Diagnosis of vascular cognitive impairment and its main categories

Modulation of the Circadian Rhythm and Oxidative Stress as Molecular Targets to Improve Vascular Dementia: A Pharmacological Perspective

The circadian rhythms generated by the master biological clock located in the brain's hypothalamus influence central physiological processes. At the molecular level, a core set of clock genes interact to form transcription-translation feedback loops that provide the molecular basis of the circadian rhythm. In animal models of disease, a desynchronization of clock genes in peripheral tissues with the central master clock has been detected. Interestingly, patients with vascular dementia have sleep disorders and irregular sleep patterns. These alterations in circadian rhythms impact hormonal levels, cardiovascular health (including blood pressure regulation and blood vessel function), and the pattern of expression and activity of antioxidant enzymes. Additionally, oxidative stress in vascular dementia can arise from ischemia-reperfusion injury, amyloid-beta production, the abnormal phosphorylation of tau protein, and alterations in neurotransmitters, among others. Several signaling pathways are involved in the pathogenesis of vascular dementia. While the precise mechanisms linking circadian rhythms and vascular dementia are still being studied, there is evidence to suggest that maintaining healthy sleep patterns and supporting proper circadian rhythm function may be important for reducing the risk of vascular dementia. Here, we reviewed the main mechanisms of action of molecular targets related to the circadian cycle and oxidative stress in vascular dementia.

Research trends and hotspots of post-stroke cognitive impairment: a bibliometric analysis

Background: Post-stroke cognitive impairment (PSCI) is a major complication of stroke that affects more than one-third of stroke survivors, threatening their quality of life and increasing the risk of disability and death. Although various studies have described the etiology, epidemiology, and risk factors of PSCI, there are a limited number of comprehensive and accurate reports on research trends and hotspots in this field. Therefore, this review aimed to evaluate research trends, hotspots, and frontiers in PSCI using bibliometric analysis. Methods: We screened the literature spanning 20 years in the Web of Science Core Collection: Science Citation Index Expanded (SCI-Expanded) database from 1 January 2003 to 31 December 2022. We included all eligible literature reports based on our comprehensive search strategy, inclusion criteria, and exclusion criteria. The analysis of annual publications, countries/regions, institutions, journals, co-cited references, and keywords was conducted using CiteSpace and VOSviewer, and the hotspots and major findings of PSCI were summarized. Results: A total of 1,024 publications were included in this review. We found that the number of publications on PSCI increased annually. These publications were published in 75 countries or regions by over 400 institutions. Although Chinese institutions had the highest number of publications, their international influence was limited. The United States showed a strong influence in the field. The journal "Stroke" published the most publications (57) with a high impact factor and was considered the most co-cited journal. The most frequently cited references focused on the prevalence, incidence, neuropsychological assessment scales, criteria, and guidelines of PSCI. The strongest citation burst keywords for PSCI were "neurotrophic factor" and "synaptic plasticity", which were regarded as research focuses and research hotspots, respectively. Conclusion: This review provided a comprehensive summary of the literature of PSCI, identified the authoritative and frequently cited literature and journals, clarified the trends in PSCI research, and highlighted the hotspots in this field. Currently, studies on the mechanisms and treatment of PSCI are limited, and we hope that this review has effectively highlighted the research trajectory of PSCI and will lay the foundation for more innovative research in the future.

Diagnostic accuracy of brief cognitive screening tools to diagnose vascular cognitive impairment in Peru

INTRODUCTION

To evaluate the diagnostic accuracy of three brief cognitive screening (BCS) tools, Peruvian version of Addenbrooke's Cognitive Examination (ACE-Pe), of INECO Frontal Screening (IFS-Pe) and of the Mini-Mental State Examination (MMSE-Pe), for the diagnosis of vascular cognitive impairment (VCI) and its non-dementia stages (VCI-ND) and vascular dementia (VD) in patients with cerebral stroke in Lima-Peru.

MATERIALS AND METHODS

A cohort analysis to evaluate the diagnostic accuracy of three BCS for VCI.

