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

Sex differences in clot, vessel and tissue characteristics in patients with a large vessel occlusion treated with endovascular thrombectomy

INTRODUCTION

To improve our understanding of the relatively poor outcome after endovascular treatment (EVT) in women we assessed possible sex differences in baseline neuroimaging characteristics of acute ischemic stroke patients with large anterior vessel occlusion (LVO).

PATIENTS AND METHODS

We included all consecutive patients from the MR CLEAN Registry who underwent EVT between 2014 and 2017. On baseline non-contrast CT and CT angiography, we assessed clot location and clot burden score (CBS), vessel characteristics (presence of atherosclerosis, tortuosity, size, and collateral status), and tissue characteristics with the Alberta Stroke Program Early Computed Tomography Score (ASPECTS). Radiological outcome was assessed with the extended thrombolysis in cerebral infarction score (eTICI) and functional outcome with the modified Rankin Scale score (mRS) at 90 days. Sex-differences were assessed with multivariable regression analyses with adjustments for possible confounders.

RESULTS

3180 patients were included (median age 72 years, 48% women). Clots in women were less often located in the intracranial internal carotid artery (ICA) (25%vs 28%, odds ratio (OR) 0.85;95% confidence interval: 0.73-1.00). CBS was similar between sexes (median 6, IQR 4-8). Intracranial (aOR 0.73;95% CI:0.62-0.87) and extracranial (aOR 0.64;95% CI:0.43-0.95) atherosclerosis was less prevalent in women. Vessel tortuosity was more frequent in women in the cervical ICA (aOR 1.89;95% CI:1.39-2.57) and women more often had severe elongation of the aortic arch (aOR 1.38;95% CI:1.00-1.91). ICA radius was smaller in women (2.3vs 2.5 mm, mean difference 0.22;95% CI:0.09-0.35) while M1 radius was essentially equal (1.6vs 1.7 mm, mean difference 0.09;95% CI:-0.02-0.21). Women had better collateral status (⩾50% filling in 62%vs 53% in men, aOR 1.48;95% CI:1.29-1.70). Finally, ASPECT scores were equal between women and men (median 9 in both sexes, IQR 8-10vs 9-10). Reperfusion rates were similar between women and men (acOR 0.94;95% CI:0.83-1.07). However, women less often reached functional independence than men (34%vs 46%, aOR 0.68;95% CI:0.53-0.86).

DISCUSSION AND CONCLUSION

On baseline imaging of this Dutch Registry, men and women with LVO mainly differ in vessel characteristics such as atherosclerotic burden, extracranial vessel tortuosity, and collateral status. These sex differences do not result in different reperfusion rates and are, therefore, not likely to explain the worse functional outcome in women after EVT.

Differences in stroke clinical presentation among sexes

INTRODUCTION

There are sex-based differences in stroke epidemiology, treatment, and outcomes. In this manuscript, we discuss the differences that exist in the clinical presentation of acute stroke among sexes.

DISCUSSION

We present the differences in stroke presentation among sexes including age at the time of presentation, severity of stroke on presentation, and stroke type and location. We discuss the atypical clinical presentations, explore the radiographic findings on presentation (including location, infarct core volume, the impact of collateral circulation, hematoma location in intracranial hemorrhage), and discuss differences in time elapsed between symptom onset and management amongst sexes.

CONCLUSION

Differences exist in stroke clinical presentation amongst sexes. These disparities have public health implications, and as they become better understood, impact awareness campaigns in both the public and healthcare communities.

Prognostic Determinants of Anterior Large Vessel Occlusion in Acute Stroke in Elderly Patients

This study investigated prognostic factors in elderly patients (80 years and older) undergoing mechanical thrombectomy (MT) for anterior circulation large vessel occlusion (LVO) in acute stroke treatment. Of 59 cases, 47.5% achieved a favorable outcome (mRS ≤ 3) at three months, with a mortality rate of 20.3%. Factors associated with better outcomes included younger age, lower admission National Institute of Health Stroke Scale (NIHSS) scores, lower N-terminal pro-brain natriuretic peptide (NT-proBNP) and D-dimer levels, the presence of the first pass effect (FPE), and successful recanalization. However, logistic regression showed that only lower admission NIHSS scores were significantly correlated with favorable outcomes. In addition, this study suggests that lower admission NT-proBNP and D-dimer levels could potentially serve as prognostic indicators for elderly LVO patients undergoing MT.

The role of gender in cognitive outcomes from stroke

OBJECTIVE

Stroke can cause cognitive impairment, which can lead to challenges returning to day-to-day activities. Knowing what factors are associated with cognitive impairment post-stroke can be useful for predicting outcomes and guiding rehabilitation. One such factor is gender: previous studies are inconclusive as to whether gender influences cognitive outcomes post-stroke. Accounting for key variables, we examined whether there are gender differences in cognitive outcomes after stroke.

METHOD

We analyzed data from neuropsychological assessments of 237 individuals tested in the chronic epoch (≥ 3 months) following ischemic stroke. Using ANCOVA and linear mixed modeling, we examined gender as a predictor of cognition as measured by general cognitive ability (g), Full-Scale IQ, and 18 cognitive tests, controlling for age at stroke onset, education, premorbid intelligence, and lesion volume.

RESULTS

There were no significant gender differences in overall cognitive outcomes as measured by g (p = .887) or Full-Scale IQ (p = .801). There were some significant gender differences on specific cognitive tests, with women outperforming men on scores from the Rey Auditory Verbal Learning Test (ps < .01) and men outperforming women on the Wechsler Adult Intelligence Scale Arithmetic and Information subtests (ps < .01).

CONCLUSIONS

Our findings indicate that men and women have similar overall cognitive outcomes after stroke, when demographic and lesion factors are accounted for. Although men and women differed in their performance on some individual cognitive tests, neither gender performed systematically better or worse. However, for learning, working memory, and verbal knowledge/comprehension, gender may be an important predictor of outcome post-stroke.

Bayesian stroke modeling details sex biases in the white matter substrates of aphasia

Ischemic cerebrovascular events often lead to aphasia. Previous work provided hints that such strokes may affect women and men in distinct ways. Women tend to suffer strokes with more disabling language impairment, even if the lesion size is comparable to men. In 1401 patients, we isolate data-led representations of anatomical lesion patterns and hand-tailor a Bayesian analytical solution to carefully model the degree of sex divergence in predicting language outcomes ~3 months after stroke. We locate lesion-outcome effects in the left-dominant language network that highlight the ventral pathway as a core lesion focus across different tests of language performance. We provide detailed evidence for sex-specific brain-behavior associations in the domain-general networks associated with cortico-subcortical pathways, with unique contributions of the fornix in women and cingular fiber bundles in men. Our collective findings suggest diverging white matter substrates in how stroke causes language deficits in women and men. Clinically acknowledging such sex disparities has the potential to improve personalized treatment for stroke patients worldwide.

Sexual dimorphism in immune cell responses following stroke

Recent bodies of work in regard to stroke have revealed significant sex differences in terms of risk and outcome. While differences in sex hormones have been the focus of earlier research, the reasons for these differences are much more complex and require further identification. This review covers differences in sex related immune responses with a focus on differences in immune cell composition and function. While females are more susceptible to immune related diseases, they seem to have better outcomes from stroke at the experimental level with reduced pro-inflammatory responses. However, at the clinical level, the picture is much more complex with worse neurological outcomes from stroke. While the use of exogenous sex steroids can replicate some of these findings, it is apparent that many other factors are involved in the modulation of immune responses. As a result, more research is needed to better understand these differences and identify appropriate interventions and risk modification.

