Clinical determinants of dementia related to stroke

Association of socioeconomic status and poststroke cognitive function: A systematic review and meta-analysis

BACKGROUND

Stroke survivors are at high risk of coping with cognitive problems after stroke. In recent decades, the relationship between socioeconomic status (SES) and health-related outcomes has been a topic of considerable interest. Learning more about the potential impact of SES on poststroke cognitive dysfunction is of great importance.

OBJECTIVE

The purpose of this systematic review and meta-analysis was to summarize the association between SES and poststroke cognitive function by quantifying the effect sizes of the existing studies.

METHOD

We searched studies from PubMed, Ovid, Embase, Cochrane, Scopus, and PsychINFO up to January 30th 2024 and the references of relevant reviews. Studies reporting the risk of poststroke cognitive dysfunction as assessed by categorized SES indicators were included. The Newcastle-Ottawa scale and the Agency for Healthcare Research and Quality were used to evaluate the study quality. Meta-analyses using fixed-effect models or random-effect models based on study heterogeneity were performed to estimate the influence of SES on cognitive function after stroke, followed by subgroup analyses stratified by study characteristics.

RESULTS

Thirty-four studies were eligible for this systematic review and meta-analysis. Of which, 19 studies reported poststroke cognitive impairment (PSCI) as the outcome, 13 reported poststroke dementia (PSD), one reported both PSCI and PSD, and one reported vascular cognitive impairment no dementia. The findings showed that individuals with lower SES levels had a higher risk of combined poststroke cognitive dysfunction (odds ratio (OR) = 1.91, 95% confidence interval (CI) = 1.59-2.29), PSCI (OR = 2.09, 95% CI = 1.57-2.78), and PSD (OR = 1.95, 95% CI = 1.48-2.57). Subgroup analyses stratified by SES indicators demonstrated the protective effects of education and occupation against the diagnoses of combined poststroke cognitive dysfunction, PSCI, and PSD.

CONCLUSIONS

Stroke survivors belonging to a low SES are at high risk of poststroke cognitive dysfunction. Our findings add evidence for public health strategies to reduce the risk of poststroke cognitive dysfunction by reducing SES inequalities.

Analysis of radiological features in patients with post-stroke depression and cognitive impairment

Post-stroke depression (PSD) and post-stroke cognitive impairment (PSCI) are common complications following a stroke, significantly impacting the quality of life and survival time of survivors. Currently, the comorbidity of PSCI and PSD is receiving increasing attention, as they share some common clinical characteristics, mechanisms, risk factors, radiological features, and treatment strategies. They influence each other, with the clinical prevalence of PSD comorbid with PSCI reaching as high as 26.15 %. The prevention, screening, diagnosis, and treatment of PSD and PSCI require collaboration across clinical, radiological, and neuropsychological evaluations. This paper aims to summarize the common radiological features of both conditions from a radiological perspective, which may aid in identifying early screening and predictive imaging biomarkers.

Dementia Risk Following Ischemic Stroke: A Systematic Review and Meta-Analysis of Factors Collected at Time of Stroke Diagnosis

BACKGROUND

The majority of stroke cases are ischemic in origin and ischemic stroke survivors represent a high-risk population for progression to dementia.

OBJECTIVE

To determine incidence rates and predictors of dementia after ischemic stroke.

METHODS

A systematic review and meta-analysis compliant with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA).

RESULTS

5,843 studies were screened for title and abstract. 292 eligible studies were screened for full text. A total of 22 studies met the inclusion criteria and were included, representing 55,929 ischemic stroke survivors. Cumulative incidence of dementia after stroke was 20% at 5 years, 30% at 15 years, and 48% at 25 years of follow-up. Dementia incidence rates were 1.5 times higher among patients with recurrent ischemic stroke compared to patients with first-time stroke. Predictors of dementia after ischemic stroke included female gender (OR 1.2, 95% CI (1.1, 1.4)), hypertension (1.4, (1.1, 2.0)), diabetes mellitus (1.6, (1.3, 2.1)), atrial fibrillation (1.9, (1.2, 3.0)), previous stroke (2.0, (1.6, 2.6)), presence of stroke lesion in dominant hemisphere (2.4, (1.3, 4.5)), brain stem or cerebellum (OR 0.5, (0.3, 0.9)) or frontal lobe (3.7, (1.2, 12.0)), presence of aphasia (OR 7.9, (2.4, 26.0)), dysphasia (5.8, (3.0, 11.3)), gait impairment (1.7, (1.1, 2.7)), presence of white matter hyperintensities (3.2, (2.0, 5.3)), and medial temporal lobe atrophy (3.9, (1.9, 8.3)).

CONCLUSION

Factors routinely collected for stroke patients are a useful resource for monitoring dementia progression in this population. In the present meta-analysis, cardiovascular factors, stroke location, stroke-related disability and chronic brain changes were predictors of dementia after ischemic stroke.

Economic Burden of Dementia Caused by Cardiovascular Disease in Australia

Background: The established link between cardiovascular disease (CVD) and dementia may provide new insights into dementia prevention. Objective: It aims to quantify the burden of dementia attributable to people with CVD. Methods: A Markov microsimulation model was developed to simulate the lifetime cost and quality-adjusted life-years (QALYs) related to people with and without CVD in Australia. A de-novo systematic review was undertaken to identify all evidence around the association between CVD [i.e., stroke, myocardial infarction (MI), atrial fibrillation (AF), and heart failure (HF)] and the risk of developing dementia. Incremental costs and QALY losses were estimated for people by type of CVD compared to the general Australian population without CVD. Results: Of the comprehensive literature search, 19 observational studies were included in the qualitative synthesis. Patients who had CVD incurred both higher healthcare costs over their lifetime (ranging from $73,131 for patients with AF to $127,396 for patients with HF) and fewer QALYs gains (from –1.099 for patients with MI to –5.163 for patients with stroke), compared to people who did not have CVD. The total incremental economic burden of dementia from patients aged 65 years and over with CVD was $6.45 billion (stroke), $11.89 billion (AF), $17.57 billion (MI), or $7.95 billion (HF) over their remaining life expectancy. Conclusion: The results highlighted the importance of CVD prevention to reduce the CVD burden and decrease the prevalence of dementia. Interventions that target patients with dementia risk factors like CVD may prove to be effective and cost-effective strategies.

Associations Between Neuroanatomic Patterns of Cerebral Infarctions and Vascular Dementia

OBJECTIVE

A history of multiple cerebral infarctions is generally regarded as an important risk factor for vascular dementia. The authors examined the risk of vascular dementia in patients with multiple acute ischemic lesions.

METHODS

The authors conducted a hospital-based prospective study of 11,200 patients with first-time stroke who underwent 1.5 or 3-T MRI and a global cognitive assessment. Univariate and multivariate logistic regression analyses estimated the risk of dementia associated with multiple lesions versus a single lesion.

RESULTS

Having multiple lesions, compared with having a single lesion, was significantly associated with dementia in patients with stroke (odds ratio=5.83, 95% CI=5.08, 6.70; p<0.001). The apoliproprotein ε4 allele was more frequent in patients with multiple lesions than in those with a single lesion (odds ratio=1.70, 95% CI=1.39, 2.07; p<0.001). Severe leukoaraiosis (odds ratio=15.77, 95% CI=8.38, 29.68; p<0.001) and microbleedings (odds ratio=1.31, 95% CI=1.06, 1.63; p<0.01) were strong confounders for dementia in the multivariate analysis. Multiple logistic regression analysis showed that multiple lesions in one hemisphere versus a single lesion (odds ratio=2.14, 95% CI=1.83, 2.51; p<0.001), involvement of strategic regions (odds ratio=4.73, 95% CI=4.07, 5.49; p<0.001), and stroke lesion volume (odds ratio=1.31, 95% CI=1.03, 1.66; p=0.03) were significantly associated with dementia. There was a preponderance of lesions on the left side in patients with dementia (odds ratio=2.56, 95% CI=2.11, 3.11; p<0.001).

CONCLUSIONS

Multiple spontaneous anterior or posterior circulation lesions after stroke increase a patient's risk of developing dementia. Recognition of multiple ischemic lesions after stroke may allow targeted rapid therapeutic interventions to prevent subsequent cognitive deterioration.

