Cerebral vascular disease in Hiroshima, Japan

Ciprofloxacin and pegylated G-CSF combined therapy mitigates brain hemorrhage and mortality induced by ionizing irradiation

Introduction

Brain hemorrhage was found between 13 and 16 days after acute whole-body 9.5 Gy 60Co-γ irradiation (IR). This study tested countermeasures mitigating brain hemorrhage and increasing survival from IR. Previously, we found that pegylated G-CSF therapy (PEG) (i.e., Neulasta®, an FDA-approved drug) improved survival post-IR by 20-40%. This study investigated whether Ciprofloxacin (CIP) could enhance PEG-induced survival and whether IR-induced brain hemorrhage could be mitigated by PEG alone or combined with CIP.

Methods

B6D2F1 female mice were exposed to 60Co-γ-radiation. CIP was fed to mice for 21 days. PEG was injected on days 1, 8, and 15. 30-day survival and weight loss were studied in mice treated with vehicles, CIP, PEG, or PEG + CIP. For the early time point study, blood and sternums on days 2, 4, 9, and 15 and brains on day 15 post-IR were collected. Platelet numbers, brain hemorrhage, and histopathology were analyzed. The cerebellum/pons/medulla oblongata were detected with glial fibrillary acidic protein (GFAP), p53, p16, interleukin-18 (IL-18), ICAM1, Claudin 2, ZO-1, and complement protein 3 (C3).

Results

CIP + PEG enhanced survival after IR by 85% vs. the 30% improvement by PEG alone. IR depleted platelets, which was mitigated by PEG or CIP + PEG. Brain hemorrhage, both surface and intracranial, was observed, whereas the sham mice displayed no hemorrhage. CIP or CIP + PEG significantly mitigated brain hemorrhage. IR reduced GFAP levels that were recovered by CIP or CIP + PEG, but not by PEG alone. IR increased IL-18 levels on day 4 only, which was inhibited by CIP alone, PEG alone, or PEG + CIP. IR increased C3 on day 4 and day 15 and that coincided with the occurrence of brain hemorrhage on day 15. IR increased phosphorylated p53 and p53 levels, which was mitigated by CIP, PEG or PEG + CIP. P16, Claudin 2, and ZO-1 were not altered; ICAM1 was increased.

Discussion

CIP + PEG enhanced survival post-IR more than PEG alone. The Concurrence of brain hemorrhage, C3 increases and p53 activation post-IR suggests their involvement in the IR-induced brain impairment. CIP + PEG effectively mitigated the brain lesions, suggesting effectiveness of CIP + PEG therapy for treating the IR-induced brain hemorrhage by recovering GFAP and platelets and reducing C3 and p53.

A novel therapy, using Ghrelin with pegylated G-CSF, inhibits brain hemorrhage from ionizing radiation or combined radiation injury

Medical treatment becomes challenging when complicated injuries arise from secondary reactive metabolic and inflammatory products induced by initial acute ionizing radiation injury (RI) or when combined with subsequent trauma insult(s) (CI). With such detrimental effects on many organs, CI exacerbates the severity of primary injuries and decreases survival. Previously, in a novel study, we reported that ghrelin therapy significantly improved survival after CI. This study aimed to investigate whether brain hemorrhage induced by RI and CI could be inhibited by ghrelin therapy with pegylated G-CSF (i.e., Neulasta®, an FDA-approved drug). B6D2F1 female mice were exposed to 9.5 Gy 60Co-γ-radiation followed by 15% total-skin surface wound. Several endpoints were measured at several days. Brain hemorrhage and platelet depletion were observed in RI and CI mice. Brain hemorrhage severity was significantly higher in CI mice than in RI mice. Ghrelin therapy with pegylated G-CSF reduced the severity in brains of both RI and CI mice. RI and CI did not alter PARP and NF-κB but did significantly reduce PGC-1α and ghrelin receptors; the therapy, however, was able to partially recover ghrelin receptors. RI and CI significantly increased IL-6, KC, Eotaxin, G-CSF, MIP-2, MCP-1, MIP-1α, but significantly decreased IL-2, IL-9, IL-10, MIG, IFN-γ, and PDGF-bb; the therapy inhibited these changes. RI and CI significantly reduced platelet numbers, cellular ATP levels, NRF1/2, and AKT phosphorylation. The therapy significantly mitigated these CI-induced changes and reduced p53-mdm2 mediated caspase-3 activation. Our data are the first to support the view that Ghrelin therapy with pegylated G-CSF is potentially a novel therapy for treating brain hemorrhage after RI and CI.