Nomogram to predict 3-month unfavorable outcome after thrombectomy for stroke

Background

Mechanical thrombectomy (MT) is an effective treatment for large-vessel occlusion in acute ischemic stroke, however, only some revascularized patients have a good prognosis. For stroke patients undergoing MT, predicting the risk of unfavorable outcomes and adjusting the treatment strategies accordingly can greatly improve prognosis. Therefore, we aimed to develop and validate a nomogram that can predict 3-month unfavorable outcomes for individual stroke patient treated with MT.

Methods

We analyzed 258 patients with acute ischemic stroke who underwent MT from January 2018 to February 2021. The primary outcome was a 3-month unfavorable outcome, assessed using the modified Rankin Scale (mRS), 3–6. A nomogram was generated based on a multivariable logistic model. We used the area under the receiver-operating characteristic curve to evaluate the discriminative performance and used the calibration curve and Spiegelhalter’s Z-test to assess the calibration performance of the risk prediction model.

Results

In our visual nomogram, gender (odds ratio [OR], 3.40; 95%CI, 1.54–7.54), collateral circulation (OR, 0.46; 95%CI, 0.28–0.76), postoperative mTICI (OR, 0.06; 95%CI, 0.01–0.50), stroke-associated pneumonia (OR, 5.76; 95%CI, 2.79–11.87), preoperative Na (OR, 0.82; 95%CI, 0.72–0.92) and creatinine (OR, 1.02; 95%CI, 1.01–1.03) remained independent predictors of 3-month unfavorable outcomes in stroke patients treated with MT. The area under the nomogram curve was 0.8791 with good calibration performance (P = 0.873 for the Spiegelhalter’s Z-test).

Conclusions

A novel nomogram consisting of gender, collateral circulation, postoperative mTICI, stroke-associated pneumonia, preoperative Na and creatinine can predict the 3-month unfavorable outcomes in stroke patients treated with MT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02633-1.

Sex-specific lesion pattern of functional outcomes after stroke

Stroke represents a considerable burden of disease for both men and women. However, a growing body of literature suggests clinically relevant sex differences in the underlying causes, presentations and outcomes of acute ischaemic stroke. In a recent study, we reported sex divergences in lesion topographies: specific to women, acute stroke severity was linked to lesions in the left-hemispheric posterior circulation. We here determined whether these sex-specific brain manifestations also affect long-term outcomes. We relied on 822 acute ischaemic patients [age: 64.7 (15.0) years, 39% women] originating from the multi-centre MRI-GENIE study to model unfavourable outcomes (modified Rankin Scale >2) based on acute neuroimaging data in a Bayesian hierarchical framework. Lesions encompassing bilateral subcortical nuclei and left-lateralized regions in proximity to the insula explained outcomes across men and women (area under the curve = 0.81). A pattern of left-hemispheric posterior circulation brain regions, combining left hippocampus, precuneus, fusiform and lingual gyrus, occipital pole and latero-occipital cortex, showed a substantially higher relevance in explaining functional outcomes in women compared to men [mean difference of Bayesian posterior distributions (men - women) = -0.295 (90% highest posterior density interval = -0.556 to -0.068)]. Once validated in prospective studies, our findings may motivate a sex-specific approach to clinical stroke management and hold the promise of enhancing outcomes on a population level.

Racial and Socioeconomic Disparities in the Use and Outcomes of Endovascular Thrombectomy for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Racial and socioeconomic disparities in the incidence, treatment, and outcomes of acute ischemic stroke exist and have been described. We aimed to characterize disparities in the use of endovascular thrombectomy in a nationally representative analysis.

MATERIALS AND METHODS

Discharge data from the Nationwide Inpatient Sample between 2006 and 2016 were queried using validated International Classification of Disease codes. Patients admitted to US hospitals with acute ischemic stroke were included and stratified on the basis of race, income, and primary payer. Trends in endovascular thrombectomy use, good outcome (discharge to home/acute rehabilitation), and poor outcome (discharge to skilled nursing facility, hospice, in-hospital mortality) were studied using univariate and multivariable analyses.

RESULTS

In this analysis of 1,322,162 patients, endovascular thrombectomy use increased from 53/111,829 (0.05%) to 3054/146,650 (2.08%) between 2006 and 2016, respectively. Less increase was observed in black patients from 4/12,733 (0.03%) to 401/23,836 (1.68%) and those in the lowest income quartile from 10/819 (0.03%) to 819/44,984 (1.49%). Greater increase was observed in the highest income quartile from 18/22,138 (0.08%) to 669/27,991 (2.39%). Black race predicted less endovascular thrombectomy use (OR = 0.79; 95% CI, 0.72-0.86). The highest income group predicted endovascular thrombectomy use (OR = 1.24; 95% CI, 1.13-1.36) as did private insurance (OR = 1.30; 95% CI, 1.23-1.38). High income predicted good outcome (OR = 1.10; 95% CI. 1.06-1.14), as did private insurance (OR = 1.36; 95% CI, 1.31-1.39). Black race predicted poor outcome (OR = 1.33; 95% CI, 1.30-1.36). All results were statistically significant (P < .01).

CONCLUSIONS

Despite a widespread increase in endovascular thrombectomy use, black and low-income patients may be less likely to receive endovascular thrombectomy. Future effort should attempt to better understand the causes of these disparities and develop strategies to ensure equitable access to potentially life-saving treatment.

Outcome after acute ischemic stroke is linked to sex-specific lesion patterns

Acute ischemic stroke affects men and women differently. In particular, women are often reported to experience higher acute stroke severity than men. We derived a low-dimensional representation of anatomical stroke lesions and designed a Bayesian hierarchical modeling framework tailored to estimate possible sex differences in lesion patterns linked to acute stroke severity (National Institute of Health Stroke Scale). This framework was developed in 555 patients (38% female). Findings were validated in an independent cohort (n = 503, 41% female). Here, we show brain lesions in regions subserving motor and language functions help explain stroke severity in both men and women, however more widespread lesion patterns are relevant in female patients. Higher stroke severity in women, but not men, is associated with left hemisphere lesions in the vicinity of the posterior circulation. Our results suggest there are sex-specific functional cerebral asymmetries that may be important for future investigations of sex-stratified approaches to management of acute ischemic stroke.

Female Stroke: Sex Differences in Acute Treatment and Early Outcomes of Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Men and women are differently affected by acute ischemic stroke (AIS) in many aspects. Prior studies on sex disparities were limited by moderate sample sizes, varying years of data acquisition, and inconsistent inclusions of covariates leading to controversial findings. We aimed to analyze sex differences in AIS severity, treatments, and early outcome and to systematically evaluate the effect of important covariates in a large German stroke registry.

METHODS

Analyses were based on the Stroke Registry of Northwestern Germany from 2000 to 2018. We focused on admission-stroke severity and disability, acute recanalization treatment, and early stroke outcomes. Potential sex divergences were investigated via odds ratio (OR) using logistic regression models. Covariates were introduced in 3 steps: (1) base models (age and admission year), (2) partially adjusted models (additionally corrected for acute stroke severity and recanalization treatment), (3) fully adjusted models (additionally adjusted for onset-to-admission time interval, prestroke functional status, comorbidities, and stroke cause). Models were separately fitted for the periods 2000 to 2009 and 2010 to 2018.