Neuroimaging in Vascular Cognitive Impairment and Dementia: A Systematic Review

Cerebrovascular diseases are well established causes of cognitive impairment. Different etiologic entities, such as vascular dementia (VaD), vascular cognitive impairment, subcortical (ischemic) VaD, and vascular cognitive disorder, are included in the umbrella definition of vascular cognitive impairment and dementia (VCID). Because of the variability of VCID clinical presentation, there is no agreement on criteria defining the neuropathological threshold of this disorder. In fact, VCID is characterized by cerebral hemodynamic alteration which ranges from decreased cerebral blood flow to small vessels disease and involves a multifactorial process that leads to demyelination and gliosis, including blood-brain barrier disruption, hypoxia, and hypoperfusion, oxidative stress, neuroinflammation and alteration on neurovascular unit coupling, cerebral microbleeds, or superficial siderosis. Numerous criteria for the definition of VaD have been described: the National Institute of Neurological Disorders and Stroke Association Internationale pour Recherche'-et-l'Enseignement en Neurosciences criteria, the State of California Alzheimer's Disease Diagnostic and Treatment Centers criteria, DSM-V criteria, the Diagnostic Criteria for Vascular Cognitive Disorders (a VASCOG Statement), and Vascular Impairment of Cognition Classification Consensus Study. Neuroimaging is fundamental for definition and diagnosis of VCID and should be used to assess the extent, location, and type of vascular lesions. MRI is the most sensible technique, especially if used according to standardized protocols, even if CT plays an important role in several conditions. Functional neuroimaging, in particular functional MRI and PET, may facilitate differential diagnosis among different forms of dementia. This systematic review aims to explore the state of the art and future perspective of non-invasive diagnostics of VCID.

Hyperbaric oxygen therapy improves neurocognitive functions of post-stroke patients - a retrospective analysis

Background:

Previous studies have shown that hyperbaric oxygen therapy (HBOT) can improve the motor functions and memory of post-stroke patients in the chronic stage.

Objective:

The aim of this study is to evaluate the effects of HBOT on overall cognitive functions of post-stroke patients in the chronic stage. The nature, type and location of the stroke were investigated as possible modifiers.

Methods:

A retrospective analysis was conducted on patients who were treated with HBOT for chronic stroke (>3 months) between 2008-2018. Participants were treated in a multi-place hyperbaric chamber with the following protocols: 40 to 60 daily sessions, 5 days per week, each session included 90 min of 100% oxygen at 2 ATA with 5 min air brakes every 20 minutes. Clinically significant improvements (CSI) were defined as > 0.5 standard deviation (SD).

Results:

The study included 162 patients (75.3% males) with a mean age of 60.75±12.91. Of them, 77(47.53%) had cortical strokes, 87(53.7%) strokes were located in the left hemisphere and 121 suffered ischemic strokes (74.6%).

HBOT induced a significant increase in all the cognitive function domains (p < 0.05), with 86% of the stroke victims achieving CSI. There were no significant differences post-HBOT of cortical strokes compared to sub-cortical strokes (p > 0.05). Hemorrhagic strokes had a significantly higher improvement in information processing speed post-HBOT (p < 0.05). Left hemisphere strokes had a higher increase in the motor domain (p < 0.05). In all cognitive domains, the baseline cognitive function was a significant predictor of CSI (p < 0.05), while stroke type, location and side were not significant predictors.

Conclusions:

HBOT induces significant improvements in all cognitive domains even in the late chronic stage. The selection of post-stroke patients for HBOT should be based on functional analysis and baseline cognitive scores rather than the stroke type, location or side of lesion.

The peri-menopause in a woman's life: a systemic inflammatory phase that enables later neurodegenerative disease

The peri-menopause or menopausal transition—the time period that surrounds the final years of a woman’s reproductive life—is associated with profound reproductive and hormonal changes in a woman’s body and exponentially increases a woman’s risk of cerebral ischemia and Alzheimer’s disease. Although our understanding of the exact timeline or definition of peri-menopause is limited, it is clear that there are two stages to the peri-menopause. These are the early menopausal transition, where menstrual cycles are mostly regular, with relatively few interruptions, and the late transition, where amenorrhea becomes more prolonged and lasts for at least 60 days, up to the final menstrual period. Emerging evidence is showing that peri-menopause is pro-inflammatory and disrupts estrogen-regulated neurological systems. Estrogen is a master regulator that functions through a network of estrogen receptors subtypes alpha (ER-α) and beta (ER-β). Estrogen receptor-beta has been shown to regulate a key component of the innate immune response known as the inflammasome, and it also is involved in regulation of neuronal mitochondrial function. This review will present an overview of the menopausal transition as an inflammatory event, with associated systemic and central nervous system inflammation, plus regulation of the innate immune response by ER-β-mediated mechanisms.

Osteocalcin, ovarian senescence, and brain health

Menopause, an inevitable event in a woman's life, significantly increases risk of bone resorption and diseases such as Alzheimer's, vascular dementia, cardiac arrest, and stroke. The sole role of bones, as traditionally regarded, is to provide structural support for skeletal muscles and allow for ambulation, however this concept is becoming quickly outdated. New literature has emerged that suggests the bone cell-derived hormone osteocalcin (OCN) plays a pivotal role in cognition. OCN levels are correlated with bone mass density and bone turnover, and thus are strongly influenced by the changes associated with menopause. The goal of the current review is to discuss potential gaps in our knowledge of OCN and cognition, discrepancies in methods of OCN quantification, and therapies to enhance circulating OCN. A discussion on implementing exercise or low frequency vibration interventions at the menopausal transition to reduce risk and severity of neurological diseases and associated cognitive decline is included.

Vascular-brain Injury Progression after Stroke (VIPS) study: concept for understanding racial and geographic determinants of cognitive decline after stroke

Cognitive impairment and dementia (CID) are major public health problems with substantial personal, social, and financial burdens. African Americans are at a heightened risk for Vascular Cognitive Impairment (VCI) compared to European Americans. Recent lines of evidence also suggest a high burden of Post-stroke VCI among indigenous Africans. A better understanding of the cause(s) of the racial disparity in CID, specifically VCI, is needed in order to develop strategies to reduce it. We propose and discuss the conceptual framework for a unique tri-population, trans-continental study titled The Vascular brain Injury Progression after Stroke (VIPS) study. The overarching objective of the VIPS Study will be to explore the interplay of multiple factors (racial, geographical, vascular, lifestyle, nutritional, psychosocial and inflammatory) influencing the level and trajectory of post-stroke cognitive outcomes and examine whether differences between indigenous Africans, African Americans and European Americans exist. We hypothesize that differences which might be due to racial factors will be observed in African Americans versus European Americans as well as Indigenous Africans versus European Americans but not in African Americans versus Indigenous Americans; differences due to geographical factors will be observed in Indigenous Americans versus African Americans and Indigenous Africans versus European Americans but not in African Americans versus European Americans. This overarching objective could be accomplished by building upon existing National Institutes of Health investments in the REasons for Geographical And Racial Differences in Stroke (REGARDS) study (based in the United States of America) and the Stroke Investigative Research and educational Network (SIREN) study (based in Sub-Saharan Africa).

Neuroimaging Determinants of Poststroke Cognitive Performance

Background and Purpose- We aimed to define the neuroimaging determinants of poststroke cognitive performance and their relative contributions among a spectrum of magnetic resonance imaging markers, including lesion burden and strategic locations. Methods- We prospectively included patients with stroke from the GRECogVASC study (Groupe de Réflexion pour l'Évaluation Cognitive Vasculaire) who underwent 3-T magnetic resonance imaging and a comprehensive standardized battery of neuropsychological tests 6 months after the index event. An optimized global cognitive score and neuroimaging markers, including stroke characteristics, cerebral atrophy markers, and small vessel diseases markers, were assessed. Location of strategic strokes was determined using a specifically designed method taking into account stroke size and cerebral atrophy. A stepwise multivariable linear regression model was used to identify magnetic resonance imaging determinants of cognitive performance. Results- Data were available for 356 patients (mean age: 63.67±10.6 years; 326 [91.6%] of the patients had experienced an ischemic stroke). Six months poststroke, 50.8% of patients presented with a neurocognitive disorder. Strategic strokes (right corticospinal tract, left antero-middle thalamus, left arcuate fasciculus, left middle frontal gyrus, and left postero-inferior cerebellum; R²=0.225; P=0.0001), medial temporal lobe atrophy ( R²=0.077; P=0.0001), total brain tissue volume ( R²=0.028; P=0.004), and stroke volume ( R²=0.013; P=0.005) were independent determinants of cognitive performance. Strategic strokes accounted for the largest proportion of the variance in the cognitive score (22.5%). The white matter hyperintensity burden, brain microbleeds, and dilated perivascular spaces were not independent determinants. Conclusions- Optimized global cognitive score and combined approach of both quantitative measures related to structure loss and qualitative measures related to the presence of strategic lesion are required to improve the determination of structure-function relationship of cognitive performance after stroke.

