Advancing the study of stroke in women: summary and recommendations for future research from an NINDS-Sponsored Multidisciplinary Working Group

Possible sex and racial disparities in myasthenia gravis care

INTRODUCTION/AIMS

Given the importance of early diagnosis and treatment of myasthenia gravis (MG), it is critical to understand disparities in MG care. We aimed to determine if there are any differences in testing, treatment, and/or access to neurologists for patients of varying sex and race/ethnicity with MG.

METHODS

We used a nationally representative healthcare claims database of privately insured individuals (2001-2018) to identify incident cases of MG using a validated definition. Diagnostic testing, steroid-sparing agents, intravenous immunoglobulin (IVIG), plasma exchange (PLEX), and thymectomy were defined using drug names or CPT codes. Steroid use was defined using AHFS class codes. We also determined whether an individual had a visit to a neurologist and the time between primary care and neurologist visits. Logistic regression determined associations between sex and race/ethnicity and testing, treatments, and access to neurologists.

RESULTS

Female patients were less likely to get a computed tomography (CT) chest (odds ratio (OR) 0.73, 95% confidence interval (CI): 0.64-0.83), receive steroids (OR: 0.85, 95% CI: 0.75-0.97), steroid-sparing agents (OR: 0.84, 95% CI: 0.72-0.97), and IVIG or PLEX (OR: 0.80, 95% CI: 0.67-0.95). Black patients were less likely to receive steroids (OR: 0.78, 95% CI: 0.63-0.96). No significant disparities were seen in access to neurologists.

DISCUSSION

We found healthcare disparities in MG treatment with female and Black patients receiving less treatment than men and those of other races/ethnicities. Further research and detailed assessments accounting for individual patient factors are needed to confirm these apparent disparities.

Trends in Demographic and Geographic Disparities in Stroke Mortality Among Older Adults in the United States

BACKGROUND

Stroke is a leading cause of morbidity and mortality in the United States among older adults. However, the impact of demographic and geographic risk factors remains ambiguous. A clear understanding of these associations and updated trends in stroke mortality can influence health policies and interventions.

METHODS

This study characterizes stroke mortality among older adults (age ≥55) in the US from January 1999 to December 2020, sourcing data from the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research. Segmented regression was used to analyze trends in crude mortality rate and age-adjusted mortality rate (AAMR) per 100,000 individuals stratified by stroke subcategory, sex, ethnicity, urbanization, and state.

RESULTS

A total of 3,691,305 stroke deaths occurred in older adults in the US between 1999 and 2020 (AAMR = 233.3), with an overall decrease in AAMR during these years. The highest mortality rates were seen in nonspecified stroke (AAMR = 173.5), those 85 or older (crude mortality rate1276.7), men (AAMR = 239.2), non-Hispanic African American adults (AAMR = 319.0), and noncore populations (AAMR = 276.1). Stroke mortality decreased in all states from 1999 to 2019 with the greatest and least decreases seen in California (-61.9%) and Mississippi (-35.0%), respectively. The coronavirus pandemic pandemic saw increased stroke deaths in most groups.

CONCLUSIONS

While there's a decline in stroke-related deaths among US older adults, outcome disparities remain across demographic and geographic sectors. The surge in stroke deaths during coronavirus pandemic reaffirms the need for policies that address these disparities.

Impact of Gender and Age on Claim Rates of Dread Disease and Cancer Insurance Policies in Taiwan

In this paper, the impact of both gender and age on the claim rates of dread disease and cancer insurance policies were examined using unique data taken from Taiwan's private health insurance policies issued by non-life insurers during the 2012 to 2015 policy years. Those aged 30-39 served as the reference group. For the total number of dread disease policies, male insureds had a higher non-cancer claim probability than female insureds, while an age under 20 was associated with much lower claim rates for dread disease policies than for ages over 50. The claim rate for dread disease policies increased rapidly beginning at age 40 for both cancerous and non-cancerous diseases amongst male insureds. Amongst female insureds, those under 20 had much lower claim rates for dread disease policies. Only those aged 50-59 had a higher claim rate for non-cancerous diseases. For the total number of cancer insurance policies, male insureds had lower claim rates than female insureds, with an upward trend being associated with age. For male (female) insureds aged over 40 (20), the claim rates of cancer increased with age.

Peripheral Markers of Neurovascular Unit Integrity and Amyloid-β in the Brains of Menopausal Women

BACKGROUND

The identification of blood-borne biomarkers for the diagnosis and prognosis of Alzheimer's disease and related dementias is more feasible at the population level than obtaining cerebrospinal fluid or neuroimaging markers.

OBJECTIVE

This study determined the association of blood microvesicles, derived from cells of the neurovascular unit, with brain amyloid-β deposition in menopausal women.

METHODS

A subset of women from the Kronos Early Estrogen Prevention Study underwent brain amyloid-β positron emission tomography three years following cessation of study treatment with placebo (PL, n = 29), transdermal 17β-estradiol (tE2; n = 21), or oral conjugated equine estrogen (oCEE; n = 17). Isolated peripheral venous blood microvesicles were analyzed by digital flow cytometry using fluorophore conjugated antibodies directed toward total tau, amyloid-β 1-42 (Aβ1-42), neuron specific class III β-tubulin (Tuj1), microglia ionized calcium -binding adaptor molecule 1(Iba1), glial fibrillary acid protein (GFAP), and low density lipoprotein receptor-related protein1 (LRP1). Principal components analysis reduced the dimensionality of these selected six markers to two principal components (PCs). Proportional odds ordinal logistic regression analysis was used with amyloid-β deposition regressed on these PCs.

RESULTS

Only the number of microvesicles positive for Aβ1-42 differed statistically among prior treatment groups (median [IQR]: 6.06 [2.11, 12.55] in PL; 2.49 [0.73, 3.59] in tE2; and 4.96 [0.83, 10.31] in oCEE; p = 0.032). The joint association between the 2 PCs and brain amyloid-β deposition was significant (p = 0.045).

CONCLUSION

Six selected markers expressing peripheral blood microvesicles derived from cells of the neurovascular unit, when summarized into two principal components, were associated with brain amyloid-β deposition.

