Toward a pathological definition of vascular dementia

BDNF Signaling in Vascular Dementia and Its Effects on Cerebrovascular Dysfunction, Synaptic Plasticity, and Cholinergic System Abnormality

Vascular dementia (VaD) is the second most common type of dementia and is characterized by memory impairment, blood-brain barrier disruption, neuronal cell loss, glia activation, impaired synaptic plasticity, and cholinergic system abnormalities. To effectively prevent and treat VaD a good understanding of the mechanisms underlying its neuropathology is needed. Brain-derived neurotrophic factor (BDNF) is an important neurotrophic factor with multiple functions in the systemic circulation and the central nervous system and is known to regulate neuronal cell survival, synaptic formation, glia activation, and cognitive decline. Recent studies indicate that when compared with normal subjects, patients with VaD have low serum BDNF levels and that BDNF deficiency in the serum and cerebrospinal fluid is an important indicator of VaD. Here, we review current knowledge on the role of BDNF signaling in the pathology of VaD, such as cerebrovascular dysfunction, synaptic dysfunction, and cholinergic system impairment.

Bilirubin and Redox Stress in Age-Related Brain Diseases

Cellular redox status has a crucial role in brain physiology, as well as in pathologic conditions. Physiologic senescence, by dysregulating cellular redox homeostasis and decreasing antioxidant defenses, enhances the central nervous system's susceptibility to diseases. The reduction of free radical accumulation through lifestyle changes, and the supplementation of antioxidants as a prophylactic and therapeutic approach to increase brain health, are strongly suggested. Bilirubin is a powerful endogenous antioxidant, with more and more recognized roles as a biomarker of disease resistance, a predictor of all-cause mortality, and a molecule that may promote health in adults. The alteration of the expression and activity of the enzymes involved in bilirubin production, as well as an altered blood bilirubin level, are often reported in neurologic conditions and neurodegenerative diseases (together denoted NCDs) in aging. These changes may predict or contribute both positively and negatively to the diseases. Understanding the role of bilirubin in the onset and progression of NCDs will be functional to consider the benefits vs. the drawbacks and to hypothesize the best strategies for its manipulation for therapeutic purposes.

Effects of Polyunsaturated Fatty Acid Serum Levels on Vascular Dementia: A Two-Sample Mendelian Randomization Study

INTRODUCTION

Several observational studies have indicated that polyunsaturated fatty acid serum levels (PUFAs) are associated with vascular dementia (VaD), but their causal relationships remain elusive. Therefore, we attempted to evaluate the causal effect of PUFAs on VaD in a two-sample Mendelian randomization (MR) analysis by using summary statistics from aggregated genome-wide association studies.

METHODS

The inverse-variance weighted (IVW) method was performed as the primary analysis. Sensitivity analyses (MR-Egger regression, weighted median, penalized weighted median, and MR pleiotropy residual sum and outlier methods) were also implemented to estimate the effects of potential violations of MR hypotheses.

RESULTS

No causality was found for PUFAs (odds ratio, 1.14; 95% confidence interval, 0.91-1.42; p = 0.25) on VaD in the IVW model. The results were consistent in sensitivity analyses. There was no notable horizontal pleiotropy or heterogeneity.

CONCLUSION

In this two-sample MR analysis, our findings did not support the assumption that PUFAs play causal role in the occurrence or development of VaD.

Vascular dementia subtypes, pathophysiology, genetics, neuroimaging, biomarkers, and treatment updates along with its association with Alzheimer's dementia and diabetes mellitus

Dementia is a chronic progressive cognitive decline illness that results in functional impairment. Vascular dementia (VaD), second only to Alzheimer's disease (AD), is one of the most prevalent forms of dementia in the elderly (aged over 65 years), with a varied presentation and unpredictable disease development caused by cerebrovascular or cardiovascular illness. To get a better understanding of the changes occurring in the brain and to drive therapy efforts, new biomarkers for early and precise diagnosis of AD and VaD are required. In this review, Firstly, we describe the subtypes of vascular dementia, their clinical features, pathogenesis, genetics implemented, and their associated neuroimaging and biomarkers, while describing extensively the recent biomarkers discovered in the literature. Secondly, we describe some of the well-documented and other less-defined risk factors and their association and pathophysiology in relation to vascular dementia. Finally, we follow recent updates in the management of vascular dementia along with its association and differentiation from Alzheimer's disease. The aim of this review is to gather the scattered updates and the most recent changes in blood, CSF, and neuroimaging biomarkers related to the multiple subtypes of vascular dementia along with its association with Alzheimer's dementia and diabetes mellitus.

Postmortem 7T MRI for guided histopathology and evaluation of cerebrovascular disease

Postmortem (PM) magnetic resonance imaging (MRI) can serve as a bridge between in vivo imaging and histology by connecting MRI observed macrostructural findings to histological staining and microstructural changes. Data were acquired from 20 formalin-fixed brains including T2, T1, PD, and T2*-weighted images of left hemispheres and 6-mm-thick coronal slices. Tissue slices were bisected, aligned to MR images and used to guide histological sampling. Markers of myelin and oligodendroglia alterations were semiquantitatively rated and compared within white matter hyperintensities (WMHs) and normal-appearing white matter. Tissue priors were created from 3T in vivo data and used to guide segmentation of WMH. PM WMH and hemisphere volumes were compared to volumes derived from in vivo data. PM T2 WMH and T1 hemisphere volumes were correlated with in vivo 3T FLAIR WMH and T1 hemisphere volumes. WMH showed significant myelin loss, decreased GFAP expression and increased vimentin expression. MR-visible perivascular spaces and cortical microvascular lesions were successfully captured on histopathological sections. PM MRI can quantify cerebrovascular disease burden and guide tissue sampling, allowing for more comprehensive characterization of cerebrovascular disease that may be used to study etiologies of age-related cognitive change.

Novel insights into non-alcoholic fatty liver disease and dementia: insulin resistance, hyperammonemia, gut dysbiosis, vascular impairment, and inflammation

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disease characterized by multiple pathologies. The progression of dementia with NAFLD may be affected by various risk factors, including brain insulin resistance, cerebrovascular dysfunction, gut dysbiosis, and neuroinflammation. Many recent studies have focused on the increasing prevalence of dementia in patients with NAFLD. Dementia is characterized by cognitive and memory deficits and has diverse subtypes, including vascular dementia, Alzheimer’s dementia, and diabetes mellitus-induced dementia. Considering the common pathological features of NAFLD and dementia, further studies on the association between them are needed to find appropriate therapeutic solutions for diseases. This review summarizes the common pathological characteristics and mechanisms of NAFLD and dementia. Additionally, it describes recent evidence on association between NAFLD and dementia progression and provides novel perspectives with regard to the treatment of patients with dementia secondary to NAFLD.

