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

Trajectory of Cognitive Decline Before and After Stroke in 14 Population Cohorts

Importance

Poststroke cognitive impairment is common, but the cognitive trajectory following a first stroke, relative to prestroke cognitive function, remains unclear.

Objective

To map the trajectory of cognitive function before any stroke and after stroke in global cognition and in 4 cognitive domains, as well as to compare the cognitive trajectory prestroke in stroke survivors with the trajectory of individuals without incident stroke over follow-up.

Design, Setting, and Participants

The study used harmonized and pooled data from 14 population-based cohort studies included in the Cohort Studies of Memory in an International Consortium collaboration. These studies were conducted from 1993 to 2019 across 11 countries among community-dwelling older adults without a history of stroke or dementia. For this study, linear mixed-effects models were used to estimate trajectories of cognitive function poststroke relative to a stroke-free cognitive trajectory. The full model adjusted for demographic and vascular risk factors. Data were analyzed from July 2022 to March 2024.

Exposure

Incident stroke.

Main outcomes and measures

The primary outcome was global cognition, defined as the standardized average of 4 cognitive domains (language, memory, processing speed, and executive function). Cognitive domain scores were formed by selecting the most commonly administered test within each domain and standardizing the scores.

Results

The study included 20 860 participants (12 261 [58.8%] female) with a mean (SD) age of 72.9 (8.0) years and follow-up of 7.51 (4.2) years. Incident stroke was associated with a substantial acute decline in global cognition (-0.25 SD; 95% CI, -0.33 to -0.17 SD), the Mini-Mental State Examination, and all cognitive domains (ranging from -0.17 SD to -0.22 SD), as well as accelerated decline in global cognition (-0.038 SD per year; 95% CI, -0.057 to -0.019 SD per year) and all domains except memory (ranging from -0.020 to -0.055 SD per year), relative to a stroke-free cognitive trajectory. There was no significant difference in prestroke slope in stroke survivors compared with the rate of decline in individuals without stroke in all cognitive measures. The mean rate of decline without a previous stroke was -0.049 SD per year (95% CI, -0.051 to -0.047 SD) in global cognition.

Conclusions and relevance

In this cohort study using pooled data from 14 cohorts, incident stroke was associated with acute and accelerated long-term cognitive decline in older stroke survivors.

Risk of Stroke, Dementia, and Cognitive Decline with Coronary and Arterial Calcification

Extant research shows that following a cerebrovascular insult to the brain, patients may develop a wide range of cognitive disorders, spanning from mild cognitive impairment (CI) to advanced dementia. Several studies have shown that atherosclerosis in the carotid, coronary, and breast arteries is associated with an increased risk of stroke, CI, and dementia. In this review, we examine the association of subclinical atherosclerotic calcification detected by computed tomography (CT) in these arterial beds and the risk of stroke, CI, and dementia. A major advantage of CT is that it can accurately quantify vascular calcification in different parts of the vasculature during a single examination. However, the strength of the association between CT findings and CI and stroke varies with the location and severity of the arteries involved. Data are still limited on this topic, highlighting the need for additional investigations to further our understanding of the risk of cognitive impairment in patients with subclinical atherosclerosis. It is equally important to test preventive strategies for managing patients in whom vascular calcifications are identified incidentally in randomized controlled trials to study the effects on outcomes, including incidents of stroke and CI.

Mediation of Post-Stroke Function by Cognition in the Canadian Longitudinal Study on Aging

INTRODUCTION

Cognitive and functional impairment after stroke are common, but the relation between cognitive and functional decline after stroke is not well studied.

METHODS

We used the comprehensive cohort in the Canadian Longitudinal Study on Aging to identify those with prior stroke, and we calculated reliable cognitive change scores from baseline to follow-up for the memory and executive domains. Functional decline was defined as an increase in the number of dependent daily activities. Using formal mediation analysis, we tested the presence and degree of mediation of the association between stroke and functional decline by cognitive decline.

RESULTS

There were 22,648 individuals with memory change scores (325 with stroke) and 17,613 individuals with executive change scores (241 with stroke). History of stroke was significantly associated with memory decline (-0.26 standard deviations, 95% CI -0.33 to -0.19), executive decline (-0.22, 95% CI -0.36 to -0.09), and new functional impairment (adjusted odds ratio 2.31, 95% CI 1.80-2.97) over a median of 3-year follow-up. Cognitive decline was a significant mediator of functional decline. Memory decline mediated only 5% of the relationship, whereas executive and overall cognitive decline mediated 13% and 22%, respectively.

CONCLUSION

Cognitive decline is a mediator of the association between prior stroke and functional decline; consequently, strategies to delay, attenuate, or prevent cognitive decline after stroke may be important to preserving long-term functional status.

Differential Impact of Stroke on Cognitive Impairment in Mexican Americans and Non-Hispanic White Americans

BACKGROUND

The association between stroke and dementia is well established. Less is known about this association in underrepresented ethnic groups. In a large ethnically diverse cohort, we examined whether history of stroke was associated with cognitive impairment, and whether this relationship differed by ethnicity (Mexican American [MA] versus non-Hispanic White).

METHODS

This was a population-based cohort study conducted in Nueces County, TX, a biethnic community with a large and primarily nonimmigrant MA population. Residents aged ≥65 were recruited door-to-door or by telephone between May 2018 and December 2021. The primary exposure was history of stroke, obtained by self-report. Demographic, medical, and educational histories were also obtained. The primary outcome was the Montreal Cognitive Assessment (MoCA), a scale that evaluates multiple domains of cognitive performance. Scores were divided into 3 ordinal categories, roughly corresponding to normal cognition (MoCA 26-30), mild cognitive impairment (MoCA 20-25), or probable dementia (MoCA 0-19).

RESULTS

One thousand eight hundred one participants completed MoCA screening (55% female; 50% MA, 44% Non-Hispanic White, 6% other), of whom 12.4% reported history of stroke. Stroke prevalence was similar across ethnicities (X2 2.1; P=0.34). In a multivariable cumulative logit regression model for the ordinal cognition outcome, a stroke by ethnicity interaction was observed (P=0.01). Models stratified by ethnicity revealed that stroke was associated with cognitive impairment across ethnicities, but had greater impact on cognition in non-Hispanic Whites (cumulative odds ratio=3.81 [95% CI, 2.37-6.12]) than in MAs (cumulative odds ratio=1.58 [95% CI, 1.04-2.41]). Increased age and lower educational attainment were also associated with cognitive impairment, regardless of ethnicity.

CONCLUSIONS

History of stroke was associated with increased odds of cognitive impairment after controlling for other factors in both MA and Non-Hispanic White participants. The magnitude of the impact of stroke on cognition was less in MA than in Non-Hispanic White participants.

Age Profiles of Cognitive Decline and Dementia in Late Life in the Aging, Demographics, and Memory Study

OBJECTIVES

To better understand the temporal dynamics of progression from cognitive decline to onset of dementia in the dementia-free older population in the United States.

METHODS

We used longitudinal data from a diverse national population-based sample of older adults (N = 531) in the Aging, Demographics, and Memory Study from the Health and Retirement Study with repeated measures of cognitive function and dementia diagnosis during 12 years of follow-up from 1996 to 2009. We employed joint latent class mixed models to estimate the association between cognitive change and competing risks of dementia and nondementia death and identify heterogeneity in the age profiles of such association adjusting for baseline characteristics.

RESULTS

Our analyses found 3 latent classes with distinct age profiles of cognitive decline and associated risk of dementia and mortality: "Rapid Cognitive Decline" (19.6%), "Moderate Progression" (44.6%), and "Optimal Cognitive Aging" (35.8%). When simultaneously accounting for cognitive trajectories and time-to-dementia/death, we also found associations of baseline covariates with slope of cognitive decline (e.g., steeper decline among non-Hispanic Blacks and more educated) and risk of dementia (e.g., greater risk for females and apolipoprotein E-4 carriers, but no difference by education level) that differ substantially from those in separate longitudinal mixed models or survival models.

