Lifetime risk of stroke and dementia: current concepts, and estimates from the Framingham Study

COVCOG 2: Cognitive and Memory Deficits in Long COVID: A Second Publication From the COVID and Cognition Study

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been often characterized as a respiratory disease. However, it is increasingly being understood as an infection that impacts multiple systems, and many patients report neurological symptoms. Indeed, there is accumulating evidence for neural damage in some individuals, with recent studies suggesting loss of gray matter in multiple regions, particularly in the left hemisphere. There are several mechanisms by which the COVID-19 infection may lead to neurological symptoms and structural and functional changes in the brain, and cognitive problems are one of the most commonly reported symptoms in those experiencing Long COVID - the chronic illness following the COVID-19 infection that affects between 10 and 25% of patients. However, there is yet little research testing cognition in Long COVID. The COVID and Cognition Study is a cross-sectional/longitudinal study aiming to understand cognitive problems in Long COVID. The first paper from the study explored the characteristics of our sample of 181 individuals who had experienced the COVID-19 infection, and 185 who had not, and the factors that predicted ongoing symptoms and self-reported cognitive deficits. In this second paper from the study, we assess this sample on tests of memory, language, and executive function. We hypothesize that performance on "objective" cognitive tests will reflect self-reported cognitive symptoms. We further hypothesize that some symptom profiles may be more predictive of cognitive performance than others, perhaps giving some information about the mechanism. We found a consistent pattern of memory deficits in those that had experienced the COVID-19 infection, with deficits increasing with the severity of self-reported ongoing symptoms. Fatigue/Mixed symptoms during the initial illness and ongoing neurological symptoms were predictive of cognitive performance.

Implications of Gut Microbiota in Neurodegenerative Diseases

The morbidity associated with neurodegenerative diseases (NDs) is increasing, posing a threat to the mental and physical quality of life of humans. The crucial effect of microbiota on brain physiological processes is mediated through a bidirectional interaction, termed as the gut–brain axis (GBA), which is being investigated in studies. Many clinical and laboratory trials have indicated the importance of microbiota in the development of NDs via various microbial molecules that transmit from the gut to the brain across the GBA or nervous system. In this review, we summarize the implications of gut microbiota in ND, which will be beneficial for understanding the etiology and progression of NDs that may in turn help in developing ND interventions and clinical treatments for these diseases.

Precise or Imprecise Probabilities? Evidence from Survey Response Related to Late-Onset Dementia

We elicit numerical expectations for late-onset dementia and long-term-care (LTC) outcomes in the US Health and Retirement Study. We provide the first empirical evidence on dementia-risk perceptions among dementia-free older Americans and establish important patterns regarding imprecision of subjective probabilities. Our elicitation distinguishes between precise and imprecise probabilities, while accounting for rounding of reports. Imprecise-probability respondents quantify imprecision using probability intervals. Nearly half of respondents hold imprecise dementia and LTC probabilities, while almost a third of precise-probability respondents round their reports. These proportions decrease substantially when LTC expectations are conditioned on hypothetical knowledge of the dementia state. Among rounding and imprecise-probability respondents, our elicitation yields two measures: an initial rounded or approximated response and a post-probe response, which we interpret as the respondent's true point or interval probability. We study the mapping between the two measures and find that respondents initially tend to over-report small probabilities and under-report large probabilities. Using a specific framework for study of LTC insurance choice with uncertain dementia state, we illustrate the dangers of ignoring imprecise or rounded probabilities for modeling and prediction of insurance demand.

Lifetime risk of cardiovascular disease and life expectancy with and without cardiovascular disease according to changes in metabolic syndrome status

BACKGROUND AND AIMS

The relationship between dynamic changes in metabolic syndrome (MetS) status and lifetime risk of cardiovascular disease (CVD) has not been reliably quantified. This study aimed to estimate lifetime risk of CVD and life expectancy with and without CVD according to dynamic MetS status.

METHODS AND RESULTS

Dynamic changes in MetS status were assessed: MetS-free, MetS-chronic, MetS-developed, and MetS-recovery groups. We used Modified Kaplan-Meier method to estimate lifetime risk and used multistate life table method to calculate life expectancy. Participants free of CVD at index ages 35 (n = 40 168), 45 (n = 33 569), and 55 (n = 18 546) years. At index age 35 years, we recorded 1341 CVD events during a median follow-up of 6.1 years. Lifetime risk of 33.9% (95% CI: 26.9%-41.0%) in MetS-recovery group was lower than that of 39.4% (95% CI: 36.1%-42.8%) in MetS-chronic group. Lifetime risk of 37.8% (95% CI: 30.6%-45.1%) in MetS-developed group was higher than that of 26.4% (95% CI: 22.7%-30.0%) in MetS-free group. At index age 35 years, life expectancy free of CVD for MetS-recovery group (44.1 years) was higher than that for MetS-chronic group (38.8 years). Life expectancy free of CVD for MetS-developed group (41.9 years) was lower than that for MetS-free group (46.7 years).

CONCLUSIONS

Recovery from MetS was associated with decreased lifetime risk of CVD and a longer life expectancy free of CVD, whereas development of MetS was associated with increased lifetime risk of CVD and a shorter life expectancy free of CVD.

A comparison of statistical methods to predict the residual lifetime risk

Lifetime risk measures the cumulative risk for developing a disease over one's lifespan. Modeling the lifetime risk must account for left truncation, the competing risk of death, and inference at a fixed age. In addition, statistical methods to predict the lifetime risk should account for covariate-outcome associations that change with age. In this paper, we review and compare statistical methods to predict the lifetime risk. We first consider a generalized linear model for the lifetime risk using pseudo-observations of the Aalen-Johansen estimator at a fixed age, allowing for left truncation. We also consider modeling the subdistribution hazard with Fine-Gray and Royston-Parmar flexible parametric models in left truncated data with time-covariate interactions, and using these models to predict lifetime risk. In simulation studies, we found the pseudo-observation approach had the least bias, particularly in settings with crossing or converging cumulative incidence curves. We illustrate our method by modeling the lifetime risk of atrial fibrillation in the Framingham Heart Study. We provide technical guidance to replicate all analyses in R.

Genetics of common cerebral small vessel disease

Cerebral small vessel disease (cSVD) is a leading cause of ischaemic and haemorrhagic stroke and a major contributor to dementia. Covert cSVD, which is detectable with brain MRI but does not manifest as clinical stroke, is highly prevalent in the general population, particularly with increasing age. Advances in technologies and collaborative work have led to substantial progress in the identification of common genetic variants that are associated with cSVD-related stroke (ischaemic and haemorrhagic) and MRI-defined covert cSVD. In this Review, we provide an overview of collaborative studies - mostly genome-wide association studies (GWAS) - that have identified >50 independent genetic loci associated with the risk of cSVD. We describe how these associations have provided novel insights into the biological mechanisms involved in cSVD, revealed patterns of shared genetic variation across cSVD traits, and shed new light on the continuum between rare, monogenic and common, multifactorial cSVD. We consider how GWAS summary statistics have been leveraged for Mendelian randomization studies to explore causal pathways in cSVD and provide genetic evidence for drug effects, and how the combination of findings from GWAS with gene expression resources and drug target databases has enabled identification of putative causal genes and provided proof-of-concept for drug repositioning potential. We also discuss opportunities for polygenic risk prediction, multi-ancestry approaches and integration with other omics data.

Comparison of Cerebral Cortex Transcriptome Profiles in Ischemic Stroke and Alzheimer’s Disease Models

Ischemic stroke and Alzheimer’s disease (AD) are representative geriatric diseases with a rapidly increasing prevalence worldwide. Recent studies have reported an association between ischemic stroke neuropathology and AD neuropathology. Ischemic stroke shares some similar characteristics with AD, such as glia activation-induced neuroinflammation, amyloid beta accumulation, and neuronal cell loss, as well as some common risk factors with AD progression. Although there are considerable similarities in neuropathology between ischemic stroke and AD, no studies have ever compared specific genetic changes of brain cortex between ischemic stroke and AD. Therefore, in this study, I compared the cerebral cortex transcriptome profile of 5xFAD mice, an AD mouse model, with those of middle cerebral artery occlusion (MCAO) mice, an ischemic stroke mouse model. The data showed that the expression of many genes with important functional implications in MCAO mouse brain cortex were related to synaptic dysfunction and neuronal cell death in 5xFAD mouse model. In addition, changes in various protein-coding RNAs involved in synaptic plasticity, amyloid beta accumulation, neurogenesis, neuronal differentiation, glial activation, inflammation and neurite outgrowth were observed. The findings could serve as an important basis for further studies to elucidate the pathophysiology of AD in patients with ischemic stroke.