Diagnosis of vascular cognitive impairment: recommendations of the scientific department of cognitive neurology and aging of the Brazilian Academy of Neurology

ABSTRACT Since the publication of the latest recommendations for the diagnosis and treatment of Vascular Dementia by the Brazilian Academy of Neurology in 2011, significant advances on the terminology and diagnostic criteria have been made. This manuscript is the result of a consensus among experts appointed by the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology (2020-2022). We aimed to update practical recommendations for the identification, classification, and diagnosis of Vascular Cognitive Impairment (VCI). Searches were performed in the MEDLINE, Scopus, Scielo, and LILACS databases. This guideline provides a comprehensive review and then synthesizes the main practical guidelines for the diagnosis of VCI not only for neurologists but also for other professionals involved in the assessment and care of patients with VCI, considering the different levels of health care (primary, secondary and tertiary) in Brazil.

Diagnóstico do comprometimento cognitivo vascular: recomendações do Departamento Científico de Neurologia Cognitiva e do Envelhecimento da Academia Brasileira de Neurologia

RESUMO Desde a publicação das últimas recomendações para o diagnóstico e tratamento da Demência Vascular pela Academia Brasileira de Neurologia em 2011, avanços significativos ocorreram na terminologia e critérios diagnósticos. O presente manuscrito é resultado do consenso entre especialistas indicados pelo Departamento Científico de Neurologia Cognitiva e do Envelhecimento da Academia Brasileira de Neurologia (2020-2022). O objetivo foi atualizar as recomendações práticas para a identificação, classificação e diagnóstico do Comprometimento Cognitivo Vascular (CCV). As buscas foram realizadas nas plataformas MEDLINE, Scopus, Scielo e LILACS. As recomendações buscam fornecer uma ampla revisão sobre o tema, então sintetizar as evidências para o diagnóstico do CCV não apenas para neurologistas, mas também para outros profissionais de saúde envolvidos na avaliação e nos cuidados ao paciente com CCV, considerando as diferentes realidades dos níveis de atenção à saúde (primário, secundário e terciário) no Brasil.

Cause of Death Determined by Full-body Autopsy in Neuropathologically Diagnosed Dementias: The Biobank for Aging Studies of the University of Sao Paulo (BAS-USP), Brazil

OBJECTIVE

This study aimed to compare causes of death in the most prevalent neuropathologically diagnosed dementias.

METHODS

We analyzed causes of death in a community-based cohort of participants aged 50 or older, submitted to full-body autopsy and a comprehensive neuropathologic examination of the brain. Individuals with Alzheimer disease (AD), vascular dementia (VaD), mixed dementia (AD+VaD), or dementia with Lewy bodies (DLBs) were compared with individuals with no dementia.

RESULTS

In a sample of 920 individuals, 456 had no dementia, 147 had AD, 120 had VaD, 53 had DLB, and 37 had AD+VaD. Pneumonia as the cause of death was more frequent in the AD (P=0.023), AD+VaD (P=0.046), and DLB (P=0.043) groups. In addition, VaD (P=0.041) and AD+VaD (P=0.028) groups had a higher frequency of atherosclerosis as detected by full-body autopsy.

CONCLUSION

Our findings highlight the importance of preventive measures regarding atherosclerosis and pneumonia in patients with dementia. Moreover, because of cognitive impairment, these patients may not fully account for symptoms to make early detection and diagnosis possible. These results confirm findings from previous studies that were based on clinical data, with added accuracy provided by neuropathologic diagnosis and full-body autopsy reports.

Vascular Dementia and Crosstalk Between the Complement and Coagulation Systems

Vascular Dementia (VaD) is a neurocognitive disorder caused by reduced blood flow to the brain tissue, resulting in infarction, and is the second most common type of dementia. The complement and coagulation systems are evolutionary host defence mechanisms activated by acute tissue injury to induce inflammation, clot formation and lysis; recent studies have revealed that these systems are closely interlinked. Overactivation of these systems has been recognised to play a key role in the pathogenesis of neurological disorders such as Alzheimer's disease and multiple sclerosis, however their role in VaD has not yet been extensively reviewed. This review aims to bridge the gap in knowledge by collating current understanding of VaD to enable identification of complement and coagulation components involved in the pathogenesis of this disorder that may have their effects amplified or supressed by crosstalk. Exploration of these mechanisms may unveil novel therapeutic targets or biomarkers that would improve current treatment strategies for VaD.

Blood-Brain Barrier Breakdown: An Emerging Biomarker of Cognitive Impairment in Normal Aging and Dementia

The blood–brain barrier (BBB) plays a vital role in maintaining the specialized microenvironment of the neural tissue. It separates the peripheral circulatory system from the brain parenchyma while facilitating communication. Alterations in the distinct physiological properties of the BBB lead to BBB breakdown associated with normal aging and various neurodegenerative diseases. In this review, we first briefly discuss the aging process, then review the phenotypes and mechanisms of BBB breakdown associated with normal aging that further cause neurodegeneration and cognitive impairments. We also summarize dementia such as Alzheimer's disease (AD) and vascular dementia (VaD) and subsequently discuss the phenotypes and mechanisms of BBB disruption in dementia correlated with cognition decline. Overlaps between AD and VaD are also discussed. Techniques that could identify biomarkers associated with BBB breakdown are briefly summarized. Finally, we concluded that BBB breakdown could be used as an emerging biomarker to assist to diagnose cognitive impairment associated with normal aging and dementia.

