Current status of the epidemiology of brain infarction associated with occlusive arterial disease

Recent Trends in Sedentary Time: A Systematic Literature Review

This paper systematically reviews and synthesizes the relevant literature on sedentary time research. A bibliometric analysis was conducted to evaluate the publications from 2010 to 2020 in the Web of Science (WoS) core collection database. Derwent Data Analyzer software was used for the cleaning, mining, and visualization of the data. Historical trends of the topics, main contributors, leading countries, leading institutions, leading research areas, and journals were explored. A total of 3020 publications were studied. The United States, the United Kingdom, and Australia are the three most productive countries. The Australian institution Baker Heart and Diabetes Institute led the list of productive institutions, and Ekelund U published the most papers. Sedentary time raised the concerns of scholars from 106 research areas, and public health was the dominant field. Physical activity, accelerometer, children, and obesity were the most frequently used keywords. The findings suggest that sedentary time is rapidly emerging as a global issue that has detrimental effects on public health. The hotspots shifted in the past 10 years, and COVID-19 was the most popular topic of sedentary time research.

Long-term complications of stroke and secondary prevention: an overview for primary care physicians

Despite a decline in mortality from stroke, the annual incidence in the general population is increasing. For many stroke survivors and their families, the acute stroke is the beginning of an ongoing struggle with physical impairment and subsequent disability. Over time, the immediate clinical consequences of the stroke are complicated by a variety of lesser-known medical, musculoskeletal and psychosocial difficulties. The primary care physician is best positioned to optimise chronic disease control, reduce risk and manage complications of stroke. Early screening and appropriate management is key. Instituting secondary prevention and attention to bowel and bladder problems can help reduce medical complications and re-admissions, while adequate analgesia, positioning/splinting of limbs and physiotherapy can lessen discomfort and preventable suffering. Primary care physicians can identify and treat post-stroke mood issues and involve psychological counselling for patients and caregivers. Adequate education and support may restore the independence of patients with stroke or minimise any resultant dependency.

The association between race/ethnicity and the prevalence of stroke among United States adults in 2015: a secondary analysis study using Behavioural Risk Factor Surveillance System (BRFSS)

Background

Worldwide, stroke is considered the second leading cause of death, accounting for 11.8% of all deaths in 2013. In the Unites States (US), approximately 795,000 people have a stroke every year. Stroke has many different risk factors that vary by race/ethnicity. There is limited contemporary published literature about the prevalence of stroke among racial/ethnic groups in the US adult population.

Objective

This study aimed to determine the association between race/ethnicity and the prevalence of stroke among US adults in 2015.

Methods

This study was an observational, non-concurrent prospective of the Behavioural Risk Factor Surveillance System (BRFSS) in 2015 to assess the association between race/ethnicity and the prevalence of stroke. The final study sample was 432,814 US adults ≥ 18 years old. Variables were excluded from the model if there were missing, refused, or did not know responses to the variables of interest. A binary logistic regression analysis was used to obtain odds ratios (OR) and 95% confidence intervals (CI) for the association between race/ethnicity and stroke. The Chi-square test was used to study bivariate associations between categorical variables. The collinearity was assessed. A p-value of <0.05 was considered statistically significant. Statistical analysis was completed using STATA version 14 (Stata Corp, College Station, TX).

Results

The highest proportion of participants (43%) were ≥ 44 years old with a balanced distribution of males and females. The highest proportion of stroke was found among Hispanics (4.2%) and non-Hispanic Blacks (4.1%) as compared to 3.2% among non-Hispanic Whites (p<0.001). Furthermore, Hispanics and Blacks were significantly more likely to develop stroke (OR=1.57, 95% CI=1.28–1.91; and OR=1.30, 95% CI=1.16–1.45, respectively) after adjusting for confounding variables.

Conclusion

Hispanics and Blacks had a higher prevalence of stroke in comparison with non-Hispanic Whites. Further studies are needed to verify these findings and to determine which factors may influence the stroke differences among these racial/ethnic groups.

Weekly variations of stroke occurrence: an observational cohort study based on the Kyoto Stroke Registry, Japan

OBJECTIVES

Understanding the temporal pattern of stroke onset and exploring the possible triggers are important strategies to reducing the incidence of stroke. If stroke occurs frequently on a specific day of the week, it is assumed that other factors, that is, 'triggering factors', induce stroke. The aim of the study is to investigate differences in the incidences of stroke among days of the week.

DESIGN

Hospital-based registry stroke over an 11-year period.

SETTING

Kyoto Prefecture, Japan.

PARTICIPANTS

A total of 13,788 patients with stroke identified from January 1999 to December 2009 inclusive in the entire Kyoto Prefecture and registered in the Kyoto Stroke Registry (KSR).

MAIN OUTCOME MEASURES

Patients with stroke were classified into seven groups based on the day of the week on which stroke developed. We confirmed the differences in the incidence among days using the χ(2) test and then performed multinomial logistic analysis referring to the stroke incidence on Sunday to calculate the OR and 95% CI of the stroke occurrence on each day of the week.

