Transient cerebral ischemic attacks in a Japanese community, Hisayama, Japan

Transient ischemic attack without self-awareness of symptoms witnessed by bystanders: analysis of the PROMISE-TIA registry

Background and purpose

A transient ischemic attack (TIA) can occur without self‐awareness of symptoms. We aimed to investigate characteristics of patients with a tissue‐based diagnosis of TIA but having no self‐awareness of their symptoms and whose symptoms were witnessed by bystanders.

Methods

We used data from the multicenter registry of 1414 patients with a clinical diagnosis of TIA. For patients without evidence of ischemic lesions on imaging, clinical characteristics were compared between patients with and without self‐awareness of their TIA symptoms.

Results

Among 896 patients (559 men, median age of 70 years), 59 (6.6%) were unaware of their TIA symptoms, but had those symptoms witnessed by bystanders. Patients without self‐awareness of symptoms were older and more frequently female, and more likely to have previous history of stroke, premorbid disability, and atrial fibrillation, but less likely to have dyslipidemia than those with self‐awareness. Patients without self‐awareness of symptoms arrive at hospitals earlier than those with self‐awareness (P < 0.001). ABCD² score was higher in patients without self‐awareness of symptoms than those with self‐awareness (median 5 vs. 4, P = 0.002). Having no self‐awareness of symptoms was a significant predictor of ischemic stroke within 1 year after adjustment for sex, ABCD² score, and onset to arrival time (hazard ratio = 2.44, 95% confidential interval: 1.10–4.83), but was not significant after further adjustment for arterial stenosis or occlusion.

Conclusions

Patients with a TIA but having no self‐awareness of their symptoms might have higher risk of subsequent ischemic stroke rather than those with self‐awareness, suggesting urgent management is needed even if patients have no self‐awareness of symptoms.

Secular trends in the incidence, risk factors, and prognosis of transient ischemic attack in Japan: The Hisayama Study

BACKGROUND AND AIMS

We aimed to investigate secular trends in the incidence, risk factors, and prognosis of transient ischemic attack (TIA) in a general Japanese population.

METHODS

Two cohorts consisting of stroke-free Japanese individuals aged ≥40 years in 1961 (n = 1621) and 1988 (n = 2646) were followed up for 24 years. The associations of potential risk factors with the development of TIA were estimated by a Cox proportional hazards model. The influence of TIA on the risk of total stroke over the subsequent 10 years was compared between the sub-cohorts of subjects with TIA and age- and sex-matched control subjects from each cohort.

RESULTS

During follow-up, 28 subjects in the 1961 cohort and 34 in the 1988 cohort experienced TIA. The age-standardized incidence of TIA was significantly lower in the 1988 cohort than the 1961 cohort (0.66 vs. 1.01 per 1000 person-years, p = 0.02). While elevated systolic blood pressure was significantly associated with the risk of TIA in both cohorts, glucose intolerance and higher serum cholesterol levels were associated with TIA risk only in the 1988 cohort. The subjects experiencing TIA had approximately 7-8-fold higher risks for the 10-year incidence of total and ischemic strokes compared with the corresponding control subjects without TIA both in the 1961 and 1988 sub-cohorts, and the relative risks were not significantly different between sub-cohorts.

CONCLUSIONS

Our results suggest that the incidence of TIA decreased during the past half century, probably due to the spread of antihypertensive treatments in the general Japanese population.

Cardiovascular risk factors and TIA characteristics in 19,872 Swedish TIA patients

BACKGROUND

Transient ischemic attack (TIA) constitutes a major risk factor for stroke, making TIA patients an important group for secondary intervention. The aim of this study was to account for risk factor prevalence in TIA patients and analyze the association between TIA characteristics and risk factors.

METHODS

We included 20,871 TIA events in 19,872 patients who were registered in the Swedish Riksstroke registry during the years 2010 through 2012. Data from other Swedish registers were used for comparison. The following variables were analyzed: age, sex, diabetes mellitus, atrial fibrillation (AF), cigarette smoking, and antihypertensive treatment.

