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

Cerebral Small Vessel Disease, Hypertension, and Vascular Contributions to Cognitive Impairment and Dementia

Hypertension-associated cerebral small vessel disease is a common finding in older people. Strongly associated with age and hypertension, small vessel disease is found at autopsy in over 50% of people aged ≥65 years, with a spectrum of clinical manifestations. It is the main cause of lacunar stroke and a major source of vascular contributions to cognitive impairment and dementia. The brain areas affected are subcortical and periventricular white matter and deep gray nuclei. Neuropathological sequelae are diffuse white matter lesions (seen as white matter hyperintensities on T2-weighted magnetic resonance imaging), small ischemic foci (lacunes or microinfarcts), and less commonly, subcortical microhemorrhages. The most common form of cerebral small vessel disease is concentric, fibrotic thickening of small penetrating arteries (up to 300 microns outer diameter) termed arteriolosclerosis. Less common forms are small artery atheroma and lipohyalinosis (the lesions described by C. Miller Fisher adjacent to lacunes). Other microvascular lesions that are not reviewed here include cerebral amyloid angiopathy and venous collagenosis. Here, we review the epidemiology, neuropathology, clinical management, genetics, preclinical models, and pathogenesis of hypertensive small vessel disease. Knowledge gaps include initiating factors, molecular pathogenesis, relationships between arterial pathology and tissue damage, possible reversibility, pharmacological targets, and molecular biomarkers. Progress is anticipated from multicell transcriptomic and proteomic profiling, novel experimental models and further target-finding and interventional clinical studies.

Red and processed meat consumption and risk of incident cardiovascular disease and mortality: Isfahan cohort study

To investigate the cardiovascular risks associated with red and/or processed meat intake in a large population-based cohort study in Iran. A total of 5432 participants from the Isfahan Cohort Study (ICS) were enrolled. Diet was assessed using a validated, 48-item food frequency questionnaire. Cox proportional hazards regression models were applied to calculate hazard ratios (HRs) for the CVD risk associated with red and processed meat intake. Median follow-up was 11.2 years. Compared to the first tertile, the highest tertile of red meat intake, either alone or in combination with processed meat was associated with a 50% reduced risk of stroke (95% CI: 0.31-0.77; 95% CI: 0.33-0.82, respectively), but increased risk of CVD mortality with corresponding HRs of 1.58 (95% CI: 1.06-2.35) and 1.47 (95% CI: 1.02-2.08), respectively. Red meat and red plus processed meat intake were inversely associated with stroke risk, but positively linked with CVD mortality.

Prospective investigation of major dietary patterns and risk of cardiovascular mortality in Bangladesh

BACKGROUND

Dietary pattern analysis is emerging as a practical, effective tool for relating comprehensive dietary intake to risk of cardiovascular disease mortality. However, no studies have applied this technique to a population outside of the developed world.

METHODS

We conducted prospective cohort analyses in 11,116 participants enrolled in the Health Effects of Arsenic Study in Araihazar, Bangladesh, measuring deaths attributable to disease of circulatory system, heart disease, and cerebrovascular disease. Participants were enrolled in 2000 and followed up for an average of 6.6 years. Dietary information was obtained through a previously validated food-frequency questionnaire at baseline.

RESULTS

Principal component analysis based on our comprehensive, 39 item FFQ yielded 3 dietary patterns: (i) a "balanced" pattern, comprised of steamed rice, red meat, fish, fruit and vegetables; (ii) an "animal protein" diet, which was more heavily weighted towards eggs, milk, red meat, poultry, bread, and vegetables; and (iii) a "gourd and root vegetable" diet that heavily relied on a variety of gourds, radishes, pumpkin, sweet potato, and spinach. We observed a positive association between increasing adherence to the animal protein diet and risk of death from both disease of the circulatory system and heart disease; the hazard ratios were 1.13 (95% CI, 1.00-1.28, p=0.05) and 1.17 (95% CI, 0.99-1.38, p=0.07), respectively, in relation to one standard deviation increase in the factor scores for the animal protein diet pattern, after controlling for age, sex, body mass index, smoking status, and energy intake. The positive association was more significant among ever smokers; the hazard ratios (95% CI) for deaths from disease of the circulatory system and heart disease were 1.17 (1.02-1.34) and 1.20 (1.00-1.45), respectively, in relation to one standard deviation increase in the factor scores for the animal protein diet pattern.