Ghrelin Therapy Decreases Incidents of Intracranial Hemorrhage in Mice after Whole-Body Ionizing Irradiation Combined with Burn Trauma

Nuclear industrial accidents and the detonation of nuclear devices cause a variety of damaging factors which, when their impacts are combined, produce complicated injuries challenging for medical treatment. Thus, trauma following acute ionizing irradiation (IR) can deteriorate the IR-induced secondary reactive metabolic and inflammatory impacts to dose-limiting tissues, such as bone marrow/lymphatic, gastrointestinal tissues, and vascular endothelial tissues, exacerbating the severity of the primary injury and decreasing survival from the exposure. Previously we first reported that ghrelin therapy effectively improved survival by mitigating leukocytopenia, thrombocytopenia, and bone-marrow injury resulting from radiation combined with burn trauma. This study was aimed at investigating whether radiation combined with burn trauma induced the cerebro-vascular impairment and intracranial hemorrhage that could be reversed by ghrelin therapy. When B6D2F1 female mice were exposed to 9.5 Gy Cobalt-60 γ-radiation followed by 15% total skin surface burn, cerebro-vascular impairment and intracranial hemorrhage as well as platelet depletion were observed. Ghrelin treatment after irradiation combined with burn trauma significantly decreased platelet depletion and brain hemorrhage. The results suggest that ghrelin treatment is an effective therapy for ionizing radiation combined with burn trauma.

Understanding the Pathophysiology and Challenges of Development of Medical Countermeasures for Radiation-Induced Vascular/Endothelial Cell Injuries: Report of a NIAID Workshop, August 20, 2015

After the events of September 11, 2001, a decade of research on the development of medical countermeasures (MCMs) to treat victims of a radiological incident has yielded two FDA-approved agents to mitigate acute radiation syndrome. These licensed agents specifically target the mitigation of radiation-induced neutropenia and infection potential, while the ramifications of the exposure event in a public health emergency incident could include the entire body, causing additional acute and/or delayed organ/tissue injuries. Anecdotal data as well as recent findings from both radiation accident survivors and animal experiments implicate radiation-induced injury or dysfunction of the vascular endothelium leading to tissue and organ injuries. There are significant gaps in our understanding of the disease processes and progression, as well as the optimum approaches to develop medical countermeasures to mitigate radiation vascular injury. To address this issue, the Radiation and Nuclear Countermeasures Program of the National Institute of Allergy and Infectious Diseases (NIAID) organized a one-day workshop to examine the current state of the science in radiation-induced vascular injuries and organ dysfunction, the natural history of the pathophysiology and the product development maturity of potential medical countermeasures to treat these injuries. Meeting presentations were followed by a NIAID-led open discussion among academic investigators, industry researchers and government agency representatives. This article provides a summary of these presentations and subsequent discussion from the workshop.

Cardiac arrhythmias and stroke: increased risk in men with high frequency of atrial ectopic beats

BACKGROUND AND PURPOSE

With the exception of atrial fibrillation (AF), little scientific attention has been given the associations between cardiac arrhythmias and incidence of stroke. We sought to study whether atrial and ventricular arrhythmias assessed during a 24-hour ambulatory ECG registration are associated with incidence of stroke.

METHODS

The population-based cohort "Men Born in 1914" was examined with 24-hour ambulatory ECG registrations at 68 years of age. Four hundred two men without previous myocardial infarction or stroke were included, and 236 of them had hypertension (>/=160/95 mm Hg or treatment). Fourteen-year rates of stroke (fatal and nonfatal) and all-cause mortality were updated from national and regional registers. Frequent or complex ventricular arrhythmias was defined as Lown class 2 to 5. A high frequency of atrial ectopic beats (AEB) was defined as the fifth quintile (ie, >/=218 AEB per 24 hours).