Cardiovascular Risk Factors and Physical Activity for the Prevention of Cardiovascular Diseases in the Elderly

Cardiovascular diseases create an important burden on the public health systems, especially in the elderly, mostly because this group of patients frequently suffer from multiple comorbidities. Accumulating cardiovascular risk factors during their lifetime has a detrimental effect on an older adult's health status. The modifiable and non-modifiable cardiovascular risk factors are very diverse, and are frequently in a close relationship with the metabolic comorbidities of the elderly, mainly obesity and Diabetes Mellitus. In this review, we aim to present the most important cardiovascular risk factors which link aging and cardiovascular diseases, starting from the pathophysiological links between these factors and the aging process. Next, we will further review the main interconnections between obesity and Diabetes Mellitus and cardiovascular diseases of the elderly. Lastly, we consider the most important aspects related to prevention through lifestyle changes and physical activity on the occurrence of cardiovascular diseases in the elderly.

Importance of sex and gender in ischaemic stroke and carotid atherosclerotic disease

Stroke is a leading cause of death and disability worldwide. Women are disproportionately affected by stroke, exhibiting higher mortality and disability rates post-stroke than men. Clinical stroke research has historically included mostly men and studies were not properly designed to perform sex- and gender-based analyses, leading to under-appreciation of differences between men and women in stroke presentation, outcomes, and response to treatment. Reasons for these differences are likely multifactorial; some are due to gender-related factors (i.e. decreased social support, lack of stroke awareness), yet others result from biological differences between sexes. Unlike men, women often present with 'atypical' stroke symptoms. Lack of awareness of 'atypical' presentation has led to delays in hospital arrival, diagnosis, and treatment of women. Differences also extend to carotid atherosclerotic disease, a cause of stroke, where plaques isolated from women are undeniably different in morphology/composition compared to men. As a result, women may require different treatment than men, as evidenced by the fact that they derive less benefit from carotid revascularization than men but more benefit from medical management. Despite this, women are less likely than men to receive medical therapy for cardiovascular risk factor management. This review focuses on the importance of sex and gender in ischaemic stroke and carotid atherosclerotic disease, summarizing the current evidence with respect to (i) stroke incidence, mortality, awareness, and outcomes, (ii) carotid plaque prevalence, morphology and composition, and gene connectivity, (iii) the role of sex hormones and sex chromosomes in atherosclerosis and ischaemic stroke risk, and (iv) carotid disease management.

Stroke-Related Mortality at Different Altitudes: A 17-Year Nationwide Population-Based Analysis From Ecuador

Introduction: Worldwide, more than 5.7% of the population reside above 1,500 m of elevation. It has been hypothesized that acute short-term hypoxia exposure could increase the risk of developing a stroke. Studies assessing the effect of altitude on stroke have provided conflicting results, some analyses suggest that long-term chronic exposure could be associated with reduced mortality and lower stroke incidence rates.

Methods: An ecological analysis of all stroke hospital admissions, mortality rates, and disability-adjusted life years in Ecuador was performed from 2001 to 2017. The cases and population at risk were categorized in low (<1,500 m), moderate (1,500–2,500 m), high (2,500–3,500 m), and very high altitude (3,500–5,500 m) according to the place of residence. The derived crude and direct standardized age-sex adjusted mortality and hospital admission rates were calculated.

Results: A total of 38,201 deaths and 75,893 stroke-related hospital admissions were reported. High altitude populations (HAP) had lower stroke mortality in men [OR: 0.91 (0.88–0.95)] and women [OR: 0.83 (0.79–0.86)]. In addition, HAP had a significant lower risk of getting admitted to the hospital when compared with the low altitude group in men [OR: 0.55 (CI 95% 0.54–0.56)] and women [OR: 0.65 (CI 95% 0.64–0.66)].

Conclusion: This is the first epidemiological study that aims to elucidate the association between stroke and altitude using four different elevation ranges. Our findings suggest that living at higher elevations offers a reduction or the risk of dying due to stroke as well as a reduction in the probability of being admitted to the hospital. Nevertheless, this protective factor has a stronger effect between 2,000 and 3,500 m.

Long-Term Incidence of Stroke and Dementia in ASCOT

Background and Purpose

Management of stroke risk factors might reduce later dementia. In ASCOT (Anglo-Scandinavian Outcome Trial), we determined whether dementia or stroke were associated with different blood pressure (BP)–lowering regimens; atorvastatin or placebo; and mean BP, BP variability, and mean cholesterol levels.

Methods

Participants with hypertension and ≥3 cardiovascular disease risk factors were randomly allocated to amlodipine- or atenolol-based BP-lowering regimen targeting BP <140/90 mm Hg for 5.5 years. Participants with total cholesterol ≤6.5 mmol/L were also randomly allocated to atorvastatin 10 mg or placebo for 3.3 years. Mean and LDL (low-density lipoprotein) cholesterol, BP, and SD of BP were calculated from 6 months to end of trial. UK participants were linked to electronic health records to ascertain deaths and hospitalization in general and mental health hospitals. Dementia and stroke were ascertained by validated code lists and within-trial ascertainment.

Results

Of 8580 UK participants, 7300 were followed up to 21 years from randomization. Atorvastatin for 3.3 years had no measurable effect on stroke (264 versus 272; adjusted hazard ratio [HR], 0.92 [95% CI, 0.78–1.09]; P=0.341) or dementia (238 versus 227; adjusted HR, 0.98 [95% CI, 0.82–1.18]; P=0.837) compared with placebo. Mean total cholesterol was not associated with later stroke or dementia. An amlodipine-based compared with an atenolol-based regimen for 5.5 years reduced stroke (443 versus 522; adjusted HR, 0.82 [95% CI, 0.72–0.93]; P=0.003) but not dementia (450 versus 465; adjusted HR, 0.94 [95% CI, 0.82–1.07]; P=0.334) over follow-up. BP variability (SD mean BP) was associated with a higher risk of dementia (per 5 mm Hg HR, 1.14 [95% CI, 1.06–1.24]; P<0.001) and stroke (HR, 1.21 [95% CI, 1.12–1.32]; P<0.001) adjusted for mean BP.

Conclusions

An amlodipine-based BP regimen reduced the long-term incidence of stroke compared with an atenolol-based regimen but had no measurable effect on dementia. Atorvastatin had no effect on either stroke or dementia. Higher BP variability was associated with a higher incidence of later dementia and stroke.

The Role of Transthoracic Echocardiography in the Evaluation of Patients With Ischemic Stroke

Background: Ischemic stroke can be classified into five etiological types, according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, and its adequate investigation and characterization can aid in its clinical management and in preventing new events. Transthoracic echocardiography (TTE) plays a key role in investigating its etiology; approximately one-third of the patients remain without an adequate definition of the etiology or are classified as the undetermined TOAST type. Objectives: To evaluate if the percentage of patients with indeterminate etiology according to the TOAST classification decreased after transthoracic echocardiography, to determine whether or not the prognosis after ischemic stroke is worse among patients classified as the undetermined TOAST type, and to verify the predictive capacity of echocardiography on the prognosis after ischemic stroke. Methods: In this retrospective cohort study, clinical, neurological, and echocardiographic examinations were conducted when the patient was hospitalized for stroke. In-hospital mortality and functional capacity were evaluated at hospital discharge and 90 days thereafter. Multiple linear regression and multiple logistic regression models were adjusted for confounding factors. The level of significance was 5%. Results: A total of 1,100 patients (men = 606; 55.09%), with a mean age of 68.1 ± 13.3 years, were included in this study. Using TTE, 977 patients (88.82%) were evaluated and 448 patients (40.7%) were classified as the undetermined TOAST type. The patients who underwent TTE were 3.1 times less likely to classified as the undetermined TOAST type (OR = 0.32; p < 0.001). Echocardiography during hospitalization was a protective factor against poor prognosis, and reduced the odds of in-hospital death by 11.1 times (OR: 0.090; p < 0.001). However, the presence of the undetermined TOAST classification elevated the chance of mortality during hospitalization by 2.0 times (OR: 2.00; p = 0.013). Conclusions: Echocardiography during hospitalization for ischemic stroke reduces the chances of an undetermined TOAST classification and the risk of in-hospital mortality. However, being classified as the undetermined TOAST type increases the chance of mortality during hospitalization, suggesting that evaluating patients using echocardiography during hospitalization for acute ischemic stroke is important.

