Vascular cognitive impairment: current concepts and clinical developments

Combined Effect of Red Wine and Mocha Pot Coffee in Mild Vascular Cognitive Impairment

OBJECTIVES

Moderate daily mocha pot coffee intake has been associated with better mood and cognition in patients with mild vascular cognitive impairment (VCI). Similarly, moderate red wine consumption has shown protective effects on cognitive disorders, including Alzheimer's disease and vascular dementia. The aim of this study was to explore the synergistic relation between red wine and coffee intake on mood and cognitive status in mild VCI patients at risk for dementia.

METHODS

A total of 300 non-demented older patients with mild VCI were asked for coffee and red wine consumption and administered with the 17-items Hamilton Depression Rating Scale (HDRS), the Mini Mental State Examination (MMSE), and the Stroop Color-Word Interference Test (Stroop T), as well as the Activities of Daily Living (ADL) and the Instrumental ADL to measure their mood status, cognitive performance, and functional independence. Linear regression models were used to test the association between variables.

RESULTS

Moderate wine drinkers tended to show the best Stroop T score at any level of coffee consumption; conversely, heavy wine consumers performed worse at the Stroop T, especially in patients reporting high coffee intake. Moderate drinkers of both coffee and wine showed the lowest HDRS scores. Finally, a progressive increase in MMSE score was evident with increasing coffee consumption, which peaks when combined with a moderate wine consumption.

CONCLUSIONS

Daily mocha pot coffee and red wine intake seem to be synergistically associated with global cognition, executive functioning, and mood status in patients with mild VCI; the association was not linear, resulting in a protective direction for moderate intake and detrimental for heavy consumption. Future studies are needed to further corroborate the present findings and the potential long-term protective effects of these dietary compounds over time.

Cerebral arteriolosclerosis, lacunar infarcts, and cognition in older Black adults

INTRODUCTION

Older Black adults are at risk of cerebral small vessel disease (CSVD), which contributes to dementia risk. Two subtypes of CSVD, arteriolosclerosis and ischemic lacunar infarcts, have been independently linked to lower cognition and higher dementia risk, but their combined effects on cognition in older Black adults are unclear.

METHODS

Mixed models were used to examine the associations of in vivo measures of arteriolosclerosis (ARTS) and ischemic lacunar infarcts to cognitive level and change in 370 older Black adults without dementia.  RESULTS: Modeled together, higher ARTS load accounted for lower levels of global cognition, episodic memory, semantic memory, and perceptual speed, whereas higher infarct load accounted for lower levels of working memory. There were no associations with rate of cognitive change.

DISCUSSION

Both arteriolosclerosis and ischemic infarcts impact the cognitive health of older Black adults, but arteriolosclerosis affects cognition more broadly and offers promise as an in vivo biomarker of dementia risk.

HIGHLIGHTS

Older Black adults are at risk of cerebral small vessel disease (CSVD) and dementia. Examined magnetic resonance imaging-derived measure of arteriolosclerosis (ARTS), infarcts, and cognition. ARTS load was widely associated with lower cognition after adjusting for infarct load. Infarct load was specifically associated with lower complex attention. More within-Black in vivo studies of CSVD subtypes and cognition are needed.

Language Impairment in Vascular Dementia: A Clinical Review

Vascular cognitive impairment (VCI) encompasses a wide range of conditions, including cognitive impairment associated with stroke or vascular brain injury, mild vascular cognitive impairment, and vascular dementia (VD). Knowledge of language impairment associated with VD is far less extensive than that of Alzheimer's disease. Although not prevalent in VD, impairment in language skills has been reported. A better understanding of the neurolinguistic features associated with the different presentations of VD could facilitate medical diagnosis. In this article, we report data on language impairment in VD, with particular attention to their primary or secondary functional origin. To better appreciate this functional origin, we also outline the main characteristics of impairment in other cognitive functions. Key elements that should be considered in the speech-language assessment of individuals with possible or proven VD are also highlighted.

Metabolic Syndrome: A Narrative Review from the Oxidative Stress to the Management of Related Diseases

Metabolic syndrome (MS) is a growing disorder affecting thousands of people worldwide, especially in industrialised countries, increasing mortality. Oxidative stress, hyperglycaemia, insulin resistance, inflammation, dysbiosis, abdominal obesity, atherogenic dyslipidaemia and hypertension are important factors linked to MS clusters of different pathologies, such as diabesity, cardiovascular diseases and neurological disorders. All biochemical changes observed in MS, such as dysregulation in the glucose and lipid metabolism, immune response, endothelial cell function and intestinal microbiota, promote pathological bridges between metabolic syndrome, diabesity and cardiovascular and neurodegenerative disorders. This review aims to summarise metabolic syndrome's involvement in diabesity and highlight the link between MS and cardiovascular and neurological diseases. A better understanding of MS could promote a novel strategic approach to reduce MS comorbidities.

The association of diffusion tensor MRI measures of normal appearing white matter and cognition

Objective

Median and peak height of fractional anisotropy (FA) and mean diffusivity (MD) are diffusion tensor imaging (DTI) markers used to quantify white matter microstructure changes. We examine the association of DTI histogram-derived measures in global normal appearing white matter (NAWM) and cognitive decline in patients with normal cognition and cognitive impairment no dementia from a memory clinic in Singapore.

Methods

A total of 252 patients (mean age: 71.1 ± 7.6 years, 53.2% women) were included. All patients underwent clinical assessments, a brain MRI scan at baseline, and neuropsychological assessments annually for 2 years. DTI scans were processed to obtain MD and FA histogram-derived measures. The National Institute of Neurological Disorders and Stroke and the Canadian Stroke Network harmonization neuropsychological battery were used to assess cognitive function. Linear regression models with generalised estimating equation (GEE) and logistic regression models were used to examine the association between DTI histogram measures and cognitive decline.

Results

When compared to baseline, MD and FA measures at Year 2 were associated with an accelerated worsening in global cognition (all p for interaction <0.001; Year 0 vs 2, MD median: -0.29 (95%CI: -0.49, -0.09) vs -0.45 (95%CI: -0.65,-0.25); MD peak height: 0.22 (95%CI: 0.07, 0.37) vs 0.37 (95%CI: 0.21, 0.53); FA median: 0.11 (95%CI: -0.05, 0.26) vs 0.22 (95%CI: 0.07, 0.37); FA peak height: -0.14 (95%CI: -0.28, 0.00) vs -0.24 (95%CI: -0.38, -0.10);). Similar findings were observed for executive function and visuomotor speed while only MD measures predicted worsening in memory domain.

Interpretation

This study shows that DTI histogram measures are associated with accelerated cognitive decline suggesting the utility of DTI as a pre-clinical marker in predicting the worsening of cognition in clinical trials.

LRP1 in vascular mural cells modulates cerebrovascular integrity and function in the presence of APOE4

Cerebrovasculature is critical in maintaining brain homeostasis; its dysregulation often leads to vascular cognitive impairment and dementia (VCID) during aging. VCID is the second most prevalent cause of dementia in the elderly, after Alzheimer's disease (AD), with frequent cooccurrence of VCID and AD. While multiple factors are involved in the pathogenesis of AD and VCID, APOE4 increases the risk for both diseases. A major apolipoprotein E (apoE) receptor, the low-density lipoprotein receptor-related protein 1 (LRP1), is abundantly expressed in vascular mural cells (pericytes and smooth muscle cells). Here, we investigated how deficiency of vascular mural cell LRP1 affects the cerebrovascular system and cognitive performance using vascular mural cell-specific Lrp1-KO mice (smLrp1-/-) in a human APOE3 or APOE4 background. We found that spatial memory was impaired in the 13- to 16-month-old APOE4 smLrp1-/- mice but not in the APOE3 smLrp1-/- mice, compared with their respective littermate control mice. These disruptions in the APOE4 smLrp1-/- mice were accompanied with excess paravascular glial activation and reduced cerebrovascular collagen IV. In addition, blood-brain barrier (BBB) integrity was disrupted in the APOE4 smLrp1-/- mice. Together, our results suggest that vascular mural cell LRP1 modulates cerebrovasculature integrity and function in an APOE genotype-dependent manner.

Association of Income with Post-Stroke Cognition and the Underlying Neuroanatomical Mechanism

OBJECTIVE

To investigate the association between income and post-stroke cognition at 3 months, and the underlying neuroanatomical mechanism.

METHODS

Patients with first-ever ischemic stroke were enrolled and analyzed. Baseline information on income and neuroimaging measurements with predictive values for post-stroke cognitive impairment (PSCI) were collected within 7 days of the admission. Three months after the index stroke, all participants underwent a detailed neuropsychological test battery. The associations between income and PSCI and between income and brain structural measurements were investigated.

RESULTS

A total of 294 patients were recruited for this study. Lower income was independently associated with poor cognitive performance on Stroop tests, Clinical Dementia Rating, Boston Naming Test, and Verbal Fluency Test. Regarding neuroimaging parameters, lower income was associated with a lower total brain volume (TBV)/total intracranial volume (TICV) ratio (p = 0.004).

CONCLUSIONS

Lower income is associated with an increased chance of post-stroke cognitive decline, particularly in executive function and language domains. Since global brain atrophy (measured by TBV/TICV ratio) is a strong predictor for PSCI, its correlation with income may help explain the neuroanatomical mechanism between income and post-stroke cognition.