RESULTS

Data from 761 106 patients with AIS were included. In fully adjusted models, there were no sex differences with respect to treatment with intravenous thrombolysis (2000-2009: OR, 0.99 [95% CI, 0.94-1.03]; 2010-2018: OR, 1.0 [0.98-1.02]), but women were more likely to receive intraarterial therapy (2010-2018: OR, 1.12 [1.08-1.15]). Despite higher disability on admission (2000-2009: OR, 1.10 [1.07-1.13]; 2010-2018: OR, 1.09 [1.07-1.10]), female patients were more likely to be discharged with a favorable functional outcome (2003-2009: OR, 1.05 [1.02-1.09]; 2010-2018: OR, 1.05 [1.04-1.07]) and experienced lower in-hospital mortality (2000-2009: OR, 0.92 [0.86-0.97]; 2010-2018: OR, 0.91 [0.88-0.93]).

CONCLUSIONS

Female patients with AIS have a higher chance of receiving intraarterial treatment that cannot be explained by clinical characteristics, such as age, premorbid disability, stroke severity, or cause. Women have a more favorable in-hospital recovery than men because their higher disability upon admission was followed by a lower in-hospital mortality and a higher likelihood of favorable functional outcome at discharge after adjustment for covariates.

Sex Differences in Outcome After Thrombectomy for Acute Ischemic Stroke are Explained by Confounding Factors

PURPOSE

The aim of this study was to analyze sex differences in outcome after thrombectomy for acute ischemic stroke in clinical practice in a large prospective multicenter registry.

METHODS

Data of consecutive stroke patients treated with thrombectomy (June 2015-April 2018) derived from an industry-independent registry (German Stroke Registry-Endovascular Treatment) were prospectively analyzed. Multivariable binary logistic regression analyses were applied to determine whether sex is a predictor of functional independence outcome (defined as a modified Rankin scale [mRS] 0-2) 90 days after stroke.

RESULTS

In total, 2316 patients were included in the analysis, 1170 (50.5%) were female and 1146 (49.5%) were male. Women were older (median age 78 vs. 72 years; p < 0.001) and more frequently had a prestroke functional impairment defined by mRS >1 (24.8% vs. 14.1%; p < 0.001). In unadjusted analyses, independent outcome at 90 days was less frequent in women (33.2%) than men (40.6%; p < 0.001). Likewise, mortality was higher in women than in men (30.7% vs. 26.4%; p = 0.024). In adjusted regression analyses, however, sex was not associated with outcome. Lower age, a lower baseline National Institutes of Health Stroke Scale score, a higher Alberta Stroke Program Early CT score, prestroke functional independence, successful reperfusion, and concomitant intravenous thrombolysis therapy predicted independent outcome.

CONCLUSION

Women showed a worse functional outcome after thrombectomy for acute ischemic stroke in clinical practice; however, after adjustment for crucial confounders sex was not a predictor of outcome. The difference in outcome thus appears to result from differences in confounding factors such as age and prestroke functional status.

Sex-Related Differences after Endovascular Treatment of Acute Ischemic Stroke in the 'Real World'

BACKGROUND

Gender differences are often reported in the field of ischemic stroke, although most of such discrepancies were observed in randomized trials involving highly selected populations. We therefore explored gender differences regarding 90-day outcomes in large vessel occlusion (LVO) strokes receiving endovascular treatment in a real world setting.

METHODS

This prospective registry included anterior and/or posterior circulation LVO strokes admitted between January 2014 and December 2019 who received mechanical thrombectomy up to 24 hours from symptoms onset or last known to be well. We explored sex-related differences in rates of functional independence (modified Rankin Scale, mRS, ≤2) at 90 days. Secondary outcomes included "National Institutes of Health Stroke Scale" (NIHSS) at 24 hours, successful reperfusion defined as modified Thrombolysis in Cerebral Infarction (mTICI) scale 2b/3, death, and symptomatic intracranial hemorrhage (sICH).

RESULTS

A total of 288 LVO stroke patients comprised the study population, involving 148 (51.4%) women. Females were older (71.4±15.7 vs. 66.1±14.0 years, p=0.003) and had lower rates of coronary artery disease (15% vs. 24%, p=0.05). The median time from symptoms onset to hospital arrival was 315 min (IQR 139.5-495.0) in females and 255.0 (IQR 117.0-405.0) in males (p=0.052). Rates of mRS ≤2 at 90 days were comparable (females 46% vs. males 49%, p=0.50). Successful reperfusion was achieved in 82% of females and 89% of males (p=0.10). Rates of sICH (females 10% vs. males 13%, p=0.47) and death (females 18% vs. males 21%, p=0.50) at 90 days were similar. NIHSS at 24 hours was the strongest predictor of functional independence at 90 days (area under ROC curve 0.92 (95%CI 0.87; 0.95)].

CONCLUSIONS

Our prospective registry involving a real world setting suggests that females are equally likely to achieve good outcomes after endovascular treatment despite being older and having delayed hospital arrival compared to males. In addition, we found that NIHSS at 24 hours was the strongest predictor of functional independence at 90 days, sICH, and death.

Sex Dimorphisms in Ischemic Stroke: From Experimental Studies to Clinic

Sex dimorphisms are important factors that influence the outcomes after ischemic stroke, which include basic health status, cerebrovascular anatomy, hormone levels, and unique factors such as pregnancy and menopause. It is widely recognized that male and female respond differently to stroke. Women aged 45–74 years old showed a lower risk of stroke incidence compared to age-matched man. This kind of protection is lost with aging. Hence, there is increasing requirement to get a more comprehensive understanding of sex-based factors to stroke on stroke incidence, symptoms, and treatments. This review focuses on sex-specific mechanisms in response to stroke based on experimental studies and highlights recent findings in clinical studies including sex-differential evaluation and outcomes of stroke. Sex-based personalized medicine should be promising in stroke therapies.

Does Sex Modify the Effect of Endovascular Treatment for Ischemic Stroke?

Supplemental Digital Content is available in the text.

Previous studies have reported less favorable outcome and less effect of endovascular treatment (EVT) after ischemic stroke in women than in men. Our aim was to study the influence of sex on outcome and on the effect of EVT for ischemic stroke in recent randomized trials on EVT.

Sex Differences in Outcome After Endovascular Stroke Therapy for Acute Ischemic Stroke

Background and Purpose- We determined the effect of sex on outcome after endovascular stroke thrombectomy in acute ischemic stroke, including lifelong disability outcomes. Methods- We analyzed patients treated with the Solitaire stent retriever in the combined SWIFT (Solitaire FR With the Intention for Thrombectomy), STAR (Solitaire FR Thrombectomy for Acute Revascularization), and SWIFT PRIME (Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment) cohorts. Ordinal and logistic regression were used to examine known factors influencing outcome after endovascular stroke thrombectomy and study the effect of sex on the association between these factors and outcomes, including age and time to reperfusion. Years of optimal life after thrombectomy were defined as disability-adjusted life years and calculated by projecting disability through adjusted poststroke life expectancy by sex. Results- Among 389 patients treated with endovascular stroke thrombectomy, 55% were females, and median National Institutes of Health Stroke Scale was 17 (interquartile range, 8-28). There were no differences between females versus males in presenting deficit severity (National Institutes of Health Stroke Scale score, 17 versus 17, P=0.21), occlusion location (69% versus 64% M1, P=0.62), presenting infarct extent (Alberta Stroke Program Early CT Score 8 versus 8, P=0.24), rate of substantial reperfusion (Thrombolysis in Cerebral Infarction 2b/3, 87% versus 83%, P=0.37), onset to reperfusion time (294 versus 302 minutes, P=0.46). Despite older ages (69 versus 64, P<0.001) and higher rate of atrial fibrillation (45% versus 30%, P=0.002) for females compared with males, adjusted rates of functional independence at 90 days were similar (odds ratio, 1.0; 95% CI, 0.6-1.6). After adjusting for age at presentation and stroke severity, females had more years of optimal life (disability-adjusted life year) after endovascular stroke thrombectomy, 10.6 versus 8.5 years (P<0.001). Conclusions- Despite greater age and higher rate of atrial fibrillation, females experienced comparable functional outcomes and greater years of optimal life after intervention compared with males.