RESULTS

Two hundred and four patients were evaluated: 61% Non-VCI, 30% VCI-ND and 9% VD. To discriminate patients with VCI from controls, the area under the curve (AUC) of ACE-Pe, IFS-Pe and MMs-Pe were 0.99 (95% confidence interval [CI] 0.98-0.99), 0.99 (95%CI 0.98-0.99) and 0.87 (95%CI 0.82-0.92), respectively. Of the three BCS, the IFS-Pe presented a larger AUC to discriminate VCI-ND from VD (AUC = 0.98 [95%CI 0.95-1]) compared to ACE-Pe (AUC = 0.84 [95%CI 0.74-0.95]) and MMSE-Pe (0.92 [95%CI 0.86-0.99]). The IFS-Pe presented a higher sensitivity (S), specificity (Sp), and positive (+LR) and negative likelihood ratios (-LR) (S = 96.72%, Sp = 89.47%, +LR = 9.1 and -LR = 0.03) than ACE-Pe (S = 96.72%, Sp = 63.16%, +LR = 2.62 and -LR = 0.05) and MMSE-Pe (S = 90.16%, Sp = 78.95%, +LR = 4.28 and -LR = 0.12). In the multiple regression analysis, the IFS-Pe was not affected by age, sex or years of schooling.

CONCLUSION

The IFS-Pe has the best diagnostic accuracy for detecting VCI and discriminating between pre-dementia (VCI-ND) and dementia (VD) stages.

Gait and balance impairments in patients with subcortical vascular cognitive impairment

Background

Subcortical vascular cognitive impairment (SVCI) is a subtype of vascular cognitive impairment associated with extensive cerebral small vessel diseases (CSVDs) imaging biomarkers. The objectives of this work were to study the existence and patterns of gait and balance impairments in patients with SVCI due to CSVDs.

Methods

The study was conducted on 28 newly diagnosed SVCI patients and 22 healthy control subjects (HCS) submitted to the advanced activity of daily living scale (AADLs), Berg balance test (BBT), Montreal Cognitive Assessment Scale (MoCA), computerized dynamic posturography (CDP), vision-based 3-D skeletal data gait analysis, and brain MRI volumetric assessment.

Results

SVCI patients showed a significant decrease in AADLs as well as total cerebral white matter volume, total cerebral cortical volume, and mean cortical thickness which were proportional to the degree of cognitive impairment as measured by the MoCA score. Regarding CDP analysis, patients with SVCI revealed prolongation of cancelation time and spectral power for mid- and high frequencies in dynamic positions. In respect to gait analysis, there were significant decreases in mean stride length and mean cadence as well as increases in mean step width and left to right step length difference in the SVCI group compared to HCS while doing a single task. These variables get highly significant during the dual-task performance with a p value < 0.001 for each one.

Conclusion

Patients with SVCI suffer from gait and balance impairments that are proportional to the severity of their cognitive decline and greatly impair their ADLs.

[The role of the inflammatory process in the development of post-stroke cognitive impairment]

Post-stroke cognitive impairment (PCI) is a common complication of stroke. PCI in most cases is associated with an increased risk of progression to dementia, with a progression rate of 8-15% per year. When post-stroke cognitive impairment reaches dementia, patients lose independence, professional and social maladjustment occurs, which, in turn, significantly worsen the quality of life and reduce the rehabilitation potential. According to many experimental and clinical studies, the inflammatory process has an important role in the development of PCI. Several previous studies have looked at the association between inflammatory markers and PCI, with some results conflicting with specific biomarkers. Based on the results of studies, inflammatory markers such as IL-8, IL-12 and ESR were closely associated with PCI, high ESR values are associated with worse cognitive impairment, especially memory. The relationship was not confirmed between the markers IFN-gamma, TNF-α and PCI. With regard to IL-1β, IL-6, IL-10, CRP, the results obtained are not unambiguous. Thus, the inflammatory process in the development of PCI has an important role, including a series of complex reactions, the combined effect of which induces neuronal damage and loss of synapses that ultimately leads to cognitive impairment.

Predictors of dementia after first ischemic stroke

Various mechanisms contribute to dementia after first ischemic stroke as lesions on strategic areas of cognition and stroke premorbidity.

Objectives

Assessing clinical and neuroimaging predictors of dementia after first ischemic stroke and its relation to stroke location, subtypes and severity.

Methods

Eighty first ischemic stroke patients were included. Forty patients with dementia after first stroke and forty patients without dementia according to DSM-IV diagnostic criteria of vascular dementia. All patients were subjected to general and neurological assessment, National Institute Health Stroke Scale (NIHSS) for stroke severity, Montreal Cognitive Assessment (MoCA) scale for cognition assessment, MRI brain and Trial of Org 10172 in acute stroke treatment (TOAST) classification for stroke subtypes.

