Excessive Incidence of Stroke in Iran

Background and Purpose— The epidemiology of stroke and its subtypes in the Middle East is unclear. Most previous studies have been performed in Western countries, and incidence rates are unlikely to apply in the Middle East. We aimed to determine the incidence of stroke in Mashhad, northeastern Iran.

Methods— During a 12-month period (2006–2007), we prospectively ascertained all strokes occurring in a population of 450 229. Multiple overlapping sources were used to identify people with stroke. A large number of volunteers assisted in finding stroke patients not admitted to hospital. Potential cases were reviewed by a group of stroke experts before inclusion.

Results— A total of 624 first-ever strokes occurred during the study period, 98.4% undergoing imaging. Despite a relatively low crude annual incidence rate of first-ever stroke FES (139; 95% CI, 128 to 149) per 100 000 residents, rates adjusted to the European population aged 45 to 84 years were higher than in most other countries: 616 (95% CI, 567 to 664) for ischemic stroke, 94 (95% CI, 75 to 113) for intracerebral hemorrhage, and 12 (95% CI, 5 to 19) for subarachnoid hemorrhage. Age-specific stroke incidence was higher in younger patients than is typically seen in Western countries. Comparison of age-specific incidence rates between regions revealed that stroke in Mashhad occurs approximately 1 decade earlier than in Western countries.

Conclusions— The results of this study provide evidence that the incidence of stroke in Iran is considerably greater than in most Western countries, with stroke occurring at younger ages. Ischemic stroke incidence was also considerably greater than reported in other regions.

Individuals with first-ever clinical presentation of a lacunar infarction syndrome: Is there an increased likelihood of developing mild cognitive impairment in the first 12 months after stroke?

Patients who have suffered a single clinical lacunar syndrome, in the absence of any previous clinical stroke, have a varying neuroradiological profile. We examined general cognition in 30 nonaphasic first-ever lacunar syndrome participants, using a battery of standard clinical neuropsychological measures. At a group level, stroke participants did not demonstrate any cognitive impairment relative to well-matched community-based controls up to 12 months after stroke. There was also no evidence of increased frequencies of mild cognitive impairment after a single clinical lacunar syndrome relative to matched control participants within the first year post-stroke. The current findings represent the first investigation of the cognitive outcome of nonaphasic individuals who have a first-ever clinical lacunar syndrome. It was concluded that a clinically diagnosed first ever stroke event, presenting as a lacunar syndrome, was not associated with an elevated risk of developing mild cognitive impairment 12 months post-stroke.

Potential roles of high salt intake and maternal malnutrition in the development of hypertension in disadvantaged populations

1. It has been argued that all major risk factors for cardiovascular disease have been identified. Yet, epidemiological studies undertaken to identify risk factors have largely focused on populations in developed nations or on the urban or relatively affluent rural populations of developing countries. Poor rural populations are seldom studied. 2. Somewhat different risk factors may operate in poor rural populations. Evidence for this is provided by the finding that, in disadvantaged rural India, the prevalence of hypertension is greater than would be expected based on established risk factors in these populations. One risk factor to be considered is a poor intrauterine environment. 3. In animals, maternal macro- and micronutrient malnutrition can lead to reduced nephron endowment. Nephron deficiency, in turn, can render blood pressure salt sensitive. The combination of nephron deficiency and excessive salt intake will predispose to hypertension. 4. Human malnutrition may have similar effects, particularly in regions of the world where malnutrition is endemic and where women are disadvantaged by existing social practices. 5. Moreover, high salt intake is endemic in many parts of Asia, including India. Therefore, we propose that maternal malnutrition (leading to reduced nephron endowment), when combined with excessive salt intake postnatally, will account, at least in part, for the unexpectedly high prevalence of hypertension in disadvantaged rural communities in India and elsewhere.

Estimating the Long-Term Costs Of Ischemic and Hemorrhagic Stroke for Australia

Background and Purpose— Stroke is associated with considerable societal costs. Cost-of-illness studies have been undertaken to estimate lifetime costs; most incorporating data up to 12 months after stroke. Costs of stroke, incorporating data collected up to 12 months, have previously been reported from the North East Melbourne Stroke Incidence Study (NEMESIS). NEMESIS now has patient-level resource use data for 5 years. We aimed to recalculate the long-term resource utilization of first-ever stroke patients and compare these to previous estimates obtained using data collected to 12 months.