The Utility of Cerebrovascular Reactivity MRI in Brain Rehabilitation: A Mechanistic Perspective

Cerebrovascular control and its integration with other physiological systems play a key role in the effective maintenance of homeostasis in brain functioning. Maintenance, restoration, and promotion of such a balance are one of the paramount goals of brain rehabilitation and intervention programs. Cerebrovascular reactivity (CVR), an index of cerebrovascular reserve, plays an important role in chemo-regulation of cerebral blood flow. Improved vascular reactivity and cerebral blood flow are important factors in brain rehabilitation to facilitate desired cognitive and functional outcomes. It is widely accepted that CVR is impaired in aging, hypertension, and cerebrovascular diseases and possibly in neurodegenerative syndromes. However, a multitude of physiological factors influence CVR, and thus a comprehensive understanding of underlying mechanisms are needed. We are currently underinformed on which rehabilitation method will improve CVR, and how this information can inform on a patient's prognosis and diagnosis. Implementation of targeted rehabilitation regimes would be the first step to elucidate whether such regimes can modulate CVR and in the process may assist in improving our understanding for the underlying vascular pathophysiology. As such, the high spatial resolution along with whole brain coverage offered by MRI has opened the door to exciting recent developments in CVR MRI. Yet, several challenges currently preclude its potential as an effective diagnostic and prognostic tool in treatment planning and guidance. Understanding these knowledge gaps will ultimately facilitate a deeper understanding for cerebrovascular physiology and its role in brain function and rehabilitation. Based on the lessons learned from our group's past and ongoing neurorehabilitation studies, we present a systematic review of physiological mechanisms that lead to impaired CVR in aging and disease, and how CVR imaging and its further development in the context of brain rehabilitation can add value to the clinical settings.

Brain arteriolosclerosis

Brain arteriolosclerosis (B-ASC), characterized by pathologic arteriolar wall thickening, is a common finding at autopsy in aged persons and is associated with cognitive impairment. Hypertension and diabetes are widely recognized as risk factors for B-ASC. Recent research indicates other and more complex risk factors and pathogenetic mechanisms. Here, we describe aspects of the unique architecture of brain arterioles, histomorphologic features of B-ASC, relevant neuroimaging findings, epidemiology and association with aging, established genetic risk factors, and the co-occurrence of B-ASC with other neuropathologic conditions such as Alzheimer's disease and limbic-predominant age-related TDP-43 encephalopathy (LATE). There may also be complex physiologic interactions between metabolic syndrome (e.g., hypertension and inflammation) and brain arteriolar pathology. Although there is no universally applied diagnostic methodology, several classification schemes and neuroimaging techniques are used to diagnose and categorize cerebral small vessel disease pathologies that include B-ASC, microinfarcts, microbleeds, lacunar infarcts, and cerebral amyloid angiopathy (CAA). In clinical-pathologic studies that factored in comorbid diseases, B-ASC was independently associated with impairments of global cognition, episodic memory, working memory, and perceptual speed, and has been linked to autonomic dysfunction and motor symptoms including parkinsonism. We conclude by discussing critical knowledge gaps related to B-ASC and suggest that there are probably subcategories of B-ASC that differ in pathogenesis. Observed in over 80% of autopsied individuals beyond 80 years of age, B-ASC is a complex and under-studied contributor to neurologic disability.

Tianzhi granule improves cognition and BPSD of vascular dementia: a randomized controlled trial

Background and purpose

Tianzhi granule (TZ) is usually used for patients with vascular dementia (VaD) in China. The aim was to assess the effect of TZ by a randomized clinical trial (RCT).

Methods

A 24-week RCT was conducted in 16 centres. Participants were grouped into TZ, donepezil or placebo. The co-primary outcomes were the Vascular Dementia Assessment Scale-cognitive subscale (VADAS-cog) and Clinician’s Interview-based Impression of Change-plus caregiver information (CIBIC-plus).

Results

A total of 543 patients with mild to moderate VaD were enrolled, of whom 242 took TZ granules, 241 took donepezil, and 60 took placebo. The least-squares mean changes from baseline and 95% CI were 6.20 (5.31, 7.09) (TZ group), 6.53 (5.63, 7.42) (donepezil group) and 3.47 (1.76, 5.19) (placebo group), both TZ and donepezil showed small but significantly improvement compared with placebo group. The percent of improvement on the global impression which was measured by CIBIC-plus was 73.71% in TZ and 58.18% in placebo, there was significant different between TZ and placebo group (P = 0.004). No significant differences were observed between TZ and donepezil. No significant differences of adverse events were found.

Conclusions

TZ and donepezil could bring symptomatic benefit for mild to moderate VaD.

Trial registration The protocol had retrospectively registered at clinical trial.gov, Unique identifier: NCT02453932, date of registration: May 27, 2015; https://www.clinicaltrials.gov/ct2/show/NCT02453932?term=NCT02453932&rank=1

Patients with the Subcortical Small Vessel Type of Dementia Have Disturbed Cardiometabolic Risk Profile

BACKGROUND

Population-based studies have shown that cardiometabolic status is associated with the amount of white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI). However, little is known of cardiometabolic risk factors in the subcortical small vessel type of dementia (SSVD), in which WMHs are one of the most prominent manifestations.

OBJECTIVE

To determine whether the profile of cardiometabolic risk factors differed between SSVD, Alzheimer's disease (AD), mixed dementia (combined AD and SSVD), and healthy controls.

METHODS

This was a mono-center, cross-sectional study of SSVD (n = 40), AD (n = 113), mixed dementia (n = 62), and healthy controls (n = 94). In the statistical analyses, we adjusted for covariates using ANCOVA and binary logistic regression.

RESULTS

The prevalence of hypertension was increased in SSVD and mixed dementia (p < 0.001 and p < 0.05 versus controls, respectively). Diabetes was more prevalent in SSVD patients, and body mass index was lower in AD and mixed dementia, compared to the controls (all p < 0.05). Serum total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) were reduced in the SSVD group (both p < 0.05 versus control). These differences remained after adjustment for covariates. In the SSVD group, Trail Making Test A score correlated positively with systolic blood pressure, mean arterial pressure, and pulse pressure.

CONCLUSION

All dementia groups had an altered cardiometabolic risk profile compared to the controls. The SSVD patients showed increased prevalence of hypertension and diabetes, and in line with previous population-based data, TC and LDL-C in serum were reduced.

Neuropathological lesions in the very old: results from a large Brazilian autopsy study

OBJECTIVE

To compare neuropathological correlates of cognitive impairment between very old and younger individuals from a Brazilian clinicopathological study.

METHODS

We assessed the frequency of neuropathological lesions and their association with cognitive impairment (Clinical Dementia Rating scale ≥0.5) in the 80 or over age group compared to younger participants, using logistic regression models adjusted for sex, race and education.