Results

Left hemispheric ischemic stroke, strategic infarctions, diabetes mellitus and stroke of anterior circulation were found to be independent risk factors for dementia after first ischemic stroke (OR=3.09, 95%CI 1.67-10.3, OR=2.33, 95%CI 1.87-8.77, OR=1.88, 95%CI 1.44-4.55, OR=1.86, 95%CI 1.45-6.54, respectively). Hypertension, dyslipidemia, smoking, ischemic heart disease, high NIHSS score and large vessel infarction were significantly higher among post stroke dementia patients. However, on binary logistic regression, they did not reach to be independent risk factors.

Conclusion

Stroke location (left stroke, strategic infarction, anterior circulation stroke) and diabetes mellitus could be predictors of dementia after first ischemic stroke, but stroke severity, stroke subtypes, hypertension, dyslipidemia, smoking and ischemic heart could not.

Renin-Angiotensin System and Alzheimer's Disease Pathophysiology: From the Potential Interactions to Therapeutic Perspectives

New roles of the Renin-Angiotensin System (RAS), apart from fluid homeostasis and Blood Pressure (BP) regulation, are being progressively unveiled, since the discoveries of RAS alternative axes and local RAS in different tissues, including the brain. Brain RAS is reported to interact with pathophysiological mechanisms of many neurological and psychiatric diseases, including Alzheimer's Disease (AD). Even though AD is the most common cause of dementia worldwide, its pathophysiology is far from elucidated. Currently, no treatment can halt the disease course. Successive failures of amyloid-targeting drugs have challenged the amyloid hypothesis and increased the interest in the inflammatory and vascular aspects of AD. RAS compounds, both centrally and peripherally, potentially interact with neuroinflammation and cerebrovascular regulation. This narrative review discusses the AD pathophysiology and its possible interaction with RAS, looking forward to potential therapeutic approaches. RAS molecules affect BP, cerebral blood flow, neuroinflammation, and oxidative stress. Angiotensin (Ang) II, via angiotensin type 1 receptors may promote brain tissue damage, while Ang-(1-7) seems to elicit neuroprotection. Several studies dosed RAS molecules in AD patients' biological material, with heterogeneous results. The link between AD and clinical conditions related to classical RAS axis overactivation (hypertension, heart failure, and chronic kidney disease) supports the hypothesized role of this system in AD. Additionally, RAStargeting drugs as Angiotensin Converting Enzyme inhibitors (ACEis) and Angiotensin Receptor Blockers (ARBs) seem to exert beneficial effects on AD. Results of randomized controlled trials testing ACEi or ARBs in AD are awaited to elucidate whether AD-RAS interaction has implications on AD therapeutics.

CuATSM PET to diagnose age-related diseases: a systematic literature review

Purpose

Cu(II)-diacetyl-bis(N4-methylthiosemicarbazone) positron emission tomography (CuATSM PET) is a non-invasive imaging technique that can be used to detect hypoxia and inform prognosis in cancer. Hypoxia and oxidative stress are also hallmarks of various age-related diseases. Whether CuATSM PET has a role in the evaluation of hypoxia and oxidative stress in age-related diseases has yet to be established. The aim of this systematic review is to evaluate the utility of CuATSM PET in the diagnosis and management of age-related diseases.

Methods

EMBASE, Medline, Scopus, Web of Science and Psychinfo were systematically searched for articles published between January 1st 1997 and February 13th 2020. We included articles published in English reporting the use of CuATSM PET in the diagnosis and management of age-related diseases in humans or animals.

Results

Nine articles were included describing CuATSM PET measures in neurological and cardiovascular disease. There was higher CuATSM uptake in diseased compared to control subjects in Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), myocardial ischemia (MI), cardiac dysautonomia and atherosclerosis. Higher CuATSM uptake was seen in diseased compared to control anatomical areas in PD, cerebrovascular disease (CVD), MI and atherosclerosis. CuATSM uptake was associated with disease severity in PD, ALS, CVD and atherosclerosis. An association between CuATSM uptake and disease duration was shown in atherosclerosis.

Conclusion

CuATSM uptake is higher in neurological and cardiovascular diseases and associated with disease severity and duration. Further investigations using CuATSM PET in other age-related diseases are needed.

Electrophysiological differences in cortical excitability in different forms of dementia: A transcranial magnetic stimulation and laboratory biomarkers study

BACKGROUND

The aim of the present study was to identify neurophysiologic markers to differentiate between Alzheimer dementia (AD), Vascular dementia (VaD), and Parkinson's disease dementia (PDD), and to examine their relationship to levels of transforming growth factor β1 (TGFβ1).