Methods— Population structure, life expectancy, and unit prices within the original cost-of-illness models were updated from 1997 to 2004. New Australian stroke survival and recurrence data up to 10 years were incorporated, as well as cross-sectional resource utilization data at 3, 4, and 5 years from NEMESIS. To enable comparisons, 1997 costs were inflated to 2004 prices and discounting was standardized.

Results— In 2004, 27 291 ischemic stroke (IS) and 4291 intracerebral hemorrhagic stroke (ICH) first-ever events were estimated. Average annual resource use after 12 months was AU$6022 for IS and AU$3977 for ICH. This is greater than the 1997 estimates for IS (AU$4848) and less than those for ICH (previously AU$10 692). The recalculated average lifetime costs per first-ever case differed for IS (AU$57 106 versus AU$52 855 [1997]), but differed more for ICH (AU$49 995 versus AU$92 308 [1997]).

Conclusion— Basing lifetime cost estimates on short-term data overestimated the costs for ICH and underestimated those for IS. Patterns of resource use varied by stroke subtype and, overall, the societal cost impact was large.

Smoking cessation at 5 years after stroke in the North East Melbourne stroke incidence study

BACKGROUND/AIMS

There is limited knowledge about smoking cessation after stroke. We examined smoking cessation and recall of smoking cessation advice among 5-year stroke survivors.

METHODS

Interviews were conducted between May 2002 and May 2004 with 5-year survivors from a population-based stroke incidence study undertaken from May 1 1997 to April 30 1999 in Melbourne, Australia. Data were gathered on smoking status at stroke onset, cessation advice recalled and periods of cessation up to 5 years after stroke. Cessation was determined by examining smoking status at stroke onset and at 5 years after stroke.

RESULTS

Of the 441 5-year stroke survivors, 343 (78%) had smoking data at follow-up. Fifty-one people were current smokers at stroke onset and 19 (37%) had quit smoking by 5 years after stroke. Of the 40 ever smokers who responded to a question regarding cessation advice, 40% (n = 16) could not recall receiving any such advice since their stroke.

CONCLUSION

The majority of smokers continued to smoke at 5 years after stroke. Few smokers recalled smoking cessation advice. Given that receiving such advice can be the first step towards cessation, improvements in the delivery of advice to this high-risk group are needed.

The effect of very early mobilisation after stroke on psychological well-being

OBJECTIVE

The immobility common to patients after acute stroke has the potential to increase negative mood symptoms. We evaluated the effect of very early mobilization after stroke on levels of depression, anxiety and irritability.

DESIGN

AVERT is a randomized controlled trial; patients in the very early mobilization group receive mobilization earlier (within 24 h of stroke) and more frequently than patients in the standard care group.

PATIENTS

Seventy-one patients with confirmed stroke were included.

METHODS

Patients were assessed on the Irritability, Depression and Anxiety (IDA) scale at multiple time-points.

RESULTS

At 7 days, very early mobilization patients were less depressed (z=2.51, p=0.012) and marginally less anxious (z=1.79, p=0.073) than standard care patients (Mann-Whitney test). Classifying IDA scores as normal or depressed, and using backward stepwise multivariable logistic regression, very early mobilization was associated with a reduced likelihood of depression at 7 days (odds ratio 0.14, 95% confidence interval 0.03-0.61; p=0.009).

CONCLUSION

Very early mobilization may reduce depressive symptoms in stroke patients at 7 days post-stroke.

Estimating the prevalence of sleep-disordered breathing in community-based, long-term stroke survivors using a validated predictive model

BACKGROUND

Assessing sleep-disordered breathing (SDB) in aged or disabled populations is difficult.

AIMS

To validate a multivariable apnea risk prediction index (MAPI) in stroke survivors and estimate SDB prevalence (apnea-hypopnea index >or=10) in a community-based stroke cohort.

METHODS

Self-reported sleep apnea symptoms, demographic and anthropometric data were obtained from a hospital-based (SCOPES II, n = 152) and a community-based (NEMESIS, n = 431) cohort at about 3 years after stroke. Logistic regression models for prediction of SDB using the MAPI were validated with home-based nocturnal polygraphic data recordings obtained in 74 SCOPES II participants.

RESULTS

NEMESIS subjects (median age 76, females 45%) were older than SCOPES II subjects (median age 70, females 42%). SDB prevalence was 44.9% in the nocturnal polygraphy subset, and estimated as 44.1% (SCOPES II) and 50.6% (NEMESIS) using a modified MAPI.

CONCLUSION

The MAPI can be reliably used in stroke cohorts and SDB affects about half of chronic stroke survivors.