Sex hormones and stroke: Beyond estrogens

Stroke risk and poor stroke outcomes in postmenopausal women have usually beeen attributed to decreased levels of estrogen. However, two lines of evidence suggest that this hormone may not be solely responsible for elevated stroke risk in this population. First, the increased risk for CVD and stroke occurs much earlier than menopause at a time when estrogen levels are not yet reduced. Second, estrogen therapy has not successfully reduced stroke risk in all studies. Other sex hormones may therefore also contribute to stroke risk. Prior to menopause, levels of the gonadotrophin Follicle Stimulating Hormone (FSH) are elevated while levels of the gonadal peptide inhibin are lowered, indicating an overall decrease in ovarian reserve. Similarly, reduced estrogen levels at menopause significantly increase the ratio of androgens to estrogens. In view of the evidence that androgens may be unfavorable for CVD and stroke, this elevated ratio of testosterone to estrogen may also contribute to the postmenopause-associated stroke risk. This review synthesizes evidence from different clinical populations including natural menopause, surgical menopause, women on chemotherapy, and preclinical stroke models to dissect the role of ovarian hormones and stroke risk and outcomes.

Predictors of Oral Feeding Resumption after Stroke in a Rehabilitation Hospital: A Retrospective Study

BACKGROUND

Dysphagia is common after stroke, requiring exclusive enteral feeding in 20% of patients. Recovery of oral feeding is associated with increased quality of life, better functional outcomes, and decreased mortality rates. However, evidence is heterogeneous and not conclusive on which factors are predictive of oral feeding recovery for stroke patients in rehabilitation units.

AIM

To investigate predictors of complete oral feeding recovery.

DESIGN

Retrospective study.

SETTING

Intensive inpatient rehabilitation hospital.

POPULATION

Poststroke dysphagic individuals with enteral feeding.

METHODS

Retrospective chart review of demographic, clinical, rehabilitation, and swallowing factors. Univariate analysis and multivariate regression analysis were used to compare variables between the oral feeding recovery group and the enteral feeding group at discharge.

RESULTS

One hundred thirty-nine patients were included in the analysis. A total of 61.9% of the sample population resumed complete oral intake at discharge. There were statistically significant differences between the 2 groups in Functional Independence Measure cognitive score, clinical swallow evaluation, and instrumental swallow evaluation at admittance, and dysphagia rehabilitation. Multiple logistic regression analysis identified the absence of aspiration signs with liquids associated with a higher probability of the resumption of complete oral feeding (odds ratio [OR] 3.57; 95% confidence interval [CI] 1.07-11.89). Age between 73 and 79 years (OR .96; 95% CI .01-.58), the presence of aspiration and/or penetration (OR .22; 95% CI .07-.72), and the presence of residue (OR .14; 95%CI .04-.43) during fiberoptic endoscopic evaluation of swallowing presented lower probability of returning to complete oral feeding.

CONCLUSION

Several demographic and swallowing characteristics predicted oral feeding recovery. Absence of dysphagia signs documented on fiberoptic endoscopic evaluation of swallowing was the strongest predictor of complete oral feeding resumption.

Sex differences in the evaluation and treatment of acute ischaemic stroke

With the greater availability of treatments for acute ischaemic stroke, including advances in endovascular therapy, personalised assessment of patients before treatment is more important than ever. Women have a higher lifetime risk of stroke; therefore, reducing potential sex differences in the acute stroke setting is crucial for the provision of equitable and fast treatment. Evidence indicates sex differences in prevalence and types of non-traditional stroke symptoms or signs, prevalence of stroke mimics, and door-to-imaging times, but no substantial differences in use of emergency medical services, stroke knowledge, eligibility for or access to thrombolysis or thrombectomy, or outcomes after either therapy. Women presenting with stroke mimics or non-traditional stroke symptoms can be misdiagnosed, which can lead to inappropriate triage, and acute treatment delays. It is essential for health-care providers to recognise possible sex differences in stroke symptoms, signs, and mimics. Future studies focused on confounders that affect treatment and outcomes, such as age and pre-stroke function, are also needed.

Do functional hamstring to quadriceps ratio differ between men and women with and without stroke?

BACKGROUND

The functional hamstrings/quadriceps ratio (FH/Q) is useful to detect muscle imbalances after stroke. However, is necessary to investigate possible differences between men and women affected by stroke and controls.

OBJECTIVES

To compare the FH/Q between men and women with stroke and matched controls.

METHOD

Cross-sectional study. Fifty-six participants (10 men - MSTK and 18 women - WSTK with stroke; and 10 men - MCONT and 18 women - WCONT, matched controls) were recruited. The concentric knee extension (conc) and eccentric flexion exercises (ecc) were performed, and peak torque (PT) was used to calculate the FH/Q. Comparisons of PT between sexes (MSTK vs WSTK; MCONT vs WCONT) and comparisons of FH/Q between sexes and groups (MSTK vs MCONT; WSTK vs WCONT), considering dominant vs non-paretic side and non-dominant vs paretic side were performed by ANOVA and Kruskal-Wallis test, when applicable.

RESULTS

No significant FH/Q differences were found between STK vs CONT and sexes (non-paretic vs dominant). The paretic FH/Q was significantly higher than the non-dominant (CONT), for both sexes. PTconc and PTecc were significant higher for men, considering limbs comparisons. No significant PTecc an PTconc differences were found between STK vs CONT, for men's non-paretic and paretic limb's. However, men's non-dominant limb presented a higher PTconc compared to men's paretic limbs.

CONCLUSIONS

Our study demonstrated that individuals affected by stroke had a higher FH/Q in the paretic limb compared to the non-dominant limb of the control group, for both men and women. One interesting finding was the absence of significant FH/Q differences between men and women with stroke.

What is the evolution of stroke unit's accessibility in metropolitan France from 2009 to 2014? A trend analysis of over 600 000 patients using national hospital databases

OBJECTIVES

We aimed to study trends in stroke unit (SU) admission during a period of their deployment in France and to assess whether this led to better and more equitable access to this specialised care.

DESIGN

Analysis of records from the national hospital database.

SETTING

All acute care hospitals in metropolitan France for the period 2009-2014.

PARTICIPANTS

Over 600 000 patients admitted in acute care with a main diagnosis of stroke.

MAIN OUTCOME MEASURES

Admission to a SU.

