Search

Background and Purpose —We estimated the incidence of first-ever cerebral infarction in regard to its subtypes and analyzed their risk factors separately in a community-based prospective cohort study in Japan. Methods —Stroke-free subjects (n=1621) aged ≥40 years were followed up for 32 years from 1961. During this period, 298 cerebral infarctions occurred and were divided into 167 lacunar, 62 atherothrombotic, 56 cardioembolic, and 13 undetermined subtypes of infarction on the basis of clinical information including brain imaging and autopsy findings. Results —The age-adjusted incidence of lacunar infarction (3.8 per 1000 person-years for men and 2.0 for women) was higher than that of atherothrombotic infarction (1.2, 0.7) and cardioembolic infarction (1.3, 0.5) in both sexes. Time-dependent Cox’s proportional hazard analysis revealed systolic blood pressure as well as age to be independent risk factors for all subtypes of cerebral infarction except for cardioembolic infarction in men. Additionally, ST depression on ECG, glucose intolerance, and smoking in men and left ventricular hypertrophy on ECG and body mass index in women remained significant risk factors for lacunar infarction. ST depression was also significantly related to events of atherothrombotic infarction in women. The risk of atrial fibrillation for cardioembolic infarction was outstandingly high in both sexes, and left ventricular hypertrophy and lower total cholesterol were additional risk factors for cardioembolic infarction in women. Conclusions —In this Japanese population, lacunar infarction was the most common subtype of cerebral infarction and had a greater variety of risk factors, including not only hypertension but also ECG abnormalities, diabetes, obesity, and smoking, than did atherothrombotic infarction or cardioembolic infarction.

Background and Purpose —Subarachnoid hemorrhage is a life-threatening disease that occurs mostly because of the rupture of intracranial saccular aneurysms. However, little is known about the prevalence of ruptured and unruptured aneurysms in the general population. The aim of the present study was to examine the prevalence of intracranial aneurysms on the basis of a consecutive autopsy series over a 30-year observation period in a general Japanese population in Hisayama. Methods —We evaluated 1230 consecutive autopsy cases with craniotomy among the total deaths of Hisayama residents during 1962 through 1991 (overall autopsy rate, 80.1%). Results —A total of 73 intracranial saccular aneurysms were found in 57 cases (4.6%). The prevalence of aneurysms for women was 2.4 times higher than that for men (7.1% versus 2.9%). Among men, the prevalence of aneurysms remained unchanged across the range of age groups. In contrast, there were 2 peaks in the prevalence of aneurysms for women falling in the 40- to 49-year (14.3%) and 60- to 69-year age groups (14.5%). The most common site of the aneurysms was the middle cerebral artery (31.5%), followed by the anterior communicating artery (30.1%), anterior cerebral artery (15.1%), vertebrobasilar artery (12.3%), and internal carotid artery (11.0%). Among these 73 aneurysms, 29 (39.7%) were ruptured. Ruptured aneurysms were common in subjects Conclusions —Our data suggest that intracranial aneurysms are more frequent in women in the general Japanese population. Aneurysms are more prevalent in the middle cerebral artery, but the risk of rupture is highest in the vertebrobasilar system.

Background and Purpose The relationship between alcohol intake and stroke has been inconsistent in previous studies. We examined the separate and combined effects of drinking habits and hypertension on stroke incidence in a prospective survey of a general Japanese population. Methods A total of 1621 stroke-free Hisayama residents aged 40 years or older were classified by their alcohol intake into nondrinkers, light drinkers ( Results During the follow-up period, cerebral infarction developed in 244 subjects and cerebral hemorrhage in 60. For men, the incidence of cerebral hemorrhage increased significantly with rising alcohol consumption. In contrast, the incidence of cerebral infarction was slightly lower in light drinkers than in nondrinkers, while it increased significantly in heavy drinkers compared with light drinkers. Female drinkers had a lower incidence of cerebral infarction but a slightly higher incidence of cerebral hemorrhage than nondrinkers, as did male light drinkers. Among the hypertensive subjects, the age- and sex-adjusted relative risk of cerebral hemorrhage was significantly elevated in heavy drinkers versus abstainers (3.13; 95% confidence interval [CI], 1.08 to 9.10), but the increase was not significant for light drinkers. In contrast, the relative risk did not significantly increase for normotensive light and heavy drinkers. Compared with hypertensive light drinkers, the relative risk of cerebral infarction significantly increased in hypertensive heavy drinkers (1.96; 95% CI, 1.08 to 3.57) but remained unchanged in normotensive heavy drinkers. Significant associations between alcohol intake and stroke were substantially the same even after controlling for other risk factors in multivariate analysis. Conclusions Among hypertensive individuals, heavy alcohol consumption leads to a significant increase in the risk of cerebral hemorrhage, suggesting a synergistic effect of alcohol and hypertension, while light alcohol consumption significantly reduces the risk of cerebral infarction.

Twenty-six first episodes of subarachnoid hemorrhage occurred among 1,621 Hisayama residents aged greater than or equal to 40 years during the 22-year follow-up of a prospective study. Subarachnoid hemorrhage was confirmed by both clinical and autopsy findings. The average annual incidence (96.1/100,000 population) was 3-13 times higher than any previously reported and steeply increased with age in both sexes, being 2.3 times higher for women than for men after adjusting for age. Nine patients (35%) died less than or equal to 8 hours after the onset of subarachnoid hemorrhage. None was correctly diagnosed on the death certificates, and four of the nine (44%) were misdiagnosed as intracerebral hemorrhage. We found the survival rate of patients suffering subarachnoid hemorrhage to be much lower than previously reported because we detected a large number of sudden deaths due to subarachnoid hemorrhage through the high rate of autopsy in our cohort (81.4%).