RESULTS

The OR (95% CI) for stroke occurring on Monday, Tuesday, Wednesday, Thursday, Friday and Saturday was 1.157 (1.030 to 1.293), 1.101 (0.981 to 1.236), 1.059 (0.943 to 1.188), 1.091 (0.972 to 1.225), 1.053 (0.938 to 1.205) and 1.074 (0.956 to 1.205), respectively. After stratification by stroke subtypes, cerebral infarction occurred more frequently on Monday than on Sunday (OR and 95% CI were 1.189 and 1.034 to 1.366, p=0.014) independent of age and gender. There was no significant day of the week variation in cerebral haemorrhage or subarachnoid haemorrhage.

CONCLUSIONS

Some factors that arise periodically appear to affect the incidence of cerebral infarction, which gradually develops over years, and this suggests an aetiological mechanism different from the conventional cumulative effect of risk factors due to long-term exposure. We propose a hypothesis that there is a 'triggering factor' for the development of cerebral infarction.

The natural history of stroke in diabetic patients

A five-year follow-up of 53 diabetic patients admitted for their first stroke in 1972--73 has been performed. They were compared with two groups of 53 non-diabetic patients each with cerebrovascular disease (CVD), one randomly selected and one matched with the diabetics for age, sex and diagnosis of CVD at discharge. All patients could be traced at follow-up. The mean age at the time of first stroke was 66.5 years in male and 73.2 years in female diabetics. Manifest diabetes was diagnosed in 19% during hospitalization for stroke; of the remainder, 74% had had diabetes since less than ten years. In 85% of the diabetics there were no signs of severe angiopathy affecting eyes, kidneys or lower extremities. The majority of diabetic as well as non-diabetic CVD patients had a history of hypertension and/or heart disease. Few were overweight. Case fatality rate was significantly higher in diabetics than in non-diabetics throughout the follow-up (p less than 0.01 for diabetics vs. matched non-diabetics, p less than 0.001 for diabetics vs. randomly selected non-diabetics). The presence of heart disorder predicted mortality in the diabetic subjects. Surprisingly, hypertension diagnosed before stroke involved a more favourable long-term prognosis in all three groups (p less than 0.05). The major causes of death in diabetic CVD patients were cardiac disorders (50%) and stroke (47%). Previous investigations have identified diabetes as a risk factor for stroke. This study shows that diabetes also adversely affects the short-term as well as the long-term outcome in stroke.

The human erythrocyte has developed the biconcave disc shape to optimise the flow properties of the blood in the large vessels

The human erythrocyte adopts a distinctive biconcave disc form in vivo. The question as to why the red blood cell should have this particular profile remains unresolved. It has been suggested that this shape maximises the surface area to volume ratio and thus expedites diffusion. This hypothesis, however does not stand up to examination. Maximal diffusion occurs in the small vessels. In order to pass through the microvasculature the erythrocyte becomes distorted and deviates from the biconcave disc shape [Branemark PI, Lindstrom J. The shape of circulating blood corpuscles. Biorheology 1963;1:139; Guest MM, Bond TP, Cooper RG, Derrick JR. Red blood cells: change in capillaries. Science 1963;142:1319-21]. Here, it is suggested the haemodynamic factors have dictated the peculiar shape of the discocyte. The deleterious nature of turbulent flow on the cardiovascular system suggests that the biconcave disc form has evolved out of a necessity to maximise laminar flow, minimise platelet scatter which in turn suppress atherogenic activity in the large vessels [Yoshizumi M, Abe J, Tsuchiya K, Berk BC, Tamaki T. Stress and vascular responses: athero-protective effect of laminar fluid shear stress in endothelial cells: possible and mitogen-activated protein kinases. J Pharmacol Sci 2003;9:172-6]. The biconcave profile of the discocyte means that much of the mass is distributed in the periphery. This increases the moment of inertia of the cell and subsequently renders the erythrocyte less prone to rotation during flow in the large vessels. Here it is suggest that this reduction in rotation promotes laminar flow and discourages platelet scattering by minimising the "Eddy currents" and it thus anti-atherogenic. A number of pathological mutations result in the red blood cell adopting a spherical shape as opposed to the biconcave disc profile. The sphere has a smaller moment of inertia when compared to the discocyte, as much of the mass is distributed round the centre. The spherocyte is hence much more prone to rotation during flow in the large vessels. There is evidence to suggest that asplenic individuals suffering from spherocytosis are at increased risk of atherogenic cerebrovascular and cardiovascular large-vessel disease, when compared with their asplenic haematological normal counterparts [Schilling RF. Spherocytosis, splenectomy, strokes and heart attacks. Lancet 1997;350:1677-8; Robinnette CD, Fraumeni Jr JF. Splenectomy and subsequent mortality in veterans of the 1939-1945 war. Lancet 1977;ii:127-9].