Association between plasma trimethylamine-N-oxide and cognitive impairment in patients with transient ischemic attack

BACKGROUND

There is increasing evidence for the association of trimethylamine-N-oxide (TMAO) with cognitive impairment after minor stroke or transient ischemic attack (TIA). However, how TMAO affects cognitive function in TIA patients has seldom been studied.

METHODS

A total of 310 TIA participants were retrospectively collected from our stroke register between January 2020 and July 2021. Plasma TMAO was measured by liquid chromatography‒mass spectrometry at baseline. Cognitive performance was assessed by neuropsychological evaluation at 3 months after TIA onset.

RESULTS

A total of 310 patients were included (mean age, 74 years; male, 160 [51.6%]; mean ABCD2 score, 2.6). TMAO was positively associated with cognitive impairment after TIA (aOR, 1.423; 95% CI, 1.125-2.561). The highest quartile of TMAO was related to an almost 2-fold increased risk of cognitive decline compared to the lowest quartile. Furthermore, executive and memory function were more susceptible to impairment after TIA in groups with higher levels of TMAO. Mediation analysis revealed that the overall mediated effect was-0.347 (p < 0.001), and the intermediary effect of CRP was-0.108.

CONCLUSION

Plasma TMAO at baseline was independently associated with cognitive impairment at the 3-month follow-up after TIA. In addition, the inflammatory marker CRP may serve as an important mediator in this relationship. Our study may provide some insights into anti-inflammatory therapy to improve the cognitive trajectory of TIA patients with high TMAO levels.

Structural atrophy and functional dysconnectivity patterns in the cerebellum relate to cerebral networks in svMCI

Subcortical vascular mild cognitive impairment (svMCI) is associated with structural and functional changes in the cerebral cortex affecting major brain networks. While recent studies have shown that the intrinsic cerebral connectivity networks can be mapped onto the cerebellum, and the cortex and cerebellum are interconnected via the cortico-basal ganglia-cerebellar circuit, structural and functional disruptions in cerebellum in svMCI are rarely studied. In this study, we conducted voxel-based morphometry analysis to investigate gray matter atrophy pattern across cerebellar regions in 40 svMCI patients, and explored alterations in functional connectivity between the basal ganglia and cerebellum. The results showed that the amount of cerebellar atrophy within the default mode, salience, and frontoparietal networks correlated with their counterpart in the cerebral cortex. Moreover, key regions of the cerebellum, including the lobule VI, VIIb, VIII, and Crus I, which are reported to have a role in cognitive function, showed both anatomical atrophy and decreased functional connectivity with the striatum. These atrophy and connectivity patterns in the cerebellum also correlated with memory performances. These findings demonstrate that there are coupled changes in cerebral and cerebellar circuits, reflecting that degeneration patterns in svMCI are not limited to the cerebral cortex but similarly extend to the cerebellum as well, and suggest the cortico-basal ganglia-cerebellar circuit may play an important role in the pathology of svMCI.

Sex differences in mild vascular cognitive impairment: A multimodal transcranial magnetic stimulation study

BACKGROUND

Sex differences in vascular cognitive impairment (VCI) at risk for future dementia are still debatable. Transcranial magnetic stimulation (TMS) is used to evaluate cortical excitability and the underlying transmission pathways, although a direct comparison between males and females with mild VCI is lacking.

METHODS

Sixty patients (33 females) underwent clinical, psychopathological, functional, and TMS assessment. Measures of interest consisted of: resting motor threshold, latency of motor evoked potentials (MEPs), contralateral silent period, amplitude ratio, central motor conduction time (CMCT), including the F wave technique (CMCT-F), short-interval intracortical inhibition (SICI), intracortical facilitation, and short-latency afferent inhibition, at different interstimulus intervals (ISIs).

RESULTS

Males and females were comparable for age, education, vascular burden, and neuropsychiatric symptoms. Males scored worse at global cognitive tests, executive functioning, and independence scales. MEP latency was significantly longer in males, from both sides, as well CMCT and CMCT-F from the left hemisphere; a lower SICI at ISI of 3 ms from the right hemisphere was also found. After correction for demographic and anthropometric features, the effect of sex remained statistically significant for MEP latency, bilaterally, and for CMCT-F and SICI. The presence of diabetes, MEP latency bilaterally, and both CMCT and CMCT-F from the right hemisphere inversely correlated with executive functioning, whereas TMS did not correlate with vascular burden.

CONCLUSIONS

We confirm the worse cognitive profile and functional status of males with mild VCI compared to females and first highlight sex-specific changes in intracortical and cortico-spinal excitability to multimodal TMS in this population. This points to some TMS measures as potential markers of cognitive impairment, as well as targets for new drugs and neuromodulation therapies.

Pharmaceutical and pharmacological studies of Shen Ma Yi Zhi granule for prevention of vascular dementia: A review

Background: With dementia significantly increasing hospitalization and disability rates, worldwide aging of the population presents major challenges to public health. The majority of cases of cognitive dysfunction among the elderly, however, are characterized by an identifiable, preventable and treatable vascular component. As such, increased study of preventative methods in the context of dementia is warranted. Traditional Chinese medicine compounds have been reported to be neuroprotective and improve cognitive function via a variety of mechanisms. Shen Ma Yi Zhi granule (SMYZG) is one such collection of compounds that has been proven clinically effective. Pharmacological mechanisms of action, pharmacokinetics and clinical applications of SMYZG have been previously studied using a variety of vascular dementia animal models. SMYZG activates and regulates four main signaling pathways relevant to vascular dementia including the AMPK/PPARα/PGC-1α/UCP2, Nrf2/HO-1, HIF-1/VEGF/Notch, and VEGF/Flk-1/p8 MAPK pathways. Furthermore, SMYZG influences anti-inflammatory and anti-oxidant stress responses, reverses demyelination of brain white matter and vascular endothelium, regulates pericyte function and normalizes mitochondrial metabolism. Neuroprotective effects of SMYZG, as well as those promoting regeneration of vascular endothelium, have also been reported in studies of rat models of vascular dementia. Future research concerning SMYG is warranted for development of vascular dementia preventative management strategies.

The mobile sleep medicine model in neurologic practice: Rationale and application

Background

Undiagnosed obstructive sleep apnea (OSA) is prevalent in neurological practice and significantly contributes to morbidity and mortality. OSA is prevalent in US adults and causes poor quality sleep and significant neurocognitive, cardiovascular, and cerebrovascular impairments. Timely treatment of OSA reduces cardio-cerebrovascular risks and improves quality of life. However, most of the US population has limited systematic access to sleep medicine care despite its clinical significance.

Focus

We discuss the importance of systematic screening, testing, and best-practice management of OSA and hypoventilation/hypoxemia syndromes (HHS) in patients with stroke, neurocognitive impairment, and neuromuscular conditions. This review aims to introduce and describe a novel integrated Mobile Sleep Medicine (iMSM) care model and provide the rationale for using an iMSM in general neurological practice to assist with systematic screening, testing and best-practice management of OSA, HHS, and potentially other sleep conditions.

Key points

The iMSM is an innovative, patient-centered, clinical outcome-based program that uses a Mobile Sleep Medicine Unit—a “sleep lab on wheels”—designed to improve access to OSA management and sleep care at all levels of health care system. The protocol for the iMSM care model includes three levels of operations to provide effective and efficient OSA screening, timely testing/treatment plans, and coordination of further sleep medicine care follow-up. The iMSM care model prioritizes effective, efficient, and patient-centered sleep medicine care; therefore, all parties and segments of care that receive and provide clinical sleep medicine services may benefit from adopting this innovative approach.

Comparison of Diffusion Tensor Imaging Metrics in Normal-Appearing White Matter to Cerebrovascular Lesions and Correlation with Cerebrovascular Disease Risk Factors and Severity

Alterations in tissue microstructure in normal-appearing white matter (NAWM), specifically measured by diffusion tensor imaging (DTI) fractional anisotropy (FA), have been associated with cognitive outcomes following stroke. The purpose of this study was to comprehensively compare conventional DTI measures of tissue microstructure in NAWM to diverse vascular brain lesions in people with cerebrovascular disease (CVD) and to examine associations between FA in NAWM and cerebrovascular risk factors. DTI metrics including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were measured in cerebral tissues and cerebrovascular anomalies from 152 people with CVD participating in the Ontario Neurodegenerative Disease Research Initiative (ONDRI). Ten cerebral tissue types were segmented including NAWM, and vascular lesions including stroke, periventricular and deep white matter hyperintensities, periventricular and deep lacunar infarcts, and perivascular spaces (PVS) using T1-weighted, proton density-weighted, T2-weighted, and fluid attenuated inversion recovery MRI scans. Mean DTI metrics were measured in each tissue region using a previously developed DTI processing pipeline and compared between tissues using multivariate analysis of covariance. Associations between FA in NAWM and several CVD risk factors were also examined. DTI metrics in vascular lesions differed significantly from healthy tissue. Specifically, all tissue types had significantly different MD values, while FA was also found to be different in most tissue types. FA in NAWM was inversely related to hypertension and modified Rankin scale (mRS). This study demonstrated the differences between conventional DTI metrics, FA, MD, AD, and RD, in cerebral vascular lesions and healthy tissue types. Therefore, incorporating DTI to characterize the integrity of the tissue microstructure could help to define the extent and severity of various brain vascular anomalies. The association between FA within NAWM and clinical evaluation of hypertension and disability provides further evidence that white matter microstructural integrity is impacted by cerebrovascular function.