RESULTS

Compared to the general population (based on data retrieved from Sweden's national public health survey 'Health on equal terms'), TIA patients more often had diabetes mellitus (prevalence ratio, PR = 2.3), AF without oral anticoagulants (OAC) (PR = 2.8), and AF on OAC (PR = 1.6). Blood pressure medication was less prevalent among TIA patients than in the general population (PR = 0.57). Increasing age was associated with longer attacks.

CONCLUSIONS

The fact that diabetes mellitus, atrial fibrillation, and smoking are more common in TIA patients than in the general population suggests that these factors are risk factors for TIA, even if causal relations cannot be proven. The relation between increasing age and longer attacks possibly reflects an increased proportion of embolic TIAs, or impaired recovery ability. Our results also suggest a significant proportion of untreated hypertension cases in the population.

Clinical Characteristics of Transient Ischemic Attack Patients with Atrial Fibrillation: Analyses of a Multicenter Retrospective Study

Background

Atrial fibrillation (AF) is an important risk factor for transient ischemic attack (TIA). However, little is known about the characteristics of TIA patients with AF. This study investigated the characteristics of such patients, using data from a retrospective, observational, multicenter study.

Methods

TIA patients admitted to 13 stroke centers in Japan within 7 days of onset between January 2008 and December 2009 were included. The present analyses compared baseline characteristics, clinical symptoms, findings from diffusion-weighted imaging (DWI), and clinical outcomes between patients with and without AF (AF and non-AF groups).

Results

A total of 464 patients (292 men; mean age 68.5 ± 13.2 years) were registered. Of these, 79 patients (17%) had AF. Patients in the AF group were older (73.9 ± 9.1 vs. 67.4 ± 13.6 years, p < 0.001) and more likely to show disturbance of consciousness (13 vs. 6%, p = 0.046) and aphasia (9 vs. 3%, p = 0.007) than patients in the non-AF group. Although no difference in the overall DWI-positive rate was seen between the groups (28 vs. 20%, p = 0.102), a single lesion (23 vs. 10%, p < 0.001), a lesion ≥15 mm (11 vs. 4%, p = 0.006), and a single lesion ≥15 mm (11 vs. 2%, p < 0.001) on DWI were more frequent in the AF group. Multivariate logistic regression analysis identified increased age [odds ratio (OR) 1.04; 95% confidence interval (CI) 1.02-1.07] and DWI single lesion ≥15 mm (OR 5.67; 95% CI 1.92-16.7) as independently associated with the presence of AF.

Conclusions

In this study, 17% of our TIA patients had AF. We found an association between the acute ischemic lesion pattern on DWI of a single lesion ≥15 mm and AF in TIA patients. These results might lead to a better diagnosis of TIA patients with AF.

Gender-related protection from or vulnerability to severe CNS diseases: gonado-structural and/or gonado-activational? A meta-analysis of relevant epidemiological studies

BACKGROUND

A vast scientific literature has dealt with gender-specific risk for brain disorder. That field is evolving toward a consensus to the effect that the estrogen hormone family is outstandingly and uniquely neuroprotective. However, the epidemiology relevant to this general outlook remains piecemeal.

METHOD

The present investigation strategically formats the relevant epidemiological findings around the world in order to quantitatively meta-analyze gender ratio of risk for a variety of relevant severe central nervous system (CNS) diseases at all three gonadal stages of the life cycle, pre pubertal, post adolescent/pre menopausal, and post menopausal.

RESULTS

The data quantitatively establish that (1) no single epidemiological study should be cited as evidence of gender-specific neuroprotection against the most common severe CNS diseases because the gender-specific risk ratios are contradictory from one study to the other; (2) risk for severe CNS disease is indeed significantly gender-specific, but either gender can be protected: it depends on the disease, not at all on the age bracket.

CONCLUSION

Our assay of gender-specific risk for severe brain disease around the world has not been able to support the idea according to which any one gender-prevalent gonadal steroid hormone dominates as a neuroprotective agent at natural concentrations.

