Christoph Lichy

Periodontal Disease as a Risk Factor for Ischemic Stroke

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 (P <0.001) and hospital (P =0.010) 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 >6 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 (≤3 mm). Severe periodontitis was a risk factor in men but not women and in younger (<60 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.

Leukocyte Count as an Independent Predictor of Recurrent Ischemic Events

Background 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 (<5.9× 109/L), patients in the top quartile (>8.2× 109/L) had higher risks for ischemic stroke (relative risk 1.30; P < 0.007), myocardial infarction (relative risk 1.56, P < 0.001), and vascular death (relative risk 1.51; P < 0.001) 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 (n= 211; mean difference +0.46×109/L; P = 0.005). 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.

Antiplatelets Versus Anticoagulation in Cervical Artery Dissection

Background and Purpose— The widespread preference of anticoagulants over antiplatelets in patients with cervical artery dissection (CAD) is empirical rather than evidence-based. Summary of Review— This article summarizes pathophysiological considerations, clinical experiences, and the findings of a systematic metaanalysis about antithrombotic agents in CAD patients. As a result, there are several putative arguments in favor as well as against immediate anticoagulation in CAD patients. Conclusions— A randomized controlled trial comparing antiplatelets with anticoagulation is needed and ethically justified. However, attributable to the large sample size which is required to gather meaningful results, such a trial represents a huge venture. This comprehensive overview may be helpful for the design and the promotion of such a trial. In addition, it could be used to encourage both participation of centers and randomization of CAD patients. Alternatively, antithrombotic treatment decisions can be customized based on clinical and paraclinical characteristics of individual CAD patients. Stroke severity with National Institutes of Health Stroke Scale score ≥15, accompanying intracranial dissection, local compression syndromes without ischemic events, or concomitant diseases with increased bleeding risk are features in which antiplatelets seem preferable. In turn, in CAD patients with (pseudo)occlusion of the dissected artery, high intensity transient signals in transcranial ultrasound studies despite (dual) antiplatelets, multiple ischemic events in the same circulation, or with free-floating thrombus immediate anticoagulation is favored.

European Stroke Initiative Recommendations for Stroke Management

This article summarises recommendations for acute management of stroke by the European Stroke Initiative (EUSI), on behalf of the European Stroke Council (ESC), the European Neurological Society (ENS), and the European Federation of Neurological Societies (EFNS).

Fever and infection early after ischemic stroke

Previous studies showed that elevated body temperature early after ischemic stroke is associated with severe neurological deficit and a poor outcome. The aim of this study was to analyse the prevalence and putative etiology of febrile body temperature (>/=38.0 degrees C) early after stroke and to investigate the association between body temperature, stroke severity and outcome. We investigated 119 consecutive patients who were admitted within 24 h after ischemic stroke. Patients were examined for infection before ischemia using a standardized questionnaire and received daily clinical examination after stroke. In case of fever, standardized radiological and microbiological examinations were performed. Fever within 48 h after stroke was observed in 30 (25.2%) patients. The probable cause of fever was infective or chemical aspiration pneumonia (n=12), other respiratory tract infection (n=7), urinary tract infection (n=4), viral infections (n=3) or insufficiently defined (n=5). (One patient had two potential causes of fever.) In thirteen of these patients, infection was most probably acquired before stroke. Fever newly developed more often during day 1 to 2 than day 3 to 7 after stroke (P=0.016). Fever was associated with a more severe deficit on admission independent from age, vascular diseases and risk factors (odds ratio 9.6; 95% confidence interval 3.1-29). Fever is a frequent complication early after stroke and in the majority of cases, it can be explained by infection or chemical aspiration pneumonia. In about half of the infected patients, infection was most probably acquired before stroke. Fever was associated with a more severe neurological deficit on admission.

Influenza Vaccination Is Associated With a Reduced Risk of Stroke

Background and Purpose— Vascular death rates and hospitalizations for stroke are increased during influenza epidemics. Influenza vaccination may prevent stroke. We investigated whether influenza vaccination is associated independently with reduced odds of stroke and whether effects are confined to stroke subgroups and winter seasons and shared by other vaccinations. Methods— During 18 months, we performed standardized interviews assessing vaccination status, risk factors, health-related behavior, and socioeconomic factors in 370 consecutive patients with ischemic or hemorrhagic stroke or transient ischemic attack (TIA) and 370 age- and sex-matched control subjects selected randomly from the population. Results— Influenza vaccination during the last vaccination campaign was less common in patients (19.2%) than control subjects (31.4%; P<0.0001). After adjustment for vascular risk factors, education, health-related behavior and other factors, influenza vaccination (odds ratio [OR], 0.46; 95% CI, 0.28 to 0.77) but not other combined recent vaccinations (OR, 0.80; 95% CI, 0.42 to 1.43) were associated with reduced odds of stroke/TIA. Significant effects were found in men, older subjects (>65 years), subjects with previous vascular diseases, and regarding ischemic stroke; nonsignificant trends existed in women, younger subjects, and regarding hemorrhagic stroke. In etiologic subgroups of cerebral ischemia, similar effects were found. No protective effects were found during summer months; however, results also varied considerably between both winter seasons examined. Conclusions— These results support the hypothesis that influenza vaccination may be associated with reduced stroke risk. However, residual confounding cannot be excluded, and interventional studies are required to evaluate the role of influenza vaccination in stroke prevention.