Stroke As a Late Treatment Effect of Hodgkin's Disease: A Report From the Childhood Cancer Survivor Study

Purpose

The objectives of this report are to examine the incidence of and risk factors for stroke among childhood Hodgkin's disease (HD) survivors.

Patients and Methods

The Childhood Cancer Survivor Study is a multi-institutional cohort study of more than 5-year cancer survivors diagnosed between 1970 and 1986 and a sibling comparison group. Incidence rates of stroke among HD survivors (n = 1,926) and siblings (n = 3,846) were calculated and compared. Cox proportional hazards models were used to estimate the hazard ratios, reported as relative risks (RR), of developing stroke between HD survivors and siblings.

Results

Nine siblings reported a stroke, for an incidence of 8.00 per 100,000 person-years (95% CI, 3.85 to 14.43 per 100,000 person-years). Twenty-four HD survivors reported a stroke. The incidence of late-occurring stroke among HD survivors was 83.6 per 100,000 person-years (95% CI, 54.5 to 121.7 per 100,000 person-years). The RR of stroke among HD survivors was 4.32 (95% CI, 2.01 to 9.29; P = .0002). All 24 survivors received mantle radiation exposure (median dose, 40 Gy). The incidence of late-occurring stroke among HD survivors treated with mantle radiation was 109.8 per 100,000 person-years (95% CI, 70.8 to 161.1 per 100,000 person-years). The RR of late-occurring stroke among HD survivors treated with mantle radiation was 5.62 (95% CI, 2.59 to 12.25; P < .0001).

Conclusion

Survivors of childhood HD are at increased risk of stroke. Mantle radiation exposure is strongly associated with subsequent stroke. Potential mechanisms may include carotid artery disease or cardiac valvular disease.

Sophorae radix extract inhibits high glucose-induced vascular cell adhesion molecule-1 up-regulation on endothelial cell line

BACKGROUND

Sophorae radix (SR) has been used for various diseases including atherosclerosis and arrhythmias. Atherosclerosis induced by hyperglycemia is an important factor in the promotion of diabetic complications. An early event in atherosclerosis is the adhesion of monocytes to endothelium via adhesion molecules. Among them, vascular cell adhesion molecule-1 (VCAM-1) expression mediates the binding of monocytes and lymphocytes to vascular endothelial cells.

METHODS

The study was performed on vascular endothelial cells (ECV304 cells) that were pretreated with various concentrations of SR extract for 3 h before exposure with high glucose (55.5 mmol/l) for 48 h. The protein expression of VCAM-1 was measured by enzyme-linked immunosorbent assay (ELISA) and its mRNA expression was by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

SR extract significantly inhibited high glucose-induced expression of VCAM-1 in a dose-dependent manner and reduced the level of VCAM-1 mRNA through interfering with translocation of nuclear factor-kappaB (NF-kappaB). Decreased VCAM-1 expression by SR extract was associated reduction of adherence between high glucose-stimulated ECV304 cells and human monocyte-like HL-60 cells.

CONCLUSIONS

These data suggest that SR extract inhibits high glucose-mediated monocytes-endothelial cells adhesions and expression of VCAM-1 via inhibition of NF-kappaB translocation.

Stroke in the female: role of biological sex and estrogen

Women are protected from stroke relative to men until the years of menopause. Because stroke is the leading cause of serious, long-term disability in the United States, modeling sex-specific mechanisms and outcomes in animals is vital to research. Important research questions are focused on the effects of hormone replacement therapy, age, reproductive status, and identification of sex-specific risk factors. Available research relevant to stroke in the female has almost exclusively utilized rodent models. Gender-linked stroke outcomes are more detectable in experimental studies than in clinical trials and observational studies. Various estrogens have been extensively studied as neuroprotective agents in women, animals, and a variety of in vitro models of neural injury and degeneration. Most data in animal and cell models are based on 17 beta estradiol and suggest that this steroid is neuroprotective in injury from ischemia/reperfusion. However, current evidence for the clinical benefits of hormone replacement therapy is unclear. Future research in this area will need to expand into stroke models utilizing higher order, gyrencephalic animals such as nonhuman primates if we are to improve extrapolation to the human scenario and to direct and enhance the design of ongoing and future clinical studies and trials.

Carotid artery stenosis: prospective comparison of CT, three-dimensional gadolinium-enhanced MR, and conventional angiography

PURPOSE

To prospectively compare gadolinium-enhanced magnetic resonance (MR) angiography and computed tomographic (CT) angiography with digital subtraction angiography (DSA) for use in detecting atheromatous stenosis and plaque morphology at the carotid bifurcation.

MATERIALS AND METHODS

Forty-four carotid arteries (in 22 patients) were analyzed by using CT angiography, enhanced MR angiography, and DSA. CT and enhanced MR angiograms were reconstructed with maximum intensity projection and multiplanar volume reconstruction. The following four features were analyzed: degree of stenosis on the basis of North American Symptomatic Carotid Endarterectomy Trial criteria, length of stenosis, luminal surface, and presence of ulcers.