Patterns of Stroke Recurrence According to Subtype of First Stroke Event: The North East Melbourne Stroke Incidence Study (NEMESIS)

Background

Specific information about the nature of recurrent events that occur after each subtype of index stroke may be useful for refining preventive therapies. We aimed to determine whether stroke recurrence rates, the pattern of subtype recurrence, and prescription of secondary prevention agents differed according to initial stroke subtype.

Methods

Multiple overlapping sources were used to recruit all first-ever stroke patients from a geographically defined region of Melbourne, Australia over a 3-year period from 1996 to 1999. Potential stroke recurrences (fatal and nonfatal) occurring within 2 years of the initial event were identified following patient interview and follow up of death records. Subjects were classified into the different Oxfordshire groups and the type of first-ever stroke was compared with recurrent stroke events.

Results

One thousand, three hundred and sixteen first-ever strokes were registered during the 3-year period (mean age 74·4 years). A total of 103 first recurrent stroke events (fatal and nonfatal) occurred among those with a first-ever ischemic stroke or intracerebral hemorrhage (ICH) during the 2-year follow-up period. The recurrent stroke subtype was different to the index stroke subtype in most (78%) patients. People with partial anterior circulation infarct had the greatest proportion of recurrences (13%), with a third of these being the more severe total anterior circulation infarct subgroup. The relative risk of ICH after an index lacunar infarct (LACI) compared with an index non-LACI was 4·06 (95% CI 1·10–14·97, P=0·038). Prescription of secondary prevention agents was greater at 2 years after stroke than at hospital discharge, and was similar between ischemic stroke subtypes.

Conclusion

Approximately 9% of people with first-ever stroke suffered a recurrent event, despite many being prescribed secondary prevention agents. This has implications for the uptake of current preventive strategies and the development of new strategies. The possibility that ICH is greater among index LACI cases needs to be confirmed.

The large and growing burden of stroke

Stroke is a disease with impacts ranging from death and disability, to reduced health-related quality of life and depression. To truly understand the burden of this disease we must investigate not only the mortality and prevalence of stroke, but also its incidence within populations. Stroke mortality and incidence declined rapidly during the 1980s and early 1990s; however, this trend appears to have slowed in more recent times. Despite many studies being conducted in Europe, and Australasia, there is a lack of reliable data from developing regions such as Asia and Africa. There are indications that although the mortality rate of stroke in such regions may be less than in developed countries, the simple fact that the populations are large means that the burden of stroke is considerable. Furthermore, as a result of epidemiological transition and rapid urbanization and industrialization many developing regions are exhibiting increased life expectancy, as well as changes in diet and other risk behaviors, such as smoking. This is contributing to a looming epidemic of stroke in these regions, as greater proportions of the population are now at risk of stroke. Fortunately, stroke is largely a preventable disease. The major risk factor for stroke, hypertension, can be controlled using both population-wide approaches, such as changes in the salt content of processed foods, and high-risk individual approaches, such as use of antihypertensive medications. Implementation of effective primary and secondary prevention strategies is likely to have an enormous benefit in reducing the burden of stroke, particularly in developing regions.

Is prestroke use of angiotensin-converting enzyme inhibitors associated with better outcome?

BACKGROUND

There is evidence that angiotensin-converting enzyme inhibitors (ACEIs) reduce the risk of stroke. However, it is unclear whether ACEI use before stroke provides a vasoprotective effect resulting in less severe stroke.

METHODS

We ascertained all strokes occurring in a defined population in Melbourne, Australia. Prestroke use of ACEIs and concomitant medications was obtained from medical records. Initial neurologic deficit was dichotomized according to a NIH Stroke Scale (NIHSS) score < 8 (less severe deficit) or > or = 8 (severe deficit). Logistic regression was used to assess the association between prestroke use of ACEIs and stroke severity (measured by severity of neurologic deficits and death at 28 days).

RESULTS

Seven hundred sixteen first-ever ischemic stroke patients were included. Previous use of ACEIs was independently associated with a reduced risk of severe neurologic deficits (odds ratio [OR] 0.56; 95% CI 0.35 to 0.91) and death within 28 days (OR 0.46; 95% CI 0.24 to 0.87). Diuretics were associated with an increased risk of severe neurologic deficits (OR 1.81; 95% CI 1.13 to 2.90). Factors associated with a greater NIHSS score were older age, atrial fibrillation, heart failure, and use of diuretics. These factors and claudication were associated with an increased risk of 28-day mortality, whereas use of anticoagulants was associated with a reduced risk of severe neurologic deficits and death.