Stroke and transient ischemic attack incidence rate in Spain: the IBERICTUS study

BACKGROUND

In Spain, stroke is a major public health concern, but large population-based studies are scarce and date from the 1990s. We estimated the incidence and in-hospital mortality of stroke through a multicentered population-based stroke register in 5 geographical areas of Spain, i.e. Lugo, Almería, Segovia, Talavera de la Reina and Mallorca, representing north, south, central (×2) and Mediterranean areas of Spain, respectively, the aim and novelty being that all methodologies were standardized, and diagnoses were verified by a neurologist using neuroimaging techniques.

METHODS

The register identified subjects >17 years of age who suffered a first-ever stroke or transient ischemic attack (TIA) between 1 January and 31 December 2006. Stroke and TIA were defined according to the WHO criteria. The Lausanne Stroke Registry definitions were used to classify ischemic stroke subtypes, as follows: (1) large-artery atherosclerosis (LAA); (2) cardioembolism (CE); (3) lacunar stroke or small-artery occlusion (SAO); (4) stroke of other infrequent cause (SIC), and (5) stroke of undetermined cause (UND). We used several complementary data sources such as hospital discharge registers, emergency room registers and primary care surveillance systems.

RESULTS

In the 1-year study period, we identified 2,700 first-ever cerebrovascular episodes (53% men; 2,257 strokes + 443 TIA episodes). Brain CT in the acute stage was performed in 99% of cases. Of a total of 2,257 stroke patients, 1,817 (81%) had cerebral infarction, 350 (16%) had intracerebral hemorrhage, 59 (3%) had subarachnoid hemorrhage (SAH) and 31 (1%) had unclassifiable stroke. The overall unadjusted annual incidence for all cerebrovascular events was 187 per 100,000 [95% confidence interval (CI) 180-194; incidence for men: 202, 95% CI 189-210; incidence for women: 187, 95% CI 180-194]. The subtype of ischemic stroke could be determined in 1,779 patients and was classified as LAA in 624 (35%), CE in 352 (20%), SAO in 316 (18%), SIC in 56 (3%) and UND in 431 (24%). The incidence rates per 100,000 (95% CI) standardized to the 2006 European population were as follows: all cerebrovascular events, 176 (169-182); all stroke (non-TIA), 147 (140-153); TIA, 29 (26-32); ischemic stroke, 118 (112-123); intracerebral hemorrhage, 23 (21-26), and SAH, 4.2 (3.1-5.2). Incidence rates clearly increased with age in both genders, with a peak at or above 85 years of age. The in-hospital mortality was 14%.

CONCLUSIONS

Our results show that the incidence of stroke and TIA in Spain is moderate compared to other Western and European countries. However, it is expected that these figures will change due to progressively aging populations.

Stroke epidemiology: advancing our understanding of disease mechanism and therapy

Stroke is the fourth killer and number one cause of adult disability in the United States. The estimated direct and indirect costs of stroke care in this country are $68.9 billion for 2009. The prevalence of stroke and its cost will undoubtedly rise as the aging population increases. In addition, stroke incidence and mortality are increasing in less developed countries in which the lifestyles and population restructuring are rapidly changing. More population-based research to assess incidence, risk factors, and outcomes are needed in these countries. Epidemiologic studies can help identify groups of individuals or regions at higher risk for stroke. They can also help us better understand the natural history of certain conditions and therefore push the direction of therapeutic investigations. Furthermore, the study of trends across different time periods and different populations can help investigators evaluate the effects of stroke care programs and treatment options.

[Classification of etiologic subtypes for transient ischemic attacks: clinical significance of lacunar transient ischemic attack]

BACKGROUND

Lacunar transient ischemic attack (lacunar TIA) may have been underestimated because of diagnostic difficulties. The aim of our study was to classify TIAs by etiologic subtypes, especially using defined criteria for diagnosis of lacunar TIA and clarify clinical characteristics of lacunar TIA.