Systematic Review and Meta-Analysis of Prevalence in Post-Stroke Neurocognitive Disorders in Hospital-Based Studies

BACKGROUND/AIMS

Post-stroke neurocognitive disorders (post-stroke NCD) have been reported with a very variable prevalence.

METHODS

Based on a systematic literature search, hospital-based studies published between January 1990 and September 2015 were selected when they reported the prevalence of total, mild, and major post-stroke NCD diagnosed by using specified criteria. Factors affecting prevalence were assessed using meta-regression analysis.

RESULTS

Among the 7,440 references evaluated, 16 hospital-based studies were selected, corresponding to a total of 3,087 patients. The overall prevalence of total post-stroke NCD was 53.4% (95% CI: 46.9-59.8): 36.4% for mild post-stroke NCD (95% CI: 29-43.8) and 16.5% (95% CI: 12.1-20.8) for major post-stroke NCD. The overall prevalence was mainly influenced by the threshold score used for categorization (p = 0.0001) and, in the subgroup of studies using a conservative threshold (i.e., ≤7th percentile), by the recurrent stroke rate (p = 0.0005). The prevalence of major post-stroke NCD was mainly influenced by age (p = 0.003).

CONCLUSION

More than half of stroke survivors experience post-stroke NCD, corresponding to mild post-stroke NCD in two-thirds of cases and major post-stroke NCD in one-third of cases. Harmonization of stroke assessment and cognitive score thresholds is urgently needed to allow more accurate estimation of post-stroke NCD prevalence, especially mild post-stroke NCD.

Prevalence of Poststroke Neurocognitive Disorders Using National Institute of Neurological Disorders and Stroke-Canadian Stroke Network, VASCOG Criteria (Vascular Behavioral and Cognitive Disorders), and Optimized Criteria of Cognitive Deficit

BACKGROUND AND PURPOSE

The prevalence of poststroke neurocognitive disorder (NCD) has yet to be accurately determined. The primary objective of the present study was to optimize operationalization of the criterion for NCD by using an external validity criterion.

METHODS

The GRECOG-VASC cohort (Groupe de Réflexion pour l'Évaluation Cognitive Vasculaire) of 404 stroke patients with cerebral infarct (91.3%) or hemorrhage (18.7%) was assessed 6 months poststroke and 1003 healthy controls, with the National Institute of Neurological Disorders and Stroke-Canadian Stroke Network standardized battery. Three dimensions of the criterion for cognitive impairment were systematically examined by using the false-positive rate as an external validity criterion. Diagnosis of mild and major NCD was based on the VASCOG criteria (Vascular Behavioral and Cognitive Disorders). The mechanisms of functional decline were systematically assessed.

RESULTS

The optimal criterion for cognitive impairment was the shortened summary score (ie, averaged performance for action speed, executive functions, and language) because it was associated with the highest (P=0.0001) corrected true-positive rate (43.5%) and a false-positive rate ≤5%. Using this criterion, the mean (95% confidence interval) prevalence of poststroke NCD was 49.5% (44.6-54.4), most of which corresponded to mild NCD (39.1%; 95% confidence interval, 34.4-43.9) rather than dementia (10.4%; 95% confidence interval, 7.4-13.4).

CONCLUSIONS

This study is the first to have optimized the operationalization of the criterion for poststroke cognitive impairment. It documented the prevalence of poststroke NCD in the GRECOG-VASC cohort and showed that mild cognitive impairment accounts for 80% of the affected patients. Finally, the method developed in the present study offers a means of harmonizing the diagnosis of NCD.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01339195.

Risk factors for dementia

There is little doubt that dementia is a very common cause of disability and dependency in our society. Since dementia of whatever type is usually more common with increasing age, then as population demographics change, so will the prevalence of dementia. Dementia is a generic term and the objective for clinicians, once dementia is suspected, is to attempt to define the cause. Alzheimer's disease is the most common cause of dementia, and in most centres vascular dementia would feature as the next most common aetiology. In some centres, Lewy body dementia is the second most common cause. Mixed Alzheimer's disease and vascular dementia would also feature high on the list at most centres.

Racial Differences in Neurocognitive Outcomes Post-Stroke: The Impact of Healthcare Variables

OBJECTIVES

The present study examined differences in neurocognitive outcomes among non-Hispanic Black and White stroke survivors using the NIH Toolbox-Cognition Battery (NIHTB-CB), and investigated the roles of healthcare variables in explaining racial differences in neurocognitive outcomes post-stroke.

METHODS

One-hundred seventy adults (91 Black; 79 White), who participated in a multisite study were included (age: M=56.4; SD=12.6; education: M=13.7; SD=2.5; 50% male; years post-stroke: 1-18; stroke type: 72% ischemic, 28% hemorrhagic). Neurocognitive function was assessed with the NIHTB-CB, using demographically corrected norms. Participants completed measures of socio-demographic characteristics, health literacy, and healthcare use and access. Stroke severity was assessed with the Modified Rankin Scale.

RESULTS

An independent samples t test indicated Blacks showed more neurocognitive impairment (NIHTB-CB Fluid Composite T-score: M=37.63; SD=11.67) than Whites (Fluid T-score: M=42.59, SD=11.54; p=.006). This difference remained significant after adjusting for reading level (NIHTB-CB Oral Reading), and when stratified by stroke severity. Blacks also scored lower on health literacy, reported differences in insurance type, and reported decreased confidence in the doctors treating them. Multivariable models adjusting for reading level and injury severity showed that health literacy and insurance type were statistically significant predictors of the Fluid cognitive composite (p<.001 and p=.02, respectively) and significantly mediated racial differences on neurocognitive impairment.

CONCLUSIONS

We replicated prior work showing that Blacks are at increased risk for poorer neurocognitive outcomes post-stroke than Whites. Health literacy and insurance type might be important modifiable factors influencing these differences. (JINS, 2017, 23, 640-652).

Incidence of Brain Infarcts, Cognitive Change, and Risk of Dementia in the General Population: The AGES-Reykjavik Study (Age Gene/Environment Susceptibility-Reykjavik Study)

BACKGROUND AND PURPOSE

The differentiation of brain infarcts by region is important because their cause and clinical implications may differ. Information on the incidence of these lesions and association with cognition and dementia from longitudinal population studies is scarce. We investigated the incidence of infarcts in cortical, subcortical, cerebellar, and overall brain regions and how prevalent and incident infarcts associate with cognitive change and incident dementia.

METHODS

Participants (n=2612, 41% men, mean age 74.6±4.8) underwent brain magnetic resonance imaging for the assessment of infarcts and cognitive testing at baseline and on average 5.2 years later. Incident dementia was assessed according to the international guidelines.

RESULTS

Twenty-one percent of the study participants developed new infarcts. The risk of incident infarcts in men was higher than the risk in women (1.8; 95% confidence interval, 1.5-2.3). Persons with both incident and prevalent infarcts showed steeper cognitive decline and had almost double relative risk of incident dementia (1.7; 95% confidence interval, 1.3-2.2) compared with those without infarcts. Persons with new subcortical infarcts had the highest risk of incident dementia compared with those without infarcts (2.6; 95% confidence interval, 1.9-3.4).