Clinical Trials of New Drugs for Vascular Cognitive Impairment and Vascular Dementia

Population aging has challenged the treatment of cognitive impairment or dementia. Vascular dementia is the second leading cause of dementia after Alzheimer’s disease. Cognitive consequences after ischemic brain injury have been recognized as a preferred target for therapeutic strategies, prompting the search for potential agents. The keyword “vascular dementia” was used to search ClinicalTrials.gov to determine agents represented in phases I, II, III, and IV. The agents were classified on the basis of their mechanisms. Of the 17 randomized controlled trials meeting our inclusion criteria, 9 were completed in the past 10 years, and 8 are ongoing or in the planning stages. We also identified one trial in phase I, nine in phase II, six in phase III, and one in phase IV. Fewer trials of new drugs for improving cognition or ameliorating the behavioral and psychological symptoms of dementia target vascular dementia than Alzheimer’s dementia. Drug trials on vascular dementia overlap with drug trials targeting functional outcomes in cerebrovascular disease. International pharmaceutical companies’ investment in new drugs targeting VCI and vascular dementia remains insufficient.

Daily mocha coffee intake and psycho-cognitive status in non-demented non-smokers subjects with subcortical ischaemic vascular disease

Coffee intake has been recently associated with better cognition and mood in mild vascular cognitive impairment (mVCI). As tobacco can reduce the caffeine half-life, we excluded smokers from the original sample. Hamilton Depression Rating Scale (HDRS), mini-mental state examination (MMSE), Stroop Colour-Word Interference Test (Stroop), activities of daily living (ADL0) and instrumental ADL were the outcome measures. Significant differences were observed in higher consumption groups (moderate intake for HDRS; high intake for MMSE and Stroop) compared to the other groups, as well as in age and education. With age, education and coffee used as independent predictors, and HDRS, Stroop and MMSE as dependent variables, a correlation was found between age and both MMSE and Stroop, as well as between education and MMSE and between HDRS and Stroop; coffee intake negatively correlated with HDRS and Stroop. Higher coffee consumption was associated with better psycho-cognitive status among non-smokers with mVCI.

Lateralized brain activities in subcortical vascular mild cognitive impairment with differential Chinese medicine patterns: A resting-state functional magnetic resonance imaging study

Background

Subcortical vascular mild cognitive impairment (svMCI) is one of the most treatable cognitive impairments, but could be hampered by the high clinical heterogeneities. Further classification by Chinese Medicine (CM) patterns has been proved to stratify its clinical heterogeneities. It remains largely unknown of the spontaneous brain activities regarding deficiency patterns (DPs) and excess patterns (EPs) of svMCI patients based on fMRI data.

Objective

We aim to provide neuroimaging evidence of altered resting-state brain activities associated with DPs and EPs in svMCI patients.

Methods

Thirty-seven svMCI patients (PAs) and 23 healthy controls (CNs) were consecutively enrolled. All patients were categorized into either the EP group (n = 16) and the DP group (n = 21) based on a quantitative CM scale. The fractional amplitude of low-frequency fluctuation (fALFF) value was used to make comparisons between different subgroups.

Results

The DP group showed significant differences of fALFF values in the right middle frontal gyrus and the right cerebellum, while the EP group showed significant differences in the left orbitofrontal gyrus and the left cerebellum, when compared with the CN group. When compared with the EP group, the DP group had markedly increased fALFF values in the left superior temporal gyrus, right middle temporal gyrus and brainstem. The decreased fALFF values was shown in the right anterior cingulate and paracingulate gyri. Among the extensive areas of frontotemporal lobe, the Montreal Cognitive Assessment (MoCA) scores were significantly correlated with the reduced fALFF value of the right middle frontal gyrus and the left orbitofrontal gyrus.

Conclusion

Our results indicated that the DPs and EPs presented the lateralization pattern in the bilateral frontal gyrus, which will probably benefit the future investigation of the pathogenesis of svMCI patients.

Serial neurocognitive changes following transcatheter aortic valve replacement: comparison between low and intermediate-high risk groups

Background: Data comparing the neurocognitive trajectory between low and intermediate-high risk patients following transcatheter aortic valve replacement (TAVR) is never reported.

Aims: To report serial neurocognitive changes up to 1 year post-TAVR in low and intermediate-high risk groups as well as overall cohort.

Methods: Prospective neurological assessments (NIHSS and Barthel Index), global cognitive tests (MMSE and Alzheimer Disease Assessment Scale–Cognitive Subtest, ADAS-cog) and executive performances (Color Trail Test A and B and verbal fluency), were applied at baseline, 3 months and 1 year post-TAVR.

Results: In overall cohort, persistent improvement to 1 year in MMSE, ADAS-cog, Color Trail Test A and B was found. According to the STS score, the study cohort was divided into low (<4%, N = 81) and intermediate-high (≧4%, N = 75) risk groups. The baseline neurologic and cognitive performance was significantly worse in intermediate-high risk group. Slight improvement on general neurological functions (Barthel index and proportion of NIHSS>0 patients) at 1 year could be observed only in intermediate-high risk group. In global cognitive assessments, improvement in MMSE and ADAS-cog at 1 year was found in both groups, but the proportion of cognitive improvement was more obvious in intermediate-high risk group. In Color Trail Tests and verbal fluency, significant and persistent improvement up to 1 year could be observed only in low risk group.

Conclusions: TAVR was associated with persistent improvement in global cognitive function, as well as in attention and psychomotor processing speed, up to 1 year in overall cohort. However, improvement in tests for executive functions can only be seen in low risk group.

A Profile of Nanoparticle-Based Plasma Neurodegenerative Biomarkers for Cognitive Function Among Patients Undergoing Hemodialysis

Purpose

This study aimed to compare the plasma levels of nanoparticle-based neurodegenerative biomarkers between hemodialysis (HD) participants with grossly normal cognitive function and healthy controls.

Patients and Methods

A cohort of participants undergoing maintenance HD and healthy controls were enrolled for comparison between July and October 2021. The immunomagnetic reduction method was used to measure plasma neurodegenerative biomarkers Aβ_1-40, Aβ_1-42, tau protein, and neurofilament light chain (NfL). The clinical dementia rating (CDR) was used to evaluate cognitive function. A receiver operating characteristic curve was used to discriminate between HD participants and healthy controls.

Results

There were 52 and 18 participants in the HD and healthy control groups, respectively. The mean age of the HD participants was 62 years, and that of the healthy controls was 57 years. The mean HD vintage in the HD cohort was 11.8 years. HD participants demonstrated significantly higher plasma levels of Aβ_1-42, tau protein, Aβ_1-42 × tau, and NfL and Aβ_1-42/Aβ_1-40 ratio and significantly lower plasma Aβ_1-40 levels than healthy controls. The measured plasma biomarkers could not discriminate between CDR0 and CDR0.5 HD participants. The area under the curve of the study biomarkers to discriminate HD participants from healthy controls ranged from 0.987 (Aβ_1-42 × tau) to 0.889 (NfL).

Conclusion

The plasma levels of nanoparticle-based neurodegenerative biomarkers were higher in HD participants with grossly normal cognitive function than in healthy controls. These findings imply that neurodegenerative changes appear in HD participants. A profile of plasma neurodegenerative biomarkers could be considered a potential surrogate for evaluating long-term cognitive function in HD participants.

Effectiveness of acupuncture for patients with vascular dementia: A systematic review and meta-analysis

OBJECTIVES

This meta-analysis assessed the treatment effectiveness of acupuncture in patients with vascular dementia.

METHODS

The PubMed, Embase, Cochrane library, and China National Knowledge Infrastructure were searched to identify eligible randomized controlled trials (RCTs). The odds ratios (ORs) and weighted mean differences (WMDs) with 95 % confidence intervals (CIs) were used to assess the pooled effect estimates using a random-effects model for categorical and continuous outcomes, respectively.

RESULTS

Thirty-four RCTs (2672 patients) were selected for the final meta-analysis. The use of acupuncture showed association with an increased incidence of effective rate (OR: 3.28; 95 % CI: 2.54-4.24; P < 0.001). The pooled WMDs revealed that acupuncture was significantly associated with an improvement in the Hasegawa dementia scale (HDS) (WMD: 4.31; 95 % CI: 3.15-5.47; P < 0.001), and Mini-Mental State Examination scores (MMSE) (WMD: 3.07; 95 % CI: 2.40-3.74; P < 0.001). However, the use of acupuncture showed no association with the level of Activities of daily living (ADL) (WMD: 1.93; 95 % CI: - 2.53 to 6.38; P = 0.397). Finally, acupuncture was associated with lower levels of Scale for the differentiation of syndromes of vascular dementia (SDSVD) (WMD: - 2.15; 95 % CI: - 4.14 to - 0.16; P = 0.034), and National Institutes of Health stroke scale (NIHSS) (WMD: - 3.90; 95 % CI: - 4.87 to - 2.94; P < 0.001).

