Two percent of the U.S. adult population, 4.4 million people, have cerebrovascular disease (stroke).2 More than 1 million of these individuals are limited in their usual activity.6 Prevalence rises from 2 percent in men at 45 to 54 years to 12.5 percent for men aged 75 and over and from 1 to 10.7 percent in the respective age groups in women (Fig. 1-9). In the Framingham Study, the most common variety of complete stroke is atherothrombotic brain infarction, which accounts for 61 percent of all strokes (excluding transient ischemic attacks).28 Next most common are cerebral embolus (24 percent), intracerebral hemorrhage, and subarachnoid hemorrhage. Intracerebral hemorrhage apparently has declined most in recent years (see also Chap. 98).
Figure 1-9: Prevalence of stroke and CHF by age and sex, United States, 1988-1994 (self-reported stroke and congestive heart failure from health interviews). (From the National Health and Nutrition Examination Survey, National Center for Health Statistics.)
In the Framingham Study, the chance of having a stroke before age 70 was 5 percent for both sexes.28 Annual incidence in the Atherosclerosis Risk in Communities Study was 5.3 per 1000 persons at risk in black men aged 45 to 64 years, 4.0 in black women, 2.0 in white men, and 1.5 in white women.29 Of the incident events, 83 percent were ischemic strokes, 10 percent were hemorrhagic, and 7 percent were subarachnoid hemorrhage. Among the 54 percent classified as definite thrombotic brain infarctions, 38 percent were classified as lacunar, more than twice as many in blacks as in whites. The time course of functional recovery is strongly related to initial stoke severity.30 Of survivors of an initial event, 50 to 70 percent return to functional independence, but 15 to 30 percent become permanently dependent. Institutional care is required by 20 percent at 3 months after onset.3!
Stroke attacks have become less severe in recent years, but prevention is essential for dealing effectively with the problem of stroke because of the irreversibility of established ischemic brain damage and the neurologic deficit it induces. The underlying cerebrovascular disease is not a necessary consequence of aging. Modifiable contributing factors offer the possibility of prevention in identified stroke candidates. Stroke prevention requires early and sustained treatment of persons with hypertension, cardiac disorders (especially atrial fibrillation), and transient cerebral ischemic attacks.
Cerebrovascular disease, the third leading cause of death, was responsible for 207,000 deaths in the United States in 1974, but by 1997, the number had declined to 160,000.4i2 This decline is remarkable because the population of older persons increased substantially during that time. The age-adjusted death rate declined by more than 50 percent over this period, but the decline appears to have almost ended in the 1990s.! This disease still accounts for 7 percent of all deaths, and 44,000 of them occur in individuals younger than 75 years of age. Under age 65, the mortality rate is three times greater in blacks than in whites, largely as a result of the higher prevalence and increased severity of hypertension in the former. The proportion of strokes that result in death within 1 year is about 22 percent in men and 25 percent in women, less if the stroke occurs before age 65 (see Fig. 1-7). For men or women under age 65, however, only 50 percent survive past 8 years (see &H0; Table 1-6; see also Chap. 98).
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