CONCLUSIONS

Men are at greater risk of developing incident brain infarcts than women. Persons with incident brain infarcts decline faster in cognition and have an increased risk of dementia compared with those free of infarcts. Incident subcortical infarcts contribute more than cortical and cerebellar infarcts to incident dementia which may indicate that infarcts of small vessel disease origin contribute more to the development of dementia than infarcts of embolic origin in larger vessels.

Lesion location and cognitive impact of cerebral small vessel disease

Cerebral small vessel disease (SVD) is an important cause of cognitive impairment. Important MRI manifestations of SVD include white matter hyperintensities (WMH) and lacunes. This narrative review addresses the role of anatomical lesion location in the impact of SVD on cognition, integrating findings from early autopsy studies with emerging findings from recent studies with advanced image analysis techniques. Early autopsy and imaging studies of small case series indicate that single lacunar infarcts in, for example the thalamus, caudate nucleus or internal capsule can cause marked cognitive impairment. However, the findings of such case studies may not be generalizable. Emerging location-based image analysis approaches are now being applied to large cohorts. Recent studies show that WMH burden in strategic white matter tracts, such as the forceps minor or anterior thalamic radiation (ATR), is more relevant in explaining variance in cognitive functioning than global WMH volume. These findings suggest that the future diagnostic work-up of memory clinic patients could potentially be improved by shifting from a global assessment of WMH and lacune burden towards a quantitative assessment of lesion volumes within strategic brain regions. In this review, a summary of currently known strategic regions for SVD-related cognitive impairment is provided, highlighting recent technical developments in SVD research. The potential and challenges of location-based approaches for diagnostic purposes in clinical practice are discussed, along with their potential prognostic and therapeutic applications.

Stroke occurring in patients with cognitive impairment or dementia

Objective

To determine how pre-stroke cognitive impairment can be detected, its mechanism, and influence on outcome and management.

Methods

Literature search.

Results

(i) A systematic approach with the Informant Questionnaire of Cognitive Decline in the Elderly is recommended; (ii) Pre-stroke cognitive impairment may be due to brain lesions of vascular, degenerative, or mixed origin; (iii) Patients with pre-stroke dementia, have worse outcomes, more seizures, delirium, and depression, and higher mortality rates; they often need to be institutionalised after their stroke; (iv) Although the safety profile of treatment is not as good as that of cognitively normal patients, the risk:benefit ratio is in favour of treating these patients like others.

Conclusion

Patients with cognitive impairment who develop a stroke have worse outcomes, but should be treated like others.

Cognitive performance in aphasia due to stroke: a systematic review

Aphasia persists in about one third of the patients with left hemisphere stroke, yet it is not known if it enhances the risk of dementia, beyond what results from any focal brain lesion. This lack of knowledge is mostly related to the difficulty of cognitive evaluation in people with aphasia. The development of tools aiming to assess cognitive functioning in people with aphasia could overcome this limitation. The aim of this systematic review was to evaluate the frequency and the profile of cognitive impairment in stroke patients with aphasia, to assemble existing non-verbal instruments to be used in patients with language disorders.

We conducted a systematic review, through Web of Science, Medline and PsycINFO electronic databases, of articles published between January 1995 and October 31, 2015 related to aphasia due to stroke and non-verbal neurobehavioral tests.

The electronic search identified 2487 citations. After screening 38 were included in this review. Additionally 53 articles were selected among the references of analyzed publications of which nine were included producing a total of 47 articles. The cognitive tests more frequently used in persons with aphasia are the Figures Memory Tests, Visual Memory Span, Progressive Matrices, Wisconsin Card Sorting Test and some measures of the Test of Everyday Attention, covering a reasonable range of cognitive domains. The majority of studies across cognitive domains reported lower scores for patients with aphasia compared with controls. No specific difficulties were reported regarding tests applicability.

There are several tools available to assess cognitive functions in aphasia. Although there is some variability, patients with aphasia tend to present lower scores than those with left hemisphere stroke without aphasia or healthy subjects. A consensus tool should be developed to screen or evaluate cognition and dementia in individuals with language impairment.

White matter hyperintensity volume predicts persistent cognitive impairment in transient ischemic attack and minor stroke

Background Temporary and permanent cognitive changes following transient ischemic attack/minor stroke have been described previously. It is unknown if persisting cognitive deficits in these patients are correlated with acute infarction identified using magnetic resonance imaging. Aims We tested the hypothesis that persistent cognitive impairment after transient ischemic attack/minor stroke can be predicted by the volume of diffusion-weighted imaging lesions. Methods Acute transient ischemic attack/minor stroke (NIH stroke scale score ≤ 3) patients were prospectively recruited within 72 h of onset. Patients underwent Montreal cognitive assessment and magnetic resonance imaging, including diffusion-weighted imaging and Fluid-Attenuated Inverse Recovery sequences, at baseline, days 7 and 30. Cognitive testing was repeated at day 90. Diffusion-weighted imaging lesion and Fluid-Attenuated Inverse Recovery chronic white matter hyperintensity volumes were measured planimetrically. Cognitive impairment was defined a priori as Montreal cognitive assessment score < 26. Results One hundred fifteen patients were imaged at a median (inter-quartile range) of 24.0 (16.6) h after onset. Acute ischemic lesions were present in 91 (79%) patients. Cognitive impairment rates were similar in patients with (47/91, 52%) and without diffusion-weighted imaging lesions (13/24, 54%; p = 0.83). Although linear regression indicated no relationship between acute diffusion-weighted imaging lesion volume and day 30 Montreal cognitive assessment scores (β = -0.163, [-2.243, 0.334], p = 0.144), white matter hyperintensity volumes at baseline were predictive of persistent cognitive deficits after 30 days (β = 2.24, [1.956, 45.369], p = 0.005). Conclusions In most transient ischemic attack/minor stroke patients who suffer acute cognitive impairment post event, deficits are temporary. Deficits after 30 days of onset are correlated with chronic white matter hyperintensity, suggesting subclinical cognitive impairment and/or impaired ability to compensate for the effects of acute ischemic infarcts.

Inflammatory Markers and Outcomes After Lacunar Stroke: Levels of Inflammatory Markers in Treatment of Stroke Study

BACKGROUND AND PURPOSE

We hypothesized that concentrations of interleukin 6 (IL-6), serum amyloid A, tumor necrosis factor-α receptor 1, CD40 ligand, and monocyte chemoattractant protein 1 would predict recurrent ischemic stroke and major vascular events after recent lacunar stroke.

METHODS

Levels of Inflammatory Markers in the Treatment of Stroke (LIMITS) was an international, multicenter, prospective ancillary biomarker study nested within the Secondary Prevention of Small Subcortical Strokes (SPS3) study, a Phase III trial in patients with recent lacunar stroke. Crude and Adjusted Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CI) for recurrence risks.

RESULTS

Among 1244 patients with lacunar stroke (mean age, 63.3±10.8 years), there were 115 major vascular events (stroke, myocardial infarction, and vascular death). The risk of major vascular events increased with elevated concentrations of both tumor necrosis factor-α receptor 1 (adjusted HR per SD, 1.21; 95% CI, 1.05-1.41; P=0.01) and IL-6 (adjusted HR per SD, 1.10; 95% CI, 1.02-1.19; P=0.008). Compared with the bottom quartile (tumor necrosis factor-α receptor 1 <2.24 ng/L), those in the top quartile of tumor necrosis factor-α receptor 1 (>3.63 ng/L) were at twice the risk of major vascular events after adjusting for demographics (partially adjusted HR, 1.98; 95% CI, 1.11-3.52), though the effect attenuated after adjusting for other risk factors and statin use (adjusted HR, 1.68; 95% CI, 0.93-3.04). Serum amyloid A, CD40 ligand, and monocyte chemoattractant protein 1 were not associated with prognosis.

CONCLUSIONS

Among recent lacunar stroke patients, IL-6 and TNF receptor concentrations predict risk of recurrent vascular events, and they are associated with the effect of antiplatelet therapies.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00059306.

Frailty modifies effectiveness of psychosocial intervention in recovery from stroke

Objective : To evaluate the impact of a psychosocial intervention on instrumental activities of daily living, physical performance, cognition and mortality after stroke.

Design : A randomized clinical trial.

Setting : Patients were recruited from hospitals and rehabilitation centres; the intervention took place in subjects' homes.