RESULTS

Between 2009 and 2014, the number of stroke admissions rose from 93 728 to 109 456, and the proportion of SU admission from 23% to 44%. Overall, characteristics associated with higher probability of SU admission were: male gender, younger age, ischaemic stroke type, medium level of comorbidity and larger size of town of residence. Although likelihood of SU admission increased in all patients' categories during the study period, we identified steeper positive temporal trends among older patients, those with more comorbidities and those residing in medium or small towns (all p values <0.001), suggesting a 'catching up' phenomena. Temporal trends of men and women did not differ however.

CONCLUSIONS

Admission to SU nearly doubled in France between 2009 and 2014. Faster trends observed for patients with lower admission to SU suggest that equity in access has improved over the period.

Sex differences in 90-day outcomes after mechanical thrombectomy for acute ischemic stroke

Background

It is largely unknown whether functional outcomes after mechanical thrombectomy for large vessel occlusion (LVO) ischemic strokes differ by sex in non-clinical trial populations. We investigated sex differences in 90-day outcomes among ischemic stroke patients receiving mechanical thrombectomy.

Methods

This was a prospective cohort of adults treated with mechanical thrombectomy for LVO at a single academic comprehensive stroke center from July 2015 to April 2017. Data on independence (mRS ≤2) at hospital discharge and 90 days were collected prospectively. Multiple logistic regression was used to determine the association between sex and 90-day independence, first adjusting for demographics, pre-stroke mRS, and NIHSS, then by co-morbidities and time to thrombectomy, and finally by vessel recanalization and use of intravenous thrombolysis.

Results

We included 279 patients, 52% of whom were female. Compared with males, females were older (median years (IQR) 81 (75–88) vs. 71.5 (60–81), P<0.001) and had higher baseline NIHSS (mean SD 18.2±7.5 vs . 16.0±7.1, P=0.02). Similar proportions of males and females had pre-stroke mRS ≤2 (73.3% vs.67.1%, P=0.27). In multivariate analyses, males and females had a similar likelihood of being independent at discharge (aOR 0.71 (95%CI 0.32 to 1.58)), but females were less likely to be independent at 90 days (aOR 0.37 95% CI 0.16 to 0.87).

Conclusions

In patients treated with mechanical thrombectomy for LVOs at a large comprehensive stroke center, females were less likely to be independent at 90 days. Future research should investigate contributors to poor outcomes post-discharge in females with LVOs, along with potential interventions to improve outcomes.

Arterial diameter and the gender disparity in stroke thrombectomy outcomes

BACKGROUND

Compared with males, females consistently fare worse following mechanical thrombectomy for large vessel ischemic strokes. Understanding why this gender disparity occurs may guide improvements in future treatment strategies. In this study, we aim to determine whether gender differences in cerebral arterial diameter correlate with clinical outcomes following stroke thrombectomy.

METHODS

We performed an observational study of consecutive acute ischemic stroke patients undergoing mechanical thrombectomy at a single, urban tertiary care medical center. Catheter angiographic images were used to manually measure proximal segment arterial diameters in a standardized fashion. Medical record review was used to obtain relevant independent and dependent variables.

RESULTS

Ninety two patients (42 females) between June 2013 and August 2016 met inclusion criteria. Internal carotid artery (ICA) terminus diameters for males and females were 3.08 mm (SD=0.46) and 2.81 mm (SD=0.45), respectively (P=0.01). M1 segment middle cerebral artery (MCA) diameters for males and females were 2.47 mm (SD=0.30) and 2.18 mm (SD=0.31), respectively (P<0.0001). 48% of patients in the upper MCA caliber tertile attained a favorable mRS 90 day value compared with 35% in each of the lower and middle tertiles (P=0.51). Larger MCA diameters correlated with favorable discharge disposition (P=0.21).

CONCLUSIONS

These results provide limited evidence that males have larger cerebral arterial diameters than females and that larger arterial diameters may improve the odds for favorable clinical outcomes. If future studies validate these findings, arterial diameter may become a relevant variable in the design of improved thrombectomy strategies.

Sex differences in the brain: Implications for behavioral and biomedical research

Biological differences between males and females are found at multiple levels. However, females have too often been under-represented in behavioral neuroscience research, which has stymied the study of potential sex differences in neurobiology and behavior. This review focuses on the study of sex differences in the neurobiology of social behavior, memory, emotions, and recovery from brain injury, with particular emphasis on the role of estrogens in regulating forebrain function. This work, presented by the authors at the 2016 meeting of the International Behavioral Neuroscience Society, emphasizes varying approaches from several mammalian species in which sex differences have not only been documented, but also become the focus of efforts to understand the mechanistic basis underlying them. This information may provide readers with useful experimental tools to successfully address recently introduced regulations by granting agencies that either require (e.g. the National Institutes of Health in the United States and the Canadian Institutes of Health Research in Canada) or recommend (e.g. Horizon 2020 in Europe) the inclusion of both sexes in biomedical research.

Gender-Related Differences and Short-Term Outcome of Stroke: Results from a Hospital-Based Registry in Sub-Saharan Africa

BACKGROUND

Studies suggest that sex differences have an impact on patients with stroke, but existing data in Africa remain inconclusive about this inference.

OBJECTIVES

To study sex differences in terms of the clinical profile and short-term outcome of stroke in the Douala General Hospital, Cameroon.

METHODS

A hospital-based prospective cohort study was carried out in a tertiary care hospital over an 8-year period, which included all patients admitted for confirmed acute stroke. Information about the history of stroke with emphasis on clinical profile and outcome was collected. Descriptive statistics, t test, and chi square test were used for comparisons, while the Kaplan-Meier curve was used for survival rate analysis.

RESULTS

Of the 818 patients included, 455 (55.6%) were male patients. When compared to males, female patients are more likely to experience a stroke at an older age (mean age 62.3 ± 14.1 vs. 58.4 ± 12.9 years, p < 0.001), to be unmarried, to remain unemployed, and to have higher rates of cardio-embolic stroke (p = 0.049), body mass index (p = 0.031), altered levels of consciousness at presentation (p = 0.005), higher mean HDL cholesterol levels (p = 0.001), and in-hospital complications (p = 0.011), especially urinary tract infections (p = 0.018). Males were more likely to have health insurance, to smoke, to consume alcohol (p < 0.001), and to have higher rates of dysarthria (p = 0.004), higher mean uric acid (p = 0.013), and creatinine (p < 0.001) concentrations. Ischemic and hemorrhagic strokes were more prevalent in men (p = 0.003). There are no sex differences in terms of stroke severity, length-of-hospital stay, case fatality, and functional outcome on admission.

CONCLUSIONS

Sex differences exist in the clinical profile of stroke but not in the outcome. Knowledge of these differences could help influence stroke prevention, thereby improving stroke burden in Africa.

Sex and Stroke in Thrombolyzed Patients and Controls

Background and Purpose—

We hypothesized that any sex-related difference in outcome poststroke is explained by other prognostic factors and that the response to intravenous recombinant tissue-type plasminogen activator (r-tPA) is equal in males and females after adjustment for such factors.

Methods—

We accessed an independent collection of randomized clinical trials—the VISTA (Virtual International Stroke Trials Archive). Data were preprocessed by selecting complete cases (n=8028) and matching females to males (coarsened exact matching, n=4575, 24.3% r-tPA). Outcome was assessed by the 7-point modified Rankin Scale (mRS) measured at 90 days after ischemic stroke. Relationship among variables was estimated by adjusted regression analysis.