RESULTS

Except for infarcts and siderocalcinosis, all neuropathological lesions were more common in the 80 or over age group (n = 412) compared to 50-79 year olds (n = 677). Very old participants had more than twice the likelihood of having ≥2 neuropathological diagnoses than younger participants (OR = 2.66, 95% CI = 2.03-3.50). Neurofibrillary tangles, infarcts and hyaline arteriolosclerosis were associated with cognitive impairment in the two age groups. Siderocalcinosis was associated with cognitive impairment in the younger participants only, while Lewy body disease was associated with cognitive impairment in the very old only. In addition, we found that the association of infarcts and multiple pathologies with cognitive impairment was attenuated in very old adults (Infarcts: P for interaction = 0.04; and multiple pathologies: P = 0.05). However, the predictive value for the aggregate model with all neuropathological lesions showed similar discrimination in both age groups [Area under Receiver Operating Characteristic curve (AUROC) = 0.778 in younger participants and AUROC = 0.765 in the very old].

CONCLUSION AND RELEVANCE

Despite a higher frequency of neuropathological findings in the very old group, as found in studies with high-income populations, we found attenuation of the effect of infarcts rather than neurofibrillary tangles and plaques as reported previously.

Neurofilament light chain protein in neurodegenerative dementia: A systematic review and network meta-analysis

The diagnostic value of neurofilament light chain protein in neurodegenerative dementia diseases is still controversial. A systematic literature search was performed to identify relevant case-control studies conducted through October 2018. Traditional and net meta-analyses were performed based on 42 studies that tested the diagnostic performance of neurofilament light chain protein (NfL) concentration in CSF and serum/plasma from patients with neurodegenerative dementia. CSF and serum/plasma NfL levels were significantly increased in patients with neurodegenerative dementia diseases. Network meta-analysis showed a significant reduction in CSF NfL levels during mild cognitive impairment, whereas an increase was observed in vascular dementia compared to Alzheimer's disease. Surface under the cumulative ranking curve and cluster analysis showed that the NfL concentration in CSF (vascular dementia, frontotemporal dementia, and Alzheimer's disease) and serum/plasma (frontotemporal dementia and Alzheimer's disease) ranked first among neurodegenerative dementia diseases. NfL is an important biomarker that can help clinical neurologists make early diagnoses of neurodegenerative diseases, so patients can receive prompt treatment.

Vascular cognitive impairment: A preventable component of dementia

For many decades during the 20th century, the common belief was that the slow strangulation of the brains' blood supply from hardening of the brain arteries led to chronic brain ischemia and neuronal death. Not surprisingly, to counter this, vasodilators rapidly became one of the most commonly used and profitable medications worldwide; however, no clinical benefits were ever proven. In the 1970s and early 1980s cerebral blood flow studies strongly disproved the idea of brain failure due to chronic ischemia. It was also shown that infarcts and not chronic ischemia caused dementia, leading to the concept of multiinfarct dementia. In addition to infarcts, it was then realized that other vascular lesions can also cause cognitive decline. Gradually, as "atherosclerotic dementia" lost ground, Alzheimer's disease (AD) that once had been considered a presenile dementia and rare, became almost synonymous with dementia. Subsequent memory-based definitions and evaluations of dementia led to a bias in favor of diagnosing AD, overshadowing vascular contributions. The widespread use of brain imaging in the 1980s and 1990s contributed to the resurgence of evidence of cerebrovascular diseases. Moreover, it was shown that most cognitive impairment of the elderly results from mixed pathologies, emphasizing the need for a change in the traditional categorical diagnosis of dementia, e.g., AD vs vascular dementia. The alternative diagnostic method was named the vascular cognitive impairment approach, meaning identifying any impairment caused by or associated with vascular factors. The importance of this approach is that vascular lesions are currently the most important treatable and preventable components of dementia, even before any symptoms manifest, i.e., at the brain at risk stage. This chapter provides a summary of the vascular cognitive impairment approach to diagnosis, treatment, and prevention of cognitive decline.

Concomitant vascular and neurodegenerative pathologies double the risk of dementia

INTRODUCTION

The relative contributions of vascular and degenerative pathology to dementia are unknown. We aim to quantify the proportion of dementia explained by potentially preventable vascular lesions.

METHODS

We systematically searched for population-based cohorts before February 2017 reporting clinicopathological data for individuals with and without dementia. We calculated the summary proportion and absolute risk of dementia comparing subjects with and without the pathology.

RESULTS

We identified 10 studies comprising 2856 subjects. Vascular-type pathology and mixed pathology are respectively two and three times more likely in demented patients. The summary proportion of dementia is 77%-86% in subjects with mixed degenerative and vascular pathology and 45% in subjects with pure Alzheimer-type pathology.

DISCUSSION

Patients with mixed pathologies have nearly twice the incremental risk of dementia compared with patients with only Alzheimer-type lesions. Consequently, many cases of dementia could be prevented or delayed by targeting the vascular component.

Depression and the risk of vascular dementia: a population-based retrospective cohort study

OBJECTIVE

To examine the association between the risks of depression and vascular dementia (VaD) based on Taiwan's National Health Insurance Research Database.

METHODS

This retrospective longitudinal matched-cohort study used National Health Insurance Research Database data from 49,955 participants (9,991 with new onset depression, 39,964 controls). A Cox regression analysis was performed on the whole sample and the subgroup of patients with depression. We further excluded patients who developed VaD within 3 or 5 years after enrollment to evaluate depression as an independent risk factor for or a prodrome of VaD.

RESULTS

During the 10-year follow-up period, the incidence rate ratio of VaD between patients with depression and controls was 4.24 [95% confidence interval (CI) 2.90-6.21, P < 0.001]. After adjustment for covariates, the hazard ratio (HR) of VaD in patients with depression was 3.10 (95% CI 2.13-4.52, P < 0.001). In the whole sample, risk factors for VaD besides depression were aged ≥60 years (HR = 20.08), hypertension (HR = 1.70), diabetes (HR = 1.61), coronary artery disease (HR = 2.26), head injury (HR = 2.20), and cerebrovascular disease (HR = 3.02). In patients with depression, aged ≥60 years (HR = 32.16), coronary artery disease (HR = 2.82), head injury (HR = 2.06), and cerebrovascular disease (HR = 2.37) remained risk factors for VaD. After excluding those who developed VaD within 3 or 5 years, HRs remained high (3.28, 95% CI 2.03-5.31, P < 0.001; 2.12, 95% CI 1.05-4.25, P = 0.035, respectively).

CONCLUSIONS

Our findings suggest that depression is an independent risk factor for subsequent VaD. Older age, cerebrovascular disease, head injury, and coronary artery disease might increase the risk of VaD among patients with depression.