Incident stroke in patients with Alzheimer's disease: systematic review and meta-analysis

Vascular mechanisms are increasingly recognized in the pathophysiology of Alzheimer's disease (AD), but less is known about the occurrence of stroke in AD patients. We aimed to quantify the risk of stroke in patients with AD and compare the incidence rates (IR) of stroke in individuals without AD. Systematic search of Embase and MEDLINE between 1970 and 2020. Inclusion criteria: reports with ≥ 50 patients with non-familial AD, which reported the occurrence of stroke (all types) and/or ischemic stroke and/or intracerebral hemorrhage (ICH) during follow-up. Meta-analyses of pooled data using random-effects model were performed. IR were calculated for each study. Incidence rate ratios (IRR) were calculated for studies presenting a control-group without AD. Among 5109 retrieved studies, 29 (0.6%) fulfilled the inclusion criteria, reporting a total of 61,824 AD patients. In AD patients the IR were 15.4/1000 person-years for stroke (all types), 13.0/1000 person-years for ischemic stroke and 3.4/1000 person-years for ICH. When compared to controls without AD, incidence rate for ICH in AD patients was significantly higher (IRR = 1.67, 95%CI 1.43-1.96), but similar for ischemic stroke. Incident stroke is not a rare event in AD population. AD is associated with an increased risk of intracerebral hemorrhage which warrants further clarification.

Age at Menopause and Risk of Ischemic and Hemorrhagic Stroke

BACKGROUND AND PURPOSE

The few epidemiological studies that addressed the association between age at menopause and ischemic and hemorrhagic stroke risk in women had conflicting findings. We aimed to investigate whether age at (natural and surgical) menopause is a risk factor for total, ischemic, and hemorrhagic stroke in women.

METHODS

We analyzed data from 16 244 postmenopausal women, aged 26 to 70 years at recruitment who were enrolled in the European Prospective Investigation into Cancer and Nutrition-Netherlands cohort between 1993 and 1997. Participants were followed for the occurrence of stroke until January 1, 2011. At baseline, participants filled in questionnaires about health, reproductive history including age at menopause, diet, and lifestyle. Cox regression was used to investigate the association between age at menopause and stroke. All analyses were adjusted for age, smoking, systolic blood pressure, and body mass index.

RESULTS

Mean age of menopause was 46.4 (7.0) years. A total of 830 strokes (571 ischemic, 162 hemorrhagic, 97 unclassified) were identified. Earlier menopause was associated with an increased risk of total stroke. Compared with women who experienced menopause between 50 and 54 years old, women who underwent menopause before age 40 years had 1.48× higher risk (95% CI, 1.19-1.85) of total stroke. In continuous analyses, we observed a 2% lower total stroke risk for each year menopause was delayed (hazard ratio, 0.98 [95% CI, 0.97-0.99]). The risk between earlier menopause and stroke was confined to ischemic stroke, earlier menopause was not associated with hemorrhagic stroke. The association with age at menopause was stronger for natural menopause (hazard ratio <40 versus 50-54 years, 1.74 [95% CI, 1.12-2.70]) than for surgical menopause (hazard ratio <40 versus 50-54 years, 1.26 [95% CI, 0.84-1.89]).

CONCLUSIONS

The risk of total and ischemic stroke decreased with an increase in age at menopause. Whether this should have clinical consequences such as intensified risk factor control should be subject of further studies.

Estimating the lifetime risk of dementia using nationwide individually linked cause-of-death and health register data

BACKGROUND

Previous estimates of the lifetime risk of dementia are restricted to older age groups and may suffer from selection bias. In this study, we estimated the lifetime risk of dementia starting at birth using nationwide integral linked health register data.

METHODS

We studied all deaths in The Netherlands in 2017 (n = 147 866). Dementia was assessed using the cause-of-death registration, individually linked with registers covering long-term care, specialized mental care, dispensed medicines, hospital discharges and claims, and primary care. The proportion of deaths with dementia was calculated for the total population and according to age at death and sex.

RESULTS

According to all data sources combined, 24.0% of the population dies in the presence of dementia. This proportion is higher for females (29.4%) than for males (18.3%). Using multiple causes of death only, the proportion with dementia is 17.9%. Sequential addition of long-term care and hospital discharge data increased the estimate by 4.0 and 1.5%-points, respectively. Further addition of dispensed medicines, hospital claims and specialized mental care data added another 0.6%-points. Among persons who die at age ≤65-70 years, the proportion with dementia is ≤6.2%. After age 70, the proportion rises sharply, with a peak of 43.9% for females and 33.1% for males at age 90-95 years.

CONCLUSIONS

Around one-fourth of the Dutch population is diagnosed with dementia at some point in life and dies in the presence of dementia. It is a major challenge to arrange optimal care for this group.

Are Functional Measures Sufficient to Capture Acceptance? A Qualitative Study on Lower Limb Exoskeleton Use for Older People

Lower limb exoskeletons (LLE) are robotic devices developed to assist walk. In the field of healthcare, this technology has been available for almost a decade, yet it still faces important acceptance issues. While LLE were first developed for patients with spinal cord injuries, we expect their use to expand to everyday settings to benefit other populations, namely that of older people with reduced mobility (RM). We propose a qualitative approach to unearth key psychosocial themes on the acceptance of LLE in daily living for older people. The study analyses perceptions of older people with RM, as well as their entourage, including informal and professional caregivers. Using a grounded theory approach we analysed 12 semi-structured interviews with older people with RM; 2 focus groups with informal caregivers, and 2 focus groups with professional caregivers. LLE were introduced to participants through photo-elicitation. Older people with RM believed that LLE would increase their autonomy. They also perceived that using LLE would make them feel less of a burden for their entourage. Beyond these expected benefits, results captured participants’ ambivalence, dependent on their experiences of the ageing process and perceptions on the human–machine interaction. Informal caregivers highlighted that LLE could provide important relief related to the burden of care. Nonetheless, professional caregivers raised the fear of LLE leading to dehumanization of care. While each group had specific concerns on how LLE use would impact their lives, psychosocial considerations played a key role in LLE acceptance.

3D Segmentation of Perivascular Spaces on T1-Weighted 3 Tesla MR Images With a Convolutional Autoencoder and a U-Shaped Neural Network

We implemented a deep learning (DL) algorithm for the 3-dimensional segmentation of perivascular spaces (PVSs) in deep white matter (DWM) and basal ganglia (BG). This algorithm is based on an autoencoder and a U-shaped network (U-net), and was trained and tested using T1-weighted magnetic resonance imaging (MRI) data from a large database of 1,832 healthy young adults. An important feature of this approach is the ability to learn from relatively sparse data, which gives the present algorithm a major advantage over other DL algorithms. Here, we trained the algorithm with 40 T1-weighted MRI datasets in which all "visible" PVSs were manually annotated by an experienced operator. After learning, performance was assessed using another set of 10 MRI scans from the same database in which PVSs were also traced by the same operator and were checked by consensus with another experienced operator. The Sorensen-Dice coefficients for PVS voxel detection in DWM (resp. BG) were 0.51 (resp. 0.66), and 0.64 (resp. 0.71) for PVS cluster detection (volume threshold of 0.5 within a range of 0 to 1). Dice values above 0.90 could be reached for detecting PVSs larger than 10 mm3 and 0.95 for PVSs larger than 15 mm3. We then applied the trained algorithm to the rest of the database (1,782 individuals). The individual PVS load provided by the algorithm showed a high agreement with a semi-quantitative visual rating done by an independent expert rater, both for DWM and for BG. Finally, we applied the trained algorithm to an age-matched sample from another MRI database acquired using a different scanner. We obtained a very similar distribution of PVS load, demonstrating the interoperability of this algorithm.

Biomarkers for neurodegenerative diseases

Biomarkers for neurodegenerative diseases are needed to improve the diagnostic workup in the clinic but also to facilitate the development and monitoring of effective disease-modifying therapies. Positron emission tomography methods detecting amyloid-β and tau pathology in Alzheimer's disease have been increasingly used to improve the design of clinical trials and observational studies. In recent years, easily accessible and cost-effective blood-based biomarkers detecting the same Alzheimer's disease pathologies have been developed, which might revolutionize the diagnostic workup of Alzheimer's disease globally. Relevant biomarkers for α-synuclein pathology in Parkinson's disease are also emerging, as well as blood-based markers of general neurodegeneration and glial activation. This review presents an overview of the latest advances in the field of biomarkers for neurodegenerative diseases. Future directions are discussed regarding implementation of novel biomarkers in clinical practice and trials.