METHOD

105 TIA patients out of consecutive 1,244 patients with acute ischemic stroke admitted to our hospital between January 2007 and June 2010 were enrolled in the present study. TIA was defined as an acute focal neurological deficit lasting less than 24 hours, suspected to be of cerebrovascular origin regardless of ischemic lesions on MRI. TIAs were classified to 5 etiologic subtypes; (1) cardioembolic TIA, (2) atherothrombotic TIA, (3) lacunar TIA, (4) other etiologies, and (5) undetermined etiology and clinical characteristics in each subtype and the incidence of recurrent stroke after TIA were investigated. Lacunar TIA was diagnosed if the following criteria were fulfilled; (1) presence of lacunar infarct on MRI and/or the presence of unilateral dysfunction of at least two of three body parts (face, arm, leg) in the absence of cortical dysfunction presumed due to subcortical ischemia. (2) absence of cardiac sources of embolism and large artery atherosclerosis.

RESULTS

In 105 patients with TIA, lacunar TIA was the most frequent etiology (31%) followed by cardioembolic TIA (27%), atherothrombotic TIA (19%), undetermined etiology (18%), and other etiologies (6%). In patients with lacunar TIA, history of repeated TIA was more frequent and systolic blood pressure on admission was higher significantly than in cardioembolic TIA. Six of 105 patients had experienced recurrent stroke after TIA during admission. Among these 6 patients, 3 patients were diagnosed as lacunar infarctions.

CONCLUSIONS

Lacunar TIA was most common TIA subtype in the present study. It is critical to identify lacunar TIA on admission because some patients with lacunar TIAs experience early recurrent stroke.

Rationale and design of a randomized, double-blind trial comparing the effects of a 3-month clopidogrel-aspirin regimen versus aspirin alone for the treatment of high-risk patients with acute nondisabling cerebrovascular event

BACKGROUND

Acute nondisabling cerebrovascular events are common and often portend a disabling stroke. Aspirin is the only antiplatelet agent to have been studied in patients presenting acutely with a cerebrovascular event, but the effect is modest and is reduced by a small increased risk of intracerebral hemorrhage. Treatment with the combination of clopidogrel and aspirin might be beneficial when taken soon after a transient ischemic attack (TIA) or minor stroke. The CHANCE trial is a randomized, double-blind, multicenter, placebo-controlled trial to test an aggressive antiplatelet regimen in acute minor stroke or TIA.

DESIGN

The study will randomize 5,100 Chinese patients with acute TIA or minor stroke to receive a 3-month regimen of clopidogrel initiated with a loading dose of 300 mg followed by 75 mg/d, combined with aspirin 75 mg/d during the first 21 days, or a 3-month regimen of aspirin 75 mg/d alone. The primary efficacy end point is percentage of patients with any stroke (ischemic or hemorrhage) at 3 months. Study visits will be performed on the day of randomization, at day 21, and at day 90.

SUMMARY

CHANCE will determine whether clopidogrel combined with aspirin can prevent more strokes after acute minor stroke or TIA compared with aspirin alone-with an acceptable risk profile.

Long term risks of stroke, myocardial infarction, and vascular death in "low risk" patients with a non-recent transient ischaemic attack

BACKGROUND

Previous studies of prognosis after a transient ischaemic attack (TIA) have recruited patients soon after the event, when the risk of stroke is very high. However, the majority of patients survive for many years after a TIA, and the need for continued preventive treatment to lower vascular risk will need to be reassessed at a later date.

OBJECTIVE

To determine the long term risks of stroke and other vascular events in patients with TIA who survive the initial high risk period.

METHODS

290 patients were studied who had initially been followed up after a TIA in the Oxford community stroke project and in a contemporaneous hospital based cohort study, and who were alive and stroke-free at the end of planned follow up in 1988. All patients were followed for a further 10 years, and the risks of major vascular events (stroke, myocardial infarction, vascular death) were determined. Standardised mortality ratios (SMR) were calculated from the observed numbers of fatal events and the number expected on the basis of age and sex in the general population.