Neuropathological diagnoses and clinical correlates in older adults in Brazil: A cross-sectional study

BACKGROUND

Clinicopathological studies are important in determining the brain lesions underlying dementia. Although almost 60% of individuals with dementia live in developing countries, few clinicopathological studies focus on these individuals. We investigated the frequency of neurodegenerative and vascular-related neuropathological lesions in 1,092 Brazilian admixed older adults, their correlation with cognitive and neuropsychiatric symptoms, and the accuracy of dementia subtype diagnosis.

METHODS AND FINDINGS

In this cross-sectional study, we describe clinical and neuropathological variables related to cognitive impairment in 1,092 participants (mean age = 74 y, 49% male, 69% white, and mean education = 4 y). Cognitive function was investigated using the Clinical Dementia Rating (CDR) and the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE); neuropsychiatric symptoms were evaluated using the Neuropsychiatric Inventory (NPI). Associations between neuropathological lesions and cognitive impairment were investigated using ordinal logistic regression. We developed a neuropathological comorbidity (NPC) score and compared it to CDR, IQCODE, and NPI scores. We also described and compared the frequency of neuropathological diagnosis to clinical diagnosis of dementia subtype. Forty-four percent of the sample met criteria for neuropathological diagnosis. Among these participants, 50% had neuropathological diagnoses of Alzheimer disease (AD), and 35% of vascular dementia (VaD). Neurofibrillary tangles (NFTs), hippocampal sclerosis, lacunar infarcts, hyaline atherosclerosis, siderocalcinosis, and Lewy body disease were independently associated with cognitive impairment. Higher NPC scores were associated with worse scores in the CDR sum of boxes (β = 1.33, 95% CI 1.20-1.46), IQCODE (β = 0.14, 95% CI 0.13-0.16), and NPI (β = 1.74, 95% CI = 1.33-2.16). Compared to neuropathological diagnoses, clinical diagnosis had high sensitivity to AD and high specificity to dementia with Lewy body/Parkinson dementia. The major limitation of our study is the lack of clinical follow-up of participants during life.

CONCLUSIONS

NFT deposition, vascular lesions, and high NPC scorewere associated with cognitive impairment in a unique Brazilian sample with low education. Our results confirm the high prevalence of neuropathological diagnosis in older adults and the mismatch between clinical and neuropathological diagnoses.

Association of Central Arterial Stiffness and Pressure Pulsatility with Mild Cognitive Impairment and Dementia: The Atherosclerosis Risk in Communities Study-Neurocognitive Study (ARIC-NCS)

BACKGROUND

The association of central arterial stiffness and pressure pulsatility with mild cognitive impairment (MCI) and dementia is not well characterized in the population-based setting.

OBJECTIVE

The aim of this study was to quantify the cross-sectional association of arterial stiffness and pressure pulsatility with MCI and dementia among 4,461 older white and black adults from the population-based Atherosclerosis Risk in Communities Study-Neurocognitive Study.

METHODS

We used race-stratified multinomial logistic regression to evaluate associations of percentile cut points of carotid-femoral pulse wave velocity, central systolic blood pressure, central pulse pressure, and pulse pressure amplification with MCI and dementia versus no cognitive impairment.

RESULTS

Among whites, those with carotid-femoral pulse wave velocity or central systolic blood pressure ≥75th percentile had a higher prevalence of MCI compared to participants <75th percentile (conditional odds ratio (OR); 95% confidence interval (CI): 1.27 (1.02, 1.56) and 1.28 (1.04, 1.57), respectively) and those with central pulse pressure ≥75th percentile had a higher prevalence of MCI (OR 1.27 (95% CI: 1.03, 1.58)) and dementia (OR 1.76 (95% CI: 1.06, 2.92) compared to participants <75th percentile. Also among whites, those with pulse pressure amplification ≤25th percentile had a higher prevalence of dementia compared to participants >25th percentile (OR 1.65; (95% CI: 1.01, 2.70). Weaker associations were seen among black participants.

CONCLUSION

Higher arterial stiffness and pulsatility were associated with MCI and dementia in white participants. Longitudinal characterization of the observed associations is warranted to assess whether arterial stiffness and pressure pulsatility predict MCI and dementia among older adults.

Post-mortem assessment in vascular dementia: advances and aspirations

BACKGROUND

Cerebrovascular lesions are a frequent finding in the elderly population. However, the impact of these lesions on cognitive performance, the prevalence of vascular dementia, and the pathophysiology behind characteristic in vivo imaging findings are subject to controversy. Moreover, there are no standardised criteria for the neuropathological assessment of cerebrovascular disease or its related lesions in human post-mortem brains, and conventional histological techniques may indeed be insufficient to fully reflect the consequences of cerebrovascular disease.

DISCUSSION

Here, we review and discuss both the neuropathological and in vivo imaging characteristics of cerebrovascular disease, prevalence rates of vascular dementia, and clinico-pathological correlations. We also discuss the frequent comorbidity of cerebrovascular pathology and Alzheimer's disease pathology, as well as the difficult and controversial issue of clinically differentiating between Alzheimer's disease, vascular dementia and mixed Alzheimer's disease/vascular dementia. Finally, we consider additional novel approaches to complement and enhance current post-mortem assessment of cerebral human tissue.

CONCLUSION

Elucidation of the pathophysiology of cerebrovascular disease, clarification of characteristic findings of in vivo imaging and knowledge about the impact of combined pathologies are needed to improve the diagnostic accuracy of clinical diagnoses.

Altered Expression of Human Mitochondrial Branched Chain Aminotransferase in Dementia with Lewy Bodies and Vascular Dementia

Cytosolic and mitochondrial human branched chain aminotransferase (hBCATc and hBCATm, respectively) play an integral role in brain glutamate metabolism. Regional increased levels of hBCATc in the CA1 and CA4 region of Alzheimer’s disease (AD) brain together with increased levels of hBCATm in frontal and temporal cortex of AD brains, suggest a role for these proteins in glutamate excitotoxicity. Glutamate toxicity is a key pathogenic feature of several neurological disorders including epilepsy associated dementia, AD, vascular dementia (VaD) and dementia with Lewy bodies (DLB). To further understand if these increases are specific to AD, the expression profiles of hBCATc and hBCATm were examined in other forms of dementia including DLB and VaD. Similar to AD, levels of hBCATm were significantly increased in the frontal and temporal cortex of VaD cases and in frontal cortex of DLB cases compared to controls, however there were no observed differences in hBCATc between groups in these areas. Moreover, multiple forms of hBCATm were observed that were particular to the disease state relative to matched controls. Real-time PCR revealed similar expression of hBCATm mRNA in frontal and temporal cortex for all cohort comparisons, whereas hBCATc mRNA expression was significantly increased in VaD cases compared to controls. Collectively our results suggest that hBCATm protein expression is significantly increased in the brains of DLB and VaD cases, similar to those reported in AD brain. These findings indicate a more global response to altered glutamate metabolism and suggest common metabolic responses that might reflect shared neurodegenerative mechanisms across several forms of dementia.