Subjects : Two-hundred and ninety-one stroke survivors over age 45. One-hundred and forty-six subjects were assigned to the intervention and 145 subjects were assigned to usual care.

Intervention : Up to 16 meetings conducted over six months in the patient's home (approximately weekly for 12 weeks, followed by tri-weekly sessions for another 12 weeks). Sessions lasted approximately 1 hour and included, when possible, the entire support system (stroke survivor, primary caregiver, additional family and friends, and professional caregivers).

Main outcome measures : Instrumental activities of daily living, physical performance, and cognition were assessed six months post stroke; mortality was assessed at an average of 47 months post stroke.

Results : No significant differences in outcomes were observed between the intervention and usual care groups when analysing the total study population. Among non-frail participants (n = 156), subjects randomized to treatment had better scores on instrumental activities of daily living (mean score among treated = 12.4 (standard deviation (SD) = 2.1), mean score among usual care subjects = 11.3 (SD = 2.9), P-value for difference in means = 0.01) and reduced risk of mortality (P = 0.03) than subjects randomized to usual care.

Conclusion : While there is evidence that the treatment benefited healthier subgroups, results also show evidence that the treatment was not effective, and possibly harmful, in frail subgroups.

Consensus statement for diagnosis of subcortical small vessel disease

Vascular cognitive impairment (VCI) is the diagnostic term used to describe a heterogeneous group of sporadic and hereditary diseases of the large and small blood vessels. Subcortical small vessel disease (SVD) leads to lacunar infarcts and progressive damage to the white matter. Patients with progressive damage to the white matter, referred to as Binswanger's disease (BD), constitute a spectrum from pure vascular disease to a mixture with neurodegenerative changes. Binswanger's disease patients are a relatively homogeneous subgroup with hypoxic hypoperfusion, lacunar infarcts, and inflammation that act synergistically to disrupt the blood-brain barrier (BBB) and break down myelin. Identification of this subgroup can be facilitated by multimodal disease markers obtained from clinical, cerebrospinal fluid, neuropsychological, and imaging studies. This consensus statement identifies a potential set of biomarkers based on underlying pathologic changes that could facilitate diagnosis and aid patient selection for future collaborative treatment trials.

Evaluation and follow-up of cognitive functions in patients with minor stroke and transient ischemic attack

BACKGROUND AND PURPOSE

We aimed to examine the incidence of cognitive impairment among patients with stroke, the associated risk factors, progression of the cognitive impairment, and the association between the localization of the lesion(s) as detected by magnetic resonance imaging and the affected areas of cognitive function.

METHODS

A total of 40 patients over 18 years of age enduring a transient ischemic stroke or minor stroke within the past 3 months who had a minimum life expectancy of 1 year were included in this study. Same number, age-, and sex-matched individuals were included as controls. Patients were inquired on the presence of risk factors for stroke. A series of neuropsychological test batteries were administered in patient and control subjects for assessing cognitive functions. These tests were readministered at 6 and 12 months of follow-up to assess the progression of cognitive functions.

RESULTS

In this study among the patients with stroke, a significant impairment was seen in multiple cognitive functional tests following ischemic stroke as compared to control groups. The most common risk factors for stroke included hypertension (72.5%), hyperlipidemia, and cigarette smoking. The number of cognitive domains with an impairment was highest (in four cognitive tests) among those with coronary artery disease and atrial fibrillation, followed by those who had a >50% stenosis in Doppler (three cognitive tests). These findings suggest that the frequency of risk factors associated with stroke does not correlate with the frequency of risk factors associated with cognitive dysfunction. The stroke localizations were classified among the patients with stroke and reviewed in accordance with cognitive impairment.

CONCLUSION

Neuropsychological tests, clinical findings, and imaging studies should be used to document the poststroke cognitive dysfunction.

CYP2C19 metabolizer status and clopidogrel efficacy in the Secondary Prevention of Small Subcortical Strokes (SPS3) study

Background

The role of the CYP2C19 genotype on clopidogrel efficacy has been studied widely, with data suggesting reduced clopidogrel efficacy in loss-of-function variant carriers taking clopidogrel after percutaneous coronary intervention; however, data are limited regarding the association between CYP2C19 genetic variants and outcomes in stroke patients. We investigated whether CYP2C19 metabolizer status affects the risk of recurrent stroke or major bleeding in subcortical stroke patients taking dual antiplatelet therapy with aspirin and clopidogrel.

Methods and Results

CYP2C19*2 and CYP2C19*17 were genotyped in 522 patients treated with dual antiplatelet therapy from the Secondary Prevention of Small Subcortical Strokes (SPS3) study. CYP2C19 metabolizer status was inferred from genotype, and associations with the risk of recurrent stroke and major bleeding were assessed in the overall cohort and by race/ethnic group with logistic regression modeling. In the overall cohort, there were no differences in outcomes by CYP2C19 metabolizer status (recurrent stroke, odds ratio 1.81 [95% CI 0.76 to 4.30]; major bleeding, odds ratio 0.67 [95% CI 0.22 to 2.03]). In white participants, those with CYP2C19 intermediate or poor metabolizer status had higher odds of recurrent stroke (odds ratio 5.19 [95% CI 1.08 to 24.90]) than those with extensive or ultrarapid metabolizer status, but there was no evidence of difference in major bleeding.

Conclusions

There were significant differences in recurrent stroke by CYP2C19 genotype-inferred metabolizer status in white subcortical stroke patients receiving dual antiplatelet therapy with aspirin and clopidogrel, consistent with cardiovascular studies on CYP2C19 and clopidogrel; however, the bleeding risk that led to early termination of the antiplatelet arm of the SPS3 trial does not appear to be explained by CYP2C19 genotype. This study was relatively underpowered; therefore, these findings should be interpreted with caution and warrant replication.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00059306.

Diagnostic criteria for vascular cognitive disorders: a VASCOG statement

BACKGROUND

Several sets of diagnostic criteria have been published for vascular dementia since the 1960s. The continuing ambiguity in vascular dementia definition warrants a critical reexamination.

METHODS

Participants at a special symposium of the International Society for Vascular Behavioral and Cognitive Disorders (VASCOG) in 2009 critiqued the current criteria. They drafted a proposal for a new set of criteria, later reviewed through multiple drafts by the group, including additional experts and the members of the Neurocognitive Disorders Work Group of the fifth revision of Diagnostic and Statistical Manual (DSM-5) Task Force.

RESULTS

Cognitive disorders of vascular etiology are a heterogeneous group of disorders with diverse pathologies and clinical manifestations, discussed broadly under the rubric of vascular cognitive disorders (VCD). The continuum of vascular cognitive impairment is recognized by the categories of Mild Vascular Cognitive Disorder, and Vascular Dementia or Major Vascular Cognitive Disorder. Diagnostic thresholds are defined. Clinical and neuroimaging criteria are proposed for establishing vascular etiology. Subtypes of VCD are described, and the frequent cooccurrence of Alzheimer disease pathology emphasized.

CONCLUSIONS

The proposed criteria for VCD provide a coherent approach to the diagnosis of this diverse group of disorders, with a view to stimulating clinical and pathologic validation studies. These criteria can be harmonized with the DSM-5 criteria such that an international consensus on the criteria for VCD may be achieved.

The role of processing speed in post-stroke cognitive dysfunction

The association between speed of information processing and cognition has been extensively validated in normal aging and other neurocognitive disorders. Our aim was to determine whether such a relationship exists in stroke. Thirty patients and 30 age- and education-matched healthy individuals were administered a comprehensive battery of neuropsychological tests divided into the following six cognitive domains: processing speed (PS), verbal memory, visual memory, visuoperceptual function, language, and cognitive flexibility. The results demonstrate that stroke patients were characterized by cognitive deficits in almost all of these domains, but have the most pronounced deficits in PS. After adjusting for symbol digit modalities test score, all significant group differences in cognitive functioning disappeared. However, group differences remained significant after controlling for the influence of other cognitive factors. These findings suggest that decreased PS appears to underlie post-stroke cognitive dysfunction and may serve as a potential target for intervention.