RESULTS

Fifty-eight men suffered a first stroke during the follow-up. Stroke rates (per 1000 person-years) among men with AF (n=14), with frequent AEB (n=77), and without AF or frequent AEB (n=311) were 34.5, 19.5, and 11.6, respectively. The corresponding values among men with hypertension were 40.7, 32.3, and 14.7, respectively. Frequent AEB (compared with absence of AF and frequent AEB) was significantly associated with stroke among all men (relative risk=1.9; 95% CI, 1.02 to 3.4; P:=0.04) and among hypertensive men (relative risk=2.5; 95% CI, 1.3 to 4.8; P:=0.009) after adjustments for potential confounders. The increased stroke rates among men with Lown class 2 to 5 did not reach statistical significance.

CONCLUSIONS

A high frequency of AEB is associated with an increased incidence of stroke.

Relation between cold pressor test and development of hypertension based on 28-year follow-up

The present study examined the relation between blood pressure reactivity to cold stimulus and the subsequent development of hypertension based on a follow-up study from 1960 through 1988 of 824 normotensive participants (mean age, 35.8 +/- 10.8 years) in the Adult Health Study in Nagasaki, Japan. Hypertension developed in 343 individuals during the 28 years of follow-up, with a mean incidence rate of 24.6 per 10(3) person-years. Confounding variables, including attained age, resting systolic and diastolic blood pressures, and body mass index at baseline, were adjusted using a Poisson regression model. Systolic response was found to be an independent and significant predictor. The relative risk of hypertension for systolic hyperreactors was 1.37, with a 95% confidence interval of 1.10 to 1.71. Diastolic response was significant only when resting diastolic blood pressure was also considered. The cold pressor test appears to be useful if performed on middle-aged subjects older than 40 years at the time of examination, when hypertension is more prevalent. The current results support the hypothesis that hyperreactivity is a predictor of the development of hypertension.

Pattern and ethnic variations in stroke in Saudi Arabia

We report our observations in 427 stroke patients (305 Saudis, 122 non-Saudis with an age range of 14 months to 85 years) seen in a tertiary hospital in the eastern province of Saudi Arabia over an 8-year period. Of these patients, 115 (27%) were between 18 and 45 years old, and constituted the "young stroke patients" for this study. The hospital frequency for the young was 5/10,000 inpatients. In general, there was a male preponderance, with a male:female ratio of 2.2:1 and 7:1 for Saudis and non-Saudis, respectively. Ischemic stroke (55%) was more frequent than hemorrhagic stroke (25%), and the stroke was unspecified in 20%. The main etiologic factors were hypertension, diabetes mellitus and cardiac disorders. In the young population, the frequencies of hemorrhagic and ischemic strokes were similar. In this group, the main causes of intracerebral hemorrhage were aneurysms and arteriovenous malformations, while arteriosclerosis and embolism of cardiac origin were responsible for the ischemic strokes. In Saudis, the stroke types were 59% ischemic, and 17% hemorrhagic, as against 45 and 48% in non-Saudis, respectively. Most ischemic strokes were found in Saudis (78%). Intracerebral hemorrhage accounted for 63% of all hemorrhagic strokes, and was more frequent in Saudis but subarachnoid hemorrhage was three times more common in non-Saudis. In the young stroke patients, interethnic comparison showed that individuals from the Far East were nine times more likely to have hemorrhagic than ischemic stroke compared to the others (odd's ratio = 8.7), and the etiology of ischemic stroke remained undetermined in 67% of those from the Indian subcontinent.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrovascular disease in north-west India: a study of necropsy material

The pattern of cerebrovascular disease in North-West India has been studied in a necropsy series of 362 cases over a 14 year period. One hundred and thirty eight cases of intracranial haemorrhage were found, 89 of cerebral embolism, 101 of cerebral arterial thrombosis and 34 of cerebral venous thrombosis. Nearly 37% of the affected patients were below 40 years of age. Cerebral embolism and cerebrovenous thrombosis were important causes of stroke in the young. Rheumatic heart disease and infective endocarditis formed the major causes of cerebral embolism. Cerebral venous thrombosis associated with pregnancy and puerperium was relatively more common in our series than has been reported in the West.