CONCLUSIONS

An animal protein-rich diet in rural Bangladesh may increase risk of heart disease mortality, especially among smokers. This emphasizes the need to further explore and address the impact of dietary patterns on cardiovascular disease in populations undergoing epidemiologic transition.

Pathology of lacunar ischemic stroke in humans--a systematic review

Twenty-five percent of ischemic strokes are lacunar in type, but the cause remains unclear. Pathological descriptions of lacunar lesions are available but have not been systematically assessed. We therefore systematically summarized studies describing lacunar lesions by extracting data on the number of patients and lesions, clinical details, pathological methods, brain regions and/or vessels examined, and both parenchymal and vascular findings. Among 39 papers describing >4000 lesions (>50% from one study), 15 papers examined patients with a clinical lacunar syndrome. Terminology varied, many studies only reported macroscopic pathology and many lesions were cavitated (ie, old). Aside from symptomatic lesions occurring more often in the internal capsule or caudate nucleus, we found no other differences between symptomatic and asymptomatic patients. Perivascular edema and thickening, inflammation and disintegration of the arteriolar wall were common, whereas vessel occlusion was rare. The causal mechanisms of lacunar stroke remain poorly defined because of methodological inconsistencies and challenges. Standardised pathological definitions based on well-characterized post-mortem derived material supported by detailed clinical and imaging data are needed.

A Review of Population-Based Retinal Studies of the Microvascular Contribution to Cerebrovascular Diseases

Studies of retinal signs, as non-invasively obtained markers of microvasculature, may help to assess the microvascular contribution to ischemic cardiovascular diseases, particularly those affecting the brain. Changes in the retinal arterioles are particularly pertinent to ischemia, and several studies show their associations with MRI-assessed cerebral lacunar infarcts and white matter changes. Data are too sparse to judge the contribution to cerebral atrophy or cognitive impairment. Confounding and imprecise measurements may cloud the results of this research. A paired comparison method is proposed for avoiding some of these issues.

Monocyte count is an underlying marker of lacunar subtype of hypertensive small vessel disease

BACKGROUND

In the hypertensive small vessel disease (HSVD), it remains unclear why some patients develop lacunar infarcts (LIs) whilst others develop deep intracerebral hemorrhages (dICHs). Inflammation might be related to LI, and leukocyte and monocyte counts are regarded as an inflammatory marker of ischemic stroke.

OBJECTIVE

We investigated the relationship between leukocyte and monocyte counts determined in the first 24 h after stroke onset in HSVD patients.

METHODS

We prospectively studied 236 patients with first acute stroke because of HSVD (129 LI and 107 dICH). We analyzed demographic data, vascular risk factors, and white blood cell count subtypes obtained in the first 24 h after stroke.

RESULTS

The multivariate analysis showed that LI subtype of HSVD was correlated with hyperlipidemia (P < 0.0001), a higher monocyte count (P = 0.002), and showed a trend with current smoking (P = 0.051), whereas dICH subtype was correlated with low serum total cholesterol (P = 0.003), low serum triglycerides (P < 0.0001), and high neutrophil count (P = 0.050).

CONCLUSIONS

In patients who developed HSVD-related stroke, high monocyte count, current smoking, and hyperlipidemia are prothrombotic factors related to LI, whereas low cholesterol and triglyceride values are related to dICH. Monocyte count might be an inflammatory risk marker for the occlusion of small vessels in hypertensive patients.

A polymorphism of the aldehyde dehydrogenase 2 gene is a risk factor for multiple lacunar infarcts in Japanese men: the Takahata Study

The objective of the present study was to examine the association between a polymorphism of the aldehyde dehydrogenase 2 (ALDH2) gene and lacunar infarcts of the brain. We conducted a population-based, cross-sectional study on residents from two age groups (61- and 72-year olds). A total of 376 subjects participated in the study, which included brain magnetic resonance image and genetic analysis of the ALDH2 gene. Of the 61- and 72-year-old subjects, 46.4% and 64.3%, respectively, had one or more lacunar infarcts. The average number of infarcts also increased from 2.0 to 2.8 in men and from 2.3 to 3.5 in women. No significant association between the ALDH2 genotype and the presence of lacunar infarction (> or =1) was found. However, in subjects with lacunar infarction, the genotype of ALDH2 *1/*1 was associated with a larger number of the lesion ['single' versus 'multiple' odds ratio (OR) 3.73, 95%CI: 1.43-9.74] in men. The OR was comparable even after adjusting for alcohol consumption, tobacco habits, age, hypertension, hypercholesterolemia, and diabetes mellitus (DM) (OR 3.88; 95% CI: 1.10-13.66). In women, there was no significant association between the ALDH2 genotypes and lacunar infarcts. The present study revealed that the ALDH2 *1/*1 genotype was significantly associated with the prevalence of multiple lacunar infarcts in Japanese men.