Alzheimer's pathogenic mechanisms and underlying sex difference

AD is a neurodegenerative disease, and its frequency is often reported to be higher for women than men: almost two-thirds of patients with AD are women. One prevailing view is that women live longer than men on average of 4.5 years, plus there are more women aged 85 years or older than men in most global subpopulations; and older age is the greatest risk factor for AD. However, the differences in the actual risk of developing AD for men and women of the same age is difficult to assess, and the findings have been mixed. An increasing body of evidence from preclinical and clinical studies as well as the complications in estimating incidence support the sex-specific biological mechanisms in diverging AD risk as an important adjunct explanation to the epidemiologic perspective. Although some of the sex differences in AD prevalence are due to differences in longevity, other distinct biological mechanisms increase the risk and progression of AD in women. These risk factors include (1) deviations in brain structure and biomarkers, (2) psychosocial stress responses, (3) pregnancy, menopause, and sex hormones, (4) genetic background (i.e., APOE), (5) inflammation, gliosis, and immune module (i.e., TREM2), and (6) vascular disorders. More studies focusing on the underlying biological mechanisms for this phenomenon are needed to better understand AD. This review presents the most recent data in sex differences in AD-the gateway to precision medicine, therefore, shaping expert perspectives, inspiring researchers to go in new directions, and driving development of future diagnostic tools and treatments for AD in a more customized way.

Acupuncture May Decrease the Incidence of Post-stroke Dementia: A Taiwan Nationwide Retrospective Cohort Study

Background: Post-stroke dementia may affect up to one-third of stroke survivors. Acupuncture as a complementary treatment for stroke has been shown to be beneficial for subsequent post-stroke rehabilitation. The purpose of this retrospective cohort study was to investigate the potential effect of acupuncture to protect stroke patients from dementia.

Methods: We included 9,547 patients receiving ambulatory or hospital care for stroke and 9.547 non-stroke patients; patients were matched for sex, age, and Charlson Comorbidity Index. Each individual was traced for the subsequent development of dementia. Two thousand four hundred and forty-nine stroke patients received acupuncture treatment and 7,098 residue stroke patients without acupuncture treatment served as control groups. This is a 3-year follow-up cohorts study: the incidence and adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of post- stroke dementia in the Cox proportional hazard regression.

Results: During the 3-year follow-up, 1,403 patients with stroke (14.70%) and 427 patients without stroke (4.47%) developed dementia. The adjusted HRs of development of dementia among stroke patients were 3.64-times (range, 3.27–4.06), and the incidence of dementia was higher in male. Stroke patients receiving acupuncture treatment had a lower probability of dementia than those without acupuncture during the follow-up period, the adjusted HRs was 0.49 (95% CI, 0.42–0.58; p < 0.001).

Conclusions: The association between stroke and dementia existed in both sexes, more prominent in male. Patients with stroke receiving acupuncture treatments showed decreased risk of dementia. Care must be taken evaluating these results because this study was limited to lack of information regarding lifestyles, stroke severities, and acupuncture methods that were used in treatments.

Smoking is associated with impaired verbal learning and memory performance in women more than men

Vascular contributions to cognitive impairment and dementia (VCID) include structural and functional blood vessel injuries linked to poor neurocognitive outcomes. Smoking might indirectly increase the likelihood of cognitive impairment by exacerbating vascular disease risks. Sex disparities in VCID have been reported, however, few studies have assessed the sex-specific relationships between smoking and memory performance and with contradictory results. We investigated the associations between sex, smoking, and cardiovascular disease with verbal learning and memory function. Using MindCrowd, an observational web-based cohort of ~ 70,000 people aged 18-85, we investigated whether sex modifies the relationship between smoking and cardiovascular disease with verbal memory performance. We found significant interactions in that smoking is associated with verbal learning performance more in women and cardiovascular disease more in men across a wide age range. These results suggest that smoking and cardiovascular disease may impact verbal learning and memory throughout adulthood differently for men and women.

Incidence of Dementia and Associated Factors in the EPIC-Spain Dementia Cohort

BACKGROUND

Dementia has become a public health priority as the number of cases continues to grow worldwide.

OBJECTIVE

To assess dementia incidence and determinants in the EPIC-Spain Dementia Cohort.

METHODS

25,015 participants (57% women) were recruited from three Spanish regions between 1992-1996 and followed-up for over 20 years. Incident cases were ascertained through individual revision of medical records of potential cases. Crude and age-adjusted incidence rates (IR) of dementia and sub-types (Alzheimer's disease (AD), and non-AD) were calculated by sex. Neelson-Aalen cumulative incidence estimates at 10, 15, and 20 years were obtained for each sex and age group. Multivariate Royston-Parmar models were used to assess independent determinants.

RESULTS

Global IR were higher in women for dementia and AD, and similar by sex for non-AD. IR ranged from 0.09 cases of dementia (95% confidence interval: 0.06-0.13) and 0.05 (0.03-0.09) of AD per 1000 person-years (py) in participants below 60 years, to 23.2 (15.9-33.8) cases of dementia and 14.6 (9.1-33.5) of AD (per 1000 py) in those ≥85 years. Adjusted IR were consistently higher in women than men for overall dementia and AD. Up to 12.5% of women and 9.1% of men 60-65 years-old developed dementia within 20 years. Low education, diabetes, and hyperlipidemia were the main independent predictors of dementia risk, whereas alcohol showed an inverse association.

CONCLUSION

Dementia incidence increased with age and was higher among women, but showed no geographical pattern. Dementia risk was higher among subjects with lower education, not drinking alcohol, and presenting cardiovascular risk factors.

Seizures and Epilepsy After Stroke: Epidemiology, Biomarkers and Management

Stroke is the leading cause of seizures and epilepsy in older adults. Patients who have larger and more severe strokes involving the cortex, are younger, and have acute symptomatic seizures and intracerebral haemorrhage are at highest risk of developing post-stroke epilepsy. Prognostic models, including the SeLECT and CAVE scores, help gauge the risk of epileptogenesis. Early electroencephalogram and blood-based biomarkers can provide information additional to the clinical risk factors of post-stroke epilepsy. The management of acute versus remote symptomatic seizures after stroke is markedly different. The choice of an ideal antiseizure medication should not only rely on efficacy but also consider adverse effects, altered pharmacodynamics in older adults, and the influence on the underlying vascular co-morbidity. Drug-drug interactions, particularly those between antiseizure medications and anticoagulants or antiplatelets, also influence treatment decisions. In this review, we describe the epidemiology, risk factors, biomarkers, and management of seizures after an ischaemic or haemorrhagic stroke. We discuss the special considerations required for the treatment of post-stroke epilepsy due to the age, co-morbidities, co-medication, and vulnerability of stroke survivors.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Brain Ischemia as a Prelude to Alzheimer's Disease

Transient ischemic brain injury causes massive neuronal death in the hippocampus of both humans and animals. This was accompanied by progressive atrophy of the hippocampus, brain cortex, and white matter lesions. Furthermore, it has been noted that neurodegenerative processes after an episode of ischemia-reperfusion in the brain can continue well-beyond the acute stage. Rarefaction of white matter was significantly increased in animals at 2 years following ischemia. Some rats that survived 2 years after ischemia developed severe brain atrophy with dementia. The profile of post-ischemic brain neurodegeneration shares a commonality with neurodegeneration in Alzheimer's disease. Furthermore, post-ischemic brain injury is associated with the deposition of folding proteins, such as amyloid and tau protein, in the intracellular and extracellular space. Recent studies on post-ischemic brain neurodegeneration have revealed the dysregulation of Alzheimer's disease-associated genes such as amyloid protein precursor, α-secretase, β-secretase, presenilin 1, presenilin 2, and tau protein. The latest data demonstrate that Alzheimer's disease-related proteins and their genes play a key role in the development of post-ischemic brain neurodegeneration with full-blown dementia in disease types such as Alzheimer's. Ongoing interest in the study of brain ischemia has provided evidence showing that ischemia may be involved in the development of the genotype and phenotype of Alzheimer's disease, suggesting that brain ischemia can be considered as a useful model for understanding the mechanisms responsible for the initiation of Alzheimer's disease.