Results—

In nonthrombolyzed patients, ordinal analysis of mRS adjusting for stroke- and sex-related prognostic factors suggested comparable outcomes for females and males (odds ratio, 0.96; 95% confidence interval, 0.85–1.06). Females responded comparably to r-tPA as did males, irrespective of the outcome definition of mRS (ordinal: P Interaction =0.46, relative excess risk because of interaction=0). The number needed to treat was 6.8 and 11.2 for 1 female to achieve mRS score of 0 to 2 and 0 to 1, which was highly congruent with males. Analysis for a nonlinear variation of age-by-sex revealed a good outcome for females <45 years with significant disadvantage thereafter (mRS score of 0–2: P Interaction =0.004). No relationship between sex, r-tPA, and bleeding complications was evident.

Conclusions—

Functional outcome (mRS) without r-tPA was overall similar between the sexes, as was the response to r-tPA. Nonlinear sex-by-age interaction improved estimates of functional independence; this should be considered in sex-related studies in stroke.

Sex differences in stroke therapies

Stroke is the fifth leading cause of death and acquired disability in aged populations. Women are disproportionally affected by stroke, having a higher incidence and worse outcomes than men. Numerous preclinical studies have discovered novel therapies for the treatment of stroke, but almost all of these have been shown to be unsuccessful in clinical trials. Despite known sex differences in occurrence and severity of stroke, few preclinical or clinical therapeutics take into account possible sex differences in treatment. Reanalysis of data from studies of tissue plasminogen activator (tPA), the only currently FDA-approved stroke therapy, has shown that tPA improves stroke outcomes for both sexes and also shows sexual dimorphism by more robust improvement in stroke outcome in females. Experimental evidence supports the inclusion of sex as a variable in the study of a number of novel stroke drugs and therapies, including preclinical studies of anti-inflammatory drugs (minocycline), stimulators of cell survival (insulin-like growth factor-1), and inhibitors of cell death pathways (pharmacological inhibition of poly[ADP-ribose] polymerase-1, nitric oxide production, and caspase activation) as well as in current clinical trials of stem cell therapy and cortical stimulation. Overall, study design and analysis in clinical trials as well as in preclinical studies must include both sexes equally, consider possible sex differences in the analyses, and report the differences/similarities in more systematic/structured ways to allow promising therapies for both sexes and increase stroke recovery. © 2016 Wiley Periodicals, Inc.

Gender disparities and thrombolysis use among patient with first-ever ischemic stroke in Malaysia

OBJECTIVE

Gender as an independent predictor in stroke has been well documented. However, data on gender differences among first-ever ischemic stroke in developing country are limited. We aim to describe gender effects on clinical characteristics, thrombolysis treatment received, and outcomes of patients with first-ever ischemic stroke.

METHODS

Data were extracted from the prospective multiethnic stroke registry, National Neurology Registry (NNEUR). Descriptive analysis and logistic regression were performed.

RESULTS

A total of 4762 first-ever ischemic stroke patients admitted to 13 government hospitals from July 2009 to June 2015 were available for this study. Slightly over half were male (55.1%), and they were 1.7 years younger than female (mean age, 63.6 versus 61.9 years, p < 0.001). Gender-age-adjusted incidence was observed to be higher in females (66.7 per 100,000) compared to males (57.4 per 100,000). First-ever ischemic stroke incidence increased by 24.3 and 11.2% among female and male annually. Female experienced significantly poorer functional outcome and greater 30-day in-hospital mortality compared to male. In subgroup analysis, only 31 (0.65%) patients were treated with thrombolysis.

DISCUSSION

First-ever ischemic stroke incidence increased by 24.3 and 11.2% among female and male annually. There were distinct symptoms at hospital presentation between genders. All our patients discharged home regardless of genders. In summary, Malaysian female first-ever ischemic stroke was older, present with severe stroke, greater number of risk factors and poorer functional outcome and 30-day in-hospital mortality compared to male.

Sex Differences in Long-Term Survival after a First Stroke with Intravenous Thrombolysis: Ebrictus Study

Background

A number of large trials have confirmed the benefits of thrombolysis in acute stroke, but there are gender differences. We sought to examine the relationship between sex and outcome after thrombolysis.

Methods

This was a prospective cohort study including 1,272 incident ischemic strokes (597 in women) from April 1, 2006 to December 31, 2014. Statistical approaches were used for analyzing survival outcomes and their relationship with thrombolysis therapy.

Results

The death rates were lower (p = 0.003) in the thrombolysis therapy group with an incidence ratio of 0.57 (95% CI 0.39-0.83). 113 (8.8%) patients (53 women) received thrombolysis. They were significantly younger (69.2 ± 12.7 vs. 73.9 ± 12.5 years; p < 0.001), had higher NIHSS score (12.7 ± 6.3 vs. 7.3 ± 7.0; p < 0.001), spent more days in hospital (10.4 ± 8.3 vs. 8.3 ± 7.9; p < 0.001), and had a higher average Barthel score at discharge (85.5 ± 24.4 vs. 79.2 ± 28.6; p = 0.023). The male/female incidence ratio showed a significant decrease (p = 0.01) in the incidence of mortality in women and a better Barthel score. The thrombolysis improved the survival in the overall group with thrombolysis versus without thrombolysis (p = 0.028), in women versus in men with thrombolysis (p = 0.023), and in women with thrombolysis versus in those without thrombolysis (p < 0.001) but not in men with thrombolysis versus in those without thrombolysis (p = 0.743). The protective factors as regards mortality were thrombolysis therapy (95% CI 0.37-0.80; p = 0.002), Barthel score ≥60 (95% CI 0.81-0.94; p = 0.002), and cardiovascular secondary prevention 1 year after stroke (0.13, 95% CI 0.06-0.28).

Conclusions

The stroke death rates were lower in women after thrombolysis treatment and suggest significant benefit for women in this setting. The overall benefit on survival of the patients treated with thrombolysis might be explained by the beneficial effect of the thrombolysis on the women.

Gender Differences in Risk Factor and Clinical Outcome in Patients with Ischemic Stroke

Objective: Gender is an important determinant for risk factors and outcomes of ischemic stroke. The aim of this study was to compare risk factors, and clinical outcomes after ischemic stroke between male and female patients. Methods: The hospital records of patients with ischemic stroke were reviewed retrospectively. Demographic data, stroke risk factors, clinical severities and outcomes after stroke were collected and compared between male and female patients. Stroke severity and clinical disability after ischemic stroke were evaluated by means of the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) respectively. Results: Among 447 patients with ischemic stroke, 195 (43.6%) patients were women. The mean age at ischemic stroke was higher in women than in men (p&lt;0.01). As compared to men, women had a significantly lower prevalence of hyperhomocysteinemia, smoking and drinking (all p&lt;0.01). NIHSS and mRS scores were not different between the 2 genders. Conclusions: Profiles of risk factors differed between the 2 genders, with men having a higher prevalence of hyperhomocysteinemia, smoking and drinking. There were no gender differences in stroke severity and disability after ischemic stroke.

Sex-related differences of acute stroke unit care: results from the Austrian stroke unit registry

BACKGROUND AND PURPOSE

Sex-related differences in quality of acute stroke care are an important concern with limited data available, specifically regarding stroke unit (SU) setting. We used the prospective nationwide Austrian SU registry to address this issue.

METHODS

Our analysis covered an 8-year time period (January 2005 to December 2012) during which all patients with transient ischemic attack or ischemic stroke admitted to 1 of 35 Austrian SU had been captured in the registry. These data were analyzed for age-adjusted preclinical and clinical characteristics and quality of acute stroke care in men and women. In addition, we assessed the outcome at 3 months in multivariate analysis.

