Stroke is a Cerebrovascular Accident

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The brain is the only organ which requires constant oxygen supply, and this small organ uses about 20 per cent of all the oxygen consumed by the body. If denied its oxygen quota for a very short time, even for a few minutes, brain tissues will die. When blood supply to the brain, or even a significant portion of it, is cut off, the severe oxygen deprivation can cause a stroke. This is almost always a disease of older people and the average age of stroke victim is 50 in our county. In the developed countries the average of stroke victim is 60 and above.

Stroke can be serious and even fatal. Major strokes can lead to prolonged and crippling illnesses, often involving loss of sensation in certain parts of the body, disturbances of speech, vision or memory, and loss of locomotion. Many stroke victims remain paralyzed and bed-ridden. However, many of them could be at least partially rehabilitated with proper medical care and attention. On the other hand, many strokes are so mild that they produce no, or few, lasting effects.

There are four major causes of strokes: (1) Blood clots, (2) Hemorrhage, (3) Tumour, and Blood vessel spasm in the brain. The commonest cause, however, is a blood clot. The clot may form in a blood vessel of the brain itself which has been damaged by arteriosclerosis, or may break off from a clot which has developed in the heart or elsewhere and travel to brain.

As commonly strokes occur due to blood clot or ischemia and hemorrhage, we will discuss these two types of strokes. In an ischemia stroke the blood supply to part of the brain is cut off because either atherosclerosis or a blood clot has blocked a blood vessel.

In a hemorrhagic stroke a blood vessel bursts, preventing normal flow and allowing blood to leak into an area of the brain and destroys it.

Ischemic Stroke:
Blockage can occur anywhere along the arterial pathways to the brain. Say for example, a large deposit of fatty material (atheroma) can develop in a carotid artery, reducing its blood flow to very negligible amount such as a trickle.

This condition is serious as each carotid artery normally supplies a large percentage of the brain's blood supply. Fatty material may also break off from the wall of the carotid artery, travel with the blood, and can get stuck up in a smaller artery, blocking it completely.

The carotid and vertebral arteries and their branches can become blocked in other ways. For example a blood clot formed in the heart or on one of its valves can break loose (thus becoming an embolus), travel through the arteries up in the brain and lodge there. This results in an embolic stroke.

A stroke can occur if inflammation or an infection narrows blood vessels that lead to the brain. Drugs such as cocaine and amphetamines also can narrow the blood vessels in the brain and produce stroke. A sudden drop in blood pressure can severely reduce blood flow to the brain, usually causing, fainting. However, a stroke can result if the low blood pressure is severe and prolonged. This situation can occur in the case of severe blood loss from trauma, injury or during surgery.

Symptoms:
many different symptoms can occur, depending on which part of the brain is affected. Neurological dysfunction is more likely to be severe, widespread, associated with a coma or stupor, and permanent. Strokes can cause depression, edema or swelling in the brain. Hemiparesis, slurring of speech and vision impairment may also occur.

Treatment:
Symptoms indicating a possible stroke require immediate medical attention. Oxygen administration and insertion of an intravenous line to ensure fluid and nourishment are the immediate steps to be taken.

For a stroke in evolution, anticoagulants such as heparin may be given, but are useless once the stroke is completed. Recent research suggests that paralysis and other symptoms may be prevented or reversed if certain drugs that break up clots such as streptokinase or tissue plasminogen activator are given within three hours of a stroke's onset. Intensive rehabilitation can help many people learn to overcome disability despite the impairment of some brain tissue.

Rehabilitation is started after intensive care treatment of stroke and as soon as blood pressure, pulse and breathing have stabilised. Doctors, the therapists and nurses combine their expertise to keep the patient's muscles strong and teach the patient to walk and talk again.

Intracranial Hemorrhage:
An intracranial hemorrhage is bleeding inside the skull. Bleeding can occur within the brain or around it. Hemorrhages occurring inside the brain are called intracerebral hemorrhage, those between the brain and sub arachnoid space are sub-arachnoid hemorrhages, those between the layers of the covering (meninges) of the brain are sub-dural hemorrhages and those between the skull and covering of the brain are epidermal hemorrhages.

An intracerebral hemorrhage begins abruptly with a headache, followed by signs of steadily increasing neurologic losses, such as weakness, inability to move (paralysis), numbness, loss of speech or vision and confusion.

Nausia, vomiting, seizures and loss of consciousness are common and may occur within a few minutes. In sub-arachnoid hemorrhage, the usual source of bleeding is a weak blood vessel that suddenly ruptures. Aneurysms that cause sub-arachnoid hemorrhages usually produce no symptoms before rupturing.

However, leakage from aneurysms may press on a nerve and warning signs such as a headache, facial pain, double vision etc. may become evident. A rupture usually Products x sudoness. Some remain in a coma. Blood and cerebrospinal fluid (CSF) around the brain irritate the surrounding membrane producing headaches, vomiting and dizziness.

Frequent fluctuation in the heartbeat and breathing rate often occur as well, sometimes accompanied by seizures. About 25 Per cent of the people have neurologic problems usually, paralysis on one side of the body.

Treatment:
Treatment for a hemorrhagic stroke is similar to that for an ischemic stroke, with two important differences: Anticoagulants are not given and surgery may save the person's life but often leaves the person with severe neurologic disabilities. The goal of surgery in such cases is to remove blood that has accumulated in the brain and to release increased pressure.

Prognosis:
Many people who suffer a stroke recover all or most normal function and enjoy years of normal life. Others are physically and mentally devastated and unable to move, speak or eat normally.

About 50 per cent cases with one-sided paralysis and most of those with less severe symptoms recover some function by the time they leave the hospital and can eventually take care of their basic needs.

They can think clearly and walk adequately, although they may have limited use of the affected arm or the leg.