HUCBC Treatment Improves Cognitive Outcome in Rats With Vascular Dementia

Background and purpose: Vascular dementia (VaD) is the second common cause of dementia after Alzheimer's disease in older people. Yet, there are no FDA approved drugs specifically for VaD. In this study, we have investigated the therapeutic effects of human umbilical cord blood cells (HUCBC) treatment on the cognitive outcome, white matter (WM) integrity, and glymphatic system function in rats subject to a multiple microinfarction (MMI) model of VaD. Methods: Male, retired breeder rats were subjected to the MMI model (800 ± 100 cholesterol crystals/300 μl injected into the internal carotid artery), and 3 days later were treated with phosphate-buffered saline (PBS) or HUCBC (5 × 10⁶, i.v.). Sham rats were included as naïve control. Following a battery of cognitive tests, rats were sacrificed at 28 days after MMI and brains extracted for immunohistochemical evaluation and Western blot analysis. To evaluate the glymphatic function, fluorescent tracers (Texas Red dextran, MW: 3 kD and FITC-dextran, MW: 500 kD) was injected into the cisterna magna over 30 min at 14 days after MMI. Rats (3-4/group/time point) were sacrificed at 30 min, 3 h, and 6 h, and the tracer movement analyzed using laser scanning confocal microscopy. Results: Compared to control MMI rats, HUCBC treated MMI rats exhibit significantly improved short-term memory and long-term memory exhibited by increased discrimination index in novel object recognition task with retention delay of 4 h and improved novel odor recognition task with retention delay of 24 h, respectively. HUCBC treatment also improves spatial learning and memory as measured using the Morris water maze test compared to control MMI rats. HUCBC treatment significantly increases axon and myelin density increases oligodendrocyte and oligodendrocyte progenitor cell number and increases Synaptophysin expression in the brain compared to control MMI rats. HUCBC treatment of MMI in rats significantly improves glymphatic function by reversing MMI induced delay in the penetration of cerebrospinal fluid (CSF) into the brain parenchyma via glymphatic pathways and reversing delayed clearance from the brain. HUCBC treatment significantly increases miR-126 expression in serum, aquaporin-4 (AQP4) expression around cerebral vessels, and decreases transforming growth factor-β (TGF-β) protein expression in the brain which may contribute to HUCBC induced improved glymphatic function. Conclusions: HUCBC treatment of an MMI rat model of VaD promotes WM remodeling and improves glymphatic function which together may aid in the improvement of cognitive function and memory. Thus, HUCBC treatment warrants further investigation as a potential therapy for VaD.

Sex-Specific Physiology and Cardiovascular Disease

Sex differences in cardiovascular diseases can be classified as those which are specific to one sex and those that differ in incidence, prevalence, etiology, symptomatology, response to treatment, morbidity, and mortality in one sex compared to the other. All sex differences in cardiovascular conditions have their basis in the combined expression of genetic and hormonal differences between women and men. This chapter addresses how understanding basic mechanisms of hormone responses, imaging diagnostics, and integration of genomics and proteomics has advanced diagnosis and improved outcomes for cardiovascular conditions, apart from those related to pregnancy that are more prevalent in women. These conditions include obstructive coronary artery disease, coronary microvascular dysfunction, spontaneous coronary artery dissection, diseases of the cardiac muscle including heart failure and takotsubo cardiomyopathy, and conditions related to neurovascular dysregulation including hot flashes and night sweats associated with menopause and effects of exogenous hormones on vascular function. Improvement in technologies allowing for noninvasive assessment of neuronally mediated vascular reactivity will further improve our understanding of the basic etiology of the neurovascular disorders. Consideration of sex, hormonal status, and pregnancy history in diagnosis and treatment protocols will improve prevention and outcomes of cardiovascular disease in women as they age.

Alkaline phosphatase: a potential biomarker for stroke and implications for treatment

Stroke is the fifth leading cause of death in the U.S., with more than 100,000 deaths annually. There are a multitude of risks associated with stroke, including aging, cardiovascular disease, hypertension, Alzheimer's disease (AD), and immune suppression. One of the many challenges, which has so far proven to be unsuccessful, is the identification of a cost-effective diagnostic or prognostic biomarker for stroke. Alkaline phosphatase (AP), an enzyme first discovered in the 1920s, has been evaluated as a potential biomarker in many disorders, including many of the co-morbidities associated with stroke. This review will examine the basic biology of AP, and its most common isoenzyme, tissue nonspecific alkaline phosphatase (TNAP), with a specific focus on the central nervous system. It examines the preclinical and clinical evidence which supports a potential role for AP in stroke and suggests potential mechanism(s) of action for AP isoenzymes in stroke. Lastly, the review speculates on the clinical utility of AP isoenzymes as potential blood biomarkers for stroke or as AP-targeted treatments for stroke patients.

Sex Differences in Stroke Attack, Incidence, and Mortality Rates in Northern France

BACKGROUND

Age and sex have a major impact on stroke onset.

AIMS

We aimed to compare the attack, incidence, and 28-day mortality rate for stroke as well as risk factors in men and women aged 35 and over.

METHODS

Data were obtained between 2008 and 2015 from the stroke population-based registry covering the city of Lille (northern France).

RESULTS

A total of 2426 strokes (1917 incident strokes) were recorded. The number of strokes was lower in women than in men when considering individuals under the age of 75 but was twice as high when considering individuals aged 75 or over. Overall, there were 25% more strokes in women than in men. The age-adjusted attack (P = .017) and incident (P = .027) rates of stroke were ~30% lower in women than in men (a ~30% lower risk of ischemic stroke (P = .02) and a ~40% lower risk of intracerebral hemorrhage (ICH) (P = .004)). The age-adjusted mortality rate after ICH was ~35% lower in women than in men (P = .014). With regard to cardiovascular risk factors, women with stroke were older, smoked less, and were more likely to have a history of migraine or atrial fibrillation than the men.

CONCLUSION

The risk of stroke is lower in women than in men under the age of 75 but is similar when comparing women and men after that age. Nevertheless, the age structure of the population (with more elderly women than elderly men) translates into a higher absolute number of strokes in women than in men.

The Influence of Sex in Stroke Thrombolysis: A Systematic Review and Meta-Analysis

Background and Purpose

There is increasing recognition of the importance of stroke in females to both clinical and public health. The natural course of stroke is worse in females than in males, but the evidence regarding sex disparities in the responses to thrombolysis in stroke patents is still controversial. We compared outcomes after thrombolysis treatment between females and males.

Methods

Clinical trials reported in the Embase, PubMed, and Cochrane Library electronic databases up to March 13, 2017 were included in this analysis. Two reviewers independently extracted the data and conducted quality assessments. Statistical tests were performed to check for heterogeneity and publication bias. Sensitivity analysis was also performed to evaluate the stability of the conclusions.

Results

Sixteen reports involving 60,159 patients were available for analysis. The female patients were a 0.89-fold [95% confidence interval (CI)=0.87–0.90, p<0.001], 0.89-fold (95% CI=0.87–0.91, p<0.001), and 1.24-fold (95% CI=1.11–1.36, p<0.001) more likely to obtain good, excellent, and poor functional outcomes, respectively, with no significant difference in the complications of symptomatic intracranial hemorrhage among the sexes [risk ratios (RR)=0.99, 95% CI=0.92–1.07, p=0.81] after thrombolysis treatment. In addition, the prevalence of a good functional outcome did not differ significantly between females and males in the intra-arterial thrombolysis (IAT) group (RR=1.05, 95% CI=0.85–1.29, p=0.67) in a subgroup analysis.

Conclusions

This study has demonstrated that females often exhibit a worse outcome than males after intravenous thrombolysis (IVT), whereas no relevant sex differences were found in outcome or recanalization after IAT, with safety regarding hemorrhage complications from thrombolysis being the same for the sexes. However, IVT should not be withheld from female stroke patients solely based on their sex before the findings are confirmed in further large-scale research.

