on behalf of the German Stroke Data Bank CollaboratorsBackground and Purpose-Data on risk factors for etiologic subtypes of ischemic stroke are still scant. The aim of this study was to characterize stroke subtypes regarding risk factor profile, outcome, and current treatment strategies. Methods-We analyzed data from 5017 patients with acute ischemic stroke (42.4% women, aged 65.9Ϯ14.1 years) who were enrolled in a large multicenter hospital-based stroke data bank. Standardized data assessment and stroke subtype classification were used by all centers. Results-Sex and age distribution, major risk factors and comorbidities, recurrent stroke, treatment strategies, and outcome were all unevenly distributed among stroke subtypes (PϽ0.001, respectively). Cardioembolism, the most frequent etiology of stroke (25.6%), was particularly common in the elderly (those aged Ͼ70 years) and associated with an adverse outcome, a low rate of early stroke recurrence, and frequent use of thrombolytic therapy and intravenous anticoagulation. Large-artery atherosclerosis (20.9%), the most common cause of stroke in middle-aged patients (those aged 45 to 70 years), showed the highest male preponderance, highest rate of early stroke recurrence, and highest prevalence of previous transient ischemic attack, current smoking, and daily alcohol consumption among all subtypes. The highest prevalence of hypertension, diabetes mellitus, hypercholesterolemia, and obesity was found in small-vessel disease (20.5%), which, in turn, was associated with the lowest stroke severity and mortality. Conclusions-Our results foster the concept of ischemic stroke as a polyetiologic disease with marked differences between subtypes regarding risk factors and outcome. Therefore, studies involving risk factors of ischemic stroke should differentiate between etiologic stroke subtypes. (Stroke. 2001;32:2559-2566.)

Background and Purpose-Chronic infectious diseases may increase the risk of stroke. We investigated whether periodontal disease, including periodontitis and gingivitis, is a risk factor for cerebral ischemia. Methods-We performed a case-control study with 303 patients examined within 7 days after acute ischemic stroke or transient ischemic attack, 300 population controls, and 168 hospital controls with nonvascular and noninflammatory neurological diseases. All subjects received a complete clinical and radiographic dental examination. The individual mean clinical attachment loss measured at 4 sites per tooth served as the main indicator for periodontitis. Results-Patients had higher clinical attachment loss than population (PϽ0.001) and hospital (Pϭ0.010) controls. After adjustment for age, sex, number of teeth, vascular risk factors and diseases, childhood and adult socioeconomic conditions, and lifestyle factors, the risk of cerebral ischemia increased with more severe periodontitis. Subjects with severe periodontitis (mean clinical attachment loss Ͼ6 mm) had a 4.3-times-higher (95% confidence interval, 1.85 to 10.2) risk of cerebral ischemia than subjects with mild or without periodontitis (Յ3 mm). Severe periodontitis was a risk factor in men but not women and in younger (Ͻ60 years) but not older subjects. Periodontitis increased the risk of cerebral ischemia caused by large-artery atherosclerosis, cardioembolism, and cryptogenic etiology. Gingivitis and severe radiologic bone loss were also independently associated with the risk of cerebral ischemia, whereas caries was not. Conclusions-Our study indicates that periodontal disease, a treatable condition, is an independent risk factor for cerebral ischemia in men and younger subjects.

MD; for the CAPRIE InvestigatorsBackground and Purpose-Inflammatory markers predict first-time ischemic events. We investigated whether leukocyte and differential counts predict recurrent events and ischemic events in high-risk populations, and whether such events are preceded by acutely exacerbated inflammation. Methods-We studied 18 558 patients with ischemic stroke, myocardial infarction, or peripheral arterial disease who participated in the trial of Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE), a study that compared the occurrence of ischemic stroke, myocardial infarction, or vascular death under randomized treatment with aspirin or clopidogrel. Leukocyte counts were frequently assessed during followup. Results-Compared with the quartile with lowest leukocyte counts at baseline (Ͻ5.9ϫ10 9 /L), patients in the top quartile (Ͼ8.2ϫ10 9 /L) had higher risks for ischemic stroke (relative risk 1.30; Pϭ0.007), myocardial infarction (relative risk 1.56, PϽ0.001), and vascular death (relative risk 1.51; PϽ0.001) after adjustment for other risk factors. Neutrophil counts contributed most to increased risk. Assessments of regression dilution effects based on replicate measurements show that these risk associations may underestimate the real associations by 30 to 50%. Treatment with aspirin or clopidogrel did not influence predictive effects by leukocytes. In the week before a recurrent event, but not at earlier time points, the leukocyte count was significantly increased over baseline levels (nϭ211; mean difference ϩ0.46ϫ10 9 /L; Pϭ0.005). Conclusions-Leukocyte counts and mainly neutrophil counts are independently associated with ischemic events in these high-risk populations. An increase of leukocyte counts over baseline levels heralds a period of increased risk lasting about one week.

Recurrent or chronic bronchial infection and poor dental status, mainly resulting from chronic dental infection, may be associated with an increased risk for cerebrovascular ischemia.