Meta-analysis of relation between cigarette smoking and stroke

There is a lack of consensus among studies on the possible risks of stroke from cigarette smoking; because of this a meta-analysis was conducted. All published data on the association were sought and the relative risk for each study obtained whenever possible. The pooled relative risks were calculated by using estimates of the precision of the individual relative risks to weight their contribution to the meta-analysis. Thirty two separate studies were analysed. The overall relative risk of stroke associated with cigarette smoking was 1.5 (95% confidence interval 1.4 to 1.6). Considerable differences were seen in relative risks among the subtypes: cerebral infarction 1.9, cerebral haemorrhage 0.7, and subarachnoid haemorrhage 2.9. An effect of age on the relative risk was also noted; less than 55 years 2.9, 55-74 years 1.8, and greater than or equal to 75 years 1.1. A dose response between the number of cigarettes smoked and relative risk was noted, and there was a small increased risk in women compared with men. Ex-smokers under the age of 75 seemed to retain an appreciably increased risk of stroke (1.5); for all ages the relative risk in ex-smokers was 1.2. The meta-analysis provides strong evidence of an excess risk of stroke among cigarette smokers. Stroke should therefore be added to the list of diseases related to smoking.

Predictive value of resting electrocardiograms for 12-year incidence of stroke in the Honolulu Heart Program

The importance of electrocardiographic (ECG) abnormalities at baseline examination for subsequent risk of stroke was analyzed in a 12-year follow-up of 7,560 men in the Honolulu Heart Program, aged 45-68 years, who were free of coronary heart disease and stroke at baseline. Age-adjusted univariate analysis showed that men with major ST depression, left ventricular strain, left ventricular hypertrophy, major T wave inversion, and overall major ECG abnormalities had considerably higher (2.5-5.4 times) incidence rates of both thromboembolic and hemorrhagic stroke than those with normal baseline ECG. When blood pressure, age, cigarette smoking, alcohol consumption, fat intake, serum glucose concentration, serum uric acid concentration, years of education, and years lived in Japan were taken into consideration through multivariate analysis, the ECG abnormalities retained a significant relation with stroke. Our study demonstrates that resting ECG abnormalities are independent predictors of both thromboembolic and hemorrhagic stroke.

Incidence of stroke in a Finnish prospective population study

The incidence of stroke was investigated in a large Finnish prospective population study. The study population consisted of 11,984 men and 11,682 women aged 15 years and over drawn from four geographical regions of the country. In a mean follow-up time of six years, 174 men and 169 women suffered a fatal or non-fatal stroke. The age-adjusted mean annual incidence of stroke in men, 4.0/1000, was statistically significantly higher than the annual incidence in women, 3.3/1000. In twelve percent of the cases stroke was caused by subarachnoid hemorrhage and in ten percent by cerebral hemorrhage. In 30 percent of the cases, cerebral infarction was ascertained as the cause of the stroke; while in 49 percent of the cases, the type of stroke could not be specified with certainty. The incidence of stroke was significantly higher in non-attendants than in attendants at the initial survey. The incidence of cerebral infarction appeared to be higher in men from eastern Finland than in men from southwestern Finland.

Stroke before 55 years of age at Karolinska Hospital 1973-77. A study of 399 well-defined cases. Risk indicators and etiological considerations

The etiological characteristics of cerebrovascular disease (CVD) before the age of 55 are reviewed in 399 patients admitted to the Department of Neurology, Karolinska Hospital, Stockholm, from 1973-77. The material was well-defined with regard to subtypes of stroke as well as to the diseased population. The control material consists of 829 males and females of corresponding age randomly selected from the Stockholm population. In the ischemic group, 61% had angiographic evidence of atherosclerosis and, compared to controls, in most patient groups a significant (P less than 0.05-0.001) association with hypertension, diabetes, heart disease and smoking was found as well as for female patients under age 40 the use of oral contraceptives (P less than 0.001). In the hemorrhagic group, angiography demonstrated aneurysms in 76% of the patients with subarachnoidal bleeding but also atherosclerotic lesions in about 12% of the whole group. This would imply that atherosclerosis is an important precursor also for hemorrhagic lesions, further supported by a significant (P less than 0.01-0.001) association of hypertension, diabetes and smoking with this group.

