Stroke

Fig - Stroke

Definition:
A stroke or brain attack occurs when blood flow to an area of the brain is interrupted by a blocked or broken blood vessel. When a stroke occurs, it kills brain cells in the immediate area. When the brain cells die, they release chemicals that set off a chain reaction that endangers brain cells in a larger, sorrounding area of brain tissue. Without prompt medical treatment, this larger area of brain cells will also die.

When brain cells die, the abilities that area of the brain control are lost or impaired. Some people recover completely from less serious strokes, while others lose their lives to very severe ones.

Types of Stroke

Brain attacks occur in two main ways:

Fig - Ischemic Stroke

Ischemic Stroke
In ischemic stroke, a clot blocks a blood vessel in the brain. A clot may form in a blood vessel in the brain or leading to the brain, or it can be formed elsewhere in the body, usually in the heart, and travel to the brain. Ischemic stroke can also happen as the result of the unhealthy blood vessels clogged with a buildup of fatty deposits and choloesterol in the wall of an artery. Approximately 80 percent of all strokes are ischemic.

Fig - Hemorrhagic Stroke

Hemorrhagic Stroke
In hemorrhagic strokes, a blood vessel in the brain breaks or ruptures. Hemorrhagic stroke can be caused by a number of disorders which affect the blood vessels, including long-standing high blood pressure and cerebral aneurysms. An aneurysm is a weak or thin spot on a blood vessel wall. Hemorrhagic strokes account for about 20 percent of all brain attacks.

Symptoms

Even among those who recognize brain attack as a medical emergency, many are unable to recognize stroke symptoms. The most typical symptoms include:

  • Sudden numbness or weakness of face, arm or leg, specially on one side of the body.
    • An entire side of the body, face, arm and leg (hemiparesis).
    • An arm or a leg (monoparesis).
  • Sudden confusion, troble speaking or understanding.
    • Expressing or comprehending words (aphasia).
    • Slurring of words (dysarthria).
  • Sudden trouble seeing in one or both eyes.
    • Loss of vision in one eye.
    • Loss of vision of one side.
    • Double vision.
  • Sudden trouble walking, dizziness, loss of balance or coordination.
    • Loss of balance on standing or walking (truncal ataxia).
    • Of arm or leg (limb ataxia).
Stroke can present with any of the above symptoms in a mild, moderate, or severe degree and in any combination. Other symptoms include:
  • Sudden severe headache with no known cause.
  • A sudden decline in the level of consciousness.

Risk Factors

Fig - Artery Blood Flow

The treatable risk factors for stroke are the following:

  • Hypertension (High blood pressure)
  • Transient Ischemic Attack
  • Carotid artery disease
  • Atrial fibrillation
  • Heart disease/Patent Foramen Ovale
  • Cigarette smoking
  • Diabetes mellitus
  • Increased Homocystein level
  • Hypercholesterolemia (High cholesterol)
  • Excessive alcohol intake
  • Overweight
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