Factors Associated with Cognitive Decline in Transient Ischemic Attack Patients

Chronic cerebrovascular disease and large ischemic stroke are both associated with cognitive impairment. Much less is known about the acute cognitive sequelae of transient ischemic attack (TIA). Although often overlooked, there is increasing evidence that cognitive impairment does occur following TIA. In some patients, cognitive changes persist after resolution of focal neurological deficits, but the temporal profile of these symptoms is unknown. In addition, clinical and imaging correlates of cognitive impairment after TIA have not been systematically studied. This under-studied and recognized problem has significant implications for TIA patient management. In this review, we summarize the evidence currently available and identify future research priorities.

Changes in memory before and after stroke differ by age and sex, but not by race

BACKGROUND

Post-stroke memory impairment is more common among older adults, women and blacks. It is unclear whether post-stroke differences reflect differential effects of stroke per se or differences in prestroke functioning. We compare memory trajectories before and after stroke by age, sex and race.

METHODS

Health and Retirement Study participants aged ≥50 years (n = 17,341), with no stroke history at baseline, were interviewed biennially up to 10 years for first self- or proxy-reported stroke (n = 1,574). Segmented linear regression models were used to compare annual rates of memory change before and after stroke among 1,169 stroke survivors, 405 stroke decedents and 15,767 stroke-free participants. Effect modification was evaluated with analyses stratified by baseline age (≤70 vs. >70), sex and race (white vs. nonwhite), and using interaction terms between age/sex/race indicators and annual memory change.

RESULTS

Older (>70 years) adults experienced a faster memory decline before stroke (-0.19 vs. -0.10 points/year for survivors, -0.24 vs. -0.13 points/year for decedents, p < 0.001 for both interactions), and among stroke survivors, larger memory decrements (-0.64 vs. -0.26 points, p < 0.001) at stroke and faster memory decline (-0.15 vs. -0.07 points/year, p = 0.003) after stroke onset, compared to younger adults. Female stroke survivors experienced a faster prestroke memory decline than male stroke survivors (-0.14 vs. -0.10 points/year, p < 0.001). However, no sex differences were seen for other contrasts. Although whites had higher post-stroke memory scores than nonwhites, race was not associated with rate of memory decline during any period of time; i.e. race did not significantly modify the rate of decline before or after stroke or the immediate effect of stroke on memory.

CONCLUSIONS

Older age predicted worse memory change before, at and after stroke onset. Sex and race differences in post-stroke memory outcomes might be attributable to prestroke disparities, which may be unrelated to cerebrovascular disease.

C-reactive protein as a prognostic marker after lacunar stroke: levels of inflammatory markers in the treatment of stroke study

BACKGROUND AND PURPOSE

Inflammatory biomarkers predict incident and recurrent cardiac events, but their relationship to stroke prognosis is uncertain. We hypothesized that high-sensitivity C-reactive protein (hsCRP) predicts recurrent ischemic stroke after recent lacunar stroke.

METHODS

Levels of Inflammatory Markers in the Treatment of Stroke (LIMITS) was an international, multicenter, prospective ancillary biomarker study nested within Secondary Prevention of Small Subcortical Strokes (SPS3), a phase III trial in patients with recent lacunar stroke. Patients were assigned in factorial design to aspirin versus aspirin plus clopidogrel, and higher versus lower blood pressure targets. Patients had blood samples collected at enrollment and hsCRP measured using nephelometry at a central laboratory. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for recurrence risks before and after adjusting for demographics, comorbidities, and statin use.

RESULTS

Among 1244 patients with lacunar stroke (mean age, 63.3±10.8 years), median hsCRP was 2.16 mg/L. There were 83 recurrent ischemic strokes (including 45 lacunes) and 115 major vascular events (stroke, myocardial infarction, and vascular death). Compared with the bottom quartile, those in the top quartile (hsCRP>4.86 mg/L) were at increased risk of recurrent ischemic stroke (unadjusted HR, 2.54; 95% CI, 1.30-4.96), even after adjusting for demographics and risk factors (adjusted HR, 2.32; 95% CI, 1.15-4.68). hsCRP predicted increased risk of major vascular events (top quartile adjusted HR, 2.04; 95% CI, 1.14-3.67). There was no interaction with randomized antiplatelet treatment.

CONCLUSIONS

Among recent lacunar stroke patients, hsCRP levels predict the risk of recurrent strokes and other vascular events. hsCRP did not predict the response to dual antiplatelets.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00059306.

Neuropsychological assessment and cerebral vascular disease: the new standards

Vascular cognitive impairment (VCI) includes vascular dementia (VaD), vascular mild cognitive impairment (VaMCI) and mixed dementia. In clinical practice, VCI concerns patients referred for clinical stroke or cognitive complaint. To improve the characterization of VCI and to refine its diagnostic criteria, an international group has elaborated a new standardized evaluation battery of clinical, cognitive, behavioral and neuroradiological data which now constitutes the reference battery. The adaption of the battery for French-speaking subjects is reported as well as preliminary results of the on-going validation study of the GRECOG-VASC group [Clinical Trial NCT01339195]. The diagnostic accuracy of various screening tests is reviewed and showed an overall sub-optimal sensitivity (<0.8). Thus, the general recommendation is to perform systematically a comprehensive assessment in stroke patients at risk of VCI. Furthermore,the use of a structured interview has been shown to increase the detection of dementia. In addition to the well known NINDS-AIREN criteria of VaD, criteria of VCI have been recently proposed which are based on the demonstration of a cognitive disorder by neuropsychological testing and either history of clinical stroke or presence of vascular lesion by neuroimaging suggestive of a link between cognitive impairment and vascular disease. A memory deficit is no longer required for the diagnosis of VaD as it is based on the cognitive decline concerning two or more domains that affect activities of daily living. Both VaMCI and VaD are classified as probable or possible. These new criteria have yet to be validated. Considerable uncertainties remain regarding the determinant of VCI, and especially the lesion amount inducing VCI and VaD. The interaction between lesion amount and its location is currently re-examined using recent techniques for the analysis of MRI data. The high frequency of associated Alzheimer pathology is now assessable in vivo using amyloid imaging. The first studies showed that about a third of patients with VaD due to small vessel disease or with poststroke dementia have amyloid PET imaging suggestive of AD. These new techniques will examine the interaction between vascular lesions and promotion of amyloid deposition. Although results of these on-going studies will be available in few years, these data indicate that efforts should be done in clinical practice to reduce underdiagnosis of VCI; VCI should be examined using a specific protocol which will be fully normalized soon for French-speaking patients; the sub-optimal sensitivity of screening tests prompts to use a structured interview to grade Rankin scale and to perform systematically a comprehensive assessment in stroke patients at risk of VCI; poststroke dementia occurring after 3 months poststroke may be preventable by treatment of modifiable vascular risk factors and secondary prevention of stroke recurrence according to recent recommendations.

Enhancing the power of genetic association studies through the use of silver standard cases derived from electronic medical records

The feasibility of using imperfectly phenotyped "silver standard" samples identified from electronic medical record diagnoses is considered in genetic association studies when these samples might be combined with an existing set of samples phenotyped with a gold standard technique. An analytic expression is derived for the power of a chi-square test of independence using either research-quality case/control samples alone, or augmented with silver standard data. The subset of the parameter space where inclusion of silver standard samples increases statistical power is identified. A case study of dementia subjects identified from electronic medical records from the Electronic Medical Records and Genomics (eMERGE) network, combined with subjects from two studies specifically targeting dementia, verifies these results.

Association between subcortical vascular lesion location and cognition: a voxel-based and tract-based lesion-symptom mapping study. The SMART-MR study

Introduction

Lacunar lesions (LLs) and white matter lesions (WMLs) affect cognition. We assessed whether lesions located in specific white matter tracts were associated with cognitive performance taking into account total lesion burden.

Methods

Within the Second Manifestations of ARTerial disease Magnetic Resonance (SMART-MR) study, cross-sectional analyses were performed on 516 patients with manifest arterial disease. We applied an assumption-free voxel-based lesion-symptom mapping approach to investigate the relation between LL and WML locations on 1.5 Tesla brain MRI and compound scores of executive functioning, memory and processing speed. Secondly, a multivariable linear regression model was used to relate the regional volume of LLs and WMLs within specific white matter tracts to cognitive functioning.