CONCLUSIONS

Acupuncture is probably helpful in vascular stroke, but strong supportive data are not yet available. Acupuncture should be used cautiously, owing to the analysis of this study based on low to moderate evidence. Further high-quality, large-scale RCTs should be conducted.

Impact of Hyperbaric Oxygen Therapy on Cognitive Functions: a Systematic Review

Hyperbaric oxygen therapy (HBOT) is a modality of treatment in which patients inhale 100% oxygen inside a hyperbaric chamber pressurised to greater than 1 atmosphere. The aim of this review is to discuss neuropsychological findings in various neurological disorders treated with HBOT and to open new perspectives for therapeutic improvement. A literature search was conducted in the MEDLINE (via PubMed) database from the inception up 10 May 2020. Eligibility criteria included original articles published in English. Case studies were excluded. Full-text articles were obtained from the selected studies and were reviewed on the following inclusion criteria (1) performed cognitive processes assessment (2) performed HBOT with described protocol. Two neuropsychologists independently reviewed titles, abstracts, full texts and extracted data. The initial search retrieved 1024 articles, and a total of 42 studies were finally included after applying inclusion and exclusion criteria. The search yielded controversial results with regard to the efficiency of HBOT in various neurological conditions with cognitive disturbance outcome. To the best of our knowledge this is the first state-of-the art, systematic review in the field. More objective and precise neuropsychological assessment methods are needed to exact evaluation of the efficacy of HBOT for neuropsychological deficits. Future studies should widen the assessment of HBOT effects on different cognitive domains because most of the existing studies have focussed on a single process. Finally, there is a need for further longitudinal studies.

Altered Microstructural Changes Detected by Diffusion Kurtosis Imaging in Patients With Cognitive Impairment After Acute Cerebral Infarction

Objective

To detect the microstructural changes in patients with cognitive impairment after acute cerebral infarction using diffusion kurtosis imaging (DKI).

Materials and Methods

A total of 70 patients with acute cerebral infarction were divided into two groups: 35 patients with cognitive impairment (VCI group), and 35 patients without cognitive impairment (N-VCI group), according to mini-mental state examination (MMSE) score. Healthy individuals (n = 36) were selected as the normal control (NORM) group. DKI parameters from 28 different brain regions of interest (ROIs) were selected, measured, and compared.

Results

VCI group patients had significantly higher mean diffusion (MD) and significantly lower mean kurtosis (MK) values in most ROIs than those in the N-VCI and NORM groups. DKI parameters in some ROIs correlated significantly with MMSE score. The splenium of corpus callosum MD was most correlated with MMSE score, the correlation coefficient was −0.652, and this parameter had good ability to distinguish patients with VCI from healthy controls; at the optimal cut-off MD value (0.9915), sensitivity was 91.4%, specificity 100%, and the area under the curve value 0.964.

Conclusions

Pathological changes in some brain regions may underlie cognitive impairment after acute cerebral infarction, especially the splenium of corpus callosum. These preliminary results suggest that, in patients with VCI, DKI may be useful for assessing microstructural tissue damage.

An introduction to therapeutic approaches to vascular cognitive impairment

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Vascular disease is a significant part of the clinical picture in common dementias.

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Multiple connections link vascular risk, vascular disease and cognitive impairment.

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This has inspired multiple therapeutic approaches, see this special issue.

Vascular cognitive impairment (VCI), encompassing vascular dementia, has been claimed as the “second-most common dementia” after Alzheimer Disease. Whether or not this is true, the clinical picture of most dementia in older people includes vascular disease. There are no validated pharmacological targets for prevention or treatment of VCI. This has inspired a multitude of potential treatment approaches, reflected by the articles in this Special Issue. These include in vitro testing of the novel oral anticoagulant dabigatran for protection against β-amyloid neurotoxicity, and an overview of neuroinflammation in VCI and the role of circulating markers (PIGF, VEGF-D) identified by the MarkVCID study. There are reviews of potential therapeutics, including adrenomedullin and nootropic preparations (exemplified by cerebrolysin). The role of sleep is reviewed, with possible therapeutic targets (5HT2A receptors). There is a clinical study protocol (INVESTIGATE-SVD) and a feasibility analysis for a secondary prevention trial in small vessel disease. Clinical data include secondary analyses of blood pressure and cerebral blood flow from a longitudinal clinical trial (NILVAD), differences between methylphenidate and galantamine responders and non-responders (STREAM-VCI), appraisal of treatment approaches in India, and primary outcomes from a randomised trial of Argentine tango dancing to preserve cognition in African American women (ACT). Treating vascular disease has great potential to improve global cognitive health, with public health impacts alongside individual benefit. Vascular disease burden varies across populations, offering the possibility of proactively addressing health inequity in dementia using vascular interventions. The next 5–10 years will witness cost-effective lifestyle interventions, repurposed drugs and novel therapeutics.

A Longitudinal Study on the Association of Interrelated Factors Among Frailty Dimensions, Cognitive Domains, Cognitive Frailty, and All-Cause Mortality

BACKGROUND

Cognitive frailty integrating impaired cognitive domains and frailty dimensions has not been explored.

OBJECTIVE

This study aimed to explore 1) associations among frailty dimensions and cognitive domains over time and 2) the extended definitions of cognitive frailty for predicting all-cause mortality.

METHODS

This four-year cohort study recruited 521 older adults at baseline (2011-2013). We utilized 1) generalized linear mixed models exploring associations of frailty dimensions (physical dimension: modified from Fried et al.; psychosocial dimension: integrating self-rated health, mood, and social relationship and support; global frailty: combining physical and psychosocial frailty) with cognition (global and domain-specific) over time and 2) time-dependent Cox proportional hazard models assessing associations between extended definitions of cognitive frailty (cognitive domains-frailty dimensions) and all-cause mortality.

RESULTS

At baseline, the prevalence was 3.0%for physical frailty and 37.6%for psychosocial frailty. Greater physical frailty was associated with poor global cognition (adjusted odds ratio = 1.43-3.29, β: -1.07), logical memory (β: -0.14 to -0.10), and executive function (β: -0.51 to -0.12). Greater psychosocial frailty was associated with poor global cognition (β: -0.44) and attention (β: -0.15 to -0.13). Three newly proposed definitions of cognitive frailty, "mild cognitive impairment (MCI)-psychosocial frailty," "MCI-global frailty," and "impaired verbal fluency-global frailty," outperformed traditional cognitive frailty for predicting all-cause mortality (adjusted hazard ratio = 3.49, 6.83, 3.29 versus 4.87; AIC = 224.3, 221.8, 226.1 versus 228.1).

CONCLUSION

Notably, extended definitions of cognitive frailty proposed by this study better predict all-cause mortality in older adults than the traditional definition of cognitive frailty, highlighting the importance of psychosocial frailty to reduce mortality in older adults.

Diagnostic contribution and therapeutic perspectives of transcranial magnetic stimulation in dementia

Transcranial magnetic stimulation (TMS) is a powerful tool to probe in vivo brain circuits, as it allows to assess several cortical properties such asexcitability, plasticity and connectivity in humans. In the last 20 years, TMS has been applied to patients with dementia, enabling the identification of potential markers of thepathophysiology and predictors of cognitive decline; moreover, applied repetitively, TMS holds promise as a potential therapeutic intervention. The objective of this paper is to present a comprehensive review of studies that have employed TMS in dementia and to discuss potential clinical applications, from the diagnosis to the treatment. To provide a technical and theoretical framework, we first present an overview of the basic physiological mechanisms of the application of TMS to assess cortical excitability, excitation and inhibition balance, mechanisms of plasticity and cortico-cortical connectivity in the human brain. We then review the insights gained by TMS techniques into the pathophysiology and predictors of progression and response to treatment in dementias, including Alzheimer's disease (AD)-related dementias and secondary dementias. We show that while a single TMS measure offers low specificity, the use of a panel of measures and/or neurophysiological index can support the clinical diagnosis and predict progression. In the last part of the article, we discuss the therapeutic uses of TMS. So far, only repetitive TMS (rTMS) over the left dorsolateral prefrontal cortex and multisite rTMS associated with cognitive training have been shown to be, respectively, possibly (Level C of evidence) and probably (Level B of evidence) effective to improve cognition, apathy, memory, and language in AD patients, especially at a mild/early stage of the disease. The clinical use of this type of treatment warrants the combination of brain imaging techniques and/or electrophysiological tools to elucidate neurobiological effects of neurostimulation and to optimally tailor rTMS treatment protocols in individual patients or specific patient subgroups with dementia or mild cognitive impairment.

EGb in the Treatment for Patients with VCI: A Systematic Review and Meta-Analysis

Background

Ginkgo biloba extract (EGb) is widely used to treat impairments in memory, cognition, activities of daily living, inflammation, edema, stroke, Alzheimer's dementia, and aging.

Aim

We aimed to evaluate the safety and efficacy of EGb in treating vascular cognitive impairment (VCI).