Ten year cumulative incidence of dementia after late onset epilepsy of unknown etiology

Recent epidemiological studies suggest late life onset epilepsy of unknown etiology (LOEU) is a risk factor for future dementia. These studies rely on inclusion and exclusion of multiple diagnostic codes rather than structured data and neuroimaging findings, and thus challenging to interpret clinically. We assessed the cumulative incidence of dementia in patients with LOEU diagnosed through admission data and neuroimaging over a 10-year follow-up and compared baseline characteristics that distinguish group level incident dementia. We screened our hospital records for patients aged 55-69 with new epilepsy, admitted between 2000 and 2008, and excluded patients diagnosed with epilepsy from an underlying cause on medical records or neuroimaging. We used retrospective hospital data to follow patients for incident dementia or mortality at 10 years and compared baseline (demographics, depression or anxiety, vascular risk factors, results of electroencephalogram (EEG) studies, antidepressant use and type of ant seizure medication) and follow up (seizure recurrence, incident cerebrovascular disease) characteristics for patients with and without incident dementia. Fifty-four LOEU cases were screened, age at first seizure was 61 ± 5. The 10-year cumulative incidence of dementia was 22.20% (95% Confidence Interval 22.08-23.10%) and time to dementia diagnosis was 5.4 ± 3.9 years. Patients with incident dementia were more likely to be women (83% vs 38%, p = 0.002), have interictal epileptic form discharges (IED) on baseline EEG (70% vs 29%, p = 0.011) and depression or anxiety (50% vs 18%, p = 0.026). No differences were found in other baseline or follow up characteristics. Our results support recent findings of dementia incidence in LOEU. Prospective studies on LOEU should evaluate phenotypic determinants of individuals with late life epilepsy and the rate of progression to dementia.

Post-stroke dementia and permanent institutionalization

BACKGROUND

Dementia is among the most frequent causes of institutionalization. To serve the purpose of preventive strategies, there are no follow-up studies that have evaluated the actual impact of post-stroke dementia on institutionalization. We therefore compared the institutionalization rate and length of stay in an institutional care facility of patients with post-stroke dementia with stroke patients without dementia.

METHODS

We included 410 consecutive patients aged 55 to 85 years with ischemic stroke who were admitted to Helsinki University Hospital (The SAM cohort). Hospitalization and nursing home admissions were reviewed from national registries. Dementia was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders 3rd edition (DSM-III) criteria using extensive clinical assessments performed 3 months post-stroke. The cohort had a follow-up 21 years later.

RESULTS

Compared to patients without dementia, post-stroke dementia was associated with shorter survival time (6.60 vs 10.10 years, p < 0.001), shorter time spent not institutionalized (5.40 vs 9.37 years, p < 0.001), but not with time spent permanently institutionalized (0.73 vs 1.10 years, p = 0.08). Post-stroke dementia was associated with higher rates and earlier permanent institutionalization compared to absence of post-stroke dementia (HR 1.53, 95% CI 1.07-2.18) in a Cox regression model adjusting for age, status of living alone at baseline, modified Rankin Scale at baseline, history of atrial fibrillation, and cardiac failure.

CONCLUSIONS

Post-stroke dementia is associated with earlier permanent institutionalization. Due to significantly shorter survival, the time spent in nursing homes was not significantly longer in patients with post-stroke dementia compared with patients without post-stroke dementia.

Identification of digital voice biomarkers for cognitive health

AIM

Human voice contains rich information. Few longitudinal studies have been conducted to investigate the potential of voice to monitor cognitive health. The objective of this study is to identify voice biomarkers that are predictive of future dementia.

METHODS

Participants were recruited from the Framingham Heart Study. The vocal responses to neuropsychological tests were recorded, which were then diarized to identify participant voice segments. Acoustic features were extracted with the OpenSMILE toolkit (v2.1). The association of each acoustic feature with incident dementia was assessed by Cox proportional hazards models.

RESULTS

Our study included 6, 528 voice recordings from 4, 849 participants (mean age 63 ± 15 years old, 54.6% women). The majority of participants (71.2%) had one voice recording, 23.9% had two voice recordings, and the remaining participants (4.9%) had three or more voice recordings. Although all asymptomatic at the time of examination, participants who developed dementia tended to have shorter segments than those who were dementia free (P < 0.001). Additionally, 14 acoustic features were significantly associated with dementia after adjusting for multiple testing (P < 0.05/48 = 1 × 10-3). The most significant acoustic feature was jitterDDP_sma_de (P = 7.9 × 10-7), which represents the differential frame-to-frame Jitter. A voice based linear classifier was also built that was capable of predicting incident dementia with area under curve of 0.812.

CONCLUSIONS

Multiple acoustic and linguistic features are identified that are associated with incident dementia among asymptomatic participants, which could be used to build better prediction models for passive cognitive health monitoring.

Impact of Anesthetic Variation in Endovascular Treatment of Acute Ischemic Stroke

Background

Given recent technological advancements leading to better outcomes in endovascular therapy for acute ischemic stroke (AIS), updated guidelines recommend thrombectomy as the standard of care in acute large vessel occlusions. However, use of general anesthesia versus conscious sedation continues to be discussed. Two previous randomized trials have shown no significant difference between the use of conscious sedation compared with general anesthesia.

Methods

The authors performed a retrospective analysis of all consecutive patients with acute ischemia who underwent intra-arterial thrombectomy between September 2014 and May 2020 at a Level 1 stroke center. Patient characteristics along with clinical and operative data were extracted. Frequency distributions of selected characteristics were obtained and statistical significance of any differences according to the mode of anesthesia was assessed.

Results

A total of 480 patients were included in this study, 257 underwent general anesthesia and 223 underwent conscious sedation. Length of stay (LOS) in the ICU nor length of hospital stay was significantly different between groups. Change in National Institutes of Health Stroke Scale (NIHSS) score from admission to discharge, procedure times, and discharge disposition were not found to be significantly associated with either group although there was a trend towards longer door to puncture time with general anesthesia. Discharge disposition was found to be significantly associated with admission NIHSS (p=0.04). There was a trend towards longer hospital stay in patients with worse admission NIHSS (p=0.09). Success of thrombectomy was not significantly different between both anesthesia groups (p=0.37).

Conclusions

This large, single-center retrospective cohort study echoes the results of two previous randomized controlled trials in demonstrating non-inferiority of general anesthesia versus conscious sedation in cases of intra-arterial thrombectomy for AIS. These results contrast those of previously published retrospective studies.

Sex differences in dementia: on the potentially mediating effects of educational attainment and experiences of psychological distress

BACKGROUND

Old-age dementias are known to disproportionally affect women as well as individuals with low educational attainment. The higher lifetime risk of dementia among women is usually attributed to their longer life expectancy. However, the impact of sex, and subsequent gender inequity, is likely to be more multifaceted than this explanation implies. Not least because of historical inequities in access to education between the sexes and the gender and socio-economic gradients in risk factors such as stress, depression and social isolation. Consequently, the present study sought to test whether differences in educational attainment and experiences of general psychological distress mediate the association between female sex and dementia.

METHODS

The study utilizes data obtained through the Gothenburg H70 Birth Cohort Study and the Prospective Populations Study on Women (n = 892). Data were analysed using Confirmatory Factor Analysis (CFA) and Structural Equation Modelling (SEM) with Weighted Least Squares Means and Variance adjusted (WLSMV) estimation. General psychological distress was indicated by a latent variable and constructed from five manifest items (previous depression, stress, self-esteem, chronic loneliness and satisfaction with social situation) that were all measured at baseline.

RESULTS

While the results could not corroborate that education directly mediates the effect of sex on dementia, level of distress was predicted by both female sex (0.607, p < .001) and education (- 0.166, p < .01) and, in turn, shown to be significantly associated with dementia (0.167, p < .05), also after controlling for confounders. When time from baseline to diagnosis was increased through sequential exclusion of dementia cases, the effect of distress on dementia was no longer significant.

CONCLUSION

The overall findings suggest that social (dis) advantage predicts general psychological distress, which thereby constitutes a potential, and rarely acknowledged, pathway between female sex, education, and dementia. They further underline the importance of attending to both education and distress as 'gendered' phenomena when considering the nature of their associations with dementia. However, the possibility of reverse causality bias must be acknowledged and the need for longitudinal studies with longer follow-up stressed.

Lifetime risks and health impacts of hemorrhagic and ischemic stroke in South Korea

This study is aimed toward estimating the lifetime risks, life expectancy, expected years of life lost (EYLL), and lifetime costs related to different subtypes of stroke in South Korea. We included 13,994 patients diagnosed with stroke (ICD-10, I60-I63) in the National Health Insurance Service-National Sample Cohort of Korea between 2006 and 2015. Lifetime risks were calculated using the cumulative incidence rate for patients aged 18–84. Lifetime survival data were obtained through the Kaplan–Meier method and extrapolated with a rolling-over extrapolation algorithm. The lifetime costs were estimated by multiplying the average monthly expenditures with the survival probabilities and adding the values over lifetime. The lifetime risks of stroke in Korea have been decreasing consistently over the last decade with the exception of subarachnoid hemorrhage in females, which appears to have slightly increased. The EYLL is higher in hemorrhagic stroke than in ischemic stroke (6–9.7 vs. 4.7). Expected lifetime costs reimbursed by the NHIS would amount to about $71,406 accompanied with $14,921 copayment from the patients for hemorrhagic stroke, and $50,551 and $11,666, respectively, for ischemic stroke. Further studies are warranted to combine survival with quality of life and functional disability to obtain a more detailed outcome assessment of the potential impact of the prevention of stroke.

