Influence of circadian and activity patterns in onset of cerebral infarction

ABSTRACT

BACKGROUND AND OBJECTIVES: Stroke onset is known to vary by several factors. Although it has been known that stroke may develop most frequently in the morning, its association with the type of activity has quite rarely been described. METHODS: We prospectively investigated by interview the time of and the activity during or before the onset of stroke in patients with acute cerebral infarction from Aug. 1995 to Mar. 1996. The activities were subdivided into basal metabolic rate state, sedentary, light, moderate, and heavy movements based on the caloric expenditure. RESULTS: One hundred-twenty five patients were enrolled. The time of day when ischemic stroke most frequently occurred was from 800 AM to noon. The type of activity was significantly associated with stroke onset in that it developed most commonly during and just after sleep or resting. The relationship between the onset of stroke and such patterns of onset time and the activity was found only in the atherothrombotic infarction, but not in the other stroke types. CONCLUSION: We demonstrated that stroke has clear diurnal variation. Our observations also suggested that the activity may be significantly associated with stroke onset. These findings may be useful for better understanding of the pathogenesis and prevention of ischemic stroke.