Methods

The systematic review was performed using the latest guidelines. We searched for EGb-related trials up to March 1, 2021, in four Chinese databases, three English databases, and clinical trial registry platforms. Randomized controlled trials (RCTs) were included if the study enrolled participants with VCI. Two reviewers independently extracted the data and critically appraised the study quality. Heterogeneity was quantified with I ². Both sensitivity and subgroup analyses were used to identify the sources of heterogeneity. Publication bias was assessed with funnel plots. We used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to rate the evidence quality. Outcomes included assessments using the Activities of Daily Living (ADL), Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), Hasegawa Dementia Scale (HDS), Barthel Index (BI), Functional Activity Questionnaire (FAQ), and adverse events.

Results

In this study, a total of 2019 patients in 23 RCTs were included. EGb appeared to be more effective than control conditions as assessed by the results of cognitive function evaluation, including MMSE (MD_{MMSE,EGb vs.blank} = 3.04, 95% CI: 0.10-5.98; MD_{MMSE,EGb vs.drugs for VCI} = 2.70, 95% CI: 1.39-4.01; MD_{MMSE,EGb+drugs for VCI vs.blank} = 5.90, 95% CI: 4.21-7.59; and MD_{MMSE,EGb+drugs for VCI vs.drugs for VCI} = 3.14, 95% CI: 2.14-4.15), MoCA (MD_{MoCA,EGb vs.blank} = 5.30, 95% CI: 2.15-8.46; MD_{MoCA,EGb+drugs for VCI vs.blank} = 2.66, 95% CI: 1.82-3.50; and MD_{MoCA,EGb+drugs for VCI vs.drugs for VCI} = 2.56, 95% CI: 1.85-3.27), HDS (MD_{HDS,EGb vs.blank} = 6.50; 95% CI: 4.86-8.14; MD_{HDS,EGb+drugs for VCI vs.drugs for VCI} = 3.60, 95% CI: 2.50-4.70), ADL (MD_{ADL,EGb vs.blank} = 7.20, 95% CI: 3.28-11.12; MD_{ADL,EGb+drugs for VCI vs.blank} = 10.00, 95% CI: 7.51-12.49; and MD_{ADL,EGb+drugs for VCI vs.drugs for VCI} = 9.20, 95% CI: 7.26-11.14), BI (MD_{BI,EGb+drugs for VCI vs.drugs for VCI} = 5.71, 95% CI: 2.99-8.43; MD_{FAQ,EGb vs.drugs for VCI} = -1.43, 95% CI: -2.78 to 0.08), and FAQ (MD_{FAQ,EGb+drugs for VCI vs.drugs for VCI} = -2.17, 95% CI: -4.13 to 0.21). Evidence of certainty ranged from medium certainty to very low certainty.

Conclusion

This meta-analysis showed that EGb may be an effective and safe treatment in improving MMSE, MOCA, ADL, and BI for VCI patients within three months of diagnosis. However, given the quality of the included RCTs, more preregistered trials are needed that explicitly examine the efficacy of EGb. This systematic review has been registered on PROSPERO, with the registration number CRD42021232967.

Validation of Indian Council of Medical Research Neurocognitive Tool Box in Diagnosis of Mild Cognitive Impairment in India: Lessons from a Harmonization Process in a Linguistically Diverse Society

BACKGROUND/AIMS

In a linguistically diverse country such as India, challenges remain with regard to diagnosis of early cognitive decline among the elderly, with no prior attempts made to simultaneously validate a comprehensive battery of tests across domains in multiple languages. This study aimed to determine the utility of the Indian Council of Medical Research-Neurocognitive Tool Box (ICMR-NCTB) in the diagnosis of mild cognitive impairment (MCI) and its vascular subtype (VaMCI) in 5 Indian languages.

METHODS

Literate subjects from 5 centers across the country were recruited using a uniform process, and all subjects were classified based on clinical evaluations and a gold standard test protocol into normal cognition, MCI, and VaMCI. Following adaptation and harmonization of the ICMR-NCTB across 5 different Indian languages into a composite Z score, its test performance against standards, including sensitivity and specificity of the instrument as well as of its subcomponents in diagnosis of MCI, was evaluated in age and education unmatched and matched groups.

RESULTS

Variability in sensitivity-specificity estimates was noted between languages when a total of 991 controls and 205 patients with MCI (157 MCI and 48 VaMCI) were compared due to a significant impact of age, education, and language. Data from a total of 506 controls, 144 patients with MCI, and 46 patients with VaMCI who were age- and education-matched were compared. Post hoc analysis after correction for multiple comparisons revealed better performance in controls relative to all-cause MCI. An optimum composite Z-score of -0.541 achieved a sensitivity of 81.1% and a specificity of 88.8% for diagnosis of all-cause MCI, with a high specificity for diagnosis of VaMCI. Using combinations of multiple-domain 2 test subcomponents retained a sensitivity and specificity of >80% for diagnosis of MCI.

CONCLUSIONS

The ICMR-NCTB is a "first of its kind" approach at harmonizing neuropsychological tests across 5 Indian languages for the diagnosis of MCI due to vascular and other etiologies. Utilizing multiple-domain subcomponents also retains the validity of this instrument, making it a valuable tool in MCI research in multilingual settings.

Cognitive Dysfunction in a Mouse Model of Cerebral Ischemia Influences Salivary Metabolomics

Vascular dementia, caused by cerebrovascular disease, is associated with cognitive impairment and reduced hippocampal metabolite levels. Specifically, cognitive impairment can be induced by decreased hippocampal brain-derived neurotrophic factor (BDNF) expression. The development of low or non-invasive biomarkers to characterize these diseases is an urgent task. Disturbance of metabolic pathways has been frequently observed in cognitive impairment, and salivary molecules also showed the potentials to reflect cognitive impairment. Therefore, we evaluated salivary metabolic profiles associated with altered hippocampal BDNF expression levels in a cerebral ischemia mouse model using metabolomic analyses. The effect of tacrine (a cholinesterase inhibitor) administration was also examined. The arteries of ICR mice were occluded with aneurysm clips to generate the cerebral ischemia model. Learning and memory performance was assessed using the elevated plus maze (EPM) test. Hippocampal and blood BDNF levels were quantified using an enzyme-linked immunosorbent assay. Glutamate decarboxylase 1 (GAD1) mRNA expression, is associated with cognitive impairment, was quantified by a real-time polymerase chain reaction. The EPM test revealed impaired spatial working memory in the cerebral ischemia mouse model; tacrine administration ameliorated this memory impairment. Cerebral ischemia suppressed GAD1 expression by decreasing hippocampal BDNF expression. In total, seven salivary metabolites, such as trimethylamine N-oxide and putrescine, were changed by cognitive impairment and tacrine administration. Our data suggest that salivary metabolite patterns were associated with cognitive function.

NEURoaid II (MLC901) in cognitively Impaired not demenTEd patientS (NEURITES): A pilot double blind, placebo-controlled randomized trial

OBJECTIVE

To investigate the efficacy and safety of MLC901 in vascular cognitive impairment no dementia (VCIND) patients.

DESIGN

This was a multi-center, double-blind, randomized, placebo-controlled pilot study.

SETTING AND PARTICIPANT

VCIND patients from hospitals in Singapore (67), Vietnam (19), and the Philippines (17) were recruited and followed-up from March 2013 to April 2018.

METHODS

The primary outcome was executive function as measured by the Verbal Fluency (VF) and 2-part Color Trails Test (CTT). The mean difference in the scores between baseline and week 12, and baseline and week 24, was compared between MLC901 and placebo using a two-sample t-test.

RESULTS

The trial randomized 103 subjects: MLC901 (n = 57) and placebo (n = 46). The mean age of participants was 68.3 ± 8.4 years and 38.8% were female. Improvement in executive function with MLC901 was not significantly better than placebo at week 12 (CTT1 mean difference [md] 3.8 seconds, 95% confidence interval [CI]: -9.0 to 16.5, CTT2 md 10.9 seconds, 95% CI: -0.2 to 22.0), and at week 24 (CTT1 md 2.8 seconds, 95% CI: -8.4 to 14.0, CTT2 md = 4.4 seconds, 95% CI: -8.2 to 16.9). Improvement in VF from baseline was not significantly different between MLC901 and placebo at weeks 12 and 24. There were no significant differences in adverse events (43.5% vs. 56.1%) or serious adverse events (13% vs. 22.8%) in placebo versus MLC901 groups. In post hoc exploratory analysis, the treatment effect of MLC901 on cognitive function appears more apparent in subjects with existing impairment in executive function: CTT2 (md 14.4 seconds [P = .05] and 9.9 seconds [P = .3] at week 12 and week 24, respectively).

CONCLUSIONS

Whilst MLC901 appears to be safe, there was no significant cognitive benefit from MLC901 in the study population. Post hoc hypotheses generating analyses suggest that VCIND patients with existing impairment in executive function may show benefit.

Reshaping the path of vascular cognitive impairment with resistance training: a study protocol for a randomized controlled trial

Background

Subcortical ischemic vascular cognitive impairment (SIVCI) is the most common form of vascular cognitive impairment. Importantly, SIVCI is considered the most treatable form of cognitive impairment in older adults, due to its modifiable risk factors such as hypertension, diabetes mellitus, and hypercholesterolemia. Exercise training is a promising intervention to delay the progression of SIVCI, as it actively targets these cardiometabolic risk factors. Despite the demonstrated benefits of resistance training on cognitive function and emerging evidence suggesting resistance training may reduce the progression of white matter hyperintensities (WMHs), research on SIVCI has predominantly focused on the use of aerobic exercise. Thus, the primary aim of this proof-of-concept randomized controlled trial is to investigate the efficacy of a 12-month, twice-weekly progressive resistance training program on cognitive function and WMH progression in adults with SIVCI. We will also assess the efficiency of the intervention.