RESULTS

Median time since last TIA was 3.8 years (interquartile range, 2.2 to 5.8 years). The risk of major vascular events was constant through time. The 10 year risk of first stroke was 18.8% (95% confidence interval (CI), 13.6 to 23.7; 45 events). The 10 year risk of myocardial infarction or death from coronary heart disease was 27.8% (95% CI, 21.8 to 33.3; 67 events) and there was a significant excess of fatal coronary events compared with that expected in the general population (SMR = 1.47; 95% CI, 1.10 to 1.93; p = 0.009). A total of 114 patients had at least one major vascular event, with a 10 year risk of any first stroke, myocardial infarction, or vascular death of 42.8% (95% CI, 36.4 to 48.5).

CONCLUSIONS

The overall risk of major vascular events remains high for 10 to 15 years after a TIA. It is important therefore that preventive treatments are continued in the long term, even in apparently "low risk" patients who have already survived free of stroke for several years.

Incidence of transient ischemic attacks in the Belluno Province, Italy. First-year results of a community-based study

OBJECTIVES

This study formed part of a larger prospective population-based survey on cerebrovascular diseases and aimed to provide reliable and comparable results on TIA incidence and on related risk factors, which could supply investigation objectives and support information for primary and secondary prevention.

MATERIAL AND METHODS

We undertook a prospective population-based study in the province of Belluno, an area located in the North-East of Italy where 211,389 people live, utilizing all the possible case-collection sources available in the territory.

RESULTS

In the first year of the study (June 1, 1992 to May 31, 1993) 271 patients with a diagnosis of transient ischemic attack were recruited. Among these, we recorded 171 cases of new TIAs. The crude annual incidence rate for new TIAs was 0.80 per 1000, 0.73 per 1000 for men and 0.87 per 1000 for women. After adjustment to the European population, the overall incidence rate decreased to 0.58 per 1000 inhabitants per year. The mean age of new TIA patients was 73.91 years and females were significantly older than males (p < 0.001). A CT scan disclosed an infarct in 21 new TIA patients.

CONCLUSION

Our first-year results on new TIAs incidence did not differ from the findings reported in previous population-based studies performed throughout the world and support data as to risk factors for TIA.

Prevalence and etiology of dementia in a Japanese community

BACKGROUND AND PURPOSE

We sought to determine the type-specific prevalence of dementia and its risk factors in elderly persons from the Japanese community of Hisayama.

METHODS

We studied the prevalence of dementia in 887 Hisayama residents (353 men and 534 women) aged 65 years or older (screening rate, 94.6%) using various items of clinical information, neurological examination, and dementia scales. We also studied brain morphology in 50 of 59 determined to have dementia by computed tomography or autopsy during the subsequent 54-month period. Factors relevant to dementia were compared between 27 patients with vascular dementia and 789 control subjects without dementia in a retrospective fashion.

RESULTS

The prevalence rate of dementia among Hisayama residents aged 65 or older was estimated at 6.7%, with a females to males ratio of 1:2. Among 50 cases of dementia in which brain morphology was examined, the frequency of vascular dementia was 56%; this rate was 2.2 times higher than that for senile dementia of the Alzheimer type. Aging, hypertension, electrocardiographic abnormalities, and high hematocrit were significantly (p less than 0.05) and independently associated with the occurrence of vascular dementia.

CONCLUSIONS

Prevalence of dementia among the Hisayama residents was relatively identical to that previously reported, but vascular dementia was more predominant. Risk factors for vascular dementia were similar to those for lacunar infarcts. Control of hypertension may be a key to reducing dementia among the Japanese population.

Transient ischemic attacks: an update

This is a review of extant concepts of transient ischemic attacks (TIAs), their definitions, prognostic significance, pathogenesis, physiology, and management. The natural history of TIAs depends upon the risk factors of the population group studied, so that therapeutic trials should be controlled and randomized and not dependent upon published natural history data. A strong association between TIAs and coronary artery disease has now been established. It may be difficult to establish the cause or pathogenesis of TIAs in any given patient in view of the relatively poor correlation between the patient's symptoms and location of arterial plaques. Recent studies have suggested mechanisms aside from impaired perfusion or embolization from carotid plaques or vertebral basilar disease. There are no proven indications for carotid endarterectomy, a procedure which has been excessively used in the United States, but presently ongoing prospective, randomized, controlled multi-center studies will likely resolve this important issue. Neither is there scientific validation for the use of long-term anticoagulants, but data support the efficacy of ASA in reducing the incidence of stroke and myocardial infarction in patients with TIAs.