DISCUSSION

The differential age patterns of cognitive decline predicting dementia incidences identified in this study suggest variation in the course of cognitive aging in older adults that may inform future etiological and intervention studies.

Neuroimaging and cognitive correlates of retinal Optical Coherence Tomography (OCT) measures at late middle age in a twin sample

Sharing in embryology and function between the eye and brain has led to interest in whether assessments of the eye reflect brain changes seen in neurodegeneration. We aimed to examine the associations between measures of retinal layer thickness using optical coherence tomography (OCT) and multimodal measures of brain structure and function. Using a convenient sample of twins discordant for type 2 diabetes, we performed cognitive testing, structural brain MRI (tissue volumetry), diffusion tensor imaging (white matter microstructure), and arterial spin labelling (cerebral blood flow). OCT images were recorded and retinal thickness maps generated. We used mixed level modelling to examine the relationship between retinal layer thicknesses and brain measures. We enrolled 35 people (18 pairs, mean age 63.8 years, 63% female). Ganglion cell layer thickness was positively associated with memory, speed, gray matter volume, and altered mean diffusivity. Ganglion cell layer thickness was strongly positively associated with regional cerebral blood flow. We found only a limited number of associations between other retinal layer thickness and measures of brain structure or function. Ganglion cell layer thickness showed consistent associations with a range of brain measures suggesting it may have utility as a marker for future dementia risk.

Sex differences in post-stroke cognitive decline: A population-based longitudinal study of nationally representative data

Background

Sex differences in post-stroke cognitive decline have not been systematically evaluated in a nationally representative cohort. We use a quasi-experimental design to investigate sex differences in rate of post-stroke cognitive decline.

Methods

Utilizing the event study design, we use the Health and Retirement Study (HRS) data (1996–2016) to evaluate the differences (percentage points [95% Confidence interval]) in the rate of change in cognitive function, measured using the modified version of the Telephone Interview for Cognitive Status (TICS-m) score, before and after incident stroke, and among patients with and without incident stroke. We estimated this event study model for the overall study population and separately fit the same model for male and female participants.

Results

Of 25,872 HRS participants included in our study, 14,459 (55.9%) were females with an overall mean age (SD) of 61.2 (9.3) years. Overall, 2,911 (11.3%) participants reported experiencing incident stroke. Participants with incident stroke (vs. no stroke) had lower baseline TICS-m score (15.6 vs. 16.1). Among participants with incident stroke, the mean pre-stroke TICS-m score was higher than the mean post-stroke TICS-m score (14.9 vs. 12.7). Event study revealed a significant short-term acceleration of cognitive decline for the overall population (4.2 [1.7–6.6] percentage points, p value = 0.001) and among female participants (5.0 [1.7–8.3] percentage points, p value = 0.003). We, however, found no evidence of long-term acceleration of cognitive decline after stroke. Moreover, among males, incident stroke was not associated with significant changes in rate of post-stroke cognitive decline.

Conclusion

Females, in contrast to males, experience post-stroke cognitive deficits, particularly during early post-stroke period. Identifying the sex-specific stroke characteristics contributing to differences in post stroke cognitive decline may inform future strategies for reducing the burden of post-stroke cognitive impairment and dementia.

New Horizons-Cognitive Dysfunction Associated With Type 2 Diabetes

The prevalence of type 2 diabetes (T2D) and cognitive dysfunction increases with age. As society ages, clinicians will be increasingly tasked with managing older people who have both T2D and cognitive dysfunction. T2D is associated with an increased risk of cognitive dysfunction and hence there is increasing interest in whether T2D is a causal factor in the pathogenesis of cognitive decline and dementia. Recent advances in the use of sensitive measures of in vivo brain dysfunction in life-course studies can help understand potential mechanistic pathways and also help guide recommendations for clinical practice. In this article we will describe new horizons in the understanding of cognitive dysfunction associated with T2D. Coming from a clinical perspective, we discuss potential mechanisms and pathways linking the 2 conditions and the contribution of multimodal neuroimaging and study designs to advancing understanding in the field. We also highlight the important issues on the horizon that will need addressing in clinical identification, management, and risk reduction for people with coexistent T2D and cognitive dysfunction.

Post-Stroke Cognitive Impairment: Epidemiology, Risk Factors, and Management

Stroke, characterized as a neurological deficit of cerebrovascular cause, is very common in older adults. Increasing evidence suggests stroke contributes to the risk and severity of cognitive impairment. People with cognitive impairment following stroke often face with quality-of-life issues and require ongoing support, which have a profound effect on caregivers and society. The high morbidity of post-stroke cognitive impairment (PSCI) demands effective management strategies, in which preventive strategies are more appealing, especially those targeting towards modifiable risk factors. In this review article, we attempt to summarize existing evidence and knowledge gaps on PSCI: elaborating on the heterogeneity in current definitions, reporting the inconsistent findings in PSCI prevalence in the literature, exploring established or less established predictors, outlining prevention and treatment strategies potentially effective or currently being tested, and proposing promising directions for future research.

Memory Trajectories Before and After First and Recurrent Strokes

BACKGROUND AND OBJECTIVES

Evidence on timing of memory change after first and recurrent strokes is limited and inconsistent. We investigated memory trajectories before and after first and recurrent strokes in 18 European countries and tested whether the country-level acute stroke care was associated with memory change after stroke.

METHODS

Data were from the Survey of Health, Ageing and Retirement in Europe (2004-2019). Incident first and recurrent strokes were identified among baseline stroke-free individuals. Within each country, each participant with incident stroke (case group) was matched with a stroke-free individual (control group) using propensity score matching. We applied multilevel segmented linear regression to quantify acute and accelerated memory changes (measured by the sum score of immediate and delayed word recall tests; 0-20 words) before and after first and recurrent strokes in both groups. Associations between stroke and memory were compared between countries with different levels of acute stroke care indicators.

RESULTS

The final analytical sample included 35,164 participants who were stroke-free at baseline (≥50 years). A total of 2,362 incident first and 341 recurrent strokes between 2004 and 2019 were identified. In case groups, mean acute decreases in memory scores were 0.48 (95% confidence interval [CI] 0.31, 0.65) and 1.14 (95% CI 0.80, 1.48) words after first and recurrent stroke, respectively, independent of a range of confounders. No such acute decreases were observed in the control group after a hypothetical nonstroke onset date. In both groups, memory declined over time but decline rates were similar (-0.07 [95% CI -0.10, -0.05] vs -0.06 [95% CI -0.08, -0.05] words per year). The mean acute decreases in memory scores after first and recurrent strokes were smaller in countries with better access to endovascular treatment.

DISCUSSION

We found acute decreases but not accelerated declines in memory after first and recurrent strokes. Improved endovascular therapy might be associated with smaller memory loss after stroke but more evidence based on individual-level data is needed. More effort should be made in early assessment and intensive prevention of stroke among the ageing population and promoting access to and delivery of acute stroke care among patients with stroke.

Neurodegeneration and Vascular Burden on Cognition After Midlife: A Plasma and Neuroimaging Biomarker Study

Background and Objectives: Neurodegeneration and vascular burden are the two most common causes of post-stroke cognitive impairment. However, the interrelationship between the plasma beta-amyloid (Aβ) and tau protein, cortical atrophy and brain amyloid accumulation on PET imaging in stroke patients is undetermined. We aimed to explore: (1) the relationships of cortical thickness and amyloid burden on PET with plasma Aβ40, Aβ42, tau protein and their composite scores in stroke patients; and (2) the associations of post-stroke cognitive presentations with these plasma and neuroimaging biomarkers.