Prevalence and correlates of carotid atherosclerosis among elderly Japanese men

We determined intima-media thickness (IMT) and diameter of carotid artery and estimated their correlations with cardiovascular risk factors in 1129 men aged 60-74 years, who participated in a cardiovascular risk survey in three Japanese communities. The multivariate odds ratios (95% confidence interval) for the maximum IMT > or = 1.1 mm in the common carotid artery (CCA) were 1.3 (1.1-1.5) per 4 years of age, 1.8 (1.4-2.5) for hypertension, 1.4 (1.2-1.7) for a 34.4 mg/dl increase in serum total cholesterol, 0.7 (0.6-0.8) for a 14.7 mg/dl increase in serum HDL-cholesterol, and 2.4 (1.1-5.0) for history of stroke, while the maximum IMT > or = 1.5mm in the internal carotid artery (ICA) were 1.6 (1.4-1.8) per 4 years of age, 1.9 (1.5-2.4) for hypertension, 1.6 (1.2-2.1) for current smoking, and 3.5 (1.6-7.6) for history of stroke. Age, height, hypertension, current smoking, ethanol intake and history of coronary heart disease were independent determinants of both the outer and inner CCA diameter. Maximum IMT correlated positively with the outer diameter and inversely with the inner diameter in the CCA. Carotid atherosclerosis suggests to be a risk factor for stroke among Japanese elderly men, although future prospective studies are required to confirm this finding.

Intake of animal products and stroke mortality in the Hiroshima/Nagasaki Life Span Study

BACKGROUND

To determine whether intake of animal products was associated with a reduced risk of stroke mortality in a large-scale population-based cohort in Japan.

METHODS

A self-administered questionnaire, including questions on dietary habits, was mailed to the members of the Life Span Study, a cohort of people exposed and non-exposed to atomic bomb radiation, who were alive as of 1 September 1979. Animal products included frequency intake of beef/pork, chicken, ham/sausage, milk, dairy products, eggs, fish, and broiled fish. Responses were obtained from 40 349 people (72%): 15 350 men (mean age 54 years) and 24 999 women (mean age 58 years). The subjects were followed for 16 years, and deaths were ascertained by linkage to the nationwide family registration system of Japan. The associations between diet and stroke mortality were examined using a Cox proportional hazard model.

RESULTS

During the follow-up period, 1462 stroke deaths occurred. Four animal products comprising eggs, dairy products, fish, and broiled fish were independently associated with a decreased risk of stroke mortality; while beef/pork, chicken, ham/ sausage, and milk consumption were not associated with stroke death. A composite measure of eggs, dairy products, fish, and broiled fish intake was calculated, and the highest tertile was significantly inversely associated with total stroke mortality (Hazards Ratio [HR] = 0.80, 95% CI: 0.68, 0.93) compared with the lowest tertile. The protective effect of animal product intake on total stroke death was largely confined to intracerebral haemorrhage death; the RH of intracerebral haemorrhage death for the highest tertile of consumption was 0.72 (95% CI: 0.53-0.98) compared with the lowest tertile; animal products intake was not related to cerebral infarction mortality (HR = 0.84; 95% CI: 0.67-1.06).

CONCLUSIONS

Intake of animal products such as eggs, dairy products, and fish may be protective against intracerebral haemorrhage, but is not related to cerebral infarction mortality.

Hypertensive cerebral small vessel disease and stroke

Lacunar infarcts and "hypertensive" primary intracerebral hemorrhages, collectively often referred to as hypertensive small vessel strokes, constitute about one third of all strokes. However, despite their public health importance, their etiopathogenesis remains ill-understood. Like all strokes, they are a heterogeneous entity, but the autopsy pathology evidence suggests that the majority are caused by a limited number of cerebral small vessel lesions. Small vessel atherosclerosis is causally implicated in a proportion of lacunar infarcts, although modern concepts of atherosclerotic plaque biology and natural history have yet to be applied to small cerebral vessels. A lesion characterized in its acute form by fibrinoid necrosis appears to be important in causing both lacunar infarcts and primary intracerebral bleeds. Advances in molecular genetics may prove instrumental in understanding the cause of this lesion and therefore in designing its targeted prevention.