Estrogens as neuroprotectants: Estrogenic actions in the context of cognitive aging and brain injury

There is ample empirical evidence to support the notion that the biological impacts of estrogen extend beyond the gonads to other bodily systems, including the brain and behavior. Converging preclinical findings have indicated a neuroprotective role for estrogen in a variety of experimental models of cognitive function and brain insult. However, the surprising null or even detrimental findings of several large clinical trials evaluating the ability of estrogen-containing hormone treatments to protect against age-related brain changes and insults, including cognitive aging and brain injury, led to hesitation by both clinicians and patients in the use of exogenous estrogenic treatments for nervous system outcomes. That estrogen-containing therapies are used by tens of millions of women for a variety of health-related applications across the lifespan has made identifying conditions under which benefits with estrogen treatment will be realized an important public health issue. Here we provide a summary of the biological actions of estrogen and estrogen-containing formulations in the context of aging, cognition, stroke, and traumatic brain injury. We have devoted special attention to highlighting the notion that estrogen appears to be a conditional neuroprotectant whose efficacy is modulated by several interacting factors. By developing criteria standards for desired beneficial peripheral and neuroprotective outcomes among unique patient populations, we can optimize estrogen treatments for attenuating the consequences of, and perhaps even preventing, cognitive aging and brain injury.

Inherited and Uncommon Causes of Stroke

PURPOSE OF REVIEW

This article is a practical guide to identifying uncommon causes of stroke and offers guidance for evaluation and management, even when large controlled trials are lacking in these rarer forms of stroke.

RECENT FINDINGS

Fabry disease causes early-onset stroke, particularly of the vertebrobasilar system; enzyme replacement therapy should be considered in affected patients. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), often misdiagnosed as multiple sclerosis, causes migraines, early-onset lacunar strokes, and dementia. Moyamoya disease can cause either ischemic or hemorrhagic stroke; revascularization is recommended in some patients. Cerebral amyloid angiopathy causes both microhemorrhages and macrohemorrhages, resulting in typical stroke symptoms and progressive dementia. Pregnancy raises the risk of both ischemic and hemorrhagic stroke, particularly in women with preeclampsia/eclampsia. Pregnant women are also at risk for posterior reversible encephalopathy syndrome (PRES), reversible cerebral vasoconstriction syndrome, and cerebral venous sinus thrombosis. Experts recommend that pregnant women with acute ischemic stroke not be systematically denied the potential benefits of IV recombinant tissue plasminogen activator.

SUMMARY

Neurologists should become familiar with these uncommon causes of stroke to provide future risk assessment and family counseling and to implement appropriate treatment plans to prevent recurrence.

Diabetes Worsens Functional Outcomes in Young Female Rats: Comparison of Stroke Models, Tissue Plasminogen Activator Effects, and Sexes

Diabetes worsens stroke outcome and increases the risk of hemorrhagic transformation (HT) after ischemic stroke, especially with tissue plasminogen activator (tPA) treatment. The widespread use of tPA is still limited by the fear of hemorrhagic transformation (HT), and underlying mechanisms are actively being pursued in preclinical studies. However, experimental models use a 10 times higher dose of tPA than the clinical dose (10 mg/kg) and mostly employ only male animals. In this translational study, we hypothesized that low-dose tPA will improve the functional recovery after the embolic stroke in both control and diabetic male and female animals. Diabetes was induced in age-matched male and female Wistar rats with high fat diet and low-dose streptozotocin (30 mg/kg, i.p.). Embolic stroke was induced with clot occlusion of the middle cerebral artery (MCA). The animals were treated with or without tPA (1 mg/kg, i.v.) at 90 min after surgery. An additional set of animals were subjected to 90 min MCAO with suture. Neurological deficits (composite score and adhesive removal test-ART), infarct size, edema ratio, and HT index were assessed 3 days after surgery. In the control groups, female rats had smaller infarcts and better functional outcomes. tPA decreased infarct size in both sexes with a greater effect in males. While there was no difference in HT between males and females without tPA, HT was less in the female + tPA group. In the diabetic groups, neuronal injury increased in females reaching that of the infarct sizes seen in male rats. tPA decreased infarct size in females but not males. HT was greater in female rats than in males and was not further increased with tPA. Diabetes worsened neurological deficits in both sexes. Male animals showed improved sensorimotor skills, especially with tPA treatment, but there was no improvement in females. These data suggest that diabetes amplifies neurovascular injury and neurological deficits in both sexes. Human dose tPA offers some degree of protection in male but not female rats. Given that control female animals experience less injury compared to male rats, the diabetes effect is more profound in females.

Sex differences in stroke: a socioeconomic perspective

BACKGROUND

A number of studies have explored the issue of sex differences in stroke from biomedical perspective; however, there are still large gaps in the existing knowledge. The purpose of this study was to assess whether the differences in socioeconomic status and living conditions between men and women may explain the part of the sex differences in incidence and outcomes of stroke.

METHODS

All stroke participants aged ≥60 years admitted in Vaseie Hospital in Sabzevar, Iran, from March 21, 2013, until March 20, 2014, were included in this study. Computerized tomography and magnetic resonance imaging were used to confirm stroke. A series of χ2 tests were performed and Statistical Program for Social Sciences, Version 21.0, was used to investigate the potential differences between older men and women in stroke incidence and outcomes.

RESULTS

A total of 159 incident stroke cases were documented during 1 year. The annual rate of stroke was statistically significantly higher in elderly women than in elderly men (401 vs 357 per 100,000; P<0.001). Female elderly participants had significantly lower socioeconomic status, poorer living conditions, and higher lifetime history of depression, hypertension, and diabetes mellitus than their male counterparts.

CONCLUSION

The findings from this study showed that elderly women are more adversely affected by stroke in terms of incidence and outcomes of stroke than elderly men. The most noticeable result is that sex differences in socioeconomic status and living conditions may result in increased incidence of stroke and poorer outcomes in elderly women. Therefore, it is imperative to identify vulnerable elderly women and provide them appropriate treatment and services.

Sex Disparities in Ischemic Stroke Care: FL-PR CReSD Study (Florida-Puerto Rico Collaboration to Reduce Stroke Disparities)

BACKGROUND AND PURPOSE

Sex-specific disparities in stroke care including thrombolytic therapy and early hospital admission are reported. In a large registry of Florida and Puerto Rico hospitals participating in the Get With The Guidelines-Stroke program, we sought to determine sex-specific differences in ischemic stroke performance metrics and overall thrombolytic treatment.

METHODS

Around 51 317 (49% women) patients were included from 73 sites from 2010 to 2014. Multivariable logistic regression with generalized estimating equations evaluated sex-specific differences in the prespecified Get With The Guidelines-Stroke metrics for defect-free care in ischemic stroke, adjusting for age, race-ethnicity, insurance status, hospital characteristics, individual risk factors, and the presenting stroke severity.