Methods: The prospective project recruited first-ever ischemic stroke patients around 3 months after stroke onset. The plasma Aβ40, Aβ42, and total tau protein were measured with the immunomagnetic reduction method. Cortical thickness was evaluated on MRI, and cortical amyloid plaque deposition was evaluated by ¹⁸F-florbetapir PET. Cognition was evaluated with Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), Dementia Rating Scale-2 (DRS-2).

Results: The study recruited 24 stroke patients and 13 normal controls. The plasma tau and tau*Aβ42 levels were correlated with mean cortical thickness after age adjustment. The Aβ42/Aβ40 ratio was correlated with global cortical ¹⁸F-florbetapir uptake value. The DRS-2 and GDS scores were associated with mean cortical thickness and plasma biomarkers, including Aβ42/Aβ40, tau, tau*Aβ42, tau/Aβ42, and tau/Aβ40 levels, in stroke patients.

Conclusion: Plasma Aβ, tau, and their composite scores were associated with cognitive performance 3 months after stroke, and these plasma biomarkers were correlated with corresponding imaging biomarkers of neurodegeneration. Further longitudinal studies with a larger sample size are warranted to replicate the study results.

Long-Term Cognitive Decline After Stroke: An Individual Participant Data Meta-Analysis

BACKGROUND AND PURPOSE

Poststroke cognitive impairment is common, but the trajectory and magnitude of cognitive decline after stroke is unclear. We examined the course and determinants of cognitive change after stroke using individual participant data from the Stroke and Cognition Consortium.

METHODS

Nine longitudinal hospital-based cohorts from 7 countries were included. Neuropsychological test scores and normative data were used to calculate standardized scores for global cognition and 5 cognitive domains. One-step individual participant data meta-analysis was used to examine the rate of change in cognitive function and risk factors for cognitive decline after stroke. Stroke-free controls were included to examine rate differences. Based on the literature and our own data that showed short-term improvement in cognitive function after stroke, key analyses were restricted to the period beginning 1-year poststroke to focus on its long-term effects.

RESULTS

A total of 1488 patients (mean age, 66.3 years; SD, 11.1; 98% ischemic stroke) were followed for a median of 2.68 years (25th-75th percentile: 1.21-4.14 years). After an initial period of improvement through up to 1-year poststroke, decline was seen in global cognition and all domains except executive function after adjusting for age, sex, education, vascular risk factors, and stroke characteristics (-0.053 SD/year [95% CI, -0.073 to -0.033]; P<0.001 for global cognition). Recurrent stroke and older age were associated with faster decline. Decline was significantly faster in patients with stroke compared with controls (difference=-0.078 SD/year [95% CI, -0.11 to -0.045]; P<0.001 for global cognition in a subgroup analysis).

CONCLUSIONS

Patients with stroke experience cognitive decline that is faster than that of stroke-free controls from 1 to 3 years after onset. An increased rate of decline is associated with older age and recurrent stroke.

Risk factors for delayed-onset dementia after stroke or transient ischemic attack-A five-year longitudinal cohort study

BACKGROUND

Stroke not only substantially increases the risk of incident dementia early after stroke but also the risk remains elevated years after.

AIM

We aimed to determine the risk factors of dementia onset more than three to six months after stroke or transient ischemic attack.

METHODS

This is a single-center prospective cohort study. We recruited consecutive subjects with stroke/transient ischemic attack without early-onset dementia. We conducted an annual neuropsychological assessment for five years. We investigated the association between baseline demographic, clinical, genetic (APOEɛ4 allele), and radiological factors as well as incident recurrent stroke with delayed-onset dementia using Cox proportional hazards models.

RESULTS

In total, 1007 patients were recruited, of which 88 with early-onset dementia and 162 who lost to follow-ups were excluded. Forty-nine (6.5%) out of 757 patients have incident delayed-onset dementia. The presence of ≥3 lacunes, history of ischemic heart disease, history of ischemic stroke, and a lower baseline Hong Kong version of the Montreal Cognitive Assessment (MoCA) score were significantly associated with delayed-onset dementia. APOEɛ4 allele, medial temporal lobe atrophy, and recurrent stroke were not predictive.

CONCLUSION

The presence of ≥3 lacunes, history of ischemic heart disease, history of ischemic stroke, and a lower baseline MoCA score are associated with delayed-onset dementia after stroke/transient ischemic attack.

Investigation of reactive astrogliosis effect on post-stroke cognitive impairment

BACKGROUND

The aim of this study is to investigate the associations between post-stroke cognitive impairment (PSCI) severity and reactive astrogliosis (RA) extent on normalized 18F-THK-5351 positron-emission tomography (PET) imaging in amyloid-negative patients with first-ever stroke.

METHODS

We prospectively enrolled 63 amyloid-negative patients with first-ever stroke. Neurocognitive evaluation, MRI, 18F-THK-5351, and 18F-florbetapir PET were performed around 3 months after stroke. The 18F-THK-5351 uptake intensity was normalized using a signal distribution template to obtain the Z-SUM scores as the RA extent in the whole brain and cerebral hemisphere ipsilateral to stroke lesion. We evaluated stroke volume, leukoaraiosis, and brain atrophy on MRI. We used a comprehensive neurocognitive battery to obtain composite cognitive scores, and defined PSCI as a general cognitive function score < - 1. We analyzed the influence of Z-SUM scores on PSCI severity after adjusting for demographic, vascular, and neurodegenerative variables.

RESULTS

Twenty-five of 63 stroke patients had PSCI. Patients with PSCI had older age, lower education, and more severe cortical atrophy and total Z-SUM scores. Total Z-SUM scores were significantly associated with general cognitive and executive functions at multiple regression models. Path analyses showed that stroke can exert cognitive influence directly by stroke itself as well as indirectly through RA, including total and ipsilateral Z-SUM scores, in patients with either right or left hemisphere stroke.

CONCLUSION

The patterns and intensity of 18F-THK-5351 uptake in amyloid-negative patients with first-ever stroke were associated with PSCI manifestations, which suggests that RA presents a modulating effect in PSCI development.

Predictors for Favorable Cognitive Outcome Post-Stroke: A-Seven-Year Follow-Up Study

BACKGROUND AND PURPOSE

Knowledge of the burden and development of post-stroke cognitive impairments (CIs) in the long-term after the first event is limited. We aimed to assess the prevalence of mild CI (MCI) and dementia 7 years after first-ever stroke or transient ischemic attack (TIA), to subclassify the impairments, and to identify predictors for a favorable cognitive outcome.

MATERIALS AND METHODS

During 2007 and 2008, 208 patients with first-ever stroke or TIA without preexisting CI were included. After 1 and 7 years, survivors were invited to a follow-up. Transitions of cognitive status from 1 to 7 years were recorded based on the 3 categories dementia, MCI, or none. Etiologic subclassification was based on clinical cognitive profile, magnetic resonance imaging (MRI) findings, and biomarkers at both time points. Favorable outcome was defined as normal cognitive function or MCI after 7 years with exclusion of those who had progression from normal to MCI.

RESULTS

Eighty patients died during follow-up, 12 patients refused further participation. After 7 years, 109 completed follow-up of whom 40 (37%) were diagnosed with MCI and 24 (22%) with dementia. Of the 64 patients diagnosed with CI, 9 were subclassified with degenerative cognitive disease, 13 with vascular disease, and 42 had mixed cognitive disease. In all, 65 patients (60%) had a favorable outcome. In multivariable logistic regression analysis, lower age and lower medial temporal lobe atrophy (MTLA) grade on MRI at 12 months were independently associated with a favorable outcome, adjusted OR (95% CI), 0.94 (0.86-0.92), and 0.55 (0.35-0.85), respectively.

CONCLUSIONS

Sixty percent of stroke survivors have a favorable cognitive outcome. Lower age and lower MTLA grade on MRI were associated with favorable outcome.

The Impact of Cognitive Impairment on Poststroke Outcomes: A 5-Year Follow-Up

AIM

To explore the impact of cognitive impairment poststroke on outcomes at 5 years.