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.

Vascular dementia

Vascular dementia is one of the most common causes of dementia after Alzheimer's disease, causing around 15% of cases. However, unlike Alzheimer's disease, there are no licensed treatments for vascular dementia. Progress in the specialty has been difficult because of uncertainties over disease classification and diagnostic criteria, controversy over the exact nature of the relation between cerebrovascular pathology and cognitive impairment, and the paucity of identifiable tractable treatment targets. Although there is an established relation between vascular and degenerative Alzheimer's pathology, the mechanistic link between the two has not yet been identified. This Series paper critiques some of the key areas and controversies, summarises treatment trials so far, and makes suggestions for what progress is needed to advance our understanding of pathogenesis and thus maximise opportunities for the search for new and effective management approaches.

Comorbid Medical Conditions in Vascular Dementia: A Matched Case-Control Study

The objective of the study was to compare the presence of comorbid medical conditions between patients with a vascular dementia (VaD) and a control group, from the Integrated Healthcare Information Services (IHCIS) database. VaD was defined by the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes 290.40, 290.4, 290.41, 290.42, and, 290.43. An individual matching method was used to select the controls, which were matched to cases on a 15:1 ratio by age, gender, type of health plan, and pharmacy benefits. Alzheimer's disease, any other dementia or cognitive deficits associated were considered exclusion criteria. Among the IHCIS patients 60 years of age or older and full year of eligibility during 2010, there were 898 VaD patients, from which 63.6% were women. Concurrent presence of cerebrovascular disease, atherosclerosis, heart failure, and atrial fibrillation were found at 12.6, 4.6, 2.8, and 1.7 times higher in VaD patients, respectively. Compared to controls, VaD patients had more septicemia, injuries, lung diseases including chronic obstructive pulmonary disease, and urinary diseases (all with df = 897,1; p < 0.0001). The present study confirms that these four medical comorbidities are frequent complications of VaD and physicians should be alert to the presence of them in patients with VaD.

Caspase-Cleaved Tau Co-Localizes with Early Tangle Markers in the Human Vascular Dementia Brain

Vascular dementia (VaD) is the second most common form of dementia in the United States and is characterized as a cerebral vessel vascular disease that leads to ischemic episodes. Whereas the relationship between caspase-cleaved tau and neurofibrillary tangles (NFTs) in Alzheimer's disease (AD) has been previously described, whether caspase activation and cleavage of tau occurs in VaD is presently unknown. To investigate a potential role for caspase-cleaved tau in VaD, we analyzed seven confirmed cases of VaD by immunohistochemistry utilizing a well-characterized antibody that specifically detects caspase-cleaved tau truncated at Asp421. Application of this antibody (TauC3) revealed consistent labeling within NFTs, dystrophic neurites within plaque-rich regions and corpora amylacea (CA) in the human VaD brain. Labeling of CA by the TauC3 antibody was widespread throughout the hippocampus proper, was significantly higher compared to age matched controls, and co-localized with ubiquitin. Staining of the TauC3 antibody co-localized with MC-1, AT8, and PHF-1 within NFTs. Quantitative analysis indicated that roughly 90% of PHF-1-labeled NFTs contained caspase-cleaved tau. In addition, we documented the presence of active caspase-3 within plaques, blood vessels and pretangle neurons that co-localized with TauC3. Collectively, these data support a role for the activation of caspase-3 and proteolytic cleavage of TauC3 in VaD providing further support for the involvement of this family of proteases in NFT pathology.

Common Aging Signature in the Peripheral Blood of Vascular Dementia and Alzheimer's Disease

Alzheimer's disease (AD) and vascular dementia (VaD) are the two most dominant forms of dementia in elderly people. Due to the large overlap between AD and VaD in clinical observations, great controversies exist regarding the distinction and connection between these two types of senile dementia. Here for the first time, we resort to the gene expression pattern of the peripheral blood to compare AD and VaD objectively. In our previous work, we have demonstrated that the dysregulation of gene expression in AD is unique among the examined diseases including neurological diseases, cancer, and metabolic diseases. In this study, we found that the dysregulation of gene expression in AD and VaD is quite similar to each other at both functional and gene levels. Interestingly, the dysregulation started at the early stages of the diseases, namely mild cognitive impairment (MCI) and vascular cognitive impairment (VCI). We have also shown that this signature is distinctive from that of peripheral vascular diseases. Comparison with aging studies revealed that the most profound change in AD and VaD, namely ribosome, is consistent with the accelerated aging scenario. This study may have implications to the common mechanism between AD and VaD.

Synaptic protein levels altered in vascular dementia

Introduction

Cerebral ischaemia is the defining pathophysiological abnormality in most forms of vascular dementia (VAD), but the pathogenesis of the dementia remains poorly understood. In Alzheimer's disease (AD), there is early loss of synaptic proteins, but these have been little studied in VAD.

Materials and Methods

We measured synaptophysin, postsynaptic density protein 95 (PSD-95), drebrin, synaptosomal-associated protein 25 (SNAP-25) and vascular endothelial growth factor (VEGF) by enzyme-linked immunosorbent assays in superior temporal cortex from 11 patients with VAD and, initially, 11 non-dementia controls. We corrected for neuronal content by measurement of neuron-specific enolase. A further 11 controls were subsequently used in a validation study. Simulation of post-mortem delay found that PSD-95 was stable at 4°C but declined slightly at RT. SNAP-25 and drebrin showed good post-mortem stability. Previous studies had shown good post-mortem preservation of synaptophysin and VEGF.

Results

The VAD cases had lower synaptophysin (but P > 0.05 in initial study), significantly lower SNAP-25 (P = 0.024) and significantly higher drebrin (P = 0.020). On comparison with the second control group, the reduction in synaptophysin was significant (P = 0.008), and the other results were confirmed.

Conclusion

There is probably a reduction in presynaptic proteins in the temporal cortex in VAD, although not as marked as in AD. In VAD, there is also an increase in drebrin, which may be a response to reduced synaptic input.