Prognosis of transient ischemic attacks in the Oxfordshire Community Stroke Project

In a community-based study of approximately 105,000 people, 184 presented with a transient ischemic attack during the 5 years between 1981 and 1986; we believe these persons represent almost all new cases of transient ischemic attack going to a doctor during that period. During a mean follow-up of 3.7 years 49 patients died, 45 had a first-ever stroke, and 17 had a myocardial infarction. Cardiac disease accounted for 17 (35%) deaths, while stroke was the cause of death in 15 patients (31%). The average actuarial risk of death was approximately 6.3%/yr, slightly greater than that expected for similar people without transient ischemic attacks (risk ratio [observed divided by expected] = 1.4). The actuarial risk of stroke was 11.6% during the first year after a transient ischemic attack and approximately 5.9%/yr over the first 5 years. Patients who suffered a transient ischemic attack had a 13-fold excess risk of stroke during the first year and a sevenfold excess risk over the first 7 years compared with people without transient ischemic attacks. The actuarial risk of death, stroke, or myocardial infarction over the first 5 years after a transient ischemic attack was approximately 8.4%/yr. The prognosis in this community-based cohort was better than that in previous reports. The high early risk of stroke means that investigation and treatment of new cases should commence as soon as possible.

Risk factors for stroke in middle-aged men in Göteborg, Sweden

To evaluate stroke risk factors in Göteborg, Sweden, during 1970-1973 a cohort of 7,495 participating men from a general population sample of 9,998 men aged 47-55 years were examined with respect to cardiovascular risk factors. Men with hypertension and hypercholesterolemia and men who were heavy smokers were treated. We assessed stroke end points and cause-specific mortality using a stroke register and death certificates. During a mean follow-up of 11.8 years, 230 strokes occurred in the entire population sample (participants and nonparticipants) (7% subarachnoid hemorrhages, 13% intracerebral hemorrhages, 42% cerebral infarctions, and 38% unspecified strokes). Using univariate analysis, we found measured high blood pressure (systolic and diastolic), smoking, known hypertension, diabetes mellitus, stroke in either parent, severe psychological stress, marital status, atrial fibrillation, previous transient ischemic attacks, previous myocardial infarction, effort-induced chest pain, and intermittent claudication to be significantly related to all stroke. Of the stroke types, subarachnoid hemorrhage was not related to any of these indicators, and intracerebral hemorrhage was related only to measured high blood pressure. Using multivariate analyses, we found measured high blood pressure, smoking, and severe psychological stress as well as atrial fibrillation, previous transient ischemic attacks, and intermittent claudication to be independent risk factors for nonhemorrhagic stroke. Serum cholesterol concentration, occupational and leisure-time physical activity, body mass index, alcohol abuse, and low occupational class were not risk factors for stroke.

Comparison of case ascertainment by medical record linkage and cohort follow-up to determine incidence rates for transient ischemic attacks and stroke

During the period 1960-1972, the medical record linkage index method provided an estimated average annual age- and sex-adjusted rate for first transient ischemic attack (TIA) of 134 per 100,000 population for those age 50 years and older. The cohort method estimate was 237 per 100,000 population (95% confidence limits (CL), 165-310). The discrepancy was due to 18 cases of TIA noted at the time of patient visits in the cohort analysis that were not identified from the medical record analysis. The cohort analysis for all strokes at age 50 years and older was not significantly different from the medical record linkage analysis. Although the cohort follow-up method provided better case ascertainment in this study, current indexing procedures provide case ascertainment equal to that of the cohort method and at less cost. No trend was found to suggest that incidence rates for TIA were decreasing in the period 1955-1979, in contrast to stroke in Rochester, Minn.