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Stroke is the fifth leading cause of death in the United States (after heart disease, cancer, chronic lung disease, and injuries and accidents) and the most common disabling neurologic disorder. Approximately 800,000 new strokes occur and ~130,000 people die from stroke in the United States each year. The lifetime risk of stroke after age 25 years is ~25% worldwide.
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The incidence of stroke increases with age; ~65% of all strokes occur in those older than 65 years. Both modifiable and genetic (usually polygenic) risk factors (Table 13-1) contribute to stroke risk. The incidence and mortality of stroke have decreased in recent decades, largely because of reduction in smoking and improved treatment of hypertension, dyslipidemia, and diabetes. At the same time, stroke incidence has increased in younger (<55-year-old) patients.
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APPROACH TO DIAGNOSIS
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Stroke is a syndrome with four key features:
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Sudden onset—The sudden onset of symptoms is documented by the history.
Focal involvement of the central nervous system—The site of involvement is suggested by symptoms, pinpointed more precisely by neurologic examination, and confirmed by CT or MRI.
Lack of rapid resolution—The duration of neurologic deficits is documented by the history. The classic definition requires that deficits persist for ≥24 hours to distinguish stroke from transient ischemic attack (discussed later). However, any such time point is arbitrary, and transient ischemic attacks usually resolve within 1 hour.
Vascular cause—A vascular cause may be ...