[Incidence of cerebrovascular accidents in a medium-sized French town]

Abstract

Beginning in 1985, the Dijon Stroke Registry has identified every case of stroke occurring in this city of 140,000 inhabitants. The systematic use of a CT scan and multiple other sources of information ranging from hospital doctors to general practitioners make it possible for us to have virtually exhaustive data on stroke incidence. The gross incidence was 170 per 100,000 among men and 126 per 100,000 among women. Specific incidence by age and sex shows female predominance up to 30 years of age, and male predominance among victims from 30 to 80 years old. Beyond 80, rates were identical for both sexes. In 68% of the cases, the strokes were caused by infarct; in 12%, by lacunae; in 15%, by cerebral hemorrhage; in 5%, by subarachnoid hemorrhage. Significant differences existed in this distribution according to age, with a clear predominance of young people among those having subarachnoid hemorrhage, while, for those over 40, cerebral hemorrhages were frequent; the proportion of infarct increased with age for both sexes. A peak of incidence for infarct appeared during winter, while transient ischemic accident was more frequent in summer. Cerebral hemorrhage had a similar incidence throughout the year. Mortality was high during the first month (12.5% during the first week, 21.5% during the first month), and reached 30% during the first year. These results are comparable to those generally observed among white occidental populations. They confirm the limited incidence of hemorrhages (contrary to what has been observed in Japan), emphasize the important and often underestimated role of lacunar syndromes, and the seasonal variations specific to each mechanism.