METHODS

Five-year follow-up of the Action on Secondary Prevention Interventions and Rehabilitation in Stroke (ASPIRE-S) prospective cohort. Two hundred twenty-six ischemic stroke survivors completed Montreal Cognitive Assessments at 6 months poststroke. Outcomes at 5 years included independence in activities of daily living, receipt of informal care, quality of life, and depressive symptoms. Data were analyzed using logistic and linear regression models. Adjusted odds ratios (ORs; 95% confidence interval [CI]) and β coefficients (95% CI) are reported.

RESULTS

One hundred one stroke survivors were followed up at 5 years. Cognitive impairment at 6 months was independently associated with worse quality of life (B [95% CI]: -0.595 [-0.943 to -0.248]), lower levels of independence (B [95% CI]: -3.605 [-5.705 to -1.505]), increased likelihood of receiving informal care (OR [95% CI]: 6.41 [1.50-27.32]), and increased likelihood of depressive symptoms (OR [95% CI]: 4.60 [1.22-17.40]). Conclusion: Cognitive impairment poststroke is associated with a range of worse outcomes. More effective interventions are needed to improve outcomes for this vulnerable group of patients.

Progression of cognitive decline before and after incident stroke

OBJECTIVE

To determine the trajectory of cognitive decline before and after incident stroke.

METHODS

By using data from the English Longitudinal Study of Ageing, we studied 9,278 participants without dementia with no history of stroke who underwent cognitive assessment at baseline (wave 1) and at least 1 other time point (waves 2-7). We used linear mixed models to analyze repeated measures and longitudinal data.

RESULTS

Among the 9,278 participants (56.8% women, mean age 63.1 ± 10.3 years), 471 (5.1%) incident stroke events were identified. Compared with stroke-free participants, multivariable-adjusted rates of prestroke cognitive decline in global cognition, memory, semantic fluency, and temporal orientation of participants who later experienced an incident stroke were increased by -0.029 , -0.016, -0.022, and -0.024 SD/y, respectively. Among the 471 stroke survivors, the multivariable-adjusted acute changes in the 4 cognitive domains were -0.257, -0.150, -0.121, and -0.272 SD, respectively. In the years after stroke, global cognition declined over time and was steeper than its prestroke slope, that is, by -0.064 SD/y after multivariable adjustment. The rates of memory, semantic fluency, and temporal orientation decline were -0.046, -0.033, and -0.037 SD/y, respectively.

CONCLUSIONS

Accelerated prestroke cognitive decline and poststroke cognitive decline were associated with incident stroke over a follow-up period of 12 years. Attention should be paid to the long-term cognitive problems of stroke survivors, and intervention and management of major vascular risk factors should start from early life or midlife to reduce the risk of cerebrovascular disease and the associated cognitive impairment.

Stroke and dementia risk: A systematic review and meta-analysis

INTRODUCTION

Stroke is an established risk factor for all-cause dementia, though meta-analyses are needed to quantify this risk.

METHODS

We searched Medline, PsycINFO, and Embase for studies assessing prevalent or incident stroke versus a no-stroke comparison group and the risk of all-cause dementia. Random effects meta-analysis was used to pool adjusted estimates across studies, and meta-regression was used to investigate potential effect modifiers.

RESULTS

We identified 36 studies of prevalent stroke (1.9 million participants) and 12 studies of incident stroke (1.3 million participants). For prevalent stroke, the pooled hazard ratio for all-cause dementia was 1.69 (95% confidence interval: 1.49-1.92; P < .00001; I2 = 87%). For incident stroke, the pooled risk ratio was 2.18 (95% confidence interval: 1.90-2.50; P < .00001; I2 = 88%). Study characteristics did not modify these associations, with the exception of sex which explained 50.2% of between-study heterogeneity for prevalent stroke.

DISCUSSION

Stroke is a strong, independent, and potentially modifiable risk factor for all-cause dementia.

Increased risk for dementia both before and after stroke: A population-based study in women followed over 44 years

INTRODUCTION

Longitudinal studies are needed to understand the long-term associations between stroke and dementia.

METHODS

A population sample of 1460 women without stroke or dementia at baseline was followed over 44 years, from 1968 to 2012. Information on stroke and dementia was obtained from neuropsychiatric examinations, key-informant interviews, hospital registry, and medical records.

RESULTS

During 44 years follow-up, 362 women developed stroke and 325, dementia. The age-specific incidence of the two disorders was similar. The incidence of dementia was higher in those with stroke than among those without (33.7% vs. 18.5%; age-adjusted hazard ratio 1.44, 95% confidence interval 1.15-1.81). The increased risk of dementia started already 5 years before stroke, was highest 1 year after stroke, and continued more than 11 years after stroke.

DISCUSSION

There is an increased risk for dementia both before and after stroke. This has implications for understanding the relation between the two disorders and for prevention of dementia and stroke.

Stepwise impairment of neural stem cell proliferation and neurogenesis concomitant with disruption of blood-brain barrier in recurrent ischemic stroke

Stroke patients are at increased risk for recurrent stroke and development of post-stroke dementia. In this study, we investigated the effects of recurrent stroke on adult brain neurogenesis using a novel rat model of recurrent middle cerebral artery occlusion (MCAO) developed in our laboratory. Using BrdU incorporation, activation and depletion of stem cells in the subgranular zone (SGZ) and subventricular zone (SVZ) were assessed in control rats and rats after one or two strokes. In vitro neurosphere assay was used to assess the effects of plasma from normal and stroke rats. Also, EM and permeability studies were used to evaluate changes in the blood-brain-barrier (BBB) of the SGZ after recurrent stroke. We found that proliferation and neurogenesis was activated 14 days after MCAO. This was correlated with increased permeability in the BBB to factors which increase proliferation in a neurosphere assay. However, with each stroke, there was a stepwise decrease of proliferating stem cells and impaired neurogenesis on the ipsilateral side. On the contralateral side, this process stabilized after a first stroke. These studies indicate that stem cells are activated after MCAO, possibly after increased access to systemic stroke-related factors through a leaky BBB. However, the recruitment of stem cells for neurogenesis after stroke results in a stepwise ipsilateral decline with each ischemic event, which could contribute to post-stroke dementia.

Elevated CRP at admission predicts post-stroke cognitive impairment in Han Chinese patients with intracranial arterial stenosis

OBJECTIVES

Elevated C-reactive protein (CRP) levels have been associated with cognitive deficits in certain patient populations, but whether this is also true of ischemic stroke patients is controversial. This study aims to examine the possible association between CRP concentration and post-stroke cognitive impairment (PSCI) in Han Chinese patients and to determine whether this association depends on intracranial arterial stenosis (ICAS).

METHODS

Patients with mild or moderate stroke admitted to a large regional medical center in Western China were consecutively enrolled in our study. Serum levels of CRP and ICAS severity were assessed at admission and cognitive status was assessed 6 months after stroke using the Six-Item Screener.

RESULTS

Of the 1116 patients included in our study, no association was observed between CRP levels at admission and cognitive performance at 6 months. However, among the subgroup of 311 patients with ICAS, a significant association did exist, and it persisted even after adjusting for potential confounders (OR 1.038, 95% CI 1.015-1.061). We did not find the same association in the subgroup of the patients without ICAS.

CONCLUSIONS

To our knowledge, this is the first study to explore the effects of CRP on PSCI in Han Chinese with ICAS. Our findings indicate that higher CRP levels at admission are associated with subsequent cognitive decline in Han Chinese patients with ICAS following ischemic stroke. Further studies in other ethnic groups are needed to validate the use of CRP to predict dementia in ICAS patients.