RESULTS

There was significant correlation between CT angiography, enhanced MR angiography, and DSA for degree and length of stenosis. With enhanced MR angiography and CT angiography, degree of stenosis was underestimated in two of 44 cases. No case of overestimation with CT angiography was found. Severe internal carotid artery stenoses were detected with high sensitivity and specificity: 100% and 100%, respectively, with CT angiography; 93% and 100%, respectively, with enhanced MR angiography. Luminal surface irregularities were most frequently seen at CT angiography. With CT angiography and enhanced MR angiography, more ulceration was detected than with DSA.

CONCLUSION

There was a significant correlation between CT angiography, enhanced MR angiography, and DSA in evaluation of carotid artery stenosis. Enhanced MR angiography or CT angiography can be used to adequately evaluate carotid stenosis.

High concentration of glucose induces the expression of intercellular adhesion molecule-1 in human umbilical vein endothelial cells

Atherosclerosis is known to be accelerated in patients with diabetes mellitus. We have examined the effect of glucose on the expression of intercellular adhesion molecule-1 (ICAM-1) in cultured human umbilical vein endothelial cells (HUVEC) and the adhesion of cells of monocyte-like cell line, THP-1, to HUVEC. HUVEC exposed to a high glucose concentration (16.7 mM) showed a 1.4-fold increase in the adhesion of THP-1 cells and a 1.3-fold increase in cell surface expression of ICAM-1 after 6 h exposure compared with those cultured in medium with a low glucose concentration (5.6 mM). ICAM-1 expression began to increase after 3 h exposure, was maximal at 6 h and gradually decreased afterwards. At 16.7 mM, raffinose stimulation produced a significantly lower expression of ICAM-1 on HUVEC than glucose, furthermore it caused a significantly lower expression than low glucose stimulation (5.6 mM). We conclude that a high concentration of glucose can induce ICAM-1 in endothelial cells and that this effect may play an important role in atherogenesis in patients with diabetes mellitus.

Stroke risk factor knowledge in university students

Cerebrovascular disease is the third leading cause of mortality in this country and is a leading cause of disability. To develop successful prevention programs to decrease the incidence of stroke, individuals should adopt cerebrovascular-healthy behaviors during youth, rather than in middle or old age, when risks for stroke are highest. The authors assessed the knowledge of stroke risk factors in university students presenting to a student health neurology clinic over a 14-month period. Half of the 98 students surveyed thought stress, a very weak risk factor, was a causative factor in the development of stroke. Only one third named hypertension or smoking as a risk factor. No significant gender, ethnic, or age differences were observed in student identification of stroke risk factors. These data indicate that university students have an incomplete understanding of the characteristics that are risk factors for stroke. This knowledge deficit is likely to have a negative influence on students' health behaviors.

Assessment of cardiovascular risk factors in the elderly: the Framingham Heart Study

In elderly Framingham men and women, systolic blood pressure and cigarette smoking status, as well as a subject's age and sex, strongly influenced the risk of developing cardiovascular disease during ten years of follow-up. Multivariable proportional hazards models were used to assess the roles of several primary risk factors and to examine their secondary effects. The first three factors were noted in both sexes, separately and combined, but the risk function for blood pressure was steeper in men than in women (hazard ratio, HR, 1.53 per 20 mmHg, 95 per cent confidence interval, CI, 1.33 to 1.75 in men; HR = 1.19, 95 per cent CI 1.07 to 1.33 in women). Systolic pressure measured ten years earlier also contributed to CVD risk (HR = 1.16 per 20 mmHg, 95 per cent CI 1.04 to 1.30). even after accounting for current level. Smoking was associated with a 64 per cent elevation in risk, male sex with a 51 per cent increase, and each 5 years increment in age with a 22 per cent increase. Body mass index measured 10 years ago had a modest association, but current body mass index did not. Among diabetic subjects, total serum cholesterol had an asymmetrical U-shaped risk function, the risk increasing to either side of sex-specific median values; diabetes per se, however, was not significant in the final model. In non-diabetic subjects, there was little change in CVD risk up to the median cholesterol values and a modest increase thereafter. None of the risk functions was age dependent.

Oral contraceptives, pregnancy and the risk of cerebral thromboembolism: the influence of diabetes, hypertension, migraine and previous thrombotic disease

OBJECTIVE

To assess the risk of developing cerebral thromboembolism among pregnant women and among fertile women with hypertension, migraine, diabetes, and previous thrombotic disease, and to investigate the interaction of these risk factors with the use of oral contraceptives.

DESIGN

A retrospective case-control study.

SETTING

All gynaecological, medical, neurological, and neurosurgical departments in Danish hospitals.

SUBJECTS

Seven hundred and ninety-four women in Denmark aged 15 to 44 who suffered a cerebral thromboembolic attack during the period 1985 to 1989 and 1588 age-matched, randomly selected controls.