METHODS

The study included 15 patients with each type of dementia (AD, VaD, PDD) and 25 control subjects. Dementia patients were diagnosed according to the DiagnosticandStatisticalManualofMentalDisorders4thedition-revised(DSM-IV-R). Modified Mini Mental State Examination (MMMSE), motor cortex excitability including resting and active motor thresholds (rMT, aMT), input-output (I/O) curve, contralateral and ipsilateral silent periods (cSP, iSP), short-interval intracortical inhibition (SICI) at 1,2 and 4ms, and serum levels of TGFβ1 were examined.

RESULTS

There were no significant differences between groups with regards to age, sex, education or socioeconomic level. There was significant neuronal hyperexcitability in the form of reduced rMT and aMT and a shallower I/O curve in all three groups of dementia compared with the control group. The durations of cSP and iSP were longer in AD and PDD groups compared with the control group, whereas there were no significant differences in VaD. SICI was less effective in the three dementia groups than in the control group at intervals of 4ms. Serum levels of TGFβ1 were significantly elevated in all dementia groups in comparison with the control group. There was a significant negative correlation between serum level of TGFβ1 and cSP, iSP, and SICI across all patients and a significant negative correlation between serum level of TGFβ1 and iSP duration in AD.

CONCLUSION

Although motor thresholds were reduced in all patients, measures of SICI, cSP and iSP could distinguish between dementia groups. Serum level of TGFβ1 negatively correlated with iSP specifically in the AD group. This suggests that levels of TGFβ1 may relate to GABAergic dysfunction in dementia.

Relationship between β-amyloid protein 1-42, thyroid hormone levels and the risk of cognitive impairment after ischemic stroke

BACKGROUND

Post-stroke cognitive impairment (PSCI) is not only a common consequence of stroke but also an important factor for adverse prognosis of patients. Biochemical indicators such as blood lipids and blood pressure are affected by many factors, and the ability of evaluating the progress of patients with PSCI is insufficient. Therefore, it is necessary to find sensitive markers for predicting the progress of patients and avoiding PSCI. Recent studies have shown that β-amyloid protein 1-42 (Aβ1-42) and thyroid hormone levels are closely related to PSCI, which may be the influencing factors of PSCI, but there are few related studies.

AIM

To investigate the relationship between serum levels of Aβ and thyroid hormones in acute stage and PSCI and its predicted value.

METHODS

A total of 195 patients with acute cerebral infarction confirmed from June 2016 to January 2018 were enrolled in this study. Baseline data and serological indicators were recorded to assess cognitive function of patients. All patients were followed up for 1 year. Their cognitive functions were evaluated within 1 wk, 3 mo, 6 mo and 1 yr after stroke. At the end of follow-up, the patients were divided into PSCI and non-PSCI according to Montreal cognitive assessment score, and the relationship between biochemical indexes and the progression of PSCI was explored.

RESULTS

Compared with patients with non-PSCI, the levels of Aβ1-42, triiodothyronine (T₃) and free thyroxin were lower in the patients with PSCI. Repeated measures analysis of variance showed that the overall content of Aβ1-42 and T₃ in PSCI was also lower than that of the non-PSCI patients. Further analysis revealed that Aβ1-42 (r = 0.348), T₃ (r = 0.273) and free thyroxin (r = 0.214) were positively correlated with disease progression (P < 0.05), suggesting that these indicators have the potential to predict disease progression and outcome. Cox regression analysis showed that Aβ1-42 and T₃ were important factors of PSCI. Then stratified analysis showed that the lower the Aβ1-42 and T₃, the higher risk of PSCI in patients who were aged over 70, female and illiterate.

CONCLUSION

Aβ1-42 and T3 have the ability to predict the progression of PSCI, which is expected to be applied clinically to reduce the incidence of PSCI and improve the quality of life of patients.