RESULTS

As compared with men, women were older (73±15 versus 69±14 years; P<0.0001), more hypertensive (67% versus 63%, P<0.0001), and had more atrial fibrillation (19% versus 16%; P<0.0001). Defect-free care was slightly lower in women than in men (odds ratio, 0.96; 95% confidence interval, 0.93-1.00). Temporal trends in defect-free care improved substantially and similarly for men and women, with a 29% absolute improvement in women (P<0.0001) and 28% in men (P<0.0001), with P value of 0.13 for time-by-sex interaction. Women were less likely to receive thrombolysis (odds ratio, 0.92; 95% confidence interval, 0.86-0.99; P=0.02) and less likely to have a door-to-needle time <1 hour (odds ratio, 0.83; 95% confidence interval, 0.71-0.97; P=0.02) as compared with men.

CONCLUSIONS

Women received comparable stroke care to men in this registry as measured by prespecified Get With The Guidelines metrics. However, women less likely received thrombolysis and had door-to-needle time <1 hour, an observation that calls for the implementation of interventions to reduce sex disparity in these measures.

Sex Differences in Stroke Incidence, Prevalence, Mortality and Disability-Adjusted Life Years: Results from the Global Burden of Disease Study 2013

BACKGROUND

Accurate information on stroke burden in men and women are important for evidence-based healthcare planning and resource allocation. Previously, limited research suggested that the absolute number of deaths from stroke in women was greater than in men, but the incidence and mortality rates were greater in men. However, sex differences in various metrics of stroke burden on a global scale have not been a subject of comprehensive and comparable assessment for most regions of the world, nor have sex differences in stroke burden been examined for trends over time.

METHODS

Stroke incidence, prevalence, mortality, disability-adjusted life years (DALYs) and healthy years lost due to disability were estimated as part of the Global Burden of Disease (GBD) 2013 Study. Data inputs included all available information on stroke incidence, prevalence and death and case fatality rates. Analysis was performed separately by sex and 5-year age categories for 188 countries. Statistical models were employed to produce globally comprehensive results over time. All rates were age-standardized to a global population and 95% uncertainty intervals (UIs) were computed.

FINDINGS

In 2013, global ischemic stroke (IS) and hemorrhagic stroke (HS) incidence (per 100,000) in men (IS 132.77 (95% UI 125.34-142.77); HS 64.89 (95% UI 59.82-68.85)) exceeded those of women (IS 98.85 (95% UI 92.11-106.62); HS 45.48 (95% UI 42.43-48.53)). IS incidence rates were lower in 2013 compared with 1990 rates for both sexes (1990 male IS incidence 147.40 (95% UI 137.87-157.66); 1990 female IS incidence 113.31 (95% UI 103.52-123.40)), but the only significant change in IS incidence was among women. Changes in global HS incidence were not statistically significant for males (1990 = 65.31 (95% UI 61.63-69.0), 2013 = 64.89 (95% UI 59.82-68.85)), but was significant for females (1990 = 64.892 (95% UI 59.82-68.85), 2013 = 45.48 (95% UI 42.427-48.53)). The number of DALYs related to IS rose from 1990 (male = 16.62 (95% UI 13.27-19.62), female = 17.53 (95% UI 14.08-20.33)) to 2013 (male = 25.22 (95% UI 20.57-29.13), female = 22.21 (95% UI 17.71-25.50)). The number of DALYs associated with HS also rose steadily and was higher than DALYs for IS at each time point (male 1990 = 29.91 (95% UI 25.66-34.54), male 2013 = 37.27 (95% UI 32.29-45.12); female 1990 = 26.05 (95% UI 21.70-30.90), female 2013 = 28.18 (95% UI 23.68-33.80)).

INTERPRETATION

Globally, men continue to have a higher incidence of IS than women while significant sex differences in the incidence of HS were not observed. The total health loss due to stroke as measured by DALYs was similar for men and women for both stroke subtypes in 2013, with HS higher than IS. Both IS and HS DALYs show an increasing trend for both men and women since 1990, which is statistically significant only for IS among men. Ongoing monitoring of sex differences in the burden of stroke will be needed to determine if disease rates among men and women continue to diverge. Sex disparities related to stroke will have important clinical and policy implications that can guide funding and resource allocation for national, regional and global health programs.

Uric Acid Therapy Improves Clinical Outcome in Women With Acute Ischemic Stroke

BACKGROUND AND PURPOSE

It is unknown whether women and men with acute ischemic stroke respond similar to an antioxidant regimen administered in combination with thrombolysis. Here, we investigated the independent effect of sex on the response to uric acid (UA) therapy in patients with acute stroke treated with alteplase.

METHODS

In the Efficacy Study of Combined Treatment With Uric Acid and rtPA in Acute Ischemic Stroke (URICO-ICTUS) trial, 206 women and 205 men were randomized to UA 1000 mg or placebo. In this reanalysis of the trial, the primary outcome was the rate of excellent outcome at 90 days (modified Rankin Scale, 0-1, or 2, if premorbid score of 2) in women and men using regression models adjusted for confounders associated with sex. The interaction of UA levels by treatment on infarct growth was assessed in selected patients.

RESULTS

Excellent outcome occurred in 47 of 111 (42%) women treated with UA, and 28 of 95 (29%) treated with placebo, and in 36 of 100 (36%) men treated with UA and 38 of 105 (34%) treated with placebo. Treatment and sex interacted significantly with excellent outcome (P=0.045). Thus, UA therapy doubled the effect of placebo to attain an excellent outcome in women (odd ratio [95% confidence interval], 2.088 [1.050-4.150]; P=0.036), but not in men (odd ratio [95% confidence interval], 0.999 [0.516-1.934]; P=0.997). The interactions between treatment and serum UA levels (P<0.001) or allantoin/UA ratio (P<0.001) on infarct growth were significant only in women.

CONCLUSIONS

In women with acute ischemic stroke treated with alteplase, the administration of UA reduced infarct growth in selected patients and was better than placebo to reach excellent outcome.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT00860366.

Gender differences in neurologic emergencies part I: a consensus summary and research agenda on cerebrovascular disease

Cerebrovascular neurologic emergencies including ischemic and hemorrhagic stroke, subarachnoid hemorrhage (SAH), and migraine are leading causes of death and disability that are frequently diagnosed and treated in the emergency department (ED). Although sex and gender differences in neurologic emergencies are beginning to become clearer, there are many unanswered questions about how emergency physicians should incorporate sex and gender into their research initiatives, patient evaluations, and overall management plans for these conditions. After evaluating the existing gaps in the literature, a core group of ED researchers developed a draft of future research priorities. Participants in the 2014 Academic Emergency Medicine consensus conference neurologic emergencies working group then discussed and approved the recommended research agenda using a standardized nominal group technique. Recommendations for future research on the role of sex and gender in the diagnosis, treatment, and outcomes pertinent to ED providers are described for each of three diagnoses: stroke, SAH, and migraine. Recommended future research also includes investigation of the biologic and pathophysiologic differences between men and women with neurologic emergencies as they pertain to ED diagnoses and treatments.