RESPONSE

Of the 692 case and 1584 control questionnaires sent out, 590 (85.1%) and 1396 (88.1%), respectively, were returned. Of the 590 cases, nine had had cerebral thrombosis before 1980, 15 refused to participate, 44 had a revised diagnosis (primarily multiple sclerosis) and 25 had an unreliable diagnosis, leaving 497 with a reliable cerebral thromboembolic diagnosis. Among the 1396 controls, 26 either refused to participate, were mentally handicapped, lived abroad or returned an uncompleted questionnaire, leaving 1370 controls included in the study.

RESULTS

After multivariate analysis, pregnancy implied an odds ratio (OR) for a cerebral thromboembolic attack of 1.3 (nonsignificant), diabetes an OR of 5.4 (P < 0.001), hypertension an OR of 3.1 (P < 0.001) and migraine an OR of 2.8 (P < 0.01). Women with previous non-cerebral thrombotic disease had an OR for cerebral thrombo-embolism of 5.3 (P < 0.001). Women with other predisposing medical diseases had an OR of 8.3 (P < 0.001). These ORs were identical among users and non-users of combined oral contraceptives.

CONCLUSION

In this study pregnancy implied a non-significant elevated odds ratio of 1.3 for cerebral thromboembolism whereas diabetes, hypertension, migraine and past thromboembolic events increased the risk of cerebral thromboembolism significantly. Women with these increased thrombotic risks should use oestrogen-containing oral contraceptives only after careful considerations of the risks, if at all.

The health consequences of smoking. Cardiovascular diseases

Cigarette smoking is a major cause of atherosclerotic diseases. Cardiovascular diseases (CVD) remain the leading disease cause of death and disability in the United States. Smoking contributes to much of the premature and overall disease burden from CVD. Smoking affects the physiologic, pathologic, hematologic, and metabolic factors that lead to the initiation, progression, and sequelae of atherosclerosis. Smoking cessation reduces the progression of atherosclerosis and the subsequent morbidity, mortality, and years of productive life lost from CVD.

Regional cerebral blood flow characteristics and variations with age in resting normal subjects

Regional cerebral blood flow (rCBF) was measured during resting in 97 normal subjects, 19-68 years old. The results showed that the mean CBF level decreased progressively with age. The decrease was more prominent in frontotemporal and inferior Rolandic areas bilaterally. Frontal areas showed the highest values in all age groups. This hyperfrontality weakened somewhat with age. Mean CBF in the right hemisphere was significantly higher than in the left, as was flow in superior frontal, inferior frontal, and parietal areas. These asymmetries were age invariant. The age-related decrease of rCBF is interpreted as reflecting aging of the brain per se, although the influence of asymptomatic brain disease can not be ruled out. The flow asymmetries are interpreted as being related to functional lateralization of some aspects of attentional activation.

Frequency of systemic hypertension in various cardiovascular diseases

The clinical frequencies of systemic hypertension and necropsy evidence of cardiomegaly in various cardiovascular conditions are summarized. Systemic hypertension is present in greater than 50% of patients with various coronary events, in greater than 75% of patients with various cerebrovascular events and in greater than 90% of patients with aortic dissection. Hypertension is the sole underlying factor in most patients with nontraumatic cerebral arterial or aortic (dissection = partial rupture) rupture. In association with hypercholesterolemia (serum total cholesterol levels greater than 150 mg/dl), hypertension clearly accelerates atherosclerosis and its devastating consequences.

Italian multicenter study of reversible cerebral ischemic attacks. Part 5. Risk factors and cerebral atherosclerosis

As part of a prospective study, the influence of several premorbid and environmental factors on the presence, extent and severity of cerebral vessel atherosclerosis was studied in 462 patients with clinical diagnosis of RIA who underwent cerebral angiography. The extent and severity of atherosclerosis of the cerebral vessels was quantified using extracranial and intracranial cerebrovascular scores (ECS, ICS) based on the number and severity of the lesions in 11 extracranial and 21 intracranial arterial segments. Results of univariate and multivariate analyses indicate that the presence of atherosclerotic changes of cerebral vessels, as shown by angiography, was strongly related with age in both sexes. The lesions were more frequent in males, in particular under age 55. Elevated cholesterol was associated with a higher incidence of atherosclerotic lesions. Smoking was associated with a higher incidence of extracranial lesions. Age, smoking and history of hypertension were the best predictors of the extent and severity of cerebral vessel atherosclerosis.