Methods

Eighty-eight community-dwelling adults, aged > 55 years, with SIVCI from metropolitan Vancouver will be recruited to participate in this study. SIVCI will be determined by the presence of cognitive impairment (Montreal Cognitive Assessment < 26) and cerebral small vessel disease using computed tomography or magnetic resonance imaging. Participants will be randomly allocated to a twice-weekly exercise program of (1) progressive resistance training or (2) balance and tone training (i.e., active control). The primary outcomes are cognitive function measured by the Alzheimer’s Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-13 with additional cognitive tests) and WMH progression.

Discussion

The burden of SIVCI is immense, and to our knowledge, this will be the first study to quantify the effect of progressive resistance training on cognitive function and WMH progression among adults with SIVCI. Slowing the rate of cognitive decline and WMH progression could preserve functional independence and quality of life. This could lead to reduced health care costs and avoidance of early institutional care.

Trial registration

ClinicalTrials.gov NCT02669394. Registered on February 1, 2016

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05156-1.

Fluoxetine May Enhance VEGF, BDNF and Cognition in Patients with Vascular Cognitive Impairment No Dementia: An Open-Label Randomized Clinical Study

PURPOSE

Selective serotonin reuptake inhibitors (SSRIs) enhance angiogenesis and neurogenesis. Brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) play an important role in neurogenesis and angiogenesis. However, the effect of SSRIs on cognition and serum BDNF and VEGF in patients with vascular cognitive impairment no dementia (VCIND) is largely unknown.

PATIENTS AND METHODS

It was an open label study. Fifty VCIND patients were randomly allocated to receive fluoxetine (20 mg/d; n = 25) or no fluoxetine (control group; n = 25) for 12 weeks. VCIND patients received fluoxetine 20 mg/d and secondary prevention of stroke for 12 weeks in the fluoxetine group, whereas the control group received only secondary prevention of stroke for 12 weeks. The primary outcome and secondary outcome were of assessment of Alzheimer's Disease Assessment Scale cognitive subscale (ADAS-cog) score, Ten Point Clock drawing test score (TPC), Verbal Fluency Test (VFT), Trail Making Test form a (TMTa), Trail Making Test form b (TMTb) and Digit Span Test score at baseline and week 12 in the both groups. And serum concentration of BDNF and VEGF was also tested at baseline and week 12 in both groups.

RESULTS

After 12 weeks, TPC scores increased more significantly in the fluoxetine group than in the control group, while TMTa score and TMTb score were decreased more significantly in the fluoxetine group than in the control group. We also found that the serum concentration of BDNF and VEGF in the fluoxetine group increased more significantly than in the control group. However, we found no significant differences in mean change from baseline between fluoxetine and control group in ADAS-Cog score, Digit Span Test score and VFT score.

CONCLUSION

Fluoxetine may enhance cognition in certain cognitive domains and serum concentration of BDNF and VEGF in patients with VCIND.

Subcortical Ischemic Vascular Cognitive Impairment: Insights from Reaction Time Measures

In this study, reaction time (RT), intraindividual variability (IIV), and errors, and the effects of practice and processing load upon such function, were compared in patients with subcortical ischemic vascular cognitive impairment (SIVCI) [n = 27] and cognitively healthy older adults (CH) [n = 26]. Compared to CH aging, SIVCI was characterized by a profile of significantly slowed RT, raised IIV, and higher error levels, particularly in the presence of distracting stimuli, indicating that the integrity and/or accessibility of the additional functions required to support high processing load, serial search strategies, are reduced in SIVCI. Furthermore, although practice speeded RT in SIVCI, unlike CH, practice did not lead to an improvement in IIV. This indicates that improvement in RT in SIVCI can in fact mask an abnormally high degree of IIV. Because IIV appears more related to disease, function, and health than RT, its status and potential for change may represent a particularly meaningful, and relevant, disease characteristic of SIVCI. Finally, a high level of within-group variation in the above measures was another characteristic of SIVCI, with such processing heterogeneity in patients with ostensibly the same diagnosis, possibly related to individual variation in pathological load. Detailed measurement of RT, IIV, errors, and practice effects therefore reveal a degree of functional impairment in brain processing not apparent by measuring RT in isolation.

Evaluation and Treatment of Vascular Cognitive Impairment by Transcranial Magnetic Stimulation

The exact relationship between cognitive functioning, cortical excitability, and synaptic plasticity in dementia is not completely understood. Vascular cognitive impairment (VCI) is deemed to be the most common cognitive disorder in the elderly since it encompasses any degree of vascular-based cognitive decline. In different cognitive disorders, including VCI, transcranial magnetic stimulation (TMS) can be exploited as a noninvasive tool able to evaluate in vivo the cortical excitability, the propension to undergo neural plastic phenomena, and the underlying transmission pathways. Overall, TMS in VCI revealed enhanced cortical excitability and synaptic plasticity that seem to correlate with the disease process and progression. In some patients, such plasticity may be considered as an adaptive response to disease progression, thus allowing the preservation of motor programming and execution. Recent findings also point out the possibility to employ TMS to predict cognitive deterioration in the so-called "brains at risk" for dementia, which may be those patients who benefit more of disease-modifying drugs and rehabilitative or neuromodulatory approaches, such as those based on repetitive TMS (rTMS). Finally, TMS can be exploited to select the responders to specific drugs in the attempt to maximize the response and to restore maladaptive plasticity. While no single TMS index owns enough specificity, a panel of TMS-derived measures can support VCI diagnosis and identify early markers of progression into dementia. This work reviews all TMS and rTMS studies on VCI. The aim is to evaluate how cortical excitability, plasticity, and connectivity interact in the pathophysiology of the impairment and to provide a translational perspective towards novel treatments of these patients. Current pitfalls and limitations of both studies and techniques are also discussed, together with possible solutions and future research agenda.

Mutual Interaction of Clinical Factors and Specific microRNAs to Predict Mild Cognitive Impairment in Patients Receiving Hemodialysis

Cognitive impairment (CI) is not uncommon in dialysis patients. Various factors have been implicated. This study aims to examine mutual interaction of various clinical factors for CI in patients receiving hemodialysis. A total of 48 hemodialysis patients in outpatient clinic were recruited from 2015 to 2017. Demographics, circulating uremic toxin concentrations, miRNA concentrations, and nerve injury protein concentrations were collected. Clinical dementia rating (CDR) scores were used to stratify the functional scores of the patients. Receiver operating characteristic (ROC) analysis was used to evaluate diagnostic test performance for predicting dichotomous results, and cumulative ROC analysis was used to examine the combined contribution of clinical factors. CDR scale 0 included 15 patients (mean age, 59.1 years); CDR > 0.5 included 33 patients (mean age, 64.0 years). On cumulative ROC analysis, the major predictors of mild CI were hemoglobin, age, sex, homocysteine, neuron-specific enolase (NSE), and miR-486. The cumulative area under the curve (AUC) on combining hemoglobin, age, and miR-486 was the highest (0.897, 95% confidence interval 0.806–0.988). Two dichotomized variables reached 81.82% sensitivity and 86.67% specificity, with the likelihood ratio for positive and negative results being 6.14 and 0.21, respectively. In conclusion, hemoglobin, age, and miR-486 display high-degree combined effects on mild CI in patients receiving hemodialysis.

Selective Aberrant Functional-Structural Coupling of Multiscale Brain Networks in Subcortical Vascular Mild Cognitive Impairment

Subcortical vascular mild cognitive impairment (svMCI) is a common prodromal stage of vascular dementia. Although mounting evidence has suggested abnormalities in several single brain network metrics, few studies have explored the consistency between functional and structural connectivity networks in svMCI. Here, we constructed such networks using resting-state fMRI for functional connectivity and diffusion tensor imaging for structural connectivity in 30 patients with svMCI and 30 normal controls. The functional networks were then parcellated into topological modules, corresponding to several well-defined functional domains. The coupling between the functional and structural networks was finally estimated and compared at the multiscale network level (whole brain and modular level). We found no significant intergroup differences in the functional-structural coupling within the whole brain; however, there was significantly increased functional-structural coupling within the dorsal attention module and decreased functional-structural coupling within the ventral attention module in the svMCI group. In addition, the svMCI patients demonstrated decreased intramodular connectivity strength in the visual, somatomotor, and dorsal attention modules as well as decreased intermodular connectivity strength between several modules in the functional network, mainly linking the visual, somatomotor, dorsal attention, ventral attention, and frontoparietal control modules. There was no significant correlation between the altered module-level functional-structural coupling and cognitive performance in patients with svMCI. These findings demonstrate for the first time that svMCI is reflected in a selective aberrant topological organization in multiscale brain networks and may improve our understanding of the pathophysiological mechanisms underlying svMCI.

