Cerebrovascular accident

A stroke or cerebrovascular accident (CVA) occurs when the blood supply to a part of the brain is suddenly interrupted by occlusion (called an ischemic stroke -- approximately 90% of strokes), by hemorrhage (called a hemorrhagic stroke -- about 10% of strokes) or other causes. Ischemia is a reduction of blood flow most commonly due to occlusion (an obstruction). On the other hand, hemorrhagic stroke (or intracranial hemorrhage), occurs when a blood vessel in the brain bursts, spilling blood into the spaces surrounding the brain cells or when a cerebral aneurysm ruptures. The mortality and long-term morbidity prognosis is generally worse for hemorrhagic strokes than for ischemic strokes. A small proportion of strokes are watershed strokes caused by hypoperfusion (usually due to hypotension) or other vascular problems including vasculitis.

Signs and symptoms

The symptoms of stroke are usually easy to spot:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• sudden numbness or weakness, especially on one side of the body;
• reflexes can initially be decreased on the affected side, but are often livelier than on the other side
• the face is normally spared (as this is served by both hemispheres), but the corner of the mouth can be affected on the same side as the limb symptoms
• sudden confusion or aphasia (trouble speaking) or understanding speech;
• sudden trouble seeing in one eye (or rarely both);
• unequal pupils
• sudden trouble walking, dizziness, or loss of balance or coordination.

A subgroup loses consciousness as part of the initial presentation. This occurs more often in bleeding than in thrombosis.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

A sudden-onset severe headache can denote subarachnoid hemorrhage, which is a stroke-like clinical entity. Some other forms of stroke can feature headaches.

Related Topics:
Headache - Subarachnoid hemorrhage

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

If the symptoms resolve within an hour, or maximum 24 hours, the diagnosis is transient ischemic attack (TIA), and not a stroke. This syndrome may be a warning sign, and a proportion of patients develop strokes in the future. The chances of suffering a stroke can be reduced by using aspirin, which inhibits platelets from aggregating and forming obstructive clots.

Related Topics:
Transient ischemic attack - Aspirin

~ ~ ~ ~ ~ ~ ~ ~ ~ ~