Predictors of stroke-associated mortality in the elderly

Although stroke is a major cause of death in older adults, few studies have examined the independent contribution of cardiovascular disease risk factors to stroke mortality in the geriatric age group. We report here a nine-year followup of a Southern California community of 2107 men and women aged 65 to 84 years. In this older cohort, age was the most significant independent risk factor for stroke-associated mortality in both sexes. Systolic blood pressure was weakly but significantly associated with stroke mortality in this older age group. Cigarette smoking was positively related and educational level of head of household negatively related to stroke mortality in both sexes, with the predominant effect in women. No significant independent effect of cholesterol, fasting plasma glucose or obesity was discernible. Both blood pressure and cigarette smoking are potentially remedial risk factors for stroke after age 65.

Cerebrovascular diseases and their underlying vascular lesions in Hisayama, Japan--a pathological study of autopsy cases

Frequency of cerebrovascular diseases (CVD) and their underlying vascular lesions were analyzed in 724 autopsy cases, aged 40 years and over, in the community of Hisayama, Japan during the period 1961 to 1981. Cerebral infarction (CI) was more frequently found at autopsy than cerebral hemorrhage (CH) with a ratio of infarction and hemorrhage of 4.4. Small CI occupied 75.7% of the cases with CI. The cases with any type of CVD showed more severe atherosclerosis of the major cerebral arteries than did those without CI or CH. Cerebral atherosclerosis of those with large and medium CI was the greatest, and with decreasing severity in those with small CI and with CH sequentially. Fibrinoid necrosis of the intracerebral small arteries was frequently found in cases with hypertension and particularly associated with CH. The decline in frequency of CH was confirmed; however, changes in frequency of CI were not evident. Fibrinoid necrosis was also reduced, although the severity of cerebral atherosclerosis showed no definite change. The decline of CH seemed to be ascribed to the reduction of fibrinoid necrosis of the intracerebral small arteries.

An evaluation of risk factors for stroke in a Dutch community

The objective of the present epidemiological study was to reevaluate the relationship of various suspect risk factors to stroke within a Dutch community. The Tilburg study lends support to findings in other countries concerning the greater stroke risk of persons with high blood pressure, heart disorders, and diabetes mellitus. Significant interactions of both age and a history of myocardial infarction with hypertension on stroke risk were noted. The presence of overweight and possible transient ischemic attacks (TIA) were found related to stroke onset. No increase in stroke risk was associated with cigarette smoking. The extent of leisure time physical activity during one's lifetime was found inversely related to one's chances for stroke.

Leukocyte counts and cerebrovascular disease

Elevated total leukocyte count in a biennial examination period is shown to be a significant (p = 0.001) predictor of cerebral infarction (CI) incidence in the subsequent 2 yr examination period, in a large Japanese cohort study. This association is not explainable on the basis of corresponding age, sex or blood pressure levels. The extent to which the association might be attributable to cigarette smoking habits could not be thoroughly examined with available data. Relative risks associated with a specific elevated leukocyte count may be larger among persons less than 65 yr of age than among older persons. When counts of specific leukocyte cell lines are considered a significant (p = 0.0006) role for neutrophil count emerges, while an additional predictive role for other leukocyte cell types could not be detected. In contrast, there is a suggestion that cerebral hemorrhage (CH) risk may be lower following an elevated leukocyte count. In particular, a negative association between lymphocyte count and CH incidence in the subsequent biennial examination cycle, is nearly significant (p = 0.07), in spite of a rather small number of CH cases in the sample.

Hypertension in the elderly: the time has come to treat

Both pure systolic, and systolic plus diastolic hypertension are risk factors for cerebrovascular and cardiovascular disease in patients over 65 years old, but the efficacy of antihypertensive therapy in preventing the complications of hypertension in the elderly has been questioned. The risks associated with such therapy seem to have been overemphasized. Although the evidence is incomplete, elderly patients should be treated when the systolic blood pressure exceeds 160 mm Hg or the diastolic pressure exceeds 95 mm Hg, or both. A revised stepped-care approach, with use of vasodilating agents as the Step-2 drugs, is proposed.