Childhood Misfortune and Late-Life Stroke Incidence, 2004-2014

BACKGROUND AND OBJECTIVES

Although most strokes occur in later life, recent studies reveal that negative exposures decades earlier are associated with stroke risk. The purpose of this study was to examine whether accumulated and/or specific domains of early misfortune are related to stroke incidence in later life.

RESEARCH DESIGN AND METHODS

A decade of longitudinal data from stroke-free participants 50 years or older in the Health and Retirement Study were analyzed (N = 12,473). Incident stroke was defined as either self-reported first incident stroke or death due to stroke between 2004 and 2014.

RESULTS

Analyses revealed that accumulated misfortune was associated with increased stroke risk, but the relationship was moderated by wealth. Examining specific domains of childhood misfortune revealed that stroke incidence was greater for persons with behavioral/psychological risks, but that this relationship also was moderated by higher wealth for those with only one behavioral/psychological risk.

DISCUSSION AND IMPLICATIONS

Accumulated childhood misfortune and adolescent depression heighten the risk of stroke in later life, but the influence is remediable through adult wealth. Reducing poverty in later life may decrease stroke incidence for persons exposed to negative childhood exposures.

An Observational Study Investigating the Need for Decompressive Hemicraniectomy after Thrombectomy in Acute Ischemic Stroke of the Middle Cerebral Artery Territory

OBJECTIVE

The frequency incidence of decompressive hemicraniectomy following intra-arterial thrombectomy (IAT) in acute ischemic stroke (AIS) involving the middle cerebral artery (MCA) territory was assessed as a surrogate for morbidity.

METHODS

A single-institution retrospective chart review was conducted involving 209 consecutive patients between September 2014 and May 2017 with infarctions affecting the MCA territory and who subsequently underwent IAT. The outcomes of interest included the frequency of hemicraniectomy following IAT and the effects of intravenous tissue plasminogen activator (IV tPA) use and primary occlusion site on the Thrombolysis in Cerebral Infarction (TICI) score.

RESULTS

Thirty-one patients were excluded for infarctions not involving the MCA territory. A total of 178 patients were included in the study. Sixty-eight patients (38.6%) had infarctions of less than one-third of the MCA territory, 50 (28.4%) had infarctions between one-third and two-thirds, and 58 (33%) had infarctions involving greater than two-thirds with 54.3% suffering infarctions of the left side. Only four patients (2.2%) required a hemicraniectomy with no statistically significant association found between TICI score and hemicraniectomy (p=0.41) or between administration of IV tPA and hemicraniectomy (p=0.36). The primary occlusion site was found to influence TICI score (p=0.045).

CONCLUSION

A very small number of patients required hemicraniectomy after IAT as compared to previously published rates in the literature. However, several factors may prevent the patient from being an appropriate hemicraniectomy candidate in the first place and the small number of these patients in this study limits statistical analysis. The variables that determine a patient's candidacy for decompressive hemicraniectomy remains multi-factorial.

Potential of Glucagon-Like Peptide 1 as a Regulator of Impaired Cholesterol Metabolism in the Brain

Cerebral vascular diseases are the most common high-mortality diseases worldwide. Their onset and development are associated with glycemic imbalance, genetic background, alteration of atherosclerotic factors, severe inflammation, and abnormal cholesterol metabolism. Recently, the gut-brain axis has been highlighted as the key to the solution for cerebral vessel dysfunction in view of cholesterol metabolism and systemic lipid circulation. In particular, glucagon-like peptide 1 (GLP-1) is a cardinal hormone that regulates blood vessel function and cholesterol homeostasis and acts as a critical messenger between the brain and gut. GLP-1 plays a systemic regulatory role in cholesterol homeostasis and blood vessel function in various organs through blood vessels. Even though GLP-1 has potential in the treatment and prevention of cerebral vascular diseases, the importance of and relation between GLP-1 and cerebral vascular diseases are not fully understood. Herein, we review recent findings on the functions of GLP-1 in cerebral blood vessels in association with cholesterol metabolism.

AIM2 inflammasome contributes to brain injury and chronic post-stroke cognitive impairment in mice

Although over one-third of stroke patients may develop post-stroke cognitive impairment (PSCI), the mechanisms underlying PSCI remain unclear. We explored here, the involvement of post-stroke inflammasomes in long-term PSCI development, using a 45 min-middle cerebral artery occlusion (MCAO)/reperfusion-induced PSCI model. Immunohistological assessment on day 1, 3, and 7 was followed by cognitive function test 28 days post-stroke. Evaluation of inflammasome sensor gene expression in aged mouse brains showed dominant expression of absent in melanoma 2 (Aim2) in 6-, 12-, and 18-month-old mouse brains. AIM2 mRNA and protein increased until 7 days post-stroke. PSCI decreased anxiety in elevated plus maze test and impaired spatial learning and memory functions in Morris water maze test 28 days post-stroke. AIM2 and other inflammasome subunit immunoreactivities, including those for caspase-1, interleukin (IL)-1β, and IL-18, were higher in the hippocampus and cortex of the PSCI than in those of the sham group 7 days post-stroke. AIM2 immunoreactivity of the PSCI group was primarily co-localized with Iba-1 (microglial marker) and CD31 (endothelial cell marker) immunoreactivities but not NeuN (neuronal marker) and GFAP (astrocyte marker) immunoreactivities, suggesting that microglia or endothelial cell-induced AIM2 production mediated PSCI pathogenesis. Additionally, inflammasome-induced pyroptosis might contribute to acute and chronic neuronal death after stroke. AIM2 knockout (KO) and Ac-YVAD-CMK-induced caspase-1 inhibition in mice significantly improved cognitive function and reversed brain volume in the hippocampus relative to those in stroke mice. Conclusively, AIM2 inflammasome-mediated inflammation and pyroptosis likely aggravated PSCI; therefore, targeting and controlling AIM2 inflammasome could potentially treat PSCI.

Epidemiology of neurological diseases in older adults

Neurological diseases refer to the diseases that target the nervous system (brain, spine or nerves). They are the second leading cause of death, and the first cause of severe long-term disability in the world. The prevalence of most neurological diseases increases sharply with age, and age also modulates the impact of risk factors, clinical presentation and the natural course of these diseases. Longitudinal population-based studies provide useful insights for a better understanding of the specificities of neurological diseases in older adults by assessment of a wide range of risk factors. Rapid population aging, especially in low-income countries, presents challenges in terms of health and social care. A multidisciplinary approach is necessary to find solutions to tackle the burden of neurological diseases in older adults.

Younger age at stroke onset but not thrombolytic treatment predicts poststroke epilepsy: An updated meta-analysis

AIMS

Stroke is the most commonly identified cause of late-onset epilepsy. Risk factors for poststroke epilepsy (PSE) are partially elucidated, and many studies have been performed in recent years. We aimed to update our previous systematic review and meta-analysis on risk factors for PSE.

METHODS

PubMed, Google Scholar, and Scopus databases were searched. Articles published in English (1987-2019) were included. Odds ratios (OR) and mean values were calculated for examined variables.

RESULTS

Thirty studies with different designs were included, enrolling 26,045 patients who experienced stroke, of whom 1800 had PSE, corresponding to a prevalence of 7%. Cortical lesions (OR: 3.58, 95% confidence interval (CI): 2.35-5.46, p < 0.001), hemorrhagic component (OR: 2.47, 95% CI: 1.68-3.64, p < 0.001), early seizures (ES) (OR: 4.88, 95% CI: 3.08-7.72, p < 0.001), and younger age at stroke onset (difference in means: 2.97 years, 95% CI: 0.78 to 5.16, p = 0.008) favor PSE. Sex and acute treatment with recombinant tissue plasminogen activator (rtPA) do not predict the occurrence of PSE.

CONCLUSION

Despite limitations due to the uneven quality and design of the studies, the present meta-analysis confirms that cortical involvement, hemorrhagic component, and ES are associated with a higher risk of PSE. In this update, younger age at stroke onset but not thrombolytic treatment seems to increase the risk for PSE. This article is part of the Special Issue "Seizures & Stroke".