The neuropathological diagnosis of Alzheimer's disease

Alzheimer's disease is a progressive neurodegenerative disease most often associated with memory deficits and cognitive decline, although less common clinical presentations are increasingly recognized. The cardinal pathological features of the disease have been known for more than one hundred years, and today the presence of these amyloid plaques and neurofibrillary tangles are still required for a pathological diagnosis. Alzheimer's disease is the most common cause of dementia globally. There remain no effective treatment options for the great majority of patients, and the primary causes of the disease are unknown except in a small number of familial cases driven by genetic mutations. Confounding efforts to develop effective diagnostic tools and disease-modifying therapies is the realization that Alzheimer's disease is a mixed proteinopathy (amyloid and tau) frequently associated with other age-related processes such as cerebrovascular disease and Lewy body disease. Defining the relationships between and interdependence of various co-pathologies remains an active area of investigation. This review outlines etiologically-linked pathologic features of Alzheimer's disease, as well as those that are inevitable findings of uncertain significance, such as granulovacuolar degeneration and Hirano bodies. Other disease processes that are frequent, but not inevitable, are also discussed, including pathologic processes that can clinically mimic Alzheimer's disease. These include cerebrovascular disease, Lewy body disease, TDP-43 proteinopathies and argyrophilic grain disease. The purpose of this review is to provide an overview of Alzheimer's disease pathology, its defining pathologic substrates and the related pathologies that can affect diagnosis and treatment.

Linguistic abilities in major vascular cognitive impairment: a comparative study with Alzheimer's disease

We assessed the linguistic abilities of multi-infarct (cortical) dementia and subcortical ischemic vascular dementia (VaD) patients and compared the linguistic performance of VaD and Alzheimer's Disease (AD) patients. A total of 23 VaD patients, 20 mild AD patients, and 31 controls participated in the study. All were evaluated using the Arizona Battery for Communication Disorders of Dementia (ABCD). Neuropsychological testing was performed to ascertain that VaD and AD patients had comparable cognitive performance. Both dementia groups performed more poorly than controls in the ABCD measures, except for the comparative question subtest. Comparison between VaD and AD patients showed statistically significant differences only in the confrontation naming subtest (p < 0.05), where paraphasias and visual errors were the most prevalent. AD patients showed a trend towards more circumlocution errors than VaD patients (p = 0.0483). When compared to controls, linguistic abilities of VaD patients were impaired in all measures of linguistic expression and linguistic comprehension, except for the comparative question subtest. Linguistic differences between VaD and AD patients were observed only in the confrontation naming subtest.

Lipo‑prostaglandin E1 modifies cognitive impairment in rats with vascular cognitive impairment by promoting angiogenesis via the VEGF/VEGFR pathway

The pathological mechanism of vascular cognitive impairment (VCI) involves ischemic lesions in the hippocampus. Prostaglandin E1 (PGE1) serves roles in the promotion of vascular endothelial growth factor (VEGF) expression, angiogenesis and enhances blood flow to ischemic regions. However, the effect of PGE1 on cognitive function in VCI rats and the underlying mechanism are unknown. In the current study, learning and memory function in VCI rats treated by lipo-PGE1 injection was assessed through Morris Water Maze test. Furthermore, the histological alterations, blood vessel numbers in the hippocampal CA1 region and relative VEGF protein and mRNA expression were researched. The results confirmed that VCI rats treated with lipo-PGE1 presented improved cognitive function, less neuronal cell loss, a greater number of blood vessels in the hippocampal region and higher VEGF protein and mRNA expression. However, the role of lipo-PGE1 in VCI rats can be inhibited by SU5416 (a specific VEGFR2 antagonist). The results indicated that lipo-PGE1 may alleviate cognitive deficits in VCI rats. The underlying mechanism may be associated with angiogenesis promoted by lipo-PGE1, which may involve the VEGF/VEGFR pathway. These findings may have therapeutic implications for cognitive impairment induced by hypoperfusion or chronic ischemic lesions.

Ratio of apoB/LDL: a potential clinical index for vascular cognitive impairment

Background

Vascular cognitive impairment (VCI), compared to vascular dementia (VD), has a broader definition and highlights the effect of vascular disease in dementia, and stroke seems play an important role in the development of VCI. However, not all patients with brain infarcts suffer from VCI; unique risk factors appear to cause such progression. This study aimed to find potential risk factors of vascular cognitive impairment among patients with brain infarcts.

Methods

Thirty-seven dementia patients and 74 brain infarction patients were included; all had infarcts in both basilar ganglia. The frequencies of risk factors, such as age, hypertension, and hyperlipidemia, were compared between the two groups.

Results

The incident rate of hyperlipidemia in the patients with dementia was 35.14%, which was significantly lower than that in the patients with infarction (59.46%, P = 0.015). In the dementia group, there was a positive correlation between the ratio of apoprotein B (apoB)/low density lipoprotein (LDL) and the Mini Mental State Examination (MMSE) score (R = 0.411, P = 0.011).

Conclusion

Our study indicated that the ratio of apoB/LDL may be a potential clinical index for vascular cognitive impairment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-016-0766-1) contains supplementary material, which is available to authorized users.