CONCLUSION

Within this large community-based cohort, prestroke use of angiotensin-converting enzyme inhibitors was associated with a reduced risk of severe stroke.

Why invest in a national public health program for stroke? An example using Australian data to estimate the potential benefits and cost implications

OBJECTIVES

Stroke is the world's second leading cause of death in people aged over 60 years. Approximately 50,000 strokes occur annually in Australia with numbers predicted to increase by about one third over 10-years. Our objectives were to assess the economic implications of a public health program for stroke by: (1) predicting what potential health-gains and cost-offsets could be achieved; and (2) determining the net level of annual investment that would offer value-for-money.

METHODS

Lifetime costs and outcomes were calculated for additional cases that would benefit if 'current practice' was feasibly improved, estimated for one indicative year using: (i) local epidemiological data, coverage rates and costs; and (ii) pooled effect sizes from systematic reviews.

INTERVENTIONS

blood pressure lowering; warfarin for atrial fibrillation; increased access to stroke units; intravenous thrombolysis and aspirin for ischemic events; and carotid endarterectomy. Value-for-money threshold: AUD$30,000/DALY recovered.

RESULTS

Improved, prevention and management could prevent about 27,000 (38%) strokes in 2015. In present terms (2004), about 85,000 DALYs and AUD$1.06 billion in lifetime cost-offsets could be recovered. The net level of annual warranted investment was AUD$3.63 billion.

CONCLUSIONS

Primary prevention, in particular blood pressure lowering, was most effective. A public health program for stroke is warranted.

Knowledge of risk factors and warning signs of stroke

In this review, we have summarized the findings of fifteen studies of knowledge of stroke warning signs and risk factors in both high- and low-risk populations. In general, there appears to be low levels of knowledge of both risk factors and stroke warning signs among the communities studied. Using free recall, between 20% and 30% of respondents could not name a single risk factor, and between 10% and 60% could not name a single warning sign of stroke. Providing survey respondents with a list of potential warning signs substantially improved the identification of warning signs. Respondents in older age groups and having lower levels of educational attainment tended to have less knowledge of risk factors and warning signs of stroke than those in younger age groups and those with more education. Public campaigns to improve stroke knowledge are needed, particularly in the older age groups where the risk of stroke is greater.

Prevalence of Depression and Use of Antidepressant Medication at 5-Years Poststroke in the North East Melbourne Stroke Incidence Study

Background and Purpose— There are few data on the prevalence or treatment of depression from unselected populations long-term poststroke. We assessed the prevalence of depression and antidepressant use at 5-years poststroke in an unselected stroke population.

Methods— Five-year survivors from a prospective community-based stroke incidence study were assessed for depression with the Irritability, Depression and Anxiety Scale. Medications indicated primarily for treatment of depression were recorded.

Results— At 5-years poststroke, 441 (45%) of 978 incident cases were alive (mean age=74±15 years, 49% female). Seventeen percent of those assessed were depressed. Twenty-two percent with depression were taking an antidepressant medication. Of those taking an antidepressant, 72% were not depressed.

Conclusions— Although nearly one-fifth of survivors were depressed, few were taking antidepressants. Further exploration of this low level of treatment is warranted.

Long-term cognitive transitions, rates of cognitive change, and predictors of incident dementia in a population-based first-ever stroke cohort

BACKGROUND AND PURPOSE

There are few data on long-term cognitive outcomes after first-ever stroke. We aimed to study long-term cognitive transitions, rates of cognitive change, and factors associated with incident dementia and cognitive impairment-no dementia (CIND) 2 years after first-ever stroke.

METHODS

A population-based cohort of incident first-ever stroke cases (n=99; mean age, 69.9 years) and an age- and sex-matched comparison group (nonstrokes, n=99) were followed up for 2 years by 3 serial examinations. Rates of cognitive change were compared by repeated-measures analyses. Factors associated with incident dementia and CIND at 2 years were determined by multinomial logistic regression.

RESULTS

Significant stroke x time interactions were present for all cognitive domains, with stroke cases showing a greater rate of decline compared with nonstrokes. Stroke recurrence during follow-up was responsible for significantly greater global decline. Strokes with recurrence (P=0.02), age (P=0.004), and baseline cognitive impairment (P<0.001) were independently associated with incident dementia at 2 years. Strokes without recurrence (P=0.008), age (P=0.001), and baseline cognitive impairment (P<0.001) were independently associated with CIND at 2 years.