Sudden death in the general population in Okinawa: incidence and causes of death

Sudden unexpected death is generally considered to be caused by acute myocardial infarction and/or arrhythmia. To document the incidence and causes of sudden death in Japan, where the incidence of myocardial infarction is low, the present study examined death certificates, hospital records, the forensic medical records, and the police records of residents of the southern part of Okinawa island who died at the age of 20-74 years during a 3-year period from January 1, 1992 to December 31, 1994. Sudden death was defined as death within 24 h from the onset of unexpected symptoms. The study documented 126 (87 men and 39 women) sudden deaths. The crude incidence rate was 0.37/1,000 person per year (0.51 in men and 0.23 in women). According to the death certificates, 78 cases died of heart diseases. However, the cause of death could be determined by examination of all available records in only 64 cases: myocardial infarction in 10, non-ischemic heart diseases in 13, and stroke in 23 cases. Even when the analysis was limited to the cases who died within 1 h from the onset of symptoms, heart disease was the cause of death in only 22% of the cases while the cause of death could not be determined in 53% of the cases. Only 13% of those diagnosed as heart diseases on the death certificate were verified. The agreement rate between the diagnosis reached by the re-evaluation of the records and that on the death certificate was 82% for stroke and 33% for other diseases. In Okinawa, Japan, the frequencies of heart disease and stroke as the cause of sudden death may be similar. Except for stroke, the diagnosis appearing on the death certificate has substantial inaccuracy.

Capsular infarcts: location, size and etiology of pure motor hemiparesis, sensorimotor stroke and ataxic hemiparesis

We investigated the types of syndrome, location, size and presumed causes of 72 patients with acute capsular lacunar infarction. Clinical syndromes were classified into pure motor hemiparesis (PM), sensorimotor stroke (SM) and ataxic hemiparesis (AH). Lesion sizes of AH were significantly smaller than those of PM (p < 0.01) or SM (p < 0.01). When the lesion volume was classified into two groups, > or = 1 ml and < 1 ml, the large volume group had more frequent cardioembolic sources than the small volume group (41% and 18% respectively, p < 0.05). In AH patients no cardioembolic sources could be detected. Significant carotid stenosis was found in only 4% of patients. Patients with anterior choroidal artery territory infarction had infrequent cardioembolic sources (7%). The results suggest that the lesion size varies with clinical syndrome and some etiological trends are seen in the volume and the location of lesions.

A nation-wide study of atherosclerosis in infants, children and young adults in Japan

This paper reports the results of a nation-wide cooperative study of atherosclerosis in young, first generation Japanese with ages ranging from 1 month to 39 years, who were autopsied between 1978 and 1982 in hospitals distributed over the entire archipelago of Japan. Atherosclerotic lesions in 2320 aortas, 1620 coronary arteries and 344 cerebral arteries were classified into fatty streaks, fibrous plaques and complicated lesions and were then quantificated with the point-counting method. Atherosclerosis of aortas, coronary arteries and cerebral arteries, determined by surface involvement (SI) of atherosclerotic lesions and atherosclerotic index (AI), increased with age; the severest were seen in aortas, and then, with decreasing severity, in the coronary and cerebral arteries. Fatty streaks preceded the other lesions and accounted for the largest portion of the lesions in aortas and coronary arteries. Fibrous plaques and complicated lesions developed in the later decades of life. The patients with collagen diseases had a greater severity of aortic atherosclerosis in the 2nd and 3rd decades of life, than those without such disorders. Correlation of antemortem clinical data with SI and AI of each artery were analyzed, using simple correlation analysis and multiple regression analysis. Age, serum cholesterol and blood pressure were significantly and positively correlated with SI and AI of aortas and coronary arteries. Serum cholesterol was more strongly correlated with the extent of fatty streaks than was mean blood pressure and vice versa with that of fibrous plaques. Atherosclerosis of cerebral arteries, however, showed a significant correlation only with the factor of mean blood pressure. Therefore the susceptibility to risk factors varies with the artery in cases of early lesions of atherosclerosis in young Japanese.

