skull and drain the liquid clot through a hollow needle.
3. Compression. A tumour, swollen brain tissue or a large clot from a cerebral blood vessel may press hard enough upon an adjoining blood vessel to stop its flow.
4. Spasm. An artery of the brain may constrict and thus reduce or pinch off the blood passage, the damage depending upon how long it takes the affected artery to relax again. The specific role of spasms of the cerebral vessels and whether they actually occur in strokes are subjects of medical controversy:
The seriousness of a stroke depends upon which blood vessel is affected, the kind of blockage, how long the brain areas involved go without oxygen, plus a number of other considerations. In many cases, especially among younger persons, other blood vessels may take over the functions of the one blocked. Sometimes, even When certain brain centres have died, other areas of the brain are gradually able to take over.
On rare occasions the victim of a stroke may be a young person, even a child. In such cases the stroke results from some illness like rheumatic fever or extremely high blood pressure. It might also result from an aneurysm (a blood-filled pouch) of a blood vessel, which the child was born with. Surgery can often remove this difficulty and, if the rest of the circulatory system is healthy, the child can look forward to a normal life span.
The average age of a stroke victim is sixty-four. There has been a steady increase in the number of strokes in recent years, because the number of elderly persons has been increasing. Elderly males seem to succumb more classify than elderly females. No reliable statistics are available on the frequency of recurrence of strokes, but it is generally agreed that, in most cases, a stroke victim is sooner or later stricken again.
If the stroke victim does not die-and he usually does not-a variety of things may happen to him. He may feel tired, numb, weak, porous or confused. He may show emotional or personality changes. He may have headaches and suffer disturbances of vision, speech or memory. He may lose sensation in certain parts of his body. He may not be able to walk. He may be stricken paralytic-ally and have to lie in bed for years.
What can you do to avoid a stroke?
You can, first of all, have a thorough annual physical examination that will include checking your blood pressure and your heart action. Strokes usually do not come without warning signs. Approximately one out of every four individuals with a systolic blood pressure of over 200 may eventually have a stroke, according to an organisation of American doctors which has made nearly three million health examinations.
Early detection of high blood pressure gives you the opportunity to reduce it. In doing so, you reduce your chance of having heart attacks as well as strokes. Additional premonitory symptoms of stroke include: severe aches in the back of the head and neck, dizziness or fainting, motor or sensory nerve disturbance, nose bleeding and certain haemorrhages in the retina of the eye. These symptoms, however, can be found with other diseases and are not necessarily indicative of high blood pressure or pending stroke.
Causes of High blood Pressure
The causes of high blood pressure remain in dispute, but doctors have come up with several methods of controlling it:
- (1) avoidance of overweight and strain of all kinds;
- (2) various diets;
- (3) surgery -the severing of nerves which constrict the arteries;
- (4) drugs which temporarily relax the blood vessels.
- Happily the body is often capable of making its own repairs. Some physicians advocate anticoagulants as a preventive measure. But there is no unanimity about the worth of this treatment; there is no certain evidence that it might not in some cases be harmful. Going on a low-fat diet in the hope of preventing a stroke is futile once atherosclerosis has made its subversive inroads.
Overview of strokes Neurological Disorders?
A stroke is obviously not to be brushed aside lightly. On the other hand, one should not get panicky when one occurs. A little stroke might do no more than make the victim feel a bit ill and cause some slight, momentary disturbance of his faculties. Even a more severe stroke is seldom as severe as it seems at first.
In the shock of the initial impact a victim and his family may feel that he is hopelessly paralysed or has gone out of his mind. This is hardly ever the case. And it does no one any good, least of all the victim, if everyone behaves as though the funeral notices had gone out. Even the severest cases can recover with astonishing rapidity.
A stroke does not necessarily mean the end of a career
Louis Pasteur, the great French scientist who fathered microbiology, lived twenty-seven years and did his greatest work after suffering a stroke at forty-six. Sir Joshua Reynolds produced a hundred canvases after a stroke at fifty-nine.
George Frederick Handel composed his immortal Messiah and lived for many years after a stroke. Great advances have been made in treating and retraining patients recovering from a stroke. Special exercises, water therapy and electric devices are employed to restore function to limbs and teach undamaged brain centres to take over the tasks from those that have been injured.
Much, of course, depends on the patient’s own courage and desire to regain his skills. It is humiliating for a man to have to learn to speak again, to have to teach his left hand to do what’s right hand did, to have to learn to tie his shoes.
He needs all the understanding that his friends and family can give him. When Pasteur was stricken with a cerebral thrombosis, his condition seemed so hopeless that construction was stopped on a laboratory the government was building for him. Pasteur learned of this, and declined rapidly. His friends appealed to Emperor Napoleon III, who ordered construction to be resumed. Pasteur then began to recover and in the new laboratory conquered rabies and half a dozen other diseases.
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Topics of General Science & Ability (CSS)