Development and validation of a risk score (CHANGE) for cognitive impairment after ischemic stroke

Post-stroke cognitive impairment (PSCI) warrants early detection and management. We sought to develop a risk score for screening patients at bedside for risk of delayed PSCI. Ischemic stroke survivors with PSCI and no cognitive impairments (NCI) 3-6 months post-stroke were studied to identify candidate variables predictive of PSCI. These variables were used to develop a risk score using regression models. The score, and the best identified clinical cutoff point, underwent development, stability testing, and internal and external validation in three independent cohorts from Singapore and Hong Kong. Across 1,088 subjects, the risk score, dubbed CHANGE, had areas under the receiver operating characteristics curve (AUROC) from 0.74 to 0.82 in detecting significant risk for PSCI, and had predicted values following actual prevalence. In validation data 3-6 and 12-18 months post-stroke, subjects with low, medium, and high scores had PSCI prevalence of 7-23%, 25-58%, and 67-82%. CHANGE was effective in screening ischemic stroke survivors for significant risk of developing PSCI up to 18 months post-stroke. CHANGE used readily available and reliable clinical data, and may be useful in identifying at-risk patients for PSCI.

Vascular Contributions to Cognitive Impairment in Late Life

Cerebrovascular disease (CVD) is the second leading cause of cognitive impairment in late life. Structural neuroimaging offers the most sensitive and specific biomarkers for hemorrhages and infarcts, but there are significant limitations in its ability to detect microvascular disease, microinfarcts, dynamic changes in the blood-brain barrier, and preclinical cerebrovascular disease. Autopsy studies disclose the common co-occurrence of vascular and neurodegenerative conditions, suggesting that in late life, a multifactorial approach to cognitive impairment may be more appropriate than traditional dichotomous classifications. Management of vascular risk factors remains a proven and practical approach to reducing acute and progressive cognitive impairment and dementia.

Early-onset and delayed-onset poststroke dementia - revisiting the mechanisms

Incident stroke has long been recognized to cause dementia shortly after the event. Patients who survive stroke without early-onset poststroke dementia (PSD) are at a high risk of developing dementia months to years after the initial stroke incident, which has generated enthusiasm for exploring treatments to prevent delayed-onset PSD in survivors of stroke. However, results from clinical trials completed in the past 10-15 years have been disappointing. In light of these results, the present Review revisits the mechanisms of both early-onset and delayed-onset PSD and proposes preventive strategies and directions for future clinical trials. Early-onset PSD results from a complex interplay between stroke lesion features and brain resilience, whereas delayed-onset PSD is associated mainly with the presence of severe sporadic small vessel disease (SVD), and to a lesser extent with Alzheimer disease pathology or recurrent stroke. As well as preventing stroke and delivering acute stroke treatments to reduce initial brain damage, measures to increase brain resilience could also reduce the risk of developing dementia if an incident stroke occurs. Future efforts to prevent delayed-onset PSD should focus on the study of sporadic SVD and on evaluating whether other strategies, in addition to conventional secondary stroke prevention, are effective in dementia prevention in this high-risk group.

STROKOG (stroke and cognition consortium): An international consortium to examine the epidemiology, diagnosis, and treatment of neurocognitive disorders in relation to cerebrovascular disease

INTRODUCTION

The Stroke and Cognition consortium (STROKOG) aims to facilitate a better understanding of the determinants of vascular contributions to cognitive disorders and help improve the diagnosis and treatment of vascular cognitive disorders (VCD).

METHODS

Longitudinal studies with ≥75 participants who had suffered or were at risk of stroke or TIA and which evaluated cognitive function were invited to join STROKOG. The consortium will facilitate projects investigating rates and patterns of cognitive decline, risk factors for VCD, and biomarkers of vascular dementia.

RESULTS

Currently, STROKOG includes 25 (21 published) studies, with 12,092 participants from five continents. The duration of follow-up ranges from 3 months to 21 years.

DISCUSSION

Although data harmonization will be a key challenge, STROKOG is in a unique position to reuse and combine international cohort data and fully explore patient level characteristics and outcomes. STROKOG could potentially transform our understanding of VCD and have a worldwide impact on promoting better vascular cognitive outcomes.

Association of dementia with death after ischemic stroke: A two-year prospective study

The association between dementia and the risk of death after ischemic stroke was investigated. Neurological, neuropsychological and functional assessments were evaluated in 619 patients with acute ischemic stroke. Dementia was diagnosed at admission and at three months after stroke onset. The patients were scheduled for a two-year follow-up after the index stroke. The Kaplan-Meier survival and Cox proportional hazards regression analyses were used to estimate the cumulative proportion of survival, and the association between dementia and risk of death after stroke. In total, 146 patients (23.6%) were diagnosed with dementia after stroke. The cumulative proportion of surviving cases was 49.3% in patients with dementia after a median follow-up of 21.2±5.6 months, and 92.5% in patients without dementia. Multivariate analysis revealed that dementia (HR, 7.21; 95% CI, 3.85–13.49) was associated with death, independent of age, atrial fibrillation, previous stroke and NIH stroke scale. In conclusion, the mortality rate is increased in stroke patients with dementia. Dementia is an important risk factor for death after stroke, independent of age, atrial fibrillation, previous stroke, and the severity of the stroke.

Delayed-onset dementia after stroke or transient ischemic attack

INTRODUCTION

Patients surviving stroke without immediate dementia are at high risk of delayed-onset dementia. Mechanisms underlying delayed-onset dementia are complex and may involve vascular and/or neurodegenerative diseases.

METHODS

Dementia-free patients with stroke and/or transient ischemic attack (TIA; n = 919) were studied for 3 years prospectively, excluding those who developed dementia 3 to 6 months after stroke and/or TIA.

RESULTS

Forty subjects (4.4%) developed dementia during the study period. Imaging markers of severe small vessel disease (SVD), namely presence of ≥3 lacunes and confluent white matter changes; history of hypertension and diabetes mellitus independently predicted delayed-onset dementia after adjustment for age, gender, and education. Only 6 of 31 (19.4%) subjects with delayed cognitive decline harbored Alzheimer's disease-like Pittsburg compound B (PiB) retention. Most PiB cases (16/25, 64%) had evidence of severe SVD.

DISCUSSION

Severe SVD contributes importantly to delayed-onset dementia after stroke and/or TIA. Future clinical trials aiming to prevent delayed-onset dementia after stroke and/or TIA should target this high-risk group.

Application and Revision of Montreal Cognitive Assessment in China's Military Retirees with Mild Cognitive Impairment

Objective

In an effort to accommodate MOCA to better fit for the Chinese context, this study was designed to employ the MOCA criteria to screen mild cognitive impairment (MCI) and analyze associated risk factors in military retirees.

Methods

Three hundred and four retired military cadres were recruited using a random cluster sampling technique with information collected including personal, prevalence, MOCA scale, and related neuropsychiatry scale. Thirty retirees were randomly chosen to be further analyzed one month later using the revised MOCA scale.

Results

①Our data indicated an incidence rate of 64.8% for mild cognitive impairment in retired military cadres. The incidence rate for MCI was significantly higher in those aged 80 or above compared with those 80 years of age or younger (P<0.05). The incidence rate of MCI was significantly higher in those with fewer than 6 years of education compared with those with over 7 years of education (P<0.05). The MCI incidence was higher for those with little exercise than those taking regular exercise (P<0.01). Moreover, the MCI incidence was higher in stroke patients than those who never had a stroke episode (P<0.05). ②There was a significant correlation between MOCA and MMSE scale scores (r = 0.81). MOCA scale scores were negatively correlated with ADL and CES-D scores (although not PSQI scores). ③ MOCA recension Cronbach’s alpha value was 0.862. The related coefficient of MOCA and MOCA recension was 0.878(P<0.01). When the Score of cut-off -point of the MOCA recension was 28, the area in ROC curve analyses was 0.859, as well as the largest area.

Conclusion

Retired cadres exhibited a greater incidence of MCI (than general population), which was closely associated with age, level of education and physical exercise and cerebral apoplexy. Revised MOCA scale displays a better validity and reaction degree of reliability and is more suitable for screening and diagnosis of MCI in the elderly in China.