Βeta-fibrinogen gene promoter A -455 allele associated with poor longterm survival among 55-71 years old Caucasian women in Finnish stroke cohort

BACKGROUND

Women die of stroke more often than men. After menopause, the incidence of ischemic stroke increases rapidly. Elevated fibrinogen levels and smoking have been associated with an increased risk of stroke. In gene-cluster haplotype analyses, the beta-fibrinogen (FGB) promoter -455 G/A polymorphic locus was most strongly associated with elevated plasma fibrinogen levels. We investigated whether the FGB -455 G/A polymorphism and smoking might interact with sex on longterm survival of acute stroke sufferers.

METHODS

The Stroke Aging Memory (SAM) cohort comprising 486 consecutive stroke patients (55-85 years, 246 men, 240 women) subjected to clinical and MRI examination was followed over 12.5 years. During this period 347 (71.4%) patients died. The genotypes of the FGB -455 G/A polymorphism were determined by PCR.

RESULTS

The FGB -455 G/A polymorphism genotype distributions were 64.7%, 32.1%, and 3.2% for GG, GA, and AA, respectively. During the follow-up, the FGB -455 A + genotype did not associate with survival, nor was there any genotype-by-smoking interaction on poor outcome in the total study population. However, women aged 55-71 years who carried the FGB -455 A-allele showed worse survival regardless of smoking status compared to non-smoking FGB -455 GG homozygotes (non-smokers, crude HR = 5.21, 95% CI: 1.38-19.7; smokers, crude HR = 7.03, 95% CI: 1.81-27.3). This association persisted in adjusted analyses. No such association was observed for women in the oldest age-group, nor among men.

CONCLUSION

The A + genotype of the FGB -455 G/A polymorphism associated with poor survival among 55-71 years old Caucasian women in the Finnish stroke cohort.

Estrogen and cerebrovascular regulation in menopause

Estrogen (E2), classically viewed as a reproductive steroid hormone, has non-reproductive functions throughout the body including in the brain and vasculature. Studies report diminished neuroprotection with declining E2 levels, corresponding with higher incidence of cerebrovascular and neurological disease. However, the effects of menopausal hormone therapy (MHT) on the cerebral vasculature and brain function remain controversial. This review will focus on evidence of 17β-estradiol actions in the cerebral vasculature, with a particular emphasis on the vasoactive, anti-inflammatory, anti-oxidant, metabolic and molecular properties. Controversies surrounding MHT in relation to cerebrovascular disease and stroke risk will be discussed, particularly the emerging evidence from clinical trials supporting the critical period hypothesis of estrogen protection.

Trends in stroke survival incidence rates in older Australians in the new millennium and forecasts into the future

AIMS

The objective of this study is (i) to evaluate trends in the incidence rates of stroke survivors aged 60 years and older over a 11-year period in the Australian Capital Territory (ACT) and (ii) to forecast future trends in Australia until 2051.

METHODS

Analysis of age- and sex-specific standardized incidence rates of older first-ever stroke survivors in ACT from 1999-2000 to 2009-2010 and projections of number of stroke survivors (NSS) in 2021 and 2051 using 2 models based only on (i) demographic changes and (ii) assuming changing of both incidence rates and demography.

RESULTS

In the ACT in the first decade of the 21st century, the absolute numbers and age-adjusted standardized incidence rates of stroke survivors (measured as a function of age and period) increased among both men and women aged 60 years or older. The trend toward increased survival rates in both sexes was driven mainly by population aging, whereas the effect of stroke year was more pronounced in men compared with women. The absolute NSS (and the financial burden to the society) in Australia is predicted to increase by 35.5%-59.3% in 2021 compared with 2011 and by 1.6- to 4.6-fold in 2051 if current only demographic (first number) or both demographic and incidence trends (second number) continue.

CONCLUSIONS

Our study demonstrates favorable trends in stroke survivor rates in Australia in the first decade of the new millennium and projects in the foreseeable future significant increases in the absolute numbers of older stroke survivors, especially among those aged 70 years or older and men.

Premature menopause or early menopause and risk of ischemic stroke

OBJECTIVE

The general consensus has been that estrogen is invariably a risk factor for ischemic stroke (IS). We reviewed new observational studies that challenge this simple conclusion.

METHODS

This was a review of observational studies of the association of premature or early menopause with stroke or IS published in English from 2006 through 2010.

RESULTS

Three cohort studies showed an increased risk of all types of stroke in women who underwent bilateral oophorectomy compared with women who conserved their ovaries before age 50 years. The increased risk of stroke was reduced by hormone therapy in one of the studies, suggesting that estrogen deprivation is involved in the association. Four additional observational studies showed an association of all types of stroke or IS with the early onset of menopause or with a shorter life span of ovarian activity. In three of the seven studies, the association was restricted to IS. Age at menopause was more important than type of menopause (natural vs induced).

CONCLUSIONS

The findings from seven recent observational studies challenge the consensus that estrogen is invariably a risk factor for IS and can be reconciled by a unifying timing hypothesis. We hypothesize that estrogen is protective for IS before age 50 years and may become a risk factor for IS after age 50 years or, possibly, after age 60 years. These findings are relevant to women who experienced premature or early menopause or to women considering prophylactic bilateral oophorectomy before the onset of natural menopause.

The gender gap in stroke: a meta-analysis

Several studies have indicated that gender differences might exist in stroke.

OBJECTIVES AND METHODS

Our goal was to perform a comprehensive meta-analysis in order to evaluate and quantify stroke gender disparities through a systematic search of relevant articles published up to October 2009 and addressing gender related differences in ischemic stroke risk factors, stroke subtype and severity, diagnostic tests, and acute phase and secondary prevention treatments.

RESULTS

Forty-five articles were included in the analysis, representing a total of 673,935 patients. Women were globally older than men (+5.2 years) and suffered more hypertension (P = 0.017) and atrial fibrillation (P < 0.001), although they were less likely to drink alcohol (P < 0.001), smoke cigarettes (P < 0.001), present hyperlipidemia (P = 0.033) or diabetes (P = 0.003) than men. Baseline stroke severity was not different between genders. Women suffered more cardioembolic strokes, while men had more atherothrombotic strokes. Moreover, women were less likely to receive stroke-related treatments, such as antiplatelets (P < 0.001), statins (P < 0.001), and tPA (P < 0.001) than men. Although meta-regression did not identify age or stroke etiology as sources of heterogeneity, caution should be taken as that analysis was possible only for gender differences in secondary prevention with antiplatelets because of limited data for other end points.

CONCLUSIONS

Gender differences have been identified on the risk factors profile and diagnostic and therapeutic management of patients with ischemic stroke. Active measures should thus be taken to avoid bias in clinical practice.