Microvascular pathology and morphometrics of sporadic and hereditary small vessel diseases of the brain

Small vessel diseases (SVDs) of the brain are likely to become increasingly common in tandem with the rise in the aging population. In recent years, neuroimaging and pathological studies have informed on the pathogenesis of sporadic SVD and several single gene (monogenic) disorders predisposing to subcortical strokes and diffuse white matter disease. However, one of the limitations toward studying SVD lies in the lack of consistent assessment criteria and lesion burden for both clinical and pathological measures. Arteriolosclerosis and diffuse white matter changes are the hallmark features of both sporadic and hereditary SVDs. The pathogenesis of the arteriopathy is the key to understanding the differential progression of disease in various SVDs. Remarkably, quantification of microvascular abnormalities in sporadic and hereditary SVDs has shown that qualitatively the processes involved in arteriolar degeneration are largely similar in sporadic SVD compared with hereditary disorders such as cerebral autosomal arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Important significant regional differences in lesion location within the brain may enable one to distinguish SVDs, where frontal lobe involvement appears consistently with almost every SVD, but others bear specific pathologies in other lobes, such as the temporal pole in CADASIL and the pons in pontine autosomal dominant microangiopathy and leukoencephalopathy or PADMAL. Additionally, degenerative changes in the vascular smooth muscle cells, the cerebral endothelium and the basal lamina are often rapid and more aggressive in genetic disorders. Further quantification of other microvascular elements and even neuronal cells is needed to fully characterize SVD pathogenesis and to differentiate the usefulness of vascular interventions and treatments on the resulting pathology.

Apolipoprotein E pathology in vascular dementia

Vascular dementia (VaD) is the second most common form of dementia and is currently defined as a cerebral vessel vascular disease leading to ischemic episodes. Apolipoprotein E (apoE) gene polymorphism has been proposed as a risk factor for VaD, however, to date there are few documented post-mortem studies on apoE pathology in the VaD brain. To investigate a potential role for the apoE protein, we analyzed seven confirmed cases of VaD by immunohistochemistry utilizing an antibody that specifically detects the amino-terminal fragment of apoE. Application of this antibody, termed N-terminal, apoE cleavage fragment (nApoECF) revealed consistent labeling within neurofibrillary tangles (NFTs), blood vessels, and reactive astrocytes. Labeling occurred in VaD cases that had confirmed APOE genotypes of 3/3, 3/4, and 4/4, with respect to NFTs, staining of the nApoECF co-localized with PHF-1 and was predominantly localized to large, stellate neurons in layer II of the entorhinal cortex. Quantitative analysis indicated that approximately 38.4% of all identified NFTs contained the amino-terminal fragment of apoE. Collectively, these data support a role for the proteolytic cleavage of apoE in the VaD and support previous reports that APOE polymorphism is significantly associated with susceptibility in this disease.

Antioxidant and cholinesterase inhibitory activity of a new peptide from Ziziphus jujuba fruits

Antioxidant agents and cholinesterase inhibitors are the foremost drugs for the treatment of Alzheimer's disease (AD). In this study, a new peptide from Ziziphus jujuba fruits was investigated for its inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes as well as antioxidant activity. This peptide was introduced as a new peptide and named Snakin-Z. The Snakin-Z displayed considerable cholinesterase inhibition against AChE and BChE. The half maximal inhibitory concentration (IC50) values of Snakin-Z against AChE and BChE are 0.58 ± 0.08 and 0.72 ± 0.085 mg/mL, respectively. This peptide has 80% enzyme inhibitory activity on AChE and BChE at 1.5 mg/mL. The Snakin-Z also had the high antioxidant activity (IC50 = 0.75 ± 0.09 mg/mL). Thus, it is suggested that Snakin-Z may be beneficial in the treatment of AD. However, more detailed researches are still required as in vivo testing its anticholinesterase and antioxidant activities.

The effects of high- and low-risk environments on cognitive function in rats following 2-vessel occlusion of the carotid arteries: a behavioral study

In a prospective study of environmental factors affecting cognitive recovery from stroke, adult male rats were reared for 3 months in a high-risk (relatively isolated, low activity, high-fat diet, high-stress) or low-risk (social, healthy diet, low-stress, physically active) environment. They then received cognitive testing to assess various aspects of learning and memory before undergoing 2-vessel occlusion (2VO) of the carotid arteries, or sham surgery. Rats were returned to their respective environments post-operatively. Relative to pre-operative levels, 2VO rats exhibited significant cognitive losses that were consistently greater in the high-risk group than its low-risk counterpart. As well, the high-risk 2VO group was impaired, relative to the low-risk 2VO group on tests of new learning introduced post-operatively. At 3-month follow-up testing, rats that had undergone 2VO surgery exhibited further decline on some tests but recovery on others, with recovery generally slower in the high-risk 2VO group. The high-risk environment also affected rats' pre-operative cognitive performance and, to a lesser extent, their performance following sham surgery. Overall, the study shows that rats experiencing cerebral ischemia are more likely to experience severe cognitive deficits if exposed to a high-risk environment and recover more slowly than ischemic rats in a more favorable environment. The results underscore the importance of lifestyle factors with respect to the impact of stroke on cognition and in assessing prospects for recovery of function.

Stroke prevention and cognitive reserve: emerging approaches to modifying risk and delaying onset of dementia

Demographic changes and improvements in health care are projected to result in dramatic increases in the prevalence of dementia. Alzheimer’s disease is widely considered to be the primary cause of dementia – a disease for which there is currently no cure nor effective treatment, and for which it is thought that little can be done to mitigate risk. However, an increasing understanding of the role and extent of vascular contributions to the development of dementia, and appreciation of the interactions between stroke and Alzheimer’s disease, suggest that targeting vascular risk factors may be very beneficial in reducing the impact of dementia. We also describe how active stimulation of the brain throughout the life course builds cognitive reserve that can offset or compensate for cognitive decline in later life. Finally, we discuss the implications of these emerging approaches for dementia prevention and advocate for the urgent implementation of more extensive public health strategies to improve vascular health.