Role of neuroimaging in multidisciplinary approach towards Non-Alzheimer's dementia

Dementia is defined as chronic deterioration of intellectual function and cognitive skills significant enough to interfere with the ability to perform daily activities. Recent advances in the treatment of dementia have renewed interest in the use of various neuroimaging techniques that can assist in the diagnosis and differentiation of various subtypes. Neuroimaging and computational techniques have helped the radiological community to monitor disease progression of various neurodegenerative conditions presenting with dementia, such as Alzheimer disease, frontotemporal lobe dementia (FTLD), progressive supranuclear palsy (PSP) and multisystem atrophy-cerebellar variant (MSA-C), and their response to newer therapies. Prompt identification of treatable or reversible forms of dementia, such as tumours, subdural haemorrhage and intracranial dAVF, is crucial for the effective management of these conditions. It is also prudent to recognize the imaging spectrum of metabolic, infective and autoimmune diseases with rapidly progressing dementia, such as methanol toxicity, central pontine myelinolysis (CPM), delayed post hypoxic leukoencephalopathy (DPHL), HIV, Creutzfeldt-Jakob Disease (CJD), Sjogren's syndrome, multiple sclerosis (MS), radiation necrosis and Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS), which are difficult to treat and often require palliative care. This pictorial review emphasizes various non-Alzheimer’s dementia entities and discusses their imaging highlights.

Teaching Points

• Non Alzheimer’s dementia constitutes a broad spectrum of conditions.

• Neuroimaging plays an important role in differentiating treatable from irreversible dementia.

• Neuroimaging is often non-specific in early stages of neurodegenerative conditions with dementia.

• Neuroimaging plays an important role in the multimodal approach towards management of dementia.

Trajectory of Cognitive Decline After Incident Stroke

IMPORTANCE

Cognitive decline is a major cause of disability in stroke survivors. The magnitude of survivors' cognitive changes after stroke is uncertain.

OBJECTIVE

To measure changes in cognitive function among survivors of incident stroke, controlling for their prestroke cognitive trajectories.

DESIGN, SETTING, AND PARTICIPANTS

Prospective study of 23,572 participants 45 years or older without baseline cognitive impairment from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, residing in the continental United States, enrolled 2003-2007 and followed up through March 31, 2013. Over a median follow-up of 6.1 years (interquartile range, 5.0-7.1 years), 515 participants survived expert-adjudicated incident stroke and 23,057 remained stroke free.

EXPOSURE

Time-dependent incident stroke.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in global cognition (Six-Item Screener [SIS], range, 0-6). Secondary outcomes were change in new learning (Consortium to Establish a Registry for Alzheimer Disease Word-List Learning; range, 0-30), verbal memory (Word-List Delayed Recall; range, 0-10), and executive function (Animal Fluency Test; range, ≥0), and cognitive impairment (SIS score <5 [impaired] vs ≥5 [unimpaired]). For all tests, higher scores indicate better performance.

RESULTS

Stroke was associated with acute decline in global cognition (0.10 points [95% CI, 0.04 to 0.17]), new learning (1.80 points [95% CI, 0.73 to 2.86]), and verbal memory (0.60 points [95% CI, 0.13 to 1.07]). Participants with stroke, compared with those without stroke, demonstrated faster declines in global cognition (0.06 points per year faster [95% CI, 0.03 to 0.08]) and executive function (0.63 points per year faster [95% CI, 0.12 to 1.15]), but not in new learning and verbal memory, compared with prestroke slopes. Among survivors, the difference in risk of cognitive impairment acutely after stroke, compared with immediately before stroke, was not statistically significant (odds ratio, 1.32 [95% CI, 0.95 to 1.83]; P = .10); however, there was a significantly faster poststroke rate of incident cognitive impairment compared with the prestroke rate (odds ratio, 1.23 per year [95% CI, 1.10 to 1.38]; P < .001). For a 70-year-old black woman with average values for all covariates at baseline, stroke at year 3 was associated with greater incident cognitive impairment: absolute difference of 4.0% (95% CI, -1.2% to 9.2%) at year 3 and 12.4% (95% CI, 7.7% to 17.1%) at year 6.

CONCLUSIONS AND RELEVANCE

Incident stroke was associated with an acute decline in cognitive function and also accelerated and persistent cognitive decline over 6 years.

Progression of cognitive impairment in stroke/TIA patients over 3 years

OBJECTIVES

To examine how cognitive deficits progress in the years following a stroke or transient ischaemic attack (TIA).

METHODS

A follow-up study, with neuropsychological and MRI assessments undertaken 3 years after baseline assessments made 3-6 months poststroke in 183 stroke/TIA patients and 97 healthy controls participating in the Sydney Stroke Study. Additional measures included cardiovascular risk factors and apolipoprotein E (APOE) genotype.

RESULTS

Stroke/TIA patients had poorer cognitive function and more vascular risk factors than controls at baseline, but did not show greater decline in cognitive function over 3 years except for verbal memory. Patients with a subsequent stroke/TIA showed greater decline in global cognitive function and a number of domains. Rates of incident dementia were 5.9% per year in patients and 0.4% in controls. Both groups showed increased atrophy of the hippocampus, amygdala and whole brain, and an increase in white matter hyperintensities over 3 years; whole brain atrophy was greater in patients. Cognitive decline was greater in women and in those with smaller hippocampi at baseline. For patients without a subsequent stroke/TIA, those with smaller hippocampi or the APOE ε4 allele had greater global cognitive and verbal memory decline.

CONCLUSIONS

In poststroke patients, cognitive decline was not greater than in comparison subjects, except for verbal memory, unless they had another stroke/TIA. However, dementia incidence was higher in patients, as might be expected from their poorer baseline cognitive functioning. Smaller hippocampi were associated with an increased risk of decline in memory, and APOE ε4 was a risk factor in those without a subsequent stroke/TIA.

The importance of cognition to quality of life after stroke

OBJECTIVE

Suffering a stroke typically has a negative impact on a person's quality of life. There is some evidence that post-stroke cognitive impairment is associated with poor quality of life, but the relative importance of deficits in different cognitive domains has not been established.

METHODS

Patients with confirmed stroke were recruited in the acute hospital. A subgroup of patients completed 2 computerized cognitive tasks (simple and choice reaction time) within 2 weeks of stroke. The full cohort was followed up at 3 months with a comprehensive neuropsychological battery and then at 12 months with the Assessment of Quality of Life ('AQoL).

RESULTS

Sixty patients participated in the study (mean age 72.1 years, SD 13.9), with a subgroup of 33 patients tested acutely (mean age 75.5 years, SD 11.9). Presence of cognitive impairment at 3 months was independently associated with lower quality of life at 12 months (p=0.021). Attention and visuospatial ability were the cognitive domains most closely associated with quality of life. Faster choice reaction time in the acute stage (mean 5.4 days post-stroke) was significantly associated with better quality of life at 12 months (p=0.003).

CONCLUSION

Cognition, particularly attention and visuospatial ability, is strongly associated with quality of life after stroke. It is possible that straightforward reaction time tasks are sensitive to the extent of brain damage, and might therefore be surrogate markers for quality of life.

Cognitive state following stroke: the predominant role of preexisting white matter lesions

Background and purpose

Stroke is a major cause of cognitive impairment and dementia in adults, however the role of the ischemic lesions themselves, on top of other risk factors known in the elderly, remains controversial. This study used structural equation modeling to determine the respective impact of the new ischemic lesions' volume, preexisting white matter lesions and white matter integrity on post stroke cognitive state.