Development and Validation of a Prognostic Model of Swallowing Recovery and Enteral Tube Feeding After Ischemic Stroke

Importance

Predicting the duration of poststroke dysphagia is important to guide therapeutic decisions. Guidelines recommend nasogastric tube (NGT) feeding if swallowing impairment persists for 7 days or longer and percutaneous endoscopic gastrostomy (PEG) placement if dysphagia does not recover within 30 days, but, to our knowledge, a systematic prediction method does not exist.

Objective

To develop and validate a prognostic model predicting swallowing recovery and the need for enteral tube feeding.

Design, Setting, and Participants

We enrolled participants with consecutive admissions for acute ischemic stroke and initially severe dysphagia in a prospective single-center derivation (2011-2014) and a multicenter validation (July 2015-March 2018) cohort study in 5 tertiary stroke referral centers in Switzerland.

Exposures

Severely impaired oral intake at admission (Functional Oral Intake Scale score <5).

Main Outcomes and Measures

Recovery of oral intake (primary end point, Functional Oral Intake Scale ≥5) or return to prestroke diet (secondary end point) measured 7 (indication for NGT feeding) and 30 (indication for PEG feeding) days after stroke.

Results

In total, 279 participants (131 women [47.0%]; median age, 77 years [interquartile range, 67-84 years]) were enrolled (153 [54.8%] in the derivation study; 126 [45.2%] in the validation cohort). Overall, 64% (95% CI, 59-71) participants failed to recover functional oral intake within 7 days and 30% (95% CI, 24-37) within 30 days. Prolonged swallowing recovery was independently associated with poor outcomes after stroke. The final prognostic model, the Predictive Swallowing Score, included 5 variables: age, stroke severity on admission, lesion location, initial risk of aspiration, and initial impairment of oral intake. Predictive Swallowing Score prediction estimates ranged from 5% (score, 0) to 96% (score, 10) for a persistent impairment of oral intake on day 7 and from 2% to 62% on day 30. Model performance in the validation cohort showed a discrimination (C statistic) of 0.84 (95% CI, 0.76-0.91; P < .001) for predicting the recovery of oral intake on day 7 and 0.77 (95% CI, 0.67-0.87; P < .001) on day 30, and a discrimination for a return to prestroke diet of 0.94 (day 7; 95% CI, 0.87-1.00; P < .001) and 0.71 (day 30; 95% CI, 0.61-0.82; P < .001). Calibration plots showed high agreement between the predicted and observed outcomes.

Conclusions and Relevance

The Predictive Swallowing Score, available as a smartphone application, is an easily applied prognostic instrument that reliably predicts swallowing recovery. It will support decision making for NGT or PEG insertion after ischemic stroke and is a step toward personalized medicine.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Sex difference in Alzheimer's disease: An updated, balanced and emerging perspective on differing vulnerabilities

Sex biology influences Alzheimer's disease (AD). Sex differences exist in the epidemiologic, imaging, biomarker, and pathology studies of this uniquely human condition. The mandate to understand sex differences in major diseases like AD is important for many reasons. First, AD is the most common neurodegenerative condition and a devastating disease-experienced as an insidious and progressive erosion of memory, cognition, and other brain functions. Second, since true sex differences in AD exist, their precise understanding could reveal what protects one sex or makes the other vulnerable-and this knowledge could inform development of new therapeutic approaches to benefit both sexes. Third, AD develops in the aging brain in a milieu of decreased circulating gonadal hormones. Thus, how sex-specific depletion affects the brain along with how replacement of androgens in men and estrogens and progestins in women alters vulnerability to AD are relevant questions, with clinical implications in a future of personalized medicine. This review will highlight advances in sex differences in AD in human populations with a focused perspective on epidemiology, biomarkers, and clinical trials. A thorough and concise overview of sex differences reviewed here indicates varying vulnerabilities in men and women. This review examines several lines of recent and strong evidence that collectively indicate the following: (1) men die faster with AD, (2) more women live with AD, (3) both sexes show similar risk of developing AD until advanced ages when women show increased risk, (4) both sexes show largely similar AD biomarker burden with notable exceptions for higher tau levels in subgroups of women with high amyloid, (5) women show brain reserve and resilience to tau pathology, (6) both sexes are vulnerable to the genetic risk of carrying APOE4, with women showing higher risk, and (7) neither sex has shown clear benefit of hormone replacement for AD or dementia risk in randomized clinical trials to date.

Clinical Significance of Magnetic Resonance Imaging Markers of Vascular Brain Injury: A Systematic Review and Meta-analysis

Importance

Covert vascular brain injury (VBI) is highly prevalent in community-dwelling older persons, but its clinical and therapeutic implications are debated.

Objective

To better understand the clinical significance of VBI to optimize prevention strategies for the most common age-related neurological diseases, stroke and dementia.

Data Source

We searched for articles in PubMed between 1966 and December 22, 2017, studying the association of 4 magnetic resonance imaging (MRI) markers of covert VBI (white matter hyperintensities [WMHs] of presumed vascular origin, MRI-defined covert brain infarcts [BIs], cerebral microbleeds [CMBs], and perivascular spaces [PVSs]) with incident stroke, dementia, or death.

Study Selection

Data were taken from prospective, longitudinal cohort studies including 50 or more adults.

Data Extraction and Synthesis

We performed inverse variance-weighted meta-analyses with random effects and z score-based meta-analyses for WMH burden. The significance threshold was P < .003 (17 independent tests). We complied with the Meta-analyses of Observational Studies in Epidemiology guidelines.

Main Outcomes and Measures

Stroke (hemorrhagic and ischemic), dementia (all and Alzheimer disease), and death.

Results

Of 2846 articles identified, 94 studies were eligible, with up to 14 529 participants for WMH, 16 012 participants for BI, 15 693 participants for CMB, and 4587 participants for PVS. Extensive WMH burden was associated with higher risk of incident stroke (hazard ratio [HR], 2.45; 95% CI, 1.93-3.12; P < .001), ischemic stroke (HR, 2.39; 95% CI, 1.65-3.47; P < .001), intracerebral hemorrhage (HR, 3.17; 95% CI, 1.54-6.52; P = .002), dementia (HR, 1.84; 95% CI, 1.40-2.43; P < .001), Alzheimer disease (HR, 1.50; 95% CI, 1.22-1.84; P < .001), and death (HR, 2.00; 95% CI, 1.69-2.36; P < .001). Presence of MRI-defined BIs was associated with higher risk of incident stroke (HR, 2.38; 95% CI, 1.87-3.04; P < .001), ischemic stroke (HR, 2.18; 95% CI, 1.67-2.85; P < .001), intracerebral hemorrhage (HR, 3.81; 95% CI, 1.75-8.27; P < .001), and death (HR, 1.64; 95% CI, 1.40-1.91; P < .001). Presence of CMBs was associated with increased risk of stroke (HR, 1.98; 95% CI, 1.55-2.53; P < .001), ischemic stroke (HR, 1.92; 95% CI, 1.40-2.63; P < .001), intracerebral hemorrhage (HR, 3.82; 95% CI, 2.15-6.80; P < .001), and death (HR, 1.53; 95% CI, 1.31-1.80; P < .001). Data on PVS were limited and insufficient to conduct meta-analyses but suggested an association of high PVS burden with increased risk of stroke, dementia, and death; this requires confirmation.

Conclusions and Relevance

We report evidence that MRI markers of VBI have major clinical significance. This research prompts careful evaluation of the benefit-risk ratio for available prevention strategies in individuals with covert VBI.

A Multi-Center Competing Risks Model and Its Absolute Risk Calculation Approach

In the competing risks frame, the cause-specific hazard model (CSHM) can be used to test the effects of some covariates on one particular cause of failure. Sometimes, however, the observed covariates cannot explain the large proportion of variation in the time-to-event data coming from different areas such as in a multi-center clinical trial or a multi-center cohort study. In this study, a multi-center competing risks model (MCCRM) is proposed to deal with multi-center survival data, then this model is compared with the CSHM by simulation. A center parameter is set in the MCCRM to solve the spatial heterogeneity problem caused by the latent factors, hence eliminating the need to develop different models for each area. Additionally, the effects of the exposure factors in the MCCRM are kept consistent for each individual, regardless of the area they inhabit. Therefore, the coefficient of the MCCRM model can be easily explained using the scenario of each model for each area. Moreover, the calculating approach of the absolute risk is given. Based on a simulation study, we show that the estimate of coefficients of the MCCRM is unbiased and precise, and the area under the curve (AUC) is larger than that of the CSHM when the heterogeneity cannot be ignored. Furthermore, the disparity of the AUC increases progressively as the standard deviation of the center parameter (SDCP) rises. In order to test the calibration, the expected number (E) of strokes is calculated and then compared with the corresponding observed number (O). The result is promising, so the SDCP can be used to select the most appropriate model. When the SDCP is less than 0.1, the performance of the MCCRM and CSHM is analogous, but when the SDCP is equal to or greater than 0.1, the performance of the MCCRM is significantly superior to the CSHM. This suggests that the MCCRM should be selected as the appropriate model.