RESULTS

A total of 47 209 individuals (47% women) had received SU care. Women were significantly older (median age: 77.9 versus 70.3 years), had higher pre-existing disability and more severe strokes. Correcting for age, no significant sex-related differences in quality of care were identified with comparable onset-to-door times, times to and rates of neuroimaging, as well as door-to-needle times and rates of intravenous thrombolysis (14.5% for both sexes). Despite equal acute stroke care and a comparable rate of neurorehabilitation, women had a worse functional outcome at 3-month follow-up (modified Rankin scale 3-5: odds ratio, 1.26; 95% confidence interval [1.17-1.36]), but a lower mortality (odds ratio, 0.70; 95% confidence interval [0.78-0.88]) after correcting for confounders.

CONCLUSIONS

We identified no disproportions in quality of care in the acute SU setting between men and women, but the outcome was significantly different. Further studies on the poststroke period including socioeconomic aspects are needed to clarify this finding.

Racial and gender differences in stroke severity, outcomes, and treatment in patients with acute ischemic stroke

BACKGROUND

Previous research has indicated that women and blacks have worse outcomes after acute ischemic stroke (AIS). Little research has been done to investigate the combined influence of race and gender in the presentation, treatment, and outcome of patients with AIS. We sought to determine the association of race and gender on initial stroke severity, thrombolysis, and functional outcome after AIS.

METHODS

AIS patients who presented to 2 academic medical centers in the United States (2004-2011) were identified through prospective registries. In-hospital strokes were excluded. Stroke severity, measured by admission National Institutes of Health Stroke Scale (NIHSS) scores, treatment with tissue plasminogen activator (tPA), neurologic deterioration (defined by a ≥2-point increase in NIHSS score), and functional outcome at discharge, measured by the modified Rankin Scale, were investigated. These outcomes were compared across race/gender groups. A subanalysis was conducted to assess race/gender differences in exclusion criteria for tPA.

RESULTS

Of the 4925 patients included in this study, 2346 (47.6%) were women and 2310 (46.9%) were black. White women had the highest median NIHSS score on admission (8), whereas white men had the lowest median NIHSS score on admission (6). There were no differences in outcomes between black men and white men. A smaller percentage of black women than white women were treated with tPA (27.6% versus 36.6%, P < .0001), partially because of a greater proportion of white women presenting within 3 hours (51% versus 45.5%, P = .0005). Black women had decreased odds of poor functional outcome relative to white women (odds ratio [OR] = .85, 95% confidence interval [CI] .72-1.00), but after adjustment for baseline differences in age, NIHSS, and tPA use, this association was no longer significant (OR = 1.2, 95% CI .92-1.46, P = .22). Black women with an NIHSS score less than 7 on admission were at lower odds of receiving tPA than the other race/gender groups, even after adjusting for arriving within 3 hours and admission glucose (OR = .66, 95% CI .44-.99, P = .0433).

CONCLUSION

Race and gender were not significantly associated with short-term outcome, although black women were significantly less likely to be treated with tPA. Black women had more tPA exclusions than any other group. The primary reason for tPA exclusion in this study was not arriving within 3 hours of stroke symptom onset. Given the growth in incident strokes projected in minority groups in the next 4 decades, identifying factors that contribute to black women not arriving to the emergency department in time are of great importance.

Age-related changes in brain support cells: Implications for stroke severity

Stroke is one of the leading causes of adult disability and the fourth leading cause of mortality in the US. Stroke disproportionately occurs among the elderly, where the disease is more likely to be fatal or lead to long-term supportive care. Animal models, where the ischemic insult can be controlled more precisely, also confirm that aged animals sustain more severe strokes as compared to young animals. Furthermore, the neuroprotection usually seen in younger females when compared to young males is not observed in older females. The preclinical literature thus provides a valuable resource for understanding why the aging brain is more susceptible to severe infarction. In this review, we discuss the hypothesis that stroke severity in the aging brain may be associated with reduced functional capacity of critical support cells. Specifically, we focus on astrocytes, that are critical for detoxification of the brain microenvironment and endothelial cells, which play a crucial role in maintaining the blood brain barrier. In view of the sex difference in stroke severity, this review also discusses studies of middle-aged acyclic females as well as the effects of the estrogen on astrocytes and endothelial cells.

Cerebral ischemic stroke: is gender important?

Cerebral stroke continues to be a major cause of death and the leading cause of long-term disability in developed countries. Evidence reviewed here suggests that gender influences various aspects of the clinical spectrum of ischemic stroke, in terms of influencing how a patients present with ischemic stroke through to how they respond to treatment. In addition, this review focuses on discussing the various pathologic mechanisms of ischemic stroke that may differ according to gender and compares how intrinsic and hormonal mechanisms may account for such gender differences. All clinical trials to date investigating putative neuroprotective treatments for ischemic stroke have failed, and it may be that our understanding of the injury cascade initiated after ischemic injury is incomplete. Revealing aspects of the pathophysiological consequences of ischemic stroke that are gender specific may enable gender relevant and effective neuroprotective strategies to be identified. Thus, it is possible to conclude that gender does, in fact, have an important role in ischemic stroke and must be factored into experimental and clinical investigations of ischemic stroke.

Topographic hub maps of the human structural neocortical network

Hubs within the neocortical structural network determined by graph theoretical analysis play a crucial role in brain function. We mapped neocortical hubs topographically, using a sample population of 63 young adults. Subjects were imaged with high resolution structural and diffusion weighted magnetic resonance imaging techniques. Multiple network configurations were then constructed per subject, using random parcellations to define the nodes and using fibre tractography to determine the connectivity between the nodes. The networks were analysed with graph theoretical measures. Our results give reference maps of hub distribution measured with betweenness centrality and node degree. The loci of the hubs correspond with key areas from known overlapping cognitive networks. Several hubs were asymmetrically organized across hemispheres. Furthermore, females have hubs with higher betweenness centrality and males have hubs with higher node degree. Female networks have higher small-world indices.

Gender differences in 1-year clinical characteristics and outcomes after stroke: results from the China National Stroke Registry

Background

Previous reports have shown inconsistent results on clinical outcomes between women and men after stroke, and little is known about gender differences on outcomes in Chinese post-stroke patients. The aim of this study was to explore whether there were gender differences on clinical characteristics and outcomes in Chinese patients after ischemic stroke by using the data from the China National Stroke Registry (CNSR).

Methods and Findings

Out of 12,415 consecutively recruited patients with acute ischemic stroke in the CNSR from 2007 to 2008, 11,560 (93.1%) patients were followed up for 12 months. Their clinical characteristics and outcomes on death, recurrence, and dependency were recorded. The multivariate logistic regression was performed to determine whether there were gender differences in these outcomes. Women were older than men at baseline (67.9 vs. 64.0 years, P<0.001). Women had a higher mortality, recurrence rate, and dependency rate at 3, 6, and 12 months than men, but after adjusting for age, history of diabetes, pre-stroke dependency, stroke severity, in-hospital complications, and other confounders, there were no statistically significant differences in gender on mortality and recurrence rate at 3, 6, and 12 months; and dependency rate at 3, and 6 months. However, the dependency rate at 12 months remained significantly higher in women (odds ratio, 1.24; 95% confidence interval, 1.06 to 1.45).