Stroke and alcohol consumption

We conducted a retrospective case-control study to investigate a possible association between alcohol intake and stroke. Reported recent alcohol consumption and biochemical and hematologic markers of alcohol intake were examined for 230 patients with stroke (20 to 70 years old) and compared with concurrently collected data on controls matched for age, sex, and race. A single estimate of current intake was used as a measure of alcohol consumption. Among men, the relative risk of stroke (adjusted for hypertension, cigarette smoking, and medication) was lower in light drinkers (those consuming 10 to 90 g of alcohol weekly) than in nondrinkers (relative risk, 0.5), but was four times higher in heavy drinkers (consuming greater than or equal to 300 g weekly) than in nondrinkers. Because very few women in our study drank heavily, we were unable to determine whether heavy alcohol intake influenced the risk of stroke in women. With increasing serum concentrations of the biochemical markers of alcohol intake (aspartate aminotransferase, uric acid, and gamma-glutamyl transferase), we observed similar trends in the relative risk of stroke. Only the erythrocyte mean cell volume did not follow this pattern. We conclude that heavy alcohol consumption is an important and underrecognized independent risk factor for stroke in men, but our data are not adequate to settle the issue for women. Our conclusions are qualified by our reliance on reported recent alcohol consumption as the primary measure of intake.

Risk of stroke in male cigarette smokers

From 1965 to 1968, the Honolulu Heart Program began following 8006 men of Japanese ancestry in a prospective study of cardiovascular disease. Of the subjects who had not had a stroke by the time of study entry, 3435 were cigarette smokers and 4437 were nonsmokers. In 12 years of follow-up, 171 smokers and 117 nonsmokers had a stroke. As compared with nonsmokers, cigarette smokers had two to three times the risk of thromboembolic or hemorrhagic stroke, after control for age, diastolic blood pressure, coronary heart disease, and other risk factors (P less than 0.001). Subjects who continued to smoke in the course of follow-up had the highest risk of stroke. When these subjects were compared with those who never smoked, their risk of hemorrhagic events was increased four- to six-fold (P less than 0.001). Subjects who were smokers at study entry but stopped smoking in the course of follow-up had a slight excess risk of stroke. When these subjects were compared with those who continued to smoke, however, their risk was reduced by more than half after adjustment for risk factors (P less than 0.05), indicating that stopping smoking had significant benefits.

Inhibitors of "spontaneous" platelet aggregation in whole blood

In vitro 'spontaneous' platelet aggregation has been studied in whole blood. The spectrum of activity of materials known to influence platelet aggregation in platelet-rich plasma proved different in whole blood. Thus dipyridamole and one of its analogues SH1242 had a striking effect in whole blood whilst aspirin, chlorpromazine and K3920 had little or no effect. The combination of aspirin and dipyridamole as currently employed in clinical practice had no greater inhibitory effect than dipyridamole alone. The possible clinical relevance of these findings is discussed.

Dietary and other risk factors for stroke in Hawaiian Japanese men

As part of an on-going longitudinal study, 7895 men of Japanese ancestry living on the island of Oahu, aged 45-68 and free of evidence of prior stroke at entry examination, have been followed by re-examinations and surveillance. During ten years of follow-up 154 men developed thromboembolic stroke, 65 developed intracranial hemorrhage, and 19 developed stroke of unknown type. There were 79 deaths attributed to stroke. The independent risk factors for thrombo-embolic stroke were elevated blood pressure, glucose intolerance, age, electrocardiographic evidence of left ventricular hypertrophy or strain, cigarette smoking and proteinuria. Attributes associated with increased risk of intracranial hemorrhage were age, elevated blood pressure, cigarette smoking, serum uric acid and, inversely, serum cholesterol level. Electrocardiographic evidence of left ventricular hypertrophy or strain significantly increased the risk of cerebral hemorrhage, but was not associated with subarachnoid hemorrhage. In univariate analysis, there was an inverse relation between dietary fat intake and thrombo-embolic and total stroke incidence. An inverse relation was also shown between protein intake and total stroke incidence. These dietary relations became statistically not significant in multivariate analysis. No relation was found between salt intake and the incidence of stroke.

CBF and time thresholds for the formation of ischemic cerebral edema, and effect of reperfusion in baboons

Ischemic cerebral edema has been studied in 41 baboons, with regional cerebral blood flow (CBF) determined by hydrogen clearance, and edema measured by microgravimetry. A threshold of ischemia has been identified for baboon cortex and subcortical white matter, which has to be crossed before edema formation begins. This threshold is 40.5% of normal CBF in cortex, and 34.4% of normal flow in subcortical white matter. A time threshold has also been determined, and the baboon brain can withstand 30 minutes of ischemia of the middle cerebral artery without significant edema formation. Reperfusion of ischemic brain has no effect on tissue water if the ischemic flow and time thresholds have not been crossed. Reperfusion of cortex, where water has begun to accumulate, exacerbates the water accumulation in proportion to the extent of the reperfusion. If these results are applicable to man, restoration of flow should not be attempted after an ischemic insult that reduces flow to less than 40% of normal unless it can be accomplished within 30 minutes of the insult. Provided CBF can be restored to above the 40% threshold within 30 minutes, reversal of the neurological deficit and prevention of ischemic edema can be expected.