Cerebrovascular and degenerative changes in the brain; a study of 233 Japanese 50 or more years of age

A neuropathologic study, chiefly cerebrovascular lesions and degenerative changes, was conducted on the brains of 233 subjects 50 years of age and over among 557 autopsy cases of RERF-ABCC Hiroshima in 1972-1974. There were some discrepancies between the principal clinical diagnosis and principal pathologic diagnosis in cerebrovascular disease. For cerebral hemorrhage, 8.6% were accounted for in the clinical diagnosis of the entire subjects while only 2.1% were accounted for in the pathologic diagnosis of the same subject. The degenerative changes in the central nervous system have been increasing with age and these changes were seen more in the females than in the males. Intracerebral arteriosclerosis of a moderate extension or more existed in 36.5% of the subjects and the frequency of this disease increased with age. the frequency of cerebral infarct increased with age. The location of the infarcts was most often seen in the basal ganglia and cortex of cerebrum, the size of the cortical infarct was within 0.5 cm in diameter and multiple. The vascular lesions or degenerative changes were seen in about 74% of the brains of 50 years and over.

Sex differences in the incidence of cerebrovascular disease

Incidence rates for cerebrovascular disease reported by community-based and hospital-based studies during the past 15 years are analysed. The range of variation between area is wide, with Japan and Finland experiencing the highest age-adjusted rates. Of 16 studies reporting incidence rates by sex, 15 showed a male excess, and nine of these were significant when the incidence rate was age-adjusted. Overall, the excess is about 30% for both community-bases and hospital-based studies. For cerebral infarction the excess is about 45%. Intracerebral haemorrhage shows little difference between the two sexes and subarachnoid haemorrhage shows a male deficit of about 50%. These findings are self-consistent.

Decreasing trend in incidence and mortality from stroke in Hisayama residents, Japan

The incidence and mortality from stroke during the period 1961 to 1976, among 1,621 subjects aged 40 and over at entry, in Hisayama community, Kyushu Island, Japan, were analyzed. A major age-related decline in the incidence of cerebral infarction occurred in both sexes. The average annual incidence of cerebral infarction also fell continuously in both sexes throughout the whole observation period. The 5-year annual mortality rate from cerebral hemorrhage also showed a decrease in men, but fluctuated in women. The 5-year mortality from cerebral infarction slightly increased in both sexes.

Factors related to stroke incidence in Hawaii Japanese men. The Honolulu Heart Study

As part of an ongoing longitudinal study of coronary heart disease and stroke among Japanese men in Hawaii, 8,006 men of Japanese ancestry living on the island of Oahu and aged 45-68 at entry examination have been followed by reexamination and surveillance. One hundred and eleven were found to have evidence of prior stroke at the time of the initial examination. During a six-year follow up period of the remaining 7,895 men, 94 developed definite thromboembolic stroke, 33 definite intracranial hemorrhage, and 6 developed stroke of unknown type. The principal risk factors for thromboembolic stroke were: elevated blood pressure, glucose intolerance, age, and electrocardiography evidence of left ventricular hypertrophy or strain. Attributes associated with increased risk of intracranial hemorrhage were elevated blood pressure, electrocardiographic evidence of left ventricular hypertrophy or strain, and alcohol intake. Serum cholesterol level was negatively associated with risk of intracranial hemorrhage.

Autopsy study of cerebrovascular disease in Japanese men who lived in Hiroshima, Japan, and Honolulu, Hawaii

Evidence of cerebrovascular disease at autopsy was compared in 2 groups of men: 186 long-time residents of Hiroshima, Japan, and 253 men of Japanese ancestry long resident in Honolulu, Hawaii. They were 45 to 71 years-of-age at death. Atherosclerosis of the circle of Willis and its major branches, sclerosis of the intraparenchymal arteries and the frequency of cerebral hemorrhage and cerebral infarct were compared in the 2 populations. The Honolulu subjects had significantly more atherosclerosis of the circle of Willis, but less intraparenchymal artery sclerosis and less cerebral infarction. Cerebral hemorrhage was equally frequent in the 2 cities. It was concluded that cerebral infarction is more frequent in Japanese men in Hiroshima than Honolulu, and that men of Japanese ancestry in Honolulu are spared an appreciable risk of cerebral infarction through decreased frequency of intraparenchymal arterial sclerosis despite higher levels of atherosclerosis of large intracranial arteries.