Determination of vascular dementia brain in distinct frequency bands with whole brain functional connectivity patterns

Recent studies have shown that multivariate pattern analysis (MVPA) can be useful for distinguishing brain disorders into categories. Such analyses can substantially enrich and facilitate clinical diagnoses. Using MPVA methods, whole brain functional networks, especially those derived using different frequency windows, can be applied to detect brain states. We constructed whole brain functional networks for groups of vascular dementia (VaD) patients and controls using resting state BOLD-fMRI (rsfMRI) data from three frequency bands - slow-5 (0.01 ≈ 0.027 Hz), slow-4 (0.027∼0.073 Hz), and whole-band (0.01 ≈ 0.073 Hz). Then we used the support vector machine (SVM), a type of MVPA classifier, to determine the patterns of functional connectivity. Our results showed that the brain functional networks derived from rsfMRI data (19 VaD patients and 20 controls) in these three frequency bands appear to reflect neurobiological changes in VaD patients. Such differences could be used to differentiate the brain states of VaD patients from those of healthy individuals. We also found that the functional connectivity patterns of the human brain in the three frequency bands differed, as did their ability to differentiate brain states. Specifically, the ability of the functional connectivity pattern to differentiate VaD brains from healthy ones was more efficient in the slow-5 (0.01 ≈ 0.027 Hz) band than in the other two frequency bands. Our findings suggest that the MVPA approach could be used to detect abnormalities in the functional connectivity of VaD patients in distinct frequency bands. Identifying such abnormalities may contribute to our understanding of the pathogenesis of VaD.

Prevalence of dementia subtypes in a developing country: a clinicopathological study

OBJECTIVES

To assess the distribution of dementia subtypes in Brazil using a population-based clinicopathological study.

METHOD

Brains from deceased individuals aged ≥50 years old were collected after the next of kin signed an informed consent form and provided information through standardized questionnaires. Post-mortem clinical diagnoses were established in consensus meetings, and only cases with moderate or severe dementia or without cognitive impairment were included in the analysis. Immunohistochemical neuropathological examinations were performed following the universally accepted guidelines. A diagnosis of Alzheimer's disease was made when there were at least both a moderate density of neuritic plaques (Consortium to Establish a Register for Alzheimer's disease B or C) and Braak stage III for neurofibrillary tangle distribution. For the diagnosis of vascular dementia, at least three zones or strategic areas had to be affected by infarcts, lacunae, or microinfarcts.

RESULTS

From 1,291 subjects, 113 cases were classified as having moderate or severe dementia, and 972 cases were free of cognitive impairment. The neuropathological diagnoses of the dementia sub-group were Alzheimer's disease (35.4%), vascular dementia (21.2%), Alzheimer's disease plus vascular dementia (13.3%), and other causes of dementia (30.1%). Small-vessel disease, which alone was not considered sufficient for a vascular dementia diagnosis, was present in 38.9% of all of the dementia cases and in 16.8% of the group without cognitive impairment (odds ratio = 2.91; 95% confidence interval, 1.53-5.51), adjusted for age, sex, and education.

CONCLUSIONS

The relatively high frequencies of vascular dementia and small-vessel disease in the dementia sub-group constitute relevant findings for public health initiatives because control of vascular risk factors could decrease the prevalence of dementia in developing countries.

Vascular dementia: different forms of vessel disorders contribute to the development of dementia in the elderly brain

The diagnosis of vascular dementia (VaD) describes a group of various vessel disorders with different types of vascular lesions that finally contribute to the development of dementia. Most common forms of VaD in the elderly brain are subcortical vascular encephalopathy, strategic infarct dementia, and the multi infarct encephalopathy. Hereditary forms of VaD are rare. Most common is the cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Sporadic forms of VaD are caused by degenerative vessel disorders such as atherosclerosis, small vessel disease (SVD) including small vessel arteriosclerosis, arteriolosclerosis, and lipohyalinosis, and cerebral amyloid angiopathy (CAA). Less frequently inflammatory vessel disorders and tumor-associated vessel lesions (e.g. angiocentric T-cell or angiotropic large cell lymphoma) can cause symptoms of dementia. Here, we review and discuss the impact of vessel disorders to distinct vascular brain tissue lesions and to the development of dementia in elderly individuals. The impact of coexisting neurodegenerative pathology in the elderly brain to VaD as well as the correlation between SVD and CAA expansion in the brain parenchyma with that of Alzheimer's disease (AD)-related pathology is highlighted. We conclude that "pure" VaD is rare and most frequently caused by infarctions. However, there is a significant contribution of vascular lesions and vessel pathology to the development of dementia that may go beyond tissue damage due to vascular lesions. Insufficient blood blow and alterations of the perivascular drainage mechanisms of the brain may also lead to a reduced protein clearance from extracellular space and subsequent increase of proteins in the brain parenchyma, such as the amyloid β-protein, and foster, thereby, the development of AD-related neurodegeneration. As such, it seems to be important for clinical practice to consider treatment of potentially coexisting AD pathology in cognitively impaired patients with vascular lesions.

Vascular dementia: Current concepts and nomenclature harmonization

Several types of cerebrovascular lesions are associated with cognitive decline, but the role of each type in dementia manifestation has yet to be determined. One of the greatest barriers of conducting clinicopathological studies in vascular dementia concerns the overlapping of nomenclature for these lesions. The aim of the present review was to discuss current nomenclature for cerebrovascular lesions and suggest modifications to allow better diagnostic reproducibility in this field.

Diagnosis of vascular cognitive impairment and its main categories

OBJECTIVE

A review of current criteria for the diagnosis of categories related with vascular cognitive impairment, in particular the nomenclature, diagnostic criteria, and differential clinical-radiological findings.

DEVELOPMENT

The criteria for the diagnosis of vascular cognitive impairment have evolved, but available criteria were designed basically for differentiating between vascular dementia and dementia due to Alzheimer disease, and for research purposes. Nevertheless, in clinical practice precise elements are required for: 1) Clinical diagnosis of dementia and mild cognitive impairment; 2) Clinical and neuroimaging criteria for identification of the various cerebrovascular lesions associated with cognitive dysfunction, and 3) A formulation of the aetiogenic-pathogenic relationship between cognitive impairment and cerebrovascular lesions. For this reason, a review was carried out on the diagnostic elements of vascular cognitive impairment categories, classification, and their most relevant characteristics. It highlights the characteristic for the diagnosis of multi-infarction dementia, strategic single infarct dementia, small vessel disease with dementia, mixed dementia, and vascular mild cognitive impairment.

CONCLUSIONS

Standardisation is required, by a multidisciplinary expert team, as regards nomenclature and criteria for the diagnosis of the full spectrum associated with vascular cognitive impairment and especially for vascular dementia and its categories.