Cerebrovascular Accident (CVA), more commonly known as a stroke, is a sudden interruption of blood flow in a vessel that supplies the brain. Strokes are the third leading cause of death worldwide; 600,000 strokes occur in the U.S. each year (Taber's 2069). CVA is the most serious type of stroke. A transient ischemic attack (TIA), also known as a mini-stroke, is a temporary interruption of blood flow to the brain. This type of stroke is most commonly a blood clot or thrombus that quickly breaks apart or becomes dislodged (Butler 419).
Risk factors for stroke include advanced age (esp. greater then 65), hypertension, carotid artery disease, smoking, hyperlipidemia, diabetes, atrial fibrillation, history of myocardial infarction and atherosclerosis (Taber's 2069).
CVA's are most commonly caused by blockage of the carotid or intracerebral arteries by clot or atherosclerosis, known as cerebral infarction. CVA's of this type account for 80% of all strokes (Taber's 2069). Cerebral infarction is usually treated with thrombolytic drugs (breaks up thrombus) or blood thinners. Although these drugs can reduce the chances for another cerebral infarction, they triple the chances of intracerebral hemorrhage (Taber's 2069.
Most other strokes are caused by intracerebral hemorrhage (bleeding in the brain) caused by a ruptured blood vessel. Hypertension is the most common cause of intracerebral hemorrhage (Tyner 160). Hemorrhagic strokes have a 50% mortality rate. If caught early, they can sometimes be treated by repairing intracerebral aneurysms (Taber's 2069).
The seriousness of the stroke depends on how long blood flow was interrupted, the area of the brain affected, and the extent of permanent neurological damage. For example, occlusion of the right middle cerebral artery would affect the frontal and parietal lobes. Occlusion of the right or left posterior cerebral artery would affect the occipital lobe (Tyrer 161-162).