Effects of chronic and acute oestrogen replacement therapy in aged animals after experimental stroke

The effect of oestrogen replacement therapy (ERT) on stroke incidence and severity has been extensively debated. Clinical trials of ERT have demonstrated an increased risk of stroke in treated women, although the study participants were well past menopause when therapy was initiated. It has been suggested that detrimental effects of ERT may be unmasked after prolonged periods of hypoestrogenicity. To date, very few studies have examined the effect of ERT in aged animals, although the timing of replacement may be critical to the neuroprotective effects of ERT. We hypothesised that chronic ERT initiated in late middle age would decrease infarct size in the brain after an induced stroke, whereas acute ERT would have no beneficial effects in aged females. To test this hypothesis, two paradigms of ERT were administered to aged mice of both sexes aiming to determine the effects on stroke outcome and to explore the possible mechanisms by which ERT interacts with age. Female mice that received chronic ERT from 17-20 months of age showed improved stroke outcomes after experimental stroke, whereas females that had acute ERT initiated at 20 months of age did not. Chronic ERT females exhibited diminished levels of nuclear factor kappa B (NF-κB) translocation compared to acute ERT females after stroke. Acute ERT females demonstrated both an increase in nuclear NF-κB and enhanced expression of pro-inflammatory cytokines. In addition, a sexual dimorphic effect of ERT was seen because males benefited from ERT, regardless of the timing of initiation. Aged males had significantly reduced expression of pro-inflammatory markers after stroke compared to age-matched females, suggesting a pro-inflammatory milieu emerges with age in females. These results are consistent with the emerging clinical literature suggesting that ERT should be initiated at the time of menopause to achieve beneficial effects. The present study demonstrates the importance of using appropriate animal models in preclinical studies.

Risks and Benefits of Thrombolysis in the Elderly

Background and purpose

Stroke incidence continues to rise exponentially with age even as temporal trends in some population risk factors increase and others decline. In general, older patients with stroke have worse outcomes compared to their younger counterparts. Stroke severity, concurrent medical problems, prestroke disability, and less-aggressive acute and chronic management are a few contributing factors to account for this poor prognosis. Acute thrombolysis therapy is the only proven treatment in acute ischemic stroke. However, elderly patients have mostly been excluded from acute revascularization studies, due predominantly to their overall poor prognosis and the fear of hemorrhagic complications from these treatments. Despite this, there is no evidence to suggest that the risk benefit ratio of thrombolysis treatment is substantially different in the elderly than in younger ischemic stroke patients.

Summary of review

In this review, we briefly examine the stroke risk factor profile and outcome in the elderly and review the current evidence regarding intravenous and intra-arterial revascularization treatments.

Conclusion

We feel that carefully selected patients who meet eligibility criteria for thrombolysis should not be denied this therapy on the basis of age alone.

Gender differences in presenting signs and symptoms of acute ischemic stroke: a population-based study

BACKGROUND

There are few population-based data regarding gender differences in signs and symptoms of acute ischemic stroke, and previously reported data have been inconsistent and conflicting.

OBJECTIVE

The goal of this study was to address the gender differences of the presenting signs and symptoms of acute ischemic stroke in a population-based study.

METHODS

All patients with first ischemic stroke occurring between 1985 and 1989 were identified; subjects were residents of Rochester, Minnesota. Signs and symptoms were collected via review of comprehensive medical records. Differences were identified using the Pearson χ(2) test.

RESULTS

A total of 449 cases of first ischemic stroke were identified; 268 (60%) were women. Symptoms at ischemic stroke presentation differed between men and women. Women more commonly presented with generalized weakness (P = 0.005) and mental status change (P = 0.0001). Men more commonly presented with paresthesia (P = 0.003), ataxia (P = 0.006), and double vision (P = 0.005). Signs at ischemic stroke presentation differed between men and women. Men more commonly presented with nystagmus (P = 0.002) on examination. Significant trends were that women more commonly presented with fatigue (P = 0.02), disorientation (P = 0.04), and fever (P = 0.02), whereas men more commonly presented with sensory abnormalities (P = 0.02).

CONCLUSIONS

There were gender differences in signs and symptoms at presentation of ischemic stroke in these study patients. In addition to selected focal symptoms, women more commonly presented with diffuse symptoms of generalized weakness, fatigue, disorientation, and mental status change.

Thrombolysis Treatment for Acute Stroke: Issues of Efficacy and Utilization in Women

Background: Some studies report that women with ischemic stroke are more likely to benefit from intravenous tissue thrombolysis (IV tPA) treatment, but are less likely to receive the treatment compared with men. We review the literature on sex differences in utilization and efficacy of IV tPA and suggest directions for future studies. Methods: We identified studies that reported on sex differences in either the utilization or efficacy of IV tPA treatment for acute ischemic stroke. Results: Data from observational studies of IV tPA use show evidence of under-utilization in women, although wide variability between studies suggests that differences are specific to local conditions and populations. Prior analyses of randomized trial data show strong evidence that women but not men receive statistically and clinically significant benefit from IV tPA treatment. Observational studies of the effectiveness of IV tPA treatment in men and women have limited validity because of the absence of comparable control groups. Conclusion: There is good evidence that there are clinically important sex differences in both the efficacy and utilization of IV tPA, with women gaining more benefit from treatment than men. The current paradox between greater efficacy but lower utilization of IV tPA in women requires greater attention from the stroke community. Larger placebo-controlled thrombolysis trials, specifically powered to look at sex differences in treatment efficacy, and more studies designed to understand the underlying reasons for the lower utilization of IV tPA in women are required.

17β-estradiol increases astrocytic vascular endothelial growth factor (VEGF) in adult female rat hippocampus

Vascular endothelial growth factor (VEGF) is critical to angiogenesis and vascular permeability. It is also important in the endocrine system, in which VEGF mediates the vascular effects of estrogens in target tissues such as the uterus, a response attributed to an estrogen response element on the VEGF gene. Here we asked whether 17β-estradiol increases VEGF levels in the brain. We focused on the hippocampus, in which 17β-estradiol and VEGF both have important actions, and used immunocytochemistry to evaluate VEGF protein. VEGF immunoreactivity was compared in adult female rats sampled during the estrous cycle when serum levels of 17β-estradiol peak (proestrous morning) as well as when they are low (metestrous morning). In addition, adult rats were ovariectomized and compared after treatment with 17β-estradiol or vehicle. The results demonstrated that VEGF immunoreactivity was increased when serum levels of 17β-estradiol were elevated. Confocal microscopy showed that VEGF immunofluorescence was predominantly nonneuronal, often associated with astrocytes. Glial VEGF labeling was primarily punctate rather than diffuse and labile because glial VEGF immunoreactivity was greatly reduced if tissue sections were left in an aqueous medium overnight. We conclude that VEGF protein in normal female hippocampus is primarily nonneuronal rather than neuronal and suggest that glial VEGF immunoreactivity has been underestimated by past studies with other methods because there is a labile extracellular pool. We suggest that estrogens may exert actions on female hippocampal structure and function by increasing hippocampal VEGF.