Results

Voxel-based lesion-symptom mapping identified several clusters of voxels with a significant correlation between WMLs and executive functioning, mostly located within the superior longitudinal fasciculus and anterior thalamic radiation. In the multivariable linear regression model, a statistically significant association was found between regional LL volume within the superior longitudinal fasciculus and anterior thalamic radiation and executive functioning after adjustment for total LL and WML burden.

Conclusion

These findings identify the superior longitudinal fasciculus and anterior thalamic radiation as key anatomical structures in executive functioning and emphasize the role of strategically located vascular lesions in vascular cognitive impairment.

Effects of clopidogrel added to aspirin in patients with recent lacunar stroke

BACKGROUND

Lacunar infarcts are a frequent type of stroke caused mainly by cerebral small-vessel disease. The effectiveness of antiplatelet therapy for secondary prevention has not been defined.

METHODS

We conducted a double-blind, multicenter trial involving 3020 patients with recent symptomatic lacunar infarcts identified by magnetic resonance imaging. Patients were randomly assigned to receive 75 mg of clopidogrel or placebo daily; patients in both groups received 325 mg of aspirin daily. The primary outcome was any recurrent stroke, including ischemic stroke and intracranial hemorrhage.

RESULTS

The participants had a mean age of 63 years, and 63% were men. After a mean follow-up of 3.4 years, the risk of recurrent stroke was not significantly reduced with aspirin and clopidogrel (dual antiplatelet therapy) (125 strokes; rate, 2.5% per year) as compared with aspirin alone (138 strokes, 2.7% per year) (hazard ratio, 0.92; 95% confidence interval [CI], 0.72 to 1.16), nor was the risk of recurrent ischemic stroke (hazard ratio, 0.82; 95% CI, 0.63 to 1.09) or disabling or fatal stroke (hazard ratio, 1.06; 95% CI, 0.69 to 1.64). The risk of major hemorrhage was almost doubled with dual antiplatelet therapy (105 hemorrhages, 2.1% per year) as compared with aspirin alone (56, 1.1% per year) (hazard ratio, 1.97; 95% CI, 1.41 to 2.71; P<0.001). Among classifiable recurrent ischemic strokes, 71% (133 of 187) were lacunar strokes. All-cause mortality was increased among patients assigned to receive dual antiplatelet therapy (77 deaths in the group receiving aspirin alone vs. 113 in the group receiving dual antiplatelet therapy) (hazard ratio, 1.52; 95% CI, 1.14 to 2.04; P=0.004); this difference was not accounted for by fatal hemorrhages (9 in the group receiving dual antiplatelet therapy vs. 4 in the group receiving aspirin alone).

CONCLUSIONS

Among patients with recent lacunar strokes, the addition of clopidogrel to aspirin did not significantly reduce the risk of recurrent stroke and did significantly increase the risk of bleeding and death. (Funded by the National Institute of Neurological Disorders and Stroke and others; SPS3 ClinicalTrials.gov number, NCT00059306.).

Different patterns of language activation in post-stroke aphasia are detected by overt and covert versions of the verb generation fMRI task

Background

Post-stroke language functions depend on the relative contributions of the dominant and non-dominant hemispheres. Thus, we aimed to identify the neural correlates of overt and covert verb generation in adult post-stroke aphasia.

Material/Methods

Sixteen aphasic LMCA stroke patients (SPs) and 32 healthy controls (HCs) underwent language testing followed by fMRI while performing an overt event-related verb generation task (ER-VGT) isolating activations related to noun-verb semantic processing or to articulation and auditory processing, and a covert block design verb generation task (BD-VGT).

Results

BD-VGT activation patterns were consistent with previous studies, while ER-VGT showed different patterns in SPs relative to HCs including less left-hemispheric involvement during semantic processing and predominantly right-sided activation related to articulation and auditory processing. ER-VGT intra-scanner performance was positively associated with activation during semantic associations in the left middle temporal gyrus for HCs (p=0.031) and left middle frontal gyrus for SPs (p=0.042). Increased activation in superior frontal/cingulate gyri was associated with better intra-scanner performance (p=0.020). Lesion size negatively impacted verbal fluency tested with Controlled Oral Word Association Test (p=0.0092) and the Semantic Fluency Test (p=0.033) and trended towards a negative association with verb generation performance on the event-related verb generation task (p=0.081).

Conclusions

Greater retention of pre-stroke language skills is associated with greater involvement of the left hemisphere with different cortical recruitment patterns observed in SPs versus HCs. Post-stroke verbal fluency may depend more upon the structural and functional integrity of the dominant left hemisphere language network rather than the shift to contralateral homologues.

Characteristics of MR infarcts associated with dementia and cognitive function in the elderly

BACKGROUND

Little information exists on the simultaneous effects of magnetic resonance (MR) infarct characteristics, that may increase the likelihood of dementia or lower cognitive function in community populations.

METHODS

Participants were 580 community-dwelling individuals from the Chicago Health and Aging Project (CHAP) who underwent detailed clinical evaluation and MR imaging. The association of MR infarct characteristics (region, number, side, and size) with dementia, global cognition and cognition in five separate cognitive domains was examined using logistic and linear regression analyses controlling for age, sex, race, education and time elapsed between clinical evaluation and MRI.

RESULTS

A total of 156 persons had MR infarcts: 108 with 1 infarct and 48 with multiple. Poorer cognitive function and, in particular, slower perceptual speed, were associated with infarcts characterized as cortical, multiple, bilateral or large (all p < 0.05). Multiple infarcts in multiple regions were associated with poor performance in all cognitive domains except visuospatial ability (p < 0.05). Race did not modify any of these associations.

CONCLUSIONS

In this community sample, cortical and multiple infarcts in multiple regions were associated with dementia; cortical, multiple, large and bilateral infarcts were associated with lower cognition, particularly lower memory function and perceptual speed. These effects were not modified by race.

Therapeutic potential of copper chelation with triethylenetetramine in managing diabetes mellitus and Alzheimer's disease

This article reviews recent evidence, much of which has been generated by my group's research programme, which has identified for the first time a previously unknown copper-overload state that is central to the pathogenesis of diabetic organ damage. This state causes tissue damage in the blood vessels, heart, kidneys, retina and nerves through copper-mediated oxidative stress. This author now considers this copper-overload state to provide an important new target for therapeutic intervention, the objective of which is to prevent or reverse the diabetic complications. Triethylenetetramine (TETA) has recently been identified as the first in a new class of anti-diabetic molecules through the original work reviewed here, thus providing a new use for this molecule, which was previously approved by the US FDA in 1985 as a second-line treatment for Wilson's disease. TETA acts as a highly selective divalent copper (Cu(II)) chelator that prevents or reverses diabetic copper overload, thereby suppressing oxidative stress. TETA treatment of diabetic animals and patients has identified and quantified the interlinked defects in copper metabolism that characterize this systemic copper overload state. Copper overload in diabetes mellitus differs from that in Wilson's disease through differences in their respective causative molecular mechanisms, and resulting differences in tissue localization and behaviour of the excess copper. Elevated pathogenetic tissue binding of copper occurs in diabetes. It may well be mediated by advanced-glycation endproduct (AGE) modification of susceptible amino-acid residues in long-lived fibrous proteins, for example, connective tissue collagens in locations such as blood vessel walls. These AGE modifications can act as localized, fixed endogenous chelators that increase the chelatable-copper content of organs such as the heart and kidneys by binding excessive amounts of catalytically active Cu(II) in specific vascular beds, thereby focusing the related copper-mediated oxidative stress in susceptible tissues. In this review, summarized evidence from our clinical studies in healthy volunteers and diabetic patients with left-ventricular hypertrophy, and from nonclinical models of diabetic cardiac, arterial, renal and neural disease is used to construct descriptions of the mechanisms by which TETA treatment prevents injury and regenerates damaged organs. Our recent phase II proof-of-principle studies in patients with type 2 diabetes and in nonclinical models of diabetes have helped to define the pathogenetic defects in copper regulation, and have shown that they are reversible by TETA. The drug tightly binds and extracts excess systemic Cu(II) into the urine whilst neutralizing its catalytic activity, but does not cause systemic copper deficiency, even after prolonged use. Its physicochemical properties, which are pivotal for its safety and efficacy, clearly differentiate it from all other clinically available transition metal chelators, including D-penicillamine, ammonium tetrathiomolybdate and clioquinol. The studies reviewed here show that TETA treatment is generally effective in preventing or reversing diabetic organ damage, and support its ongoing development as a new medicine for diabetes. Trientine (TETA dihydrochloride) has been used since the mid-1980s as a second-line treatment for Wilson's disease, and our recent clinical studies have reinforced the impression that it is likely to be safe for long-term use in patients with diabetes and related metabolic disorders. There is substantive evidence to support the view that diabetes shares many pathogenetic mechanisms with Alzheimer's disease and vascular dementia. Indeed, the close epidemiological and molecular linkages between them point to Alzheimer's disease/vascular dementia as a further therapeutic target where experimental pharmacotherapy with TETA could well find further clinical application.