Soluble epoxide hydrolase inhibition improves cognitive function and parenchymal artery dilation in a hypertensive model of chronic cerebral hypoperfusion

OBJECTIVE

Parenchymal arterioles (PAs) regulate perfusion of the cerebral microcirculation, and impaired PA endothelium-dependent dilation occurs in dementia models mimicking chronic cerebral hypoperfusion (CCH). Epoxyeicosatrienoic acids (EETs) are vasodilators; their actions are potentiated by soluble epoxide hydrolase (sEH) inhibition. We hypothesized that chronic sEH inhibition with trifluoromethoxyphenyl-3 (1-propionylpiperidin-4-yl) urea (TPPU) would prevent cognitive dysfunction and improve PA dilation in a hypertensive CCH model.

METHODS

Bilateral carotid artery stenosis (BCAS) was used to induce CCH in twenty-week-old male stroke-prone spontaneously hypertensive rats (SHSRP) that were treated with vehicle or TPPU for 8 weeks. Cognitive function was assessed by novel object recognition. PA dilation and structure were assessed by pressure myography, and mRNA expression in brain tissue was assessed by qRT-PCR.

RESULTS

TPPU did not enhance resting cerebral perfusion, but prevented CCH-induced memory deficits. TPPU improved PA endothelium-dependent dilation but reduced the sensitivity of PAs to a nitric oxide donor. TPPU treatment had no effect on PA structure or biomechanical properties. TPPU treatment increased brain mRNA expression of brain derived neurotrophic factor, doublecortin, tumor necrosis factor-alpha, sEH, and superoxide dismutase 3, CONCLUSIONS: These data suggest that sEH inhibitors may be viable treatments for cognitive impairments associated with hypertension and CCH.

Update on the Neurobiology of Vascular Cognitive Impairment: From Lab to Clinic

In the last years, there has been a significant growth in the literature exploring the pathophysiology of vascular cognitive impairment (VCI). As an "umbrella term" encompassing any degree of vascular-related cognitive decline, VCI is deemed to be the most common cognitive disorder in the elderly, with a significant impact on social and healthcare expenses. Interestingly, some of the molecular, biochemical, and electrophysiological abnormalities detected in VCI seem to correlate with disease process and progression, eventually promoting an adaptive plasticity in some patients and a maladaptive, dysfunctional response in others. However, the exact relationships between vascular lesion, cognition, and neuroplasticity are not completely understood. Recent findings point out also the possibility to identify a panel of markers able to predict cognitive deterioration in the so-called "brain at risk" for vascular or mixed dementia. This will be of pivotal importance when designing trials of disease-modifying drugs or non-pharmacological approaches, including non-invasive neuromodulatory techniques. Taken together, these advances could make VCI a potentially preventable cause of both vascular and degenerative dementia in late life. This review provides a timely update on the recent serological, cerebrospinal fluid, histopathological, imaging, and neurophysiological studies on this "cutting-edge" topic, including the limitations, future perspectives and translational implications in the diagnosis and management of VCI patients.

Update on the Neurobiology of Vascular Cognitive Impairment: From Lab to Clinic

In the last years, there has been a significant growth in the literature exploring the pathophysiology of vascular cognitive impairment (VCI). As an "umbrella term" encompassing any degree of vascular-related cognitive decline, VCI is deemed to be the most common cognitive disorder in the elderly, with a significant impact on social and healthcare expenses. Interestingly, some of the molecular, biochemical, and electrophysiological abnormalities detected in VCI seem to correlate with disease process and progression, eventually promoting an adaptive plasticity in some patients and a maladaptive, dysfunctional response in others. However, the exact relationships between vascular lesion, cognition, and neuroplasticity are not completely understood. Recent findings point out also the possibility to identify a panel of markers able to predict cognitive deterioration in the so-called "brain at risk" for vascular or mixed dementia. This will be of pivotal importance when designing trials of disease-modifying drugs or non-pharmacological approaches, including non-invasive neuromodulatory techniques. Taken together, these advances could make VCI a potentially preventable cause of both vascular and degenerative dementia in late life. This review provides a timely update on the recent serological, cerebrospinal fluid, histopathological, imaging, and neurophysiological studies on this "cutting-edge" topic, including the limitations, future perspectives and translational implications in the diagnosis and management of VCI patients.

Evaluation and Treatment of Vascular Cognitive Impairment by Transcranial Magnetic Stimulation

The exact relationship between cognitive functioning, cortical excitability, and synaptic plasticity in dementia is not completely understood. Vascular cognitive impairment (VCI) is deemed to be the most common cognitive disorder in the elderly since it encompasses any degree of vascular-based cognitive decline. In different cognitive disorders, including VCI, transcranial magnetic stimulation (TMS) can be exploited as a noninvasive tool able to evaluate in vivo the cortical excitability, the propension to undergo neural plastic phenomena, and the underlying transmission pathways. Overall, TMS in VCI revealed enhanced cortical excitability and synaptic plasticity that seem to correlate with the disease process and progression. In some patients, such plasticity may be considered as an adaptive response to disease progression, thus allowing the preservation of motor programming and execution. Recent findings also point out the possibility to employ TMS to predict cognitive deterioration in the so-called "brains at risk" for dementia, which may be those patients who benefit more of disease-modifying drugs and rehabilitative or neuromodulatory approaches, such as those based on repetitive TMS (rTMS). Finally, TMS can be exploited to select the responders to specific drugs in the attempt to maximize the response and to restore maladaptive plasticity. While no single TMS index owns enough specificity, a panel of TMS-derived measures can support VCI diagnosis and identify early markers of progression into dementia. This work reviews all TMS and rTMS studies on VCI. The aim is to evaluate how cortical excitability, plasticity, and connectivity interact in the pathophysiology of the impairment and to provide a translational perspective towards novel treatments of these patients. Current pitfalls and limitations of both studies and techniques are also discussed, together with possible solutions and future research agenda.

Effect of low-dose Levamlodipine Besylate in the treatment of vascular dementia

Vascular dementia (VaD) is a complex disorder caused by reduced blood flow in the brain. However, there is no effective pharmacological treatment option available until now. Here, we reported that low-dose levamlodipine besylate could reverse the cognitive impairment in VaD mice model of right unilateral common carotid arteries occlusion (rUCCAO). Oral administration of levamlodipine besylate (0.1 mg/kg) could reduce the latency to find the hidden platform in the MWM test as compared to the vehicle group. Furthermore, vehicle-treated mice revealed reduced phospho-CaMKII (Thr286) levels in the hippocampus, which can be partially restored by levamlodipine besylate (0.1 mg/kg and 0.5 mg/kg) treatment. No significant outcome on microglia and astrocytes were observed following levamlodipine besylate treatment. This data reveal novel findings of the therapeutic potential of low-dose levamlodipine besylate that could considerably enhance the cognitive function in VaD mice.

White Matter Hyperintensities Relate to Basal Ganglia Functional Connectivity and Memory Performance in aMCI and SVMCI

Cerebral small vessel diseases play a crucial role in both vascular and non-vascular dementias. The location of white matter hyperintensities (WMHs), a neuroimaging marker of cerebral small vessel disease, has been found to vary between different types of dementias, and those in the basal ganglia (BG) have been particularly associated with vascular cognitive impairment (VCI). However, anatomical variation of WMHs across BG nuclei and its effect on brain network dysconnectivity has not been clearly elucidated. The study sample consisted of 40 patients with amnestic mild cognitive impairment (aMCI), 40 with subcortical vascular MCI (SVMCI), and 40 healthy control subjects. We examined the volume of WMH using T2-weighted magnetic resonance imaging. We also assessed the disturbances in BG-cortical communication by measuring resting-state functional connectivity (rsFC) from the functional magnetic resonance imaging signal. WMHs were more pronounced in the SVMCI group particularly in the caudate regions. In SVMCI patients, while higher WMHs in the dorsal caudate correlated with weaker FC with executive control regions and worse immediate recall performance, WMHs in the ventral caudate were associated with weaker FC with anterior default mode regions and worse delayed recall performance. In contrast, in aMCI patients, BG WMHs were not correlated with their changes in functional connectivity changes, which showed weaker connectivity with almost all BG structures, rather than restricting to specific BG subdivisions as observed in the SVMCI group. Our findings demonstrate that heterogeneously distributed BG WMHs are associated with changes in functional network interactions and verbal episodic memory performance only in SVMCI patients, which establishes a link between cerebrovascular-related structural abnormality, functional integrity of BG circuits, and episodic memory impairments in SVMCI, and may reflect a differential role of the cerebrovascular pathology in disrupting network-level communications and cognition between Alzheimer's and subcortical vascular dementia.

Cerebrolysin for vascular dementia

BACKGROUND

Although vascular dementia is the second most common cause of dementia globally, evidence-based treatments are still lacking. Cerebrolysin is a porcine brain-derived preparation that is said to have neurotrophic and neuroprotective activity. In many parts of the world Cerebrolysin, given as a series of daily intravenous infusions, is used as a potential intervention for vascular dementia. A previous Cochrane Review on Cerebrolysin in vascular dementia yielded inconsistent results. We wished to update the review to add new studies from the international literature and employ contemporary methods for appraising the strength of the evidence. This is the first update of a review first published in 2013.

