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.