Risk factors in stroke: a clinical study in Mexican patients

Mexicans hospitalized between July, 1967, and June, 1968, with clinically diagnosed stroke provided information on risk factors in a population from which little systematically collected information on stroke exists. The patients were beneficiaries of ISSSTE, a government-sponsored health care system. Postmortem examination in 20 patients indicated virtually 100% validity of diagnosis. Cerebral thrombosis, hemorrhage and embolus occurred in a ratio of 6:2:1. There was no sex difference in stroke frequency. Thrombosis and hemorrhage increased with age; embolus occurred more often in younger patients. Thrombosis tended to occur when at repose and in individuals with sedentary occupations; the opposite was found with hemorrhage and embolus. Obesity did not seem to predispose to stroke. Hypertension, heart disease and diabetes mellitus emerged as common antecedent conditions. There was a morning peak in onset of thrombosis and hemorrhage and an afternoon peak for embolus. No relation of onset to holidays or stress was noted. Thrombosis, hemorrhage and embolus all were associated with increased ambient temperature, and with low, slightly decreased and high humidity, respectively. An August-September (end of rainy season) peak in seasonal frequency occurred. The risk factors previously identified as being important mainly in northern populations seemed to be important in this Mexican population as well. Thus, ethnic and cultural variability exerted little effect on stroke frequency.

Stroke in Jerusalem district 1960 through 1967: an epidemiological study

An epidemiological study was performed in Jerusalem district on the incidence of new stroke patients during the years 1960 through 1967.

On the assumption that the vast majority of patients with a new cerebrovascular event were either hospitalized in one of the three local hospitals or later referred to the Neurological Outpatient Clinic at the Hadassah University Hospital, a retrospective study was performed in order to obtain a close estimation of the incidence of stroke in the district of Jerusalem. In the period of 1960 through 1967, 1,522 new stroke cases were identified and included in this study. On the basis of the history, clinical picture and auxiliary tests, the patients were divided into three groups: (1) ischemic stroke, (2) stroke due to hemorrhage, and (3) stroke of undetermined type. The criteria for differentiation of cerebral ischemia from hemorrhage were rigid, demanding at least a lumbar puncture, angiography, operation, or autopsy for a diagnosis of either one to be made. These rigid criteria account for the high percentage of undetermined cases. Ischemic stroke was diagnosed in 509 (33%), stroke due to hemorrhage in 181 (12%), and stroke of undetermined type in 832 (55%).

The average annual incidence of stroke in the district of Jerusalem was 90/100,000 population.

The age-specific annual incidence rates showed an almost constant increase for both sexes and the various types of stroke, with increasing age. The age-specific and sexspecific annual incidence rates disclosed a male preponderance for all the age groups above 45 in the "ischemic" and "undetermined" types, and for the total series. This preponderance was marked in the 65 to 74 age group. In the "stroke due to hemorrhage" type there was a slight male preponderance in the 65 to 74 age group and a slight female preponderance in the 75+ age group, the ratio being equal for the total hemorrhagic series. Our findings were compared with those reported in other studies and discussed.

Cerebrovascular disease in the bi-racial population of Evans County, Georgia

An epidemiological study was made of cerebrovascular disease in a bi-racial Southern community. The study population comprised about 3,000 men and women aged 15 to 75 years at the time of entry into the study. During the 87-month period between the initial and second examinations, 94 persons developed their first cerebrovascular event.

The incidence of stroke among white men (4.77/1,000/year) was almost four times that in white women and more than twice that reported for white men in other sections of the country. The incidence rates of stroke in Negro men and women were equal (5.8/1,000/year).

The risk factors predisposing to stroke in white men appeared to be severe hypertension, obesity, high hematocrit levels, and antecedent electrocardiographical abnormalities These factors were not as prominent among the other race-sex groups.