Sex differences in the response to poly(ADP-ribose) polymerase-1 deletion and caspase inhibition after stroke

BACKGROUND AND PURPOSE

Emerging data suggest that the molecular cell death pathways triggered by ischemic insults differ in the male and female brain. Cell death in males is initiated by poly(ADP-ribose) polymerase-1 (PARP-1) activation; however, manipulation of this pathway paradoxically increases ischemic damage in females. In contrast, females are exquisitely sensitive to caspase-mediated cell death. The effect of caspase inhibition in PARP-1 knockout mice was evaluated to determine if the detrimental effects of PARP deletion in females were secondary to increased caspase activation.

METHODS

Focal stroke was induced by transient or permanent middle cerebral artery occlusion (MCAO) in wild-type (WT) and PARP-1(-/-) mice of both sexes. The pan-caspase inhibitor, quinoline-Val-Asp(Ome)-CH2-O-phenoxy (Q-VD-OPh), was administered 90 minutes after middle cerebral artery occlusion. Infarct size and neurological sores were assessed. Separate cohorts were used for protein analysis for PAR, Apoptosis inducing factor (AIF), caspase-9, and caspase-3.

RESULTS

WT mice of both sexes had increased nuclear AIF after stroke compared to PARP-1(-/-) mice. PARP-1(-/-) females had higher mitochondrial cytochrome C and activated caspase-9 and -3 levels than WT female mice. PARP-1(-/-) females also had an increase in stroke-induced cytosolic cytochrome C release compared with WT females, which was not seen in males. Q-VD-OPh decreased caspase-9 in both males and females but only led to reduction of infarct in females. PARP-1(-/-) males had smaller infarcts, whereas PARP-1(-/-) females had larger strokes compared with WT. Q-VD-OPh significantly decreased infarct in both WT and PARP-1(-/-) females in both transient and permanent MCAO models, but had no effect in males.

CONCLUSIONS

Deletion of PARP-1 reduces infarct in males but exacerbates injury in females. PARP-1(-/-) females have enhanced caspase activation. The detrimental effects of PARP loss in females can be reversed with caspase inhibition.

Persistent sex disparity in midlife stroke prevalence in the United States

BACKGROUND

A recent study found that US women aged 45-54 years in 1999-2004 were twice as likely as men to report previous stroke. The aim of this study was to evaluate the validity of this finding by assessing the sex-specific midlife stroke prevalence in the most recent nationally representative, cross-sectional sample of US individuals.

METHODS

Sex-specific stroke prevalence, sex-specific vascular risk factor prevalence and sex-specific independent predictors of stroke were assessed among 35- to 64-year olds who participated in the National Health and Nutrition Examination Surveys in 2005-2006 (n = 2,274).

RESULTS

Women aged 35-64 years were almost 3 times more likely than men to report prior stroke (2.90 vs. 1.07%; p < 0.001). This disparity was driven by the 45- to 54-year age group, where women had thrice the odds of prior stroke compared with men (OR 3.12, 95% CI 1.30-7.50). Among 45- to 54-year olds, men were more likely than women to have a history of smoking, elevated homocysteine and elevated triglyceride levels, but less likely to be abdominally obese (p < 0.001). Independent stroke risk factors among women aged 35-64 years were a homocysteine level >8.5 μmol/l (OR 6.19, 95% CI 2.57-14.93), a history of myocardial infarction (OR 5.35, 95% CI 1.09-26.27) and diabetes mellitus (OR 6.63, 95% CI 2.47-17.81).

CONCLUSION

The midlife sex disparity in US stroke prevalence persists. Greater emphasis on prompt recognition and treatment of cardiovascular risk factors among young and middle-aged women may ameliorate this worrisome trend.

Stroke: working toward a prioritized world agenda

BACKGROUND AND PURPOSE

The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke.

METHODS

Preliminary work was performed by seven working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium.

RESULTS

Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent 'silo' mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (eg, social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a 'Brain Health' concept that enables promotion of preventive measures.

CONCLUSIONS

To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Effect of bilateral oophorectomy on women's long-term health

Bilateral oophorectomy at the time of hysterectomy for benign disease is commonly practiced in order to prevent the subsequent development of ovarian cancer or other ovarian pathology that might require additional surgery. At present, bilateral oophorectomy is performed in 78% of women aged between 45 and 64 years having a hysterectomy, and a total of approximately 300,000 prophylactic oophorectomies are performed in the USA every year. Estrogen deficiency resulting from pre- and post-menopausal oophorectomies has been associated with higher risks of coronary heart disease, stroke, hip fracture, Parkinsonism, dementia, cognitive impairment, depression and anxiety in many studies. While ovarian cancer accounts for 14,800 deaths per year in the USA, coronary heart disease accounts for 350,000 deaths per year. In addition, 100,000 cases of dementia may be attributable annually to prior bilateral oophorectomy. At present, observational studies suggest that bilateral oophorectomy may do more harm than good. In women who are not at high risk of developing ovarian or breast cancer, removing the ovaries at the time of hysterectomy should be approached with caution.

Chronic inflammatory diseases in children are more severe in girls

In humans and animal models, females express higher immune reactivity and more robust inflammatory responses. We analyzed the expression of current inflammatory markers in 149 children (74 girls and 75 boys) with three chronic inflammatory diseases: 50 with asthma, 47 with cystic fibrosis, and 52 with sickle cell anemia to evaluate the potential differences in clinical response according to sex. Data including temperature, neutrophil count (NC), and C-reactive protein were recorded for each patient at several time points according to his/her disease. In asthma, NC was higher in girls than in males (P < 0.02), as were doses of cortisone (P < 0.04) or inhaled bronchodilators (P < 0.01) received at recovery. In cystic fibrosis, NC became significantly higher in girls at age 5 years (P < 0.003), whereas episodes of infection and antibiotic administration were already significantly more frequent in girls at age 2 years (P < 0.02 and P < 0.05, respectively). In sickle cell anemia, the number of crises since diagnosis and number of acute chest syndrome episodes were significantly higher in girls (P < 0.01 and P < 0.05, respectively). Our study extends the documentation of a relationship between sex, inflammatory markers, and clinical outcome in prepubescent children, suggesting a genetic predetermination is more likely than hormonal influence.

Gender differences in outcomes after ischemic stroke: role of ischemic lesion volume and intracranial large-artery occlusion

BACKGROUND

The reasons for gender disparities in stroke outcome remain unclear, and little is known about the value of acute neuroimaging characteristics in elucidating differential stroke outcomes between the sexes.

METHODS

We prospectively evaluated consecutive patients with acute ischemic stroke. CT angiography (CTA) was performed in all patients within 24 h of symptom onset. CTA source images were used to evaluate lesion volume. The primary outcome measure was a modified Rankin scale (mRS) score ≥ 3 at 6 months.

RESULTS

We evaluated 676 consecutive patients (322 women). Women were older than men (p < 0.01), more frequently had a prestroke mRS >0 (p < 0.01), and had higher admission National Institutes of Health Stroke scale scores (p = 0.01). More women had intracranial artery occlusions than men (46 vs. 33.1%, p = 0.01), but there was no significant difference between ischemic lesion volumes (p = 0.21). Using multiple regression, female gender remained an independent predictor of poor mRS scores at 6 months (odds ratio 1.57; 95% confidence interval 1.02-2.36) after adjustment for clinical and imaging covariates.