Changes in cognitive function over 3 years after first-ever stroke and predictors of cognitive impairment and long-term cognitive stability: the Erlangen Stroke Project

BACKGROUND AND PURPOSE

Cognitive impairment (CI) is frequent after stroke, but data from population-based stroke cohorts on the natural course of CI are limited. The purpose of this study was to determine changes in cognitive status over 3 years after stroke.

METHODS

Data were collected from the Erlangen Stroke Project, an ongoing population-based stroke registry. The Mini-Mental State Examination (MMSE) for assessing global cognitive function was used; CI was defined as an MMSE score <24.

RESULTS

From February 1998 to January 2006, 630 patients with first-ever stroke were included. Prevalence rates of CI at 3 months, 1 and 3 years were 15, 13, and 12%. In multivariable analysis, stroke severity, i.e. Barthel index (p < 0.001), age (OR = 1.03; 95% CI = 1.00-1.05) and diabetes mellitus (OR = 2.03; 95% CI = 1.13-3.67) were associated with CI at 3 months. Recovery rate from CI at 3 months after stroke was found to be 31% over the following 3 years. Intact cognitive function rate was 71% over 3 years and inversely associated with age (OR = 0.96; 95% CI = 0.96-0.94) and stroke severity (p < 0.001).

CONCLUSION

CI is frequent among stroke survivors and associated with age, stroke severity, and diabetes mellitus, but recovery occurs in approximately one third of the patients over the course of 3 years. Factors affecting intact cognitive function over time are increasing age and stroke severity.

Vascular cognitive impairment: disease mechanisms and therapeutic implications

The prevalence of vascular cognitive impairment (VCI) is likely to increase as the population ages and cardiovascular disease survival improves. We provide an overview of the definition and disease mechanisms of VCI and present a systematic literature review of the current evidence for the pharmacologic and nonpharmacologic therapies used to treat the VCI symptoms of cognitive dysfunction or to modify VCI through primary and secondary prevention. The Cochrane Database of Systematic Reviews was searched from 2005 to October 2010 using the keywords "vascular dementia" or "vascular cognitive impairment and therapy." MEDLINE was searched for English-language articles published within the last 10 years using the combined Medical Subject Headings (MeSH) "therapeutics and dementia," "vascular" or "vascular cognitive impairment." Although cholinesterase inhibitors and memantine produce small cognitive improvements in patients with VCI, these drugs do not improve global clinical outcomes and have adverse effects and costs. Selective serotonin reuptake inhibitors and dihydropyridine calcium channel blockers may improve short-term cognitive function in patients with VCI. Anti-hypertensive therapy with an ACE inhibitor-based regimen and statins may prevent the major subtype of VCI known as poststroke cognitive decline. Clinical and effectiveness studies with long-term follow-up are needed to determine the benefits and risks of pharmacologic and nonpharmacologic therapies to prevent and treat VCI. Given its growing health, social, and economic burden, the prevention and treatment of VCI are critical priorities for clinical care and research.

Excitatory repetitive transcranial magnetic stimulation induces improvements in chronic post-stroke aphasia

BACKGROUND

Aphasia affects 1/3 of stroke patients with improvements noted only in some of them. The goal of this exploratory study was to provide preliminary evidence regarding safety and efficacy of fMRI-guided excitatory repetitive transcranial magnetic stimulation (rTMS) applied to the residual left-hemispheric Broca's area for chronic aphasia treatment.

MATERIAL/METHODS

We enrolled 8 patients with moderate or severe aphasia >1 year after LMCA stroke. Linguistic battery was administered pre-/post-rTMS; a semantic decision/tone decision (SDTD) fMRI task was used to localize left-hemispheric Broca's area. RTMS protocol consisted of 10 daily treatments of 200 seconds each using an excitatory stimulation protocol called intermittent theta burst stimulation (iTBS). Coil placement was targeted individually to the left Broca's.

RESULTS

6/8 patients showed significant pre-/post-rTMS improvements in semantic fluency (p=0.028); they were able to generate more appropriate words when prompted with a semantic category. Pre-/post-rTMS fMRI maps showed increases in left fronto-temporo-parietal language networks with a significant left-hemispheric shift in the left frontal (p=0.025), left temporo-parietal (p=0.038) regions and global language LI (p=0.018). Patients tended to report subjective improvement on Communicative Activities Log (mini-CAL; p=0.075). None of the subjects reported ill effects of rTMS.

CONCLUSIONS

FMRI-guided, excitatory rTMS applied to the affected Broca's area improved language skills in patients with chronic post-stroke aphasia; these improvements correlated with increased language lateralization to the left hemisphere. This rTMS protocol appears to be safe and should be further tested in blinded studies assessing its short- and long-term safety/efficacy for post-stroke aphasia rehabilitation.

Hyperglycaemia, microangiopathy, diabetes and dementia risk

Brain microangiopathy increases in frequency and severity with older age, with the presence of hypertension and to a lesser extent with diabetes. Magnetic resonance imaging is used to provide anatomical descriptions, but at this time only clinical examination and neuropsychological testing can assess white matter functioning. Clinical correlates of microangiopathy appear as subcortical cognitive alterations, but data are controversial about dementia risk. Brain microangiopathy seems to be however a complication of chronic hyperglycaemia, probably due to similar mechanisms occurring in retinopathy and other microvascular complications. To date, many questions have been raised: How can brain microangiopathy progression be monitored? Is there a reversible stage of brain microangiopathy? Which preventive actions should be implemented in aging patients with diabetes? Finally, what type of care should be provided for people with diabetes and mild cognitive impairment or overt dementia to slow down cognitive worsening?

The Secondary Prevention of Small Subcortical Strokes (SPS3) study

BACKGROUND

Small subcortical strokes, also known as lacunar strokes, comprise more than 25% of brain infarcts, and the underlying vasculopathy is the most common cause of vascular cognitive impairment. How to optimally prevent stroke recurrence and cognitive decline in S3 patients is unclear. The aim of the Secondary Prevention of Small Subcortical Strokes study (Trial registration: NCT00059306) is to define strategies for reducing stroke recurrence, cognitive decline, and major vascular events.

METHODS

Secondary Prevention of Small Subcortical Strokes is a randomised, multicentre clinical trial (n = 3000) being conducted in seven countries, and sponsored by the US NINDS/NIH. Patients with symptomatic small subcortical strokes in the six-months before and an eligible lesion on magnetic resonance imaging are simultaneously randomised, in a 2 × 2 factorial design, to antiplatelet therapy--325 mg aspirin daily plus 75 mg clopidogrel daily, vs. 325 mg aspirin daily plus placebo, double-blind--and to one of two levels of systolic blood pressure targets--'intensive' (<130 mmHg) vs. 'usual' (130-149 mmHg). Participants are followed for an average of four-years. Time to recurrent stroke (ischaemic or haemorrhagic) is the primary outcome and will be analysed separately for each intervention. The secondary outcomes are the rate of cognitive decline and major vascular events. The primary and most secondary outcomes are adjudicated centrally by those unaware of treatment assignment.

CONCLUSIONS

Secondary Prevention of Small Subcortical Strokes will address several important clinical and scientific questions by testing two interventions in patients with recent magnetic resonance imaging-defined lacunar infarcts, which are likely due to small vessel disease. The results will inform the management of millions of patients with this common vascular disorder.