CONCLUSIONS

Recurrent stroke contributes importantly to global cognitive decline after a first-ever stroke. Secondary stroke prevention will be important in ameliorating dementia related to stroke. Mechanisms underlying the progression of early cognitive impairment to dementia in stroke patients need further investigation.

Control of hypertension 5 years after stroke in the North East Melbourne Stroke Incidence Study

Control of blood pressure after stroke is important for reducing the risk of recurrent stroke. We examined the control of hypertension in a community-based population of 5-year stroke survivors. Cases of first-ever stroke from the North East Melbourne Stroke Incidence Study were interviewed at 5 years poststroke. Blood pressure, history of hypertension, and antihypertensive medications were recorded. Individuals were classified as normotensive (blood pressure < 140/90 mm Hg, no history of hypertension, and no antihypertensive medications), controlled hypertensive (blood pressure < 140/90 mm Hg, history of hypertension, and/or taking antihypertensive medications), uncontrolled hypertensive (blood pressure > or = 140/90 mm Hg, history of hypertension, and/or taking antihypertensive medications), or uninformed hypertensive (blood pressure > or = 140/90 mm Hg, no known history of hypertension, and no antihypertensive medications). At 5 years poststroke, 441 (45%) of 978 first-ever stroke cases were alive. Of these, 305 (69%) had complete data on blood pressure, antihypertensive medication use, and history of hypertension. No statistical differences existed between those with or without these data. Eight-two percent were hypertensive; 63% had controlled hypertension, 30% had uncontrolled hypertension, and 7% were unaware that they were hypertensive. Overall, 67% of individuals classified as uncontrolled or uninformed hypertensive subjects were receiving treatment that was insufficient to achieve target blood pressure levels. Uncontrolled hypertensive subjects were more likely to recall receiving advice to manage their hypertension with medication (P < 0.02) and diet (P < 0.09). Although the majority of hypertensive individuals had controlled hypertension at 5 years poststroke, considerable improvement can be made in the control of hypertension after stroke.

The validity of brief screening cognitive instruments in the diagnosis of cognitive impairment and dementia after first-ever stroke

INTRODUCTION

Brief cognitive tests such as the Mini-mental State Examination (MMSE) and the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) have been used to detect cognitive impairment and dementia in studies of stroke patients. However, there are few data on their validity for such use. We have evaluated their validity in detecting cognitive impairment not dementia (CIND) and dementia in a community-based sample of first-ever stroke patients.

METHODS

The standardized MMSE (S-MMSE) and the 16-item IQCODE were administered to 79 patients 1 year after a first-ever stroke. CIND and dementia were diagnosed independently using a comprehensive cognitive battery. The performances of the two tests were evaluated using receiver operating characteristic (ROC) analyses. Combined performance was evaluated when their scores were used in parallel (the "or rule"), in series (the "and rule") or as a weighted sum (the "weighted sum rule").

RESULTS

Both tests were extremely poor at detecting CIND individually and in combination. For dementia, at traditional cut-points, the S-MMSE (< or =23) was insensitive (0.50, 95% CI 0.16-0.84) and the IQCODE (> or =3.30) nonspecific (0.63, 95% CI 0.51-0.75). An acceptable balance between sensitivity and specificity was achieved for dementia using the "or rule" combination, but with only modest positive predictive value.

CONCLUSIONS

The S-MMSE and the IQCODE were individually poor at detecting CIND and dementia after a nonaphasic first-ever stroke. The combination was useful in detecting dementia but it does not replace the need for detailed neuropsychological tests.

Cerebrovascular disease and dementia

Cerebrovascular disease and dementia are extremely prevalent and disabling disorders affecting older people. Results of previous pathological investigations and later epidemiological studies have raised the possibility that the two disorders may be causally related. The study of such causal associations may provide insights that could lead to the development of strategies intended to prevent or treat dementia more effectively. Cerebrovascular disease has many manifestations, some of which are strong causal factors in the development of a future dementia. However, uncertainty and controversy exist regarding the presence and nature of the causal contribution of others. Potential therapeutic strategies for dementia are hindered by the lack of understanding of such relationships and the consequent difficulty in identifying a clear phenotype of dementia occurring predominantly due to cerebrovascular disease. The field is ripe for further examination of the associations between vascular factors and dementia, and the mechanisms underlying such associations. The interface between basic and clinical science has much to offer in clarifying the relationships between aging, vascular factors and cognitive decline in older people. In this review, we will attempt to synthesize data available from epidemiological, clinical and basic science research in the field of dementia related to cerebrovascular disease, highlighting potential avenues for further research.