CONCLUSION

Compared with men, women are less likely to achieve independence after acute ischemic stroke. The disparity in stroke outcome is not explained by differences in ischemic lesion volume or the presence of intracranial artery occlusions.

Stroke: working toward a prioritized world agenda

BACKGROUND AND PURPOSE

The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke.

METHODS

Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium.

RESULTS

Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent "silo" mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (eg, social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a "Brain Health" concept that enables promotion of preventive measures.

CONCLUSIONS

To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Stroke: working toward a prioritized world agenda

BACKGROUND AND PURPOSE

The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke.

METHODS

Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium.

RESULTS

Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent 'silo' mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (e.g., social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a 'Brain Health' concept that enables promotion of preventive measures.

CONCLUSIONS

To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Loss of estrogen receptor beta decreases mitochondrial energetic potential and increases thrombogenicity of platelets in aged female mice

Platelets derived from aged (reproductively senescent) female mice with genetic deletion of estrogen receptor beta (betaER) are more thrombogenic than those from age-matched wild-type (WT) mice. Intracellular processes contributing to this increased thrombogenicity are not known. Experiments were designed to identify subcellular localization of estrogen receptors and evaluate both glycolytic and mitochondrial energetic processes which might affect platelet activation. Platelets and blood from aged (22-24 months) WT and estrogen receptor beta knockout (betaERKO) female mice were used in this study. Body, spleen weight, and serum concentrations of follicle-stimulating hormone and 17beta-estradiol were comparable between WT and betaERKO mice. Number of spontaneous deaths was greater in the betaERKO colony (50% compared to 30% in WT) over the course of 24 months. In resting (nonactivated) platelets, estrogen receptors did not appear to colocalize with mitochondria by immunostaining. Lactate production and mitochondrial membrane potential of intact platelets were similar in both groups of mice. However, activities of NADH dehydrogenase, cytochrome bc ( 1 ) complex, and cytochrome c oxidase of the electron transport chain were reduced in mitochondria isolated from platelets from betaERKO compared to WT mice. There were a significantly higher number of phosphatidylserine-expressing platelet-derived microvesicles in the plasma and a greater thrombin-generating capacity in betaERKO compared to WT mice. These results suggest that deficiencies in betaER affect energy metabolism of platelets resulting in greater production of circulating thrombogenic microvesicles and could potentially explain increased predisposition to thromboembolism in some elderly females.

Estrogen-receptor-mediated protection of cerebral endothelial cell viability and mitochondrial function after ischemic insult in vitro

Protective effects of estrogen against experimental stroke and neuronal ischemic insult are well-documented, but it is not known whether estrogen prevents ischemic injury to brain endothelium, a key component of the neurovascular unit. Increasing evidence indicates that estrogen exerts protective effects through mitochondrial mechanisms. We previously found 17beta-estradiol (E2) to improve mitochondrial efficiency and reduce mitochondrial superoxide in brain blood vessels and endothelial cells. Thus we hypothesized E2 will preserve mitochondrial function and protect brain endothelial cells against ischemic damage. To test this, an in vitro ischemic model, oxygen-glucose deprivation (OGD)/reperfusion, was applied to immortalized mouse brain endothelial cells (bEnd.3). OGD/reperfusion-induced cell death was prevented by long-term (24, 48 h), but not short-term (0.5, 12 h), pretreatment with 10 nmol/L E2. Protective effects of E2 on endothelial cell viability were mimicked by an estrogen-receptor (ER) agonist selective for ERalpha (PPT), but not by one selective for ERbeta (DPN). In addition, E2 significantly decreased mitochondrial superoxide and preserved mitochondrial membrane potential and ATP levels in early stages of OGD/reperfusion. All of the E2 effects were blocked by the ER antagonist, ICI-182,780. These findings indicate that E2 can preserve endothelial mitochondrial function and provide protection against ischemic injury through ER-mediated mechanisms.

Combination therapy of 17beta-estradiol and recombinant tissue plasminogen activator for experimental ischemic stroke

Thrombolysis with recombinant tissue plasminogen activator (rtPA) in ischemic stroke is limited by the increased risk of hemorrhage transformation due to blood-brain barrier breakdown. We determined the interaction of 17beta-estradiol (E2) and rtPA on activation of plasminogen system and matrix metalloproteinases (MMPs) in a transient middle cerebral artery occlusion (MCAO) model. Ovariectomized female rats were subjected to 1-h transient focal cerebral ischemia using a suture MCAO model. Ischemic lesion volume was significantly reduced with acute treatment of E2 despite of exogenous administration of rtPA. The expression and activation of urokinase (uPA), MMP2, and MMP9 were significantly increased in ischemic hemisphere after transient cerebral ischemia. Exogenous rtPA administration further enhanced expression and activation of uPA, MMP2, and MMP9, which was blocked by E2 treatment. We further determined the effect of combination therapy of E2 and rtPA in an embolic MCAO model. Although no protection was indicated upon acute treatment of E2 alone, combination treatment of E2 and rtPA provided protective action at 3 h after embolism. Collectively, the present study suggests that estrogen could be a candidate for combination therapy with rtPA to attenuate its side effect and hence expand its short therapeutic window for treatment of ischemic stroke.

Estradiol: a hormone with diverse and contradictory neuroprotective actions

The concept that estrogens exert important neuroprotective actions has gained considerable attention during the past decade. Numerous studies have provided a deep understanding of the seemingly contradictory actions of estrogens. We realize more than ever that the effects of estrogens (with and without simultaneous or sequential progestins) are diverse and sometimes opposite, depending on the use of different estrogenic and progestinic compounds, on different delivery routes, on different concentrations, on treatment sequence, and on the age and health status of the women who receive hormone therapy. During the past few years, we have gained an increasing appreciation of the impact of estrogens on the immune system and on inflammation. In addition, we have learned that estrogens cannot only protect against cell death, but can also stimulate the birth of new neurons. Here we posit the concept that estrogen's modulation of the immune status may be the basic mechanism that underlies its ability to protect against neurodegeneration and its powerful neuroregenerative actions. We hope that this update will encourage even richer dialogues between basic and clinical scientists to ensure that future clinical studies fully consider the information that can be derived from basic science studies. Only then will we have a better understanding of the impact of hormones on the menopausal and postmenopausal period in a woman's life.

Neuroprotective effects of estrogens following ischemic stroke

Our laboratory has investigated whether and how 17beta-estradiol (E(2)) protects the brain against neurodegeneration associated with cerebrovascular stroke. We have discovered that low, physiological concentrations of E(2), which are strikingly similar to low-basal circulating levels found in cycling mice, dramatically protect the brain against stroke injury, and consequently revealed multiple signaling pathways and key genes that mediate protective action of E(2). Here we will review the discoveries comprising our current understanding of neuroprotective actions of estrogens against ischemic stroke. These findings may carry far reaching implications for improving the quality of life in aging populations.