What causes a stroke?

Stroke is the primary neurological problem in the United States and in the world. Stroke is the third ranking cause of death, with the overall mortality rate of 18% to 37% for the first stroke and as high as 62% for subsequent strokes. The stroke usually results from one of four events:

*Cerebral thrombosis (a blood clot within a blood vessel of the brain or neck),
*Cerebral embolism (a blood clot or other material carried to the brain from another part of the body),
*Cerebral ischemia (decrease of blood flow to an area of the brain), and
*Cerebral hemorrhage (rupture of a cerebral blood vessel with bleeding into the brain tissue or spaces surrounding the brain).

Cerebral thrombosis
Cerebral arteriosclerosis and slowing of the cerebral circulation are the major cause of cerebral thrombosis, which is the most common cause of stroke. Cerebral thrombosis does not develop abruptly, a transient loss of speech, hemiplegia, or paresthesias in one half of the body may precede the onset of severe paralysis by a few hours or days.

Cerebral embolism
Infective endocarditis, rheumatic heart disease, myocardial infarction and pulmonary infections are the sites where emboli originate. The emboli usually lodges in the middle cerebral artery or its branches, where it disrupts the cerebral circulation.

Cerebral ischemia
Cerebral ischemia is mainly due to artheromatous constriction of the arteries supplying the brain. The most common manifestation is a transient ischemic attack.

Cerebral hemorrhage
Hemorrhage may occur in the extradural space, subdural space, sub arachnoid space or intracerebrally causing hematomas. The bleeding is usually arterial and occurs particularly around basal ganglia. The onset is abrupt, with severe headache. When the hematoma enlarges, neurological deficit occurs in the form of decreased alertness and abnormalities in the vital signs. In pronounced cases, unconsciousness or coma results.

The other risk factors are:

*Hypertension - the major risk factor. Controlling hypertension is the key to prevent stroke.
*Cardiovascular diseases - most cerebral embolism originates in the heart.
*High cholesterol.
*Obesity.
*Elevated hematocrit - increases the risk of cerebral infarction.
*Diabetes.
*Oral contraceptives.
*Smoking.
*Drug abuse (cocaine).
*Alcohol consumption.

Stroke is life changing. Being aware of the symptoms and doing all that you can to avoid those which threaten the life with stroke can make a difference. If in doubt, do contact your doctor and certainly if there is a history of stroke in the family, it would be a good idea to be vigilant and to have regular check-ups to protect yourself from the possibility of stroke, and to follow the professional advice given by your doctor.

Stroke

Stroke is the primary neurologic problem in the United states. It is the third ranking cause of death, with an overall mortality rate of 18% to 37% for the first stroke and as high as 62% for subsequent strokes. According to a recent study, there are approximately 2 million people surviving strokes who have some disability, and of these there are 40% who need assistance with the activities of daily living.

A stroke, or cerebrovascular accident (CVA), is a sudden loss of brain function resulting from disruption of the blood supply to a part of the brain. A stroke usually results from one of the four events:

1. Thrombosis - A blood clot within a blood vessel of the brain or neck.
2. Cerebral embolism - A blood clot or other material carried to the brain from another part of the body.
3. Ischemia - Decrease of blood flow to an area of the brain.
4. Cerebral hemorrhage - Rupture of the cerebral blood vessel with bleeding into the brain tissue or spaces surrounding the brain.

The result is an interruption to the blood supply to the brain, causing temporary or permanent loss of movement, thought, memory, speech or sensation. The signs of stroke varies from person to person. The common cause of stroke is the cerebral thrombosis. The signs of cerebral thrombosis are headache, dizziness, cognitive changes, or seizures. The signs of cerebral thrombosis does not develop abruptly. There is transient loss of speech, hemiplegia, or paresthesias in one half of the body which may precede the onset of severe paralysis by a few hours or days.

When it comes to cerebral embolism, the onset of signs and symptoms are sudden. Hemiparesis or hemiplegia with or without loss of speech and loss of consciousness are the common symptoms. They are found in people who are already diagnosed with cardiac or pulmonary diseases like infective endocarditis, rheumatic heart disease, myocardial infarction, as well as pulmonary infections. These are the sites where the emboli originates.

The next common manifestation of stroke caused by cerebral ischemia is the TIA. TIA is the transient ischemic attack, which is a temporary episode of neurologic dysfunction commonly presents with sudden loss of motor, sensory, or visual function. It lasts for a few seconds or minutes but no longer than 24 hours. TIA is the warning sign of impending stroke, which has its greatest incidence in the first month after the first attack. The symptoms include

a. sudden and painless loss of vision of one eye,
b. dimming or graying out of the vision field,
c. diplopia,
d. disturbances of consciousness,
e. numbness,
f. Weakness in either a hand or leg,
g. difficulty in speaking,
h. difficulty in understanding speech,
i. apraxia (inability to perform a previously learned action).

Urinary and stool incontinence affects the person once he is affected with stroke. Homogenous hemianopsia (loss of half of the visual field), diplopia (double vision), hemiparesis (one sided weakness), hemiplegia (one sided paralysis), ataxia (unsteady gait), dysarthria (difficulty in speaking), dysphagia (difficulty in swallowing), paresthesia (numbness or tingling of body parts), aphasia (difficulty to form words), and apraxia (inability to perform a previously learned action) are the classical signs of stroke.

The management is mainly supportive. Prevention of stroke is the best possible approach. They can be prevented by controlling hypertension, high cholesterol, obesity, diabetes, smoking, drug abuse (especially cocaine) and alcohol consumption.