Methods

Consecutive first ever mild to moderate stroke or transient ischemic attack patients recruited into the ongoing prospective TABASCO study underwent magnetic resonance imaging scans within seven days of stroke onset and were cognitively assessed one year after the event using a computerized neuropsychological battery. The volumes of both ischemic lesions and preexisting white matter lesions and the integrity of the normal appearing white matter tissue were measured and their contribution to cognitive state was assessed using structural equation modeling path analysis taking into account demographic parameters. Two models were hypothesized, differing by the role of ischemic lesions' volume.

Results

Structural equation modeling analysis of 142 patients confirmed the predominant role of white matter lesion volume (standardized path coefficient β = −0.231) and normal appearing white matter integrity (β = −0.176) on the global cognitive score, while ischemic lesions' volume showed no such effect (β = 0.038). The model excluding the ischemic lesion presented better fit to the data (comparative fit index 0.9 versus 0.092).

Conclusions

Mild to moderate stroke patients with preexisting white matter lesions are more vulnerable to cognitive impairment regardless of their new ischemic lesions. Thus, these patients can serve as a target group for studies on cognitive rehabilitation and neuro-protective therapies which may, in turn, slow their cognitive deterioration.

Charting Cognitive and Volumetric Trajectories after Stroke: Protocol for the Cognition and Neocortical Volume after Stroke (CANVAS) Study

Rationale

Globally, stroke and dementia are leading causes of disability and mortality. More than one third of stroke patients will develop dementia, but mechanisms are unclear.

Aims

The study aims to establish whether brain volume change is associated with poststroke dementia, and to elucidate potential causal mechanisms, including genetic markers, amyloid deposition and vascular risk factors. An understanding of whether – and in whom – stroke is neurodegenerative is critical for the strategic use of potential disease-modifying therapies.

Hypotheses

That stroke patients will exhibit greater brain volume loss than comparable cohorts of stroke-free controls; and that those who develop dementia will exhibit greater brain volume loss than those who do not.

Design

Advanced brain imaging techniques are used to longitudinally measure brain volume and cortical thickness in 135 stroke patients. Concurrent neuropsychological testing will correlate clinical profile with these measures.

Primary outcomes

Primary imaging end-point is brain volume change between three-months and three-years poststroke; primary clinical outcome is the presence of dementia at three-years.

Secondary outcomes

We will examine the correlations with the following variables: dementia subtype; physical activity levels; behavioral dysfunction as measured by patient and caregiver-reported scales; structural and functional brain connectivity disruption; apolipoprotein E; and specific neuropsychological test scores.

Discussion

Magnetic resonance imaging markers of structural brain aging and performance on neuropsychological tests are powerful predictors of dementia. We need to understand the trajectory of regional brain volume change and cognitive decline in patients after stroke. This will allow future risk stratification for prognostic counseling, service planning, and early therapeutic intervention.

Prevention of Poststroke Cognitive Decline: ASPIS – a Multicenter, Randomized, Observer-Blind, Parallel Group Clinical Trial to Evaluate Multiple Lifestyle Interventions – Study Design and Baseline Characteristics

Background

Cognitive impairment after stroke is a considerable burden to patients and their caregivers and occurs in one-third of stroke survivors. No strategy to prevent cognitive decline after stroke exists thus far. Established vascular risk factors have been associated with cognitive decline and may be a target for therapeutic interventions in stroke survivors.

Aim

To test whether intensive multifactorial non-pharmacologic interventions based on lifestyle modification can reduce the risk of cognitive decline in patients who recently suffered ischemic stroke.

Methods

A randomized, controlled, multicenter, observer-blind trial was designed. The reference group obtains stroke care according to standard guidelines. The intervention group additionally receives intensive control and motivation for better compliance with prescribed evidence-based medication, regular blood pressure measurements, healthy diet, regular physical activity and cognitive training. Primary outcomes are the rate of cognitive decline at 24 months, assessed by a neuropsychological test battery and the cognitive subscale of the Alzheimer's Disease Assessment Scale.

Results

202 patients (29% women), aged 62 ± 9 years, were recruited during 2010 to 2012. Stroke related impairment at inclusion was low (mean National Institutes of Health Stroke Scale: 1.9±1.8, median modified Rankin Scale: 1 (0-1)). At baseline, groups did not differ significantly in demographic, clinical or lifestyle characteristics.

Conclusion

The recruitment was successful and the groups are balanced regarding potential confounding variables. The study will provide essential data about the feasibility and efficacy of lifestyle intervention after stroke in order to develop a new approach to prevent cognitive decline in patients with mild ischemic stroke.

Does the influence of stroke on dementia vary by different levels of prestroke cognitive functioning?: a cohort study

BACKGROUND AND PURPOSE

The association between stroke and subsequent dementia or Alzheimer disease is well established. What is less understood is the extent to which this association is dependent on prestroke cognitive functioning. The study estimated the occurrence in poststroke dementia as a function of prestroke cognitive status and incident stroke.

METHODS

Study data were derived from the English Longitudinal Study of Ageing, a 10-year long prospective cohort study of older adults living in England. Baseline data (2002/2003) were used to group participants into tertiles of cognitive, memory, and executive functioning before an incident stroke. Data from 4 follow-up surveys were used to identify new stroke and poststroke dementia events.

RESULTS

The analyses were based on 10 809 participants aged≥50 years at baseline. High prestroke executive functioning was associated with lower relative risk (RR) of dementia (RR, 0.24; 95% confidence interval, 0.13-0.45; P<0.001). Stroke was associated with increased RR of poststroke dementia (RR, 2.63; 95% confidence interval, 1.80-3.84; P<0.001). The association of stroke with poststroke dementia was greater for participants with higher prestroke executive functioning (interaction term RR, 4.4; 95% confidence interval, 1.35-14.63; P=0.014). For participants with higher executive functioning, the probability of dementia was 0.3% without stroke and 3.1% after stroke, compared with 1.9% and 5.2% for lower executive functioning.

CONCLUSIONS

Stroke and prestroke cognition were independently associated with increased probability of poststroke dementia. Stroke results in disproportionate increase in the risk of dementia when premorbid cognitive functioning is high.

Impact of gender and blood pressure on poststroke cognitive decline among older Latinos

BACKGROUND

Poststroke cognitive decline (PSCD) is an important consequence of stroke that may be more severe in women than in men. The existence of any gender differences in PSCD among Mexican Americans, and their potential mechanisms, such as blood pressure (BP), remain unknown. We assessed PSCD stratified on gender in older Mexican Americans and explored the influence of pre- and poststroke systolic BP on PSCD.

METHODS

Among 1576 nondemented, stroke-free adults 60 years of age or older when recruited between 1998 and 1999 in the Sacramento Area Latino Study on Aging (SALSA) cohort, we examined pre- and poststroke longitudinal changes in Spanish English Verbal Learning test scores (WL), a verbal memory test, and errors on the Modified Mini Mental State Examination (3MSE) scores, a global cognition test, stratified by gender, adjusting for baseline and time-varying covariates with linear mixed effects models.

RESULTS

We identified 151 adults (mean age 72 ± 8 years) with incident first-ever stroke during 10 years of follow-up. After adjustment for age, education, and time-varying depressive symptoms, 3MSE errors increased by 22% per year (95% confidence interval [CI] 6.8-36.7%) in men and 13.2% per year (95% CI 3.5-22.9%) in women over the poststroke period. Poststroke WL scores improved by 0.05 words per year (95% CI -0.24 to 0.33) in men and by 0.09 words per year (95% CI -0.16 to 0.34) in women. Results persisted after adjustment for time-varying systolic BP.

CONCLUSIONS

Among this population of older Mexican Americans, PSCD did not differ by gender. We found no evidence that systolic BP influenced PSCD in women or men.

Montreal Cognitive Assessment and Mini-Mental State Examination are both valid cognitive tools in stroke

OBJECTIVE

To determine the validity of the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) as screening tools for cognitive impairment after stroke.

MATERIALS AND METHODS

Cognitive assessments were administered over 2 sessions (1 week apart) at 3 months post-stroke. Scores on the MoCA and MMSE were evaluated against a diagnosis of cognitive impairment derived from a comprehensive neuropsychological battery (the criterion standard).