Severe disability related to cerebral stroke: incidence and risk factors observed in a Japanese community, Hisayama

To elucidate the incidence of severe disability due to cerebral stroke and its related factors, prospective data of 1,621 Hisayama residents aged 40 and over were examined. Severe disability resulting from stroke was defined as patients who were unable to dress, take care of their toilet needs, and feed themselves without assistance, or who required a wheel chair for ambulation three months after the most recent episode. During 20 years of follow-up 255 stroke patients were observed among the sample population. The annual incidence of stroke per thousand was 9.8, and rate of severe disability was 2.8 for men and 6.4 and 2.0 for women, respectively. Of the 74 cases with severe disability, approximately 92% were attributed to cerebral infarction. Related factors to severe disability due to cerebral infarction were recurrent attacks, hypertension, changes in ocular fundi and diabetes mellitus among predispositions and quadriplegia or muscular contraction, and intelligent or mental disorders among inhibiting factors for functional recovery. Furthermore, in 59 autopsy cases with multiple cerebral infarctions, the frequency of disability increased as the number of infarcts increased. Hypertension and diabetes mellitus, as risk factors for cerebral infarction and factors inhibiting post-ictal functional recovery were discussed.

The haemorheological features of lacunar strokes

Clinical and haemorheological data were recorded in 40 patients with lacunar strokes confirmed clinically and by computed tomography. The following haemorheological variables were monitored: haematocrit, erythrocyte aggregation, erythrocyte deformability, plasma viscosity, fibrinogen concentration and yield shear stress. Clinically, most patients had case histories and features according to the description of Fisher. All haemorheological parameters with the exception of the haematocrit were pathological when compared with values obtained from a normal control group. In descending order of frequency the pathological changes were in erythrocyte aggregation, plasma viscosity and erythrocyte deformability.

X-ray computed tomography (CT) study of small, deep and recent infarcts (SDRIs) of the cerebral hemispheres in adults. Preliminary and critical report

The evolution of CT signs of small, deep infarcts of the cerebral hemispheres in thirty adults, in the first five weeks, has been retrospectively studied. The relevant literature has been reviewed and an attempt has been made to present a synthesis, accompanied by a commentary. It is impossible now to give the frequency of each type of evolution, but the main data are as follows: The shortest delay of visibility of an hypodense area is about 17 to 19 h, but at 27 h the densities may still be normal. The evolution of the hypodense area is also variable: after a minimum attenuation is reached--at approximately 72 h--there is a risk of "fogging effect", which reduces the visibility of ischemic lesions; it could be seen from the end of the 1st week to the beginning of the 4th, but its frequency and its duration have yet to be better determined. In our series, contrast enhancement has been found in the gray matter of the basal ganglia between the 8th and the 22nd days--but according to some observations recorded in the literature, it may be found from the second to the twenty sixth day--and there was no obvious contrast enhancement in the white matter. The significance of the evolving CT signs is discussed in connection with the clinical applications, principally in the management of these patients, and with the attempts to correlate the clinical and CT findings.

Cardiac disorders predisposing to development of cerebrovascular diseases in the Japanese. Data obtained at autopsy

For a clear definition of the influence of cardiac disorders on the development of cerebrovascular diseases in the Japanese, we reviewed 1,162 consecutive autopsy records aged 20 years and over in the Department of Pathology, Kyushu University, Japan. All autopsies had been done between Nov. 1971 and Oct. 1981. Cerebral infarction was found in 101 out of 196 with any type of cardiac disorder. Frequencies of cerebral infarction in those with myocardial infarction, rheumatic heart disease, non-bacterial thromboendocarditis, and atrial fibrillation were higher than in those with no heart disease. These differences can be ascribed to the higher incidence of large and medium-sized cerebral infarction, including many cases of cerebral embolism originating from the heart. Only 3.4% of those with small cerebral infarction were assessed to be cases of embolism. Non-embolic cerebral infarction was more frequently noted in those with myocardial infarction and atrial fibrillation than in those with no heart disease. These differences were probably linked to concomitant progression of arteriosclerosis of the cerebral and coronary arteries. In this consecutive autopsy study, cerebral embolism was found in 35 cases, 10.9% of the total number of those with cerebral infarction.