[Long-term prognosis of patients with juvenile infarct. Catamnestic results]

Seventy patients suffering from ischemic cerebrovascular disease had had their first attack before the age of 40 years. Of these patients 57 were re-examined 84 months (mean) after the initial event. Within 48 months, 22 of 51 patients (43.1%) without surgical treatment had recurrent ischemic events (78.6% patients with transient ischemic attacks, 33.3% patients with protracted reversible deficits, 28.6% patients with completed stroke). Of all patients 31.5% had their first recurrent attack during the first year, most of them during the first few months after the initial event. In spite of the considerably higher recurrence rate, patients with initial transient ischemic attacks or protracted reversible deficits had a lower degree of social disability at the end of the follow-up period than patients with an initial completed stroke. In 72.2% of the patients with recurrent events the ischemic focus was found in a vascular area different from the one originally concerned. Patients with arterial hypertension during the follow-up period had a somewhat less-favorable long-term prognosis, but nicotine abuse or relative body weight had no influence on the degree of social disability at the end of the follow-up period. In general, long-term prognosis was rather favorable, 78.4% of the patients being fully capable of work at the end of the follow-up period. Nevertheless, results point to the necessity of complete diagnostic evaluation without delay and introduction of individual therapy for patients suffering from "juvenile stroke."

Relationship between longitudinal changes in blood pressure and stroke incidence

The relationship of changes in blood pressure with time to stroke incidence was examined on members of the Adult Health Study sample who have participated in biennial clinical examinations at the Radiation Effects Research Foundation since their inception in 1958. The regression coefficient of blood pressure regressed on time (the increase in blood pressure per cycle) was used as an index of the change in blood pressure with time. Cox's regression analysis, a technique which is suitable for follow-up studies was used. The data suggest that a single blood pressure measurement is not sufficient for predicting risk; the accumulated value or average over a period of time should be considered for this purpose. In addition to the actual blood pressure, the increase in blood pressure with time is a risk factor, particularly for cerebral hemorrhage. Cerebral hemorrhage was more strongly related to diastolic than to systolic blood pressure, while cerebral infarction appeared to be more strongly related to systolic than to diastolic blood pressure.

Reversible cerebral ischemias: a comparative analysis of risk factors in TIAs and in RINDs

A retrospective study in which 709 patients, 522 with RIND and 187 with TIA, were compared in respect of common risk factors (RFs) for acute cerebrovascular disease. The two forms of the disease differed significantly in respect of smoking, hematocrit, hypercholesteremia, hypertriglyceridemia and hyperuricacidemia. Although these RFs do not seem to be determinants of or discriminants between the two forms of acute cerebrovascular disease, it is nonetheless highly probable that, together with all the other RFs, they have a facilitatory role.

[Doppler sonography of extracranial cerebrovascular and peripheral arteries in arteriosclerosis risk factors and in coronary heart disease]

Doppler examination of the neck and limbs of 160 patients with a predisposition to arterial vascular disease in the presence of hypertension, hyperlipoproteinaemia, cigarette smoking and diabetes mellitus, 66% of whom had a combination of two or more of these risk factors, showed in 48 cases single or combined lesions in the arteries of the neck. One patient had unilateral stenosis of the common carotid artery; 20 patients showed unilateral and seven bilateral stenosis of the internal carotid artery; nine patients had unilateral and two patients bilateral stenosis of the external carotid artery; 28 patients showed unilateral flow reduction in the vertebral artery. There was a combined lesion of two or three vessels of the neck in 12 patients. Stenotic peripheral arteries at different levels of the leg with ankle pressure index decrease of up to 22.5% were detected in 54 patients.These peripheral arterial diseases were associated with stenotic carotid arteries in 28%. Peripheral vascular lesions were present in 40% of patients stenotic carotid arteries. Of the 160 patients studied 67 had proven coronary heart disease; 22% of these showed stenotic carotid arteries and 29% showed stenotic peripheral arteries. Combined lesions of the coronary, carotid and peripheral arteries were found in 13%.

Haematocrit, hypertension and smoking in patients with transient ischaemic attacks and in age and sex matched controls

The blood pressure, smoking habit and haemotocrit of 154 patients with transient ischaemic attacks and 191 age-and sex-matched neurological controls were studied. Regression analysis revealed that the haematocrit value was related to both systolic and diastolic blood pressure, and to smoking. Smoking elevated the haematocrit by 1.9 +/- 0.59 in males and by 2.18 +/- 0.68 in females. When these associations were allowed for there was still evidence of a higher haematocrit in patients with transient ischaemic attacks (plus 1.44 +/- 0.56 in males and 0.75 +/- 0.75 in females p less than 0.02). The role of an elevated haematocrit in the pathogenesis of cerebrovascular disease and its management are briefly discussed.