The high incidence of cerebrovascular disease found in this semirural population of Georgia supports previous reports of increased mortality rates for stroke in this section of the country and represents a unique situation, the exact cause for which remains to be determined.

Cerebrovascular disease: frequency and population selectivity in an upper midwestern community

The number of new strokes diagnosed in the communities of Fargo, North Dakota, and Moorhead, Minnesota, was determined by intensive review of medical records in all hospitals, clinics and nursing homes in the area for the period 1965 to 1966. These two adjacent communities have unusual advantages for such a study because their neurological diagnostic facilities are of excellent quality, the population served is stable, and the communities are isolated from other medical facilities by many miles.

Out of a population of 94,000 about one-third of which was over 35 years of age and almost all of which was white, a total of 408 patients were diagnosed as having suffered a new cerebral thrombosis (154 cases), hemorrhage (66 cases), embolus (15 cases), subarachnoid hemorrhage (30 cases) or unspecified CVA (143 cases). The average annual incidence of these strokes was respectively 83, 35, 8, 16 and 76 per 100,000 population. These rates are similar to the rates reported elsewhere in a United States, a Japanese and an English community in which similar case-finding methods were used. The similarity in incidence of various types of stroke suggested by these data is in contrast to the appreciable differences in frequency suggested by mortality data. The possibility exists, therefore, that geographical differences in stroke rates based on mortality may represent an artifact. More valid measures of frequency and population selectivity of cerebrovascular disease may show that this disease, unlike coronary vascular disease, is actually similar in populations differing widely in environmental and racial characteristics.

Besides the average annual frequency of strokes, the age-specific frequencies were calculated and revealed a marked increase of all types with age over 40 years except for subarachnoid hemorrhage. The latter showed a bimodal age distribution with peaks in the fifth and after the seventh decade. Seasonal incidence and mortality showed a spring and late fall peak. The sex differences in frequency were very small over a wide age range.

Data were also collected on brain stem vascular accidents, ischemic attacks and cerebral arteriosclerosis. An additional 245 patients were listed under these rubrics. These vascular events tend to be underreported and accuracy of diagnosis may be less. Moreover, comparable data from other communities using similar case-ascertainment techniques are lacking. However, if they were included, the average annual incidence of "strokes" would be 347 per 100,000 population.

Additional community-wide studies with special attention to ischemic attacks, brain stem vascular accidents and patients labeled vaguely as cerebral arteriosclerosis would probably yield a more accurate estimate of the true frequency of cerebrovascular accidents. Ideally, all such patients should be examined neurologically and classified according to standardized criteria if data are desired which can be compared among different communities.

Nationwide cerebrovascular disease morbidity study

Previous studies have noted that the geographic differences in stroke mortality among areas of the United States were not due to artifacts of certification practices or accuracy of the diagnosis. A study of hospitalized stroke patients was completed in order to determine whether the mortality differences were due to a higher incidence or case fatality following a stroke in areas with high stroke death rates. Eight of the nine areas that participated in the Nationwide Mortality Study were included in this study. A total of 2,619 stroke cases were ascertained including 1,631 (62.3%) who were alive at the time of hospital discharge, 937 (35.8%) dead at discharge, 46 (1.7%) who were discharged alive but died outside of the hospital, and five (0.2%) who were dead at discharge and certified by the medical examiner.

The incidence of stroke was higher in the high stroke death rate areas especially for men. The ratio of the incidence of stroke in men as compared to women was higher in the younger age groups (45–54, 55–64) and in the high-incidence as compared to low-incidence areas.

The case-fatality percentage was lowest in Denver and highest in South Carolina. Presence of coma on admission was the principal determinant of subsequent mortality in all areas.

Finally, there was no consistent difference in the distribution of symptoms of stroke among the areas, and diagnostic procedures were performed more often in urban than rural areas. Approximately 80% of the stroke cases could be substantiated by either an autopsy verifying diagnosis, arteriography, hemorrhagic spinal fluid, hemiplegia or coma on admission. Several hypotheses to explain the differences have been suggested as well as the need for new information.