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.

Diagnosis

Stroke is diagnosed through several techniques: a neurological examination, blood tests, CT scans (without contrast enhancements) or MRI scans, Doppler ultrasound, and arteriography. The most important risk factors for stroke are hypertension, heart disease, diabetes, and cigarette smoking. Other risks include heavy alcohol consumption, high blood cholesterol levels, illicit drug use, and genetic or congenital conditions. Some risk factors for stroke apply only to women. Primary among these are pregnancy, childbirth, menopause and the treatment thereof (HRT). Stroke seems to run in some families. Family members may have a genetic tendency for stroke or share a lifestyle that contributes to stroke.

Related Topics:
Blood test - CT scan - MRI scan - Doppler ultrasound - Arteriography - Heart disease - Diabetes - HRT

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If a stroke is confirmed on imaging, various other studies may be performed to determine whether there is a peripheral source of emboli:

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• an ultrasound/doppler study of the carotid arteries (to detect carotid stenosis)
• an electrocardiogram (ECG) and echocardiogram (to identify arrhythmias and resultant clots in the heart which may spread to the brain vessels through the bloodstream)
• a Holter monitor study to identify intermittent arrhythmias
• an angiogram of the cerebral vasculature (if a bleed is thought to have originated from an aneurysm or arteriovenous malformation)