Conclusions

There are many differences in clinical characteristics between women and men after ischemic stroke in China. Compared with men, women are more dependent at 12 months after stroke. This difference still exists after controlling the potential confounders.

Leukoaraiosis and sex predict the hyperacute ischemic core volume

BACKGROUND AND PURPOSE

Leukoaraiosis (LA) and male sex have been associated with decreased cerebrovascular reactivity, which potentially adversely affects tissue viability in acute stroke. Therefore, we aimed to elucidate the contribution of LA-severity and sex to the extent of the hyperacute ischemic core volume after intracranial large artery occlusion.

METHODS

We analyzed data from 87 patients with acute intracranial large artery occlusion who had acute multimodal computed tomography-imaging. LA-severity was assessed using the van Swieten scale on noncontrast computed tomography. Computed tomography perfusion data were analyzed using automatic calculation of the mean transit time and hyperacute cerebral blood volume defects. Multivariate linear and logistic regression analyses were used to identify independent predictors of the hyperacute infarct-volume.

RESULTS

Severe LA (van Swieten Scale, 3-4; odds ratio, 43.22; 95% CI, 6.26-298.42; P<0.001) and male sex (odds ratio, 7.52; 95% CI, 1.38-40.86; P=0.020) were independently associated with a hyperacute cerebral blood volume-lesion >25 mL on multivariate logistic regression analysis. Multivariate linear regression analysis confirmed the association between severe LA (P<0.001) and male sex (P=0.01) with larger cerebral blood volume-lesions. There was no significant difference in the absolute or relative mean transit time-lesion volumes when stratified by LA-severity or sex. Women had significantly smaller cerebral blood volume-lesion volumes compared with men (P=0.036).

CONCLUSIONS

Severe LA and male sex are associated with larger infarct cores, which adds to the notion that sex and LA alter the brain's intrinsic susceptibility to acute cerebral ischemia. Future, larger studies are needed to confirm our observation that women have smaller core volumes and its significance.

Effects of gender on gene expression in the blood of ischemic stroke patients

This study examined the effects of gender on RNA expression after ischemic stroke (IS). RNA obtained from blood of IS patients (n=51; 153 samples at < or =3, 5, and 24 hours) and from matched controls (n=52) were processed on Affymetrix microarrays. Analyses of covariance for stroke versus control samples were performed separately for both genders and the regulated genes for females compared with males. In all, 242, 227, and 338 male-specific genes were regulated at < or =3, 5, and 24 hours after IS, respectively, of which 59 were regulated at all time points. Overall, 774, 3,437, and 571 female-specific stroke genes were regulated at < or =3, 5, and 24 hours, respectively, of which 152 were regulated at all time points. Male-specific stroke genes were associated with integrin, integrin-liked kinase, actin, tight junction, Wnt/β-catenin, RhoA, fibroblast growth factors (FGF), granzyme, and tumor necrosis factor receptor (TNFR)2 signaling. Female-specific stroke genes were associated with p53, high-mobility group box-1, hypoxia inducible factor (HIF)1α, interleukin (IL)1, IL6, IL12, IL18, acute-phase response, T-helper, macrophage, and estrogen signaling. Cell death signaling was overrepresented in both genders, although the molecules and pathways differed. Gender affects gene expression in the blood of IS patients, which likely implies gender differences in immune, inflammatory, and cell death responses to stroke.

Y chromosome gene expression in the blood of male patients with ischemic stroke compared with male controls

BACKGROUND

Sex is suggested to be an important determinant of ischemic stroke risk factors, etiology, and outcome. However, the basis for this remains unclear. The Y chromosome is unique in males. Genes expressed in males on the Y chromosome that are associated with stroke may be important genetic contributors to the unique features of males with ischemic stroke, which would be helpful for explaining sex differences observed between men and women.

OBJECTIVE

We compared Y chromosome gene expression in males with ischemic stroke and male controls.

METHODS

Blood samples were obtained from 40 male patients ≤3, 5, and 24 hours after ischemic stroke and from 41 male controls (July 2003-April 2007). RNA was isolated from blood and was processed using Affymetrix Human U133 Plus 2.0 expression arrays (Affymetrix Inc., Santa Clara, California). Y chromosome genes differentially expressed between male patients with stroke and male control subjects were identified using an ANCOVA adjusted for age and batch. A P < 0.05 and a fold change >1.2 were considered significant.

RESULTS

Seven genes on the Y chromosome were differentially expressed in males with ischemic stroke compared with controls. Five of these genes (VAMP7, CSF2RA, SPRY3, DHRSX, and PLCXD1) are located on pseudoautosomal regions of the human Y chromosome. The other 2 genes (EIF1AY and DDX3Y) are located on the nonrecombining region of the human Y chromosome. The identified genes were associated with immunology, RNA metabolism, vesicle fusion, and angiogenesis.

CONCLUSIONS

Specific genes on the Y chromosome are differentially expressed in blood after ischemic stroke. These genes provide insight into potential molecular contributors to sex differences in ischemic stroke.

Brain natriuretic peptide predicts functional outcome in ischemic stroke

BACKGROUND AND PURPOSE

Elevated serum levels of brain natriuretic peptide (BNP) have been associated with cardioembolic stroke and increased poststroke mortality. We sought to determine whether BNP levels were associated with functional outcome after ischemic stroke.

METHODS

We measured BNP in consecutive patients aged ≥ 18 years admitted to our stroke unit between 2002 to 2005. BNP quintiles were used for analysis. Stroke subtypes were assigned using Trial of ORG 10172 in Acute Stroke Treatment criteria. Outcomes were measured as 6-month modified Rankin Scale score ("good outcome"=0-2 versus "poor") as well as mortality. Multivariate logistic regression was used to assess association between the quintiles of BNP and outcomes. Predictive performance of BNP as compared with clinical model alone was assessed by comparing receiver operating characteristic curves.

RESULTS

Of 569 patients with ischemic stroke, 46% were female; mean age was 67.9 ± 15 years. In age- and gender-adjusted analysis, elevated BNP was associated with lower ejection fraction (P<0.0001) and left atrial dilatation (P<0.001). In multivariate analysis, elevated BNP decreased the odds of good functional outcome (OR, 0.64; 95% CI, 0.41-0.98) and increased the odds of death (OR, 1.75; 95% CI, 1.36-2.24) in these patients. Addition of BNP to multivariate models increased their predictive performance for functional outcome (P=0.013) and mortality (P<0.03) after cardioembolic stroke.

CONCLUSIONS

Serum BNP levels are strongly associated with cardioembolic stroke and functional outcome at 6 months after ischemic stroke. Inclusion of BNP improved prediction of mortality in patients with cardioembolic stroke.

Sexual dimorphism in ischemic stroke: lessons from the laboratory

Ischemic stroke is emerging as a major health problem for elderly women. Women have lower stroke incidence than men until an advanced age, when the epidemiology of ischemic stroke shifts and incidence rises dramatically in women. Experimental models of rodent stroke have replicated this clinical epidemiology, with exacerbated injury in older compared with young female rodents. Many of the detrimental effects of aging on ischemic stroke outcome in females can be replicated by ovariectomy, suggesting that hormones such as estrogen play a neuroprotective role. However, emerging data suggest that the molecular mechanisms leading to ischemic cell death differ in the two sexes, and these effects may be independent of circulating hormone levels. This article highlights recent clinical and experimental literature on sex differences in stroke outcomes and mechanisms.

Stroke epidemiology: advancing our understanding of disease mechanism and therapy

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