Keys to staying sharp: A randomized clinical trial of piano training among older adults with and without mild cognitive impairment

BACKGROUND

The prevalence of dementia, the most expensive medical condition (Kirschstein, 2000 and Hurd et al., 2013 [1,2]), and its precursor, mild cognitive impairment (MCI) are increasing [3]. Finding effective intervention strategies to prevent or delay dementia is imperative to public health. Prior research provides compelling evidence that central auditory processing (CAP) deficits are a risk factor for dementia [4-6]. Grounded in the information degradation theory [7, 8], we hypothesize that improving brain function at early perceptual levels (i.e., CAP) may be optimal to attenuate cognitive and functional decline and potentially curb dementia prevalence. Piano training is one avenue to enhance cognition [9-13] by facilitating CAP at initial perceptual stages [14-18].

OBJECTIVES

The Keys To Staying Sharp study is a two arm, randomized clinical trial examining the efficacy of piano training relative to music listening instruction to improve CAP, cognition, and everyday function among older adults. In addition, the moderating effects of MCI status on piano training efficacy will be examined and potential mediators of intervention effects will be explored.

HYPOTHESES

We hypothesize that piano training will improve CAP and cognitive performance, leading to functional improvements. We expect that enhanced CAP will mediate cognitive gains. We further hypothesize that cognitive gains will mediate functional improvements.

METHOD

We plan to enroll 360 adults aged 60 years and older who will be randomized to piano training or an active control condition of music listening instruction and complete pre- and immediate post- assessments of CAP, cognition, and everyday function.

Predicting 10-Year and Lifetime Stroke Risk in Chinese Population

Background and Purpose—

Risk assessment is essential for the primary prevention of stroke. However, the current available tools derived from Chinese populations are insufficient for individualized 10-year and lifetime stroke risk prediction. Our study aims to develop and validate personalized 10-year and lifetime stroke risk equations incorporating 4 large Chinese cohorts.

Methods—

We used 2 prospective cohorts of 21 320 participants with similar survey protocols as the derivation cohort to develop sex-specific 10-year and lifetime stroke risk equations. Two other independent cohorts with 14 123 and 70 838 participants were used for external validation. In addition, the performance of the 10-year stroke risk equations among participants aged ≥55 years was compared with the new Framingham Stroke Risk Profile.

Results—

The sex-specific equations for predicting 10-year stroke risk had C statistics being 0.810 for men and 0.810 for women, with calibration χ 2 being 15.0 ( P =0.092) and 7.8 ( P =0.550), respectively. The lifetime stroke risk equations also showed C statistics around 0.800 and calibration χ 2 below 20 for both sexes. In the validation cohorts, we found good agreement between the observed and predicted stroke probabilities for both the 10-year and lifetime stroke risk equations. Further compared with the new Framingham Stroke Risk Profile, our 10-year stroke risk equations displayed better prediction capability. In addition, based on lifetime stroke risk assessment, 5.7% of study participants aged 35 to 49 years old were further reclassified as high risk, who were initially categorized as low 10-year risk.

Conclusions—

We developed a well-performed tool for predicting personalized 10-year and lifetime stroke risk among the Chinese adults, which will facilitate the further identification of high-risk individuals and community-based stroke prevention in China.

The dynamics of Poststroke depression among Ghanaians

OBJECTIVE

The very few published data on post-stroke depression (PSD) among indigenous Africans have covered its prevalence and predictors. We sought to evaluate the dynamics of PSD in a cohort of Ghanaian stroke survivors followed for 9 months after an acute stroke.

METHODS

Stroke survivors in this prospective cohort were adults aged >18 years with CT scan confirmed stroke, recruited into a randomized controlled trial to assess the feasibility of an mHealth technology-enabled, nurse guided intervention for blood pressure control. PSD was assessed a secondary outcome measure using the Hamilton Depression Rating Scale (HDRS) at enrollment, months 3, 6, and 9. Those with a score of >7 points on HDRS were categorized as depressed. A multivariate logistic regression analysis was performed to identify independent predictors of PSF.

RESULTS

Mean age of study participants was 55.1 ± 12.7 years with 65% being males. Ischemic strokes comprised 76.6% of study population. Prevalence of PSD at baseline was 78.6%, 43.6% at month 3, 41.1% at month 6 and 18.2% at month 9 (p < .0001). Factors significantly associated with PSD at baseline were higher NIH Stoke Scale score (adjusted OR 1.51, 95% CI: 1.03-2.23) and pain (adjusted OR 7.18, 95% CI: 1.52-33.89). NIHSS score (adjusted OR, 1.99, 95% CI: 1.12-3.52) as associated with PSD at month 9.

CONCLUSION

80% Ghanaian stroke survivors have early PSD declining to 20% at month 9. Stroke severity is the persistent factor associated with PSD at baseline and follow-up, and good be a target for screening and promptly treating PSD.

Multistate models and lifetime risk estimation: Application to Alzheimer's disease

The lifetime risk of a clinical condition is the probability of onset of the condition during one's lifespan. Recent advances in Alzheimer's disease (AD) research have identified screening tests for biomarkers that can identify persons who are in the earliest stages of the AD process but who do not yet have any clinical signs or symptoms. A critical question asked by patients and clinicians is, what is the probability an individual will develop AD dementia during his or her lifetime? Here, we discuss estimation of lifetime risks using biomarkers for preclinical disease based on a discrete nonhomogeneous Markov multistate model for the disease process. We allow the transition probabilities to depend on chronological age. In addition, we allow the probabilities to depend on calendar time to account for possible calendar trends in death rates and to evaluate the impact on lifetime risks of future interventions designed to slow disease progression. We develop estimating equations for calculating the lifetime risks from the nonhomogeneous multistate Markov model. Estimates of lifetime risks for AD dementia based on biomarkers for preclinical disease are presented.

Design and sample size considerations for Alzheimer's disease prevention trials using multistate models

BACKGROUND/AIMS

Clinical trials for Alzheimer's disease have been aimed primarily at persons who have cognitive symptoms at enrollment. However, researchers are now recognizing that the pathophysiological process of Alzheimer's disease begins years, if not decades, prior to the onset of clinical symptoms. Successful intervention may require intervening early in the disease process. Critical issues arise in designing clinical trials for primary and secondary prevention of Alzheimer's disease including determination of sample sizes and follow-up duration. We address a number of these issues through application of a unifying multistate model for the preclinical course of Alzheimer's disease. A multistate model allows us to specify at which points during the long disease process the intervention exerts its effects.

METHODS

We used a nonhomogeneous Markov multistate model for the progression of Alzheimer's disease through preclinical disease states defined by biomarkers, mild cognitive impairment and Alzheimer's disease dementia. We used transition probabilities based on several published cohort studies. Sample size methods were developed that account for factors including the initial preclinical disease state of trial participants, the primary endpoint, age-dependent transition and mortality rates and specifications of which transition rates are the targets of the intervention.

RESULTS

We find that Alzheimer's disease prevention trials with a clinical primary endpoint of mild cognitive impairment or Alzheimer's disease dementia will require sample sizes of the order many thousands of individuals with at least 5 years of follow-up, which is larger than most Alzheimer's disease therapeutic trials conducted to date. The reasons for the large trial sizes include the long and variable preclinical period that spans decades, high rates of attrition among elderly populations due to mortality and losses to follow-up and potential selection effects, whereby healthier subjects enroll in prevention trials. A web application is available to perform sample size calculations using the methods reported here.

CONCLUSION

Sample sizes based on multistate models can account for the points in the disease process when interventions exert their effects and may lead to more accurate sample size determinations. We will need innovative strategies to help design Alzheimer's disease prevention trials with feasible sample size requirements and durations of follow-up.

Anthology of stroke epidemiology in the 20th and 21st centuries: Assessing the past, the present, and envisioning the future

This narrative overview of stroke epidemiology shows dramatic changes in stroke incidence, prevalence, mortality, disability, and the understanding of risk factors and primary stroke prevention strategies over the last few decades. Likely future directions of stroke epidemiology and prevention are outlined.