Lifestyle Risk Factors for Ischemic Stroke and Transient Ischemic Attack in Young Adults in the Stroke in Young Fabry Patients Study

Background and Purpose— Although many stroke patients are young or middle-aged, risk factor profiles in these age groups are poorly understood. Methods— The Stroke in Young Fabry Patients (sifap1) study prospectively recruited a large multinational European cohort of patients with cerebrovascular events aged 18 to 55 years to establish their prevalence of Fabry disease. In a secondary analysis of patients with ischemic stroke or transient ischemic attack, we studied age- and sex-specific prevalences of various risk factors. Results— Among 4467 patients (median age, 47 years; interquartile range, 40–51), the most frequent well-documented and modifiable risk factors were smoking (55.5%), physical inactivity (48.2%), arterial hypertension (46.6%), dyslipidemia (34.9%), and obesity (22.3%). Modifiable less well-documented or potentially modifiable risk factors like high-risk alcohol consumption (33.0%) and short sleep duration (20.6%) were more frequent in men, and migraine (26.5%) was more frequent in women. Women were more often physically inactive, most pronouncedly at ages <35 years (18–24: 38.2%; 25–34: 51.7%), and had high proportions of abdominal obesity at age 25 years or older (74%). Physical inactivity, arterial hypertension, dyslipidemia, obesity, and diabetes mellitus increased with age. Conclusions— In this large European cohort of young patients with acute ischemic cerebrovascular events, modifiable risk factors were highly prevalent, particularly in men and older patients. These data emphasize the need for vigorous primary and secondary prevention measures already in young populations targeting modifiable lifestyle vascular risk factors. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00414583.

Common variation in PHACTR1 is associated with susceptibility to cervical artery dissection

Cervical artery dissection (CeAD), a mural hematoma in a carotid or vertebral artery, is a major cause of ischemic stroke in young adults although relatively uncommon in the general population (incidence of 2.6/100,000 per year). Minor cervical traumas, infection, migraine and hypertension are putative risk factors, and inverse associations with obesity and hypercholesterolemia are described. No confirmed genetic susceptibility factors have been identified using candidate gene approaches. We performed genome-wide association studies (GWAS) in 1,393 CeAD cases and 14,416 controls. The rs9349379[G] allele (PHACTR1) was associated with lower CeAD risk (odds ratio (OR) = 0.75, 95% confidence interval (CI) = 0.69–0.82; P = 4.46 × 10−10), with confirmation in independent follow-up samples (659 CeAD cases and 2,648 controls; P = 3.91 × 10−3; combined P = 1.00 × 10−11). The rs9349379[G] allele was previously shown to be associated with lower risk of migraine and increased risk of myocardial infarction. Deciphering the mechanisms underlying this pleiotropy might provide important information on the biological underpinnings of these disabling conditions.

Hemorrhagic Complications After Off-Label Thrombolysis for Ischemic Stroke

Background and Purpose— Only 2% to 4% of patients with acute ischemic stroke receive thrombolytic therapy resulting from the current strict inclusion criteria among other issues. Safety of intravenous and intraarterial thrombolysis in off-label situations is controversially discussed. We sought to review the reports on such patients regarding intra- and extracranial hemorrhage. Summary of Review— A MEDLINE search for off-label uses of thrombolysis revealed reports on 273 patients treated with intraarterial or intravenous thrombolysis for ischemic stroke. Symptomatic intracranial hemorrhage occurred in 19 of 273 patients (6.95%) and extracranial hemorrhage in 17 of 273 (6.22%). Conclusions— These data suggest that the overall bleeding risk in off-label thrombolysis may not be as high as presumed. However, the small number of patients in each group and the likely underreporting of worse outcomes preclude drawing any conclusion as to specific treatment recommendations. Selected patients might benefit, however, from thrombolysis in situations not currently considered in the inclusion criteria. To obtain a meaningful database, a registry for off-label thrombolysis should be created.

A Common Polymorphism of the Protein Z Gene Is Associated With Protein Z Plasma Levels and With Risk of Cerebral Ischemia in the Young

Background and Purpose— The vitamin K–dependent protein Z (PZ) has been shown to possess anticoagulant as well as procoagulant properties. Plasma levels of PZ show a broad interindividual variation, but it is unknown to which extent this variation is under genetic control. Recent clinical studies revealed contradictory results on the association of PZ plasma levels and the risk of ischemic stroke. Methods— We performed a case-control study including 200 patients with cerebral ischemia aged ≤50 years and 199 control subjects from the same South German region. We investigated a possible association of 2 common single nucleotide mutations in the PZ gene with the risk of cerebral ischemia. Furthermore, enzyme-linked immunosorbent assay measurements were done in control subjects without vascular disease to detect a potential association of different genotypes with PZ plasma (antigen) levels. Results— In patients, the frequency of the A allele of the intron F polymorphism G79A was significantly lower than in controls (15.7% versus 24.4%; odds ratio, 0.58; 95% CI, 0.39 to 0.86; P =0.007; adjusted for age, sex, and conventional risk factors). The G allele of the promoter polymorphism A-13G tended to be less common in patients (4.2% versus 7.0%; adjusted odds ratio, 0.56; 95% CI, 0.28 to 1.13; P =0.105). In 42 control subjects, the A allele of the intron F polymorphism was associated with lower PZ antigen levels (P =0.0032; Spearman correlation coefficient rs=−0.48). Conclusions— The A allele of an intron F polymorphism of the PZ gene appears to be a novel protective genetic marker for the risk of cerebral ischemia in young adults. In the context of juvenile stroke, high PZ plasma levels may represent a prothrombotic condition.