Treatment for a nondisease: the case of low blood pressure

This paper documents diagnosis and treatment of hypotension among a sample of subjects visiting blood pressure screening booths as part of a hypertension screening survey in Montreal. Of 1019 subjects, over one quarter had been diagnosed as hypotensive. Though low blood pressure is harmless for the majority of people, almost 10% of the screened sample reported receiving treatment from their physicians for the condition. Treatment typically consisted of harmless, but ineffective placebo-like medications including veal liver extract capsules or injections, iron capsules, tonics and vitamin B12 liquid, injections or capsules. Additional analysis discovered little meaningful difference in systolic and diastolic readings among individuals treated for hypotension, those diagnosed but not treated, and an undiagnosed group. Subjects receiving the hypotensive label from practitioners were typically older women with less education and income. Findings are discussed in light of the overlap between statistical and pathological models of illness; presenting symptoms of patients and their demands for treatment; and assumptions of physicians in diagnostic decision-making. It is speculated that medical definition of a nondisease such as low blood pressure may serve to individualize discomfort when true etiology lies in the environment; legitimate neglect of responsibilities and obligations by assigning one to the sick role; or cause organization of vague impulses into symptoms. Hypotension should be included in utilization studies to determine prevalence of treatment, life history of those being treated and complaints offered for treatment.

Association of cerebral infarction and chronic alcoholism: an autopsy study

Central nervous system (CNS) infarcts were present at autopsy in 10 of 23 alcoholic patients and in 9 of 36 nonalcoholic patients. There were more males than expected in the infarct population and in the alcoholic population. Male subjects comprised the entire population of alcoholics with infarcts. In addition, a history of alcohol abuse was present in every case of cerebral infarction dying before age 75. The incidence of cardiomegaly was increased among the alcoholics. There were no differences between alcoholics and nonalcoholics in the incidence of diagnosed hypertension, moderate-to-severe coronary atherosclerosis, or adult onset diabetes. However, CNS infarction was more likely to occur at an earlier age in alcoholics than in nonalcoholics. Excessive alcohol consumption may be a risk factor in the premature development of cerebrovascular disease in males.

Cerebral ischemia in young adults

56 cerebral ischemia patients up to the age of 40 were investigated using a strict clinical and instrumental protocol in order to elicit the relative importance of the various iatrogenic factors involved. In addition to atherosclerosis risk factors (smoking, hypertension, ischemic heart disease, diabetes, dyslipidemia) other possible causes of cerebral ischemia were sought (arteritis, migraine, head injury, oral contraceptives, coagulation disorders, cardiogenic embolism, etc.). 50% of the patients examined had at least two atherosclerosis risk factors and 55% had other causes singly or in association with atherosclerosis.

[The cerebral angiogram in cases of stroke in youth (author's transl)]

Sixty-seven patients (ages: 11-40 years) suffering from ischemic cerebral circulatory disturbances were investigated clinically and angiographically. In 34 cases, transient ischemic attacks or reversible ischemic neurological defects were diagnosed; 33 patients suffered from completed strokes. In most cases the completed stroke took place without previous transient ischemic attacks. A very good tendency toward recovery was observed in 60 of 67 cases. Stenoses or occlusions were found in only 21.5% of the clinically affected vessel regions. However, 50% of those patients, on whom panangiography was performed, were shown to have stenoses or occlusions. Stenotic vessel wall lesions are also obviously to be expected in clinically nonaffected vessel regions; consequently, in cases of cerebral circulatory disturbances, angiographic investigation of all craniocervical vessels is advisable.

Survival of the ischemic brain: a progress report

The number of patients with cerebral infarctions increases as the population ages, despite campaigns against hypertension, the greatest risk factor. Cerebral ischemia initiates events that are presumed to defer the stage of irreversible injury. These events cause an increase of perfusion around the central ischemic zone and trigger the Bohr effect, both of which preserve tissue viability. Almost simultaneously, mitochondrial function fails, resulting in insufficient energy for the enzyme systems to control Na and K ion equilibrium. At the same time, protein synthesis slows and cellular respiratory enzymes decrease their activity, initiating an irreversible state of tissue change. Tissue fatty acids increase as a result of dissolution of cell membrane lipoprotein structure. Barbiturates reduce the extent of experimental infarction. Resperine and aminophylline are also effective, but there are no corroborative clinical trials. That ischemic brain damage may be the result of toxic substances in the ischemic tissue represents a new concept.

Use of oral contraceptives, cigarette smoking, and risk of subarachnoid haemorrhage

In a large cohort of women, the risk of subarachnoid haemorrhage was significantly associated both with cigarette smoking and with use of oral contraceptives (O.C.S.). The risk of cigarette smokers was 5.7 times that of non-smokers; for current users of O.C.S. the risk was 6.5 times that of non-users. The risk in women who both smoked cigarettes and used O.C.S was 22 times that of women who neither smoked nor used O.C.S. Past use of O.C.S was also significantly associated with increased risk of subarachnoid haemorrhage, the relative risk being 5.3. There was some evidence that risk may increase with duration of O.C. use. In this series no significant associations were found between occurrence of subarachnoid haemorrhage and history of hypertension or of migraine headache.