RESULTS

Sixty patients participated in the study [mean age 72.1 years (SD = 13.9), mean education 10.5 years (SD = 3.9), median acute NIHSS score 5 (IQR 3-7)]. The MoCA yielded lower scores (median = 21, IQR = 17-24; mean = 20.0, SD = 5.4) than the MMSE (median = 26, IQR = 22-27; mean = 24.2, SD = 4.5). MMSE data were more skewed towards ceiling than MoCA data (skewness = -1.09 vs -0.73). Area under the receiver operator curve was higher for MoCA than for MMSE (0.87 vs 0.84), although this difference was not significant (χ(2) = 0.48, P = 0.49). At their optimal cut-offs, the MoCA had better sensitivity than the MMSE (0.92 vs 0.82) but poorer specificity (0.67 vs 0.76).

CONCLUSIONS

The MoCA is a valid screening tool for post-stroke cognitive impairment; it is more sensitive but less specific than the MMSE. Contrary to the prevailing view, the MMSE also exhibited acceptable validity in this setting.

Stroke, cognitive deficits, and rehabilitation: still an incomplete picture

Cognitive impairment after stroke is common and can cause disability with major impacts on quality of life and independence. There are also indirect effects of cognitive impairment on functional recovery after stroke through reduced participation in rehabilitation and poor adherence to treatment guidelines. In this article, we attempt to establish the following: ● whether there is a distinct profile of cognitive impairment after stroke; ● whether the type of cognitive deficit can be associated with the features of stroke-related damage; and ● whether interventions can improve poststroke cognitive performance. There is not a consistent profile of cognitive deficits in stroke, though slowed information processing and executive dysfunction tend to predominate. Our understanding of structure-function relationships has been advanced using imaging techniques such as lesion mapping and will be further enhanced through better characterization of damage to functional networks and identification of subtle white matter abnormalities. Effective cognitive rehabilitation approaches have been reported for focal cortical deficits such as neglect and aphasia, but treatments for more diffusely represented cognitive impairment remain elusive. In the future, the hope is that different techniques that have been shown to promote neural plasticity (e.g., exercise, brain stimulation, and pharmacological agents) can be applied to improve the cognitive function of stroke survivors.

The cog-4 subset of the national institutes of health stroke scale as a measure of cognition: relationship with baseline factors and functional outcome after stroke using data from the virtual international stroke trials archive

Background. Assessing poststroke cognitive impairment is complex. A subscale of the NIHSS, the Cog-4, has been proposed as a quick test of "cognitive impairment." but a study of its properties in a larger dataset is lacking. Methods. Data from 9,147 patients with acute stroke from the VISTA archive was used to generate Cog-4 scores. The statistical properties of Cog-4, its relationship with baseline clinical characteristics, and other functional outcome measures at day 90 were assessed. Results. Mean age of patients was 69.2 years and 45.8%, were females. Day-90 Cog-4 was highly positively skewed (skewness 0.926). Patients with left hemispheric stroke had higher day-90 Cog-4 score (P < 0.001). Age, stroke severity, and previous stroke were significant predictors of Cog-4. Cog-4 was significantly correlated with dependency (modified Rankin Scale, r s = 0.512), and disability (Barthel Index, r s = -0.493). Conclusions. The Cog-4 scale at day 90 cannot be considered a useful test of cognition since it only superficially measures cognition. It is heavily dependent on the side of stroke, is inevitably associated with functional outcome (being a subset of the NIHSS), and suffers from a profound "floor" effect. Specific and validated measures are more appropriate for the assessment of poststroke cognition than Cog-4.

Cerebrolysin for vascular dementia

BACKGROUND

Vascular dementia is a common disorder without definitive treatments. Cerebrolysin seems to be a promising intervention based on its potential neurotrophic and pro-cognitive effects, but studies of its efficacy have yielded inconsistent results.

OBJECTIVES

To assess the efficacy and safety of Cerebrolysin for vascular dementia.

SEARCH METHODS

We searched ALOIS - the Cochrane Dementia and Cognitive Improvement Group's Specialized Register on 4 November 2012 using the terms: Cerebrolysin, Cere, FPF1070, FPF-1070. ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases, numerous trial registries and grey literature sources.

SELECTION CRITERIA

All randomized controlled trials of Cerebrolysin for treating vascular dementia without language restriction.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials and evaluated the methodological quality, then extracted and analysed data from the included trials.

MAIN RESULTS

Six randomized controlled trials with a total of 597 participants were eligible. The meta-analyses revealed a beneficial effect of Cerebrolysin on general cognitive function measured by mini-mental state examination (MMSE) (weighted mean difference (WMD) 1.10; 95% confidence interval (CI) 0.37 to 1.82) or Alzheimer's Disease Assessment Scale Cognitive Subpart, extended version (ADAS-cog+) (WMD -4.01; 95% CI -5.36 to -2.66). It also improved patients' global clinical function evaluated by the response rates (relative risk (RR) 2.71, 95% CI 1.83 to 4.00). Only non-serious adverse events were observed in the included trials, and there was no significant difference in occurrence of non-serious side effects between groups (RR 0.97, 95% CI 0.49 to 1.94).

AUTHORS' CONCLUSIONS

Cerebrolysin may have positive effects on cognitive function and global function in elderly patients with vascular dementia of mild to moderate severity, but there is still insufficient evidence to recommend Cerebrolysin as a routine treatment for vascular dementia due to the limited number of included trials, wide variety of treatment durations and short-term follow-up in most of the trials.

Epidemiology of Alzheimer disease

The global prevalence of dementia has been estimated to be as high as 24 million, and is predicted to double every 20 years until at least 2040. As the population worldwide continues to age, the number of individuals at risk will also increase, particularly among the very old. Alzheimer disease is the leading cause of dementia beginning with impaired memory. The neuropathological hallmarks of Alzheimer disease include diffuse and neuritic extracellular amyloid plaques in brain that are frequently surrounded by dystrophic neurites and intraneuronal neurofibrillary tangles. The etiology of Alzheimer disease remains unclear, but it is likely to be the result of both genetic and environmental factors. In this review we discuss the prevalence and incidence rates, the established environmental risk factors, and the protective factors, and briefly review genetic variants predisposing to disease.

Predictors for cognitive decline in patients with confluent white matter hyperintensities

BACKGROUND

Although patients harboring confluent white matter hyperintensities (WMH) are at high risk of cognitive decline, this risk varies among individuals. We investigated the predictors for cognitive decline in stroke patients with confluent WMH.

METHODS

We followed up 100 stroke patients with confluent WMH who were participants of the VITAmins TO Prevent Stroke study for 2 years. We investigated the association between clinical features, apolipoprotein E status, imaging measures (infarcts, microbleeds, volumes of WMH, cortical gray matter [cGM], lateral ventricles, and hippocampi), and B vitamins with changes in cognitive measures (clinical dementia rating scale, Mini-Mental State Examination, Mattis dementia rating scale--initiation/perseveration subscale). We performed Pittsburgh compound B imaging among dementia converters.

RESULTS

Multivariate regression analysis showed that increase in clinical dementia rating scale grade was associated with cGM atrophy, absence of hyperlipidemia, and lower diastolic blood pressure at baseline. cGM atrophy and absence of hyperlipidemia were also associated with deterioration in Mini-Mental State Examination and Mattis dementia rating scale--initiation/perseveration subscale scores. Pittsburgh compound B retention typical of Alzheimer's disease was found only in 10% of dementia converters. Incident stroke and B vitamins were not associated with cognitive decline.

CONCLUSIONS

Among stroke patients with confluent WMH, cGM atrophy and absence of hyperlipidemia are important predictors for cognitive decline. Significant cognitive decline can occur in the absence of incident stroke or Alzheimer's pathology.