OBJECTIVES

Primary: to assess the effect of Cerebrolysin on cognitive function, global function, and all-cause mortality in people living with vascular dementia. Secondary: to assess the adverse effects of Cerebrolysin and to assess the effect of Cerebrolysin on quality of life and caregiver burden.

SEARCH METHODS

We searched ALOIS, MEDLINE, Embase, PsycINFO, CINAHL, ISI Web of Knowledge, LILACS, the Cochrane Library, ClinicalTrials.gov, and the WHO ICTRP on 16 June 2017, 9 May 2018, and 9 May 2019. We expanded the search by adding four Chinese databases, searched from 1 January 2012 to 19 May 2019. We checked bibliographies of relevant papers identified and contacted pharmaceutical companies, trial authors, and experts in the field to identify any additional published or unpublished data.

SELECTION CRITERIA

We included all randomised controlled trials of Cerebrolysin used in people living with vascular dementia. We applied no language restriction.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and evaluated their methodological quality. Data were extracted and analysed using mean differences (MDs) or standardised mean differences (SMDs) with 95% confidence intervals (95% CI) for continuous outcomes. We reported dichotomous outcomes as risk ratio (RR) with 95% CI. We assessed the strength of the available evidence using the GRADE approach.

MAIN RESULTS

We identified six randomised controlled trials with a total of 597 participants that were eligible for inclusion in the 2013 review. No new studies were eligible for inclusion in this update. Participants in the included studies, where dementia severity was reported, had mild to moderate severity of vascular dementia (four trials). The included studies tested varying doses and duration of Cerebrolysin treatment. Follow-up ranged from 15 days to three years. Five of included studies were conducted in China (three studies), Russia (one study), and Romania (one study), while relevant information of other study was unclear. Where details of funding were available, all studies were supported by the pharmaceutical industry (three studies). Cognitive function was measured using the Mini-Mental State Examination (MMSE) or Alzheimer's Disease Assessment Scale Cognitive Subpart, extended version (ADAS-cog+). Combining the MMSE and ADAS-cog+ data (three studies, 420 people), there was a beneficial effect of Cerebrolysin (SMD 0.36, 95% CI 0.13 to 0.58; very low-quality evidence). Global function was measured by Clinician's Interview-Based Impression of Change plus Caregiver Input (CIBIC+) or Investigator's Clinical Global Impression (CGI). We assessed response rates on these measures (the proportion of participants with a CIBIC+ score of < 3; or at least moderate improvement of the CGI rating at the last visit). There was a beneficial effect of Cerebrolysin (two studies, 379 participants, RR 2.69, 95% CI 1.82 to 3.98; very low-quality evidence). Only one trial described mortality and reported no deaths. Four studies reported adverse events; data from two studies (379 people) were in a format that permitted meta-analysis, and there was no difference in rates of adverse effects (RR 0.91, 95% CI 0.29 to 2.85; very low-quality evidence). No studies reported on quality of life or caregiver burden.

AUTHORS' CONCLUSIONS

Courses of intravenous Cerebrolysin improved cognition and general function in people living with vascular dementia, with no suggestion of adverse effects. However, these data are not definitive. Our analyses were limited by heterogeneity, and the included papers had high risk of bias. If there are benefits of Cerebrolysin, the effects may be too small to be clinically meaningful. There have been no new studies of Cerebrolysin in vascular dementia since the last Cochrane Review. Cerebrolysin continues to be used and promoted as a treatment for vascular dementia, but the supporting evidence base is weak. Adequately powered, methodologically robust trials are needed to properly assess the effects of Cerebrolysin in vascular dementia.

The Emerging Roles of Ferroptosis in Vascular Cognitive Impairment

Vascular cognitive impairment (VCI) is a clinical syndrome that encompasses all forms of cognitive deficits caused by cerebrovascular disease, from mild cognitive impairment to dementia. Vascular dementia, the second most common type of dementia after Alzheimer’s disease (AD), accounts for approximately 20% of dementia patients. Ferroptosis is a recently defined iron-dependent form of cell death, which is distinct from apoptosis, necrosis, autophagy, and other forms of cell death. Emerging evidence suggests that ferroptosis has significant implications in neurological diseases such as stroke, traumatic brain injury, and AD. Additionally, ferroptosis inhibition has an obvious neuroprotective effect and ameliorates cognitive impairment in various animal models. Here, we summarize the underlying mechanisms of ferroptosis and review the close relationship between ferroptosis and VCI.

Greater Disease Burden, Greater Risk? Exploring Cognitive Change and Health Status Among Older Blacks

Objective: The objective of study is to examine the relationships between health status and changes in cognition over time among middle to older aged Blacks. Method: Data come from the Baltimore Study of Black Aging-Patterns of Cognitive Aging. At baseline, 602 Black participants, ranging from ages 48 to 95 years, were enrolled. At follow-up, approximately 3 years later, 450 participants were re-interviewed. Results: After accounting for baseline cognition, age, sex, and education, a greater number of health conditions was associated with slower perceptual speed (b = -5.099, p = .022). Average peak expiratory flow was also associated with improvements in working memory (b = 0.029, p = .019) and perceptual speed (b = 0.026, p = .026), controlling for model covariates. Discussion: Study findings demonstrate that greater disease burden is associated with declines in specific fluid cognitive abilities in middle to later life among Blacks. This finding highlights the importance of reducing health disparities that disproportionately affect Blacks.

Transcranial Doppler ultrasound in vascular cognitive impairment-no dementia

BACKGROUND

Although cerebral white matter lesions (WMLs) are considered as a risk factor for vascular dementia, data on their impact on cerebral hemodynamics are scarce. We test and compare transcranial Doppler (TCD) features in WML patients with or without associated cognitive impairment.

METHODS

A sample of non-demented elderly patients with WMLs was consecutively recruited. Mean blood flow velocity (MBFV), pulsatility index (PI), peak systolic blood flow velocity (PSV), end-diastolic blood flow velocity (EDV), and resistivity index (RI) were recorded from the middle cerebral artery bilaterally. Global cognitive functioning, frontal lobe abilities, functional status, and WML severity were also assessed.

RESULTS

161 patients satisfying the clinical criteria for vascular cognitive impairment-no dementia (VCI-ND) were age-matched with 97 presenting WMLs without any cognitive deficit. VCI-ND patients exhibited a decrease in MBFV and EDV, as well as an increase in PI, RI, and PSV. Moreover, a significant correlation between all TCD parameters and the severity of executive dysfunction was observed, whereas PI, RI, and EDV were significantly correlated with the WML load.

CONCLUSIONS

VCI-ND showed a hemodynamic pattern indicative of cerebral hypoperfusion and enhanced vascular resistance. These changes may be considered as the TCD correlate of VCI-ND due to microcirculation pathology. TCD provides useful indices of the occurrence and severity of small vessel disease and executive dysfunction in elderly patients at risk of future dementia.

Transcranial Doppler ultrasound in vascular cognitive impairment-no dementia

BACKGROUND

Although cerebral white matter lesions (WMLs) are considered as a risk factor for vascular dementia, data on their impact on cerebral hemodynamics are scarce. We test and compare transcranial Doppler (TCD) features in WML patients with or without associated cognitive impairment.

METHODS

A sample of non-demented elderly patients with WMLs was consecutively recruited. Mean blood flow velocity (MBFV), pulsatility index (PI), peak systolic blood flow velocity (PSV), end-diastolic blood flow velocity (EDV), and resistivity index (RI) were recorded from the middle cerebral artery bilaterally. Global cognitive functioning, frontal lobe abilities, functional status, and WML severity were also assessed.

RESULTS

161 patients satisfying the clinical criteria for vascular cognitive impairment-no dementia (VCI-ND) were age-matched with 97 presenting WMLs without any cognitive deficit. VCI-ND patients exhibited a decrease in MBFV and EDV, as well as an increase in PI, RI, and PSV. Moreover, a significant correlation between all TCD parameters and the severity of executive dysfunction was observed, whereas PI, RI, and EDV were significantly correlated with the WML load.

CONCLUSIONS

VCI-ND showed a hemodynamic pattern indicative of cerebral hypoperfusion and enhanced vascular resistance. These changes may be considered as the TCD correlate of VCI-ND due to microcirculation pathology. TCD provides useful indices of the occurrence and severity of small vessel disease and executive dysfunction in elderly patients at risk of future dementia.

[Possible applications of rac-hopantenic acid in the treatment of cognitive, anxiety and depressive disorders in patients with essential arterial hypertension]

Essential arterial hypertension (AH) is one of the main risk factors for the development of cognitive impairment and dementia. Cognitive decline is an early sign of brain damage as a target organ of hypertension, it occurs even in patients with uncomplicated hypertension with minimal duration of disease. Cognitive impairment progresses with increasing age and hypertension duration, as well as in non-controlled AH. In patients with hypertension, the prevalence of emotional disorders - anxiety and depression is also high. In addition to antihypertensive therapy, hypertensive patients need correction of concomitant cognitive and emotional disorders. Rat-gopantenic acid simultaneously corrects both emotional and cognitive impairment, and has a good tolerability profile as well. An analysis of the evidence base of rac-gopantenic acid showed its high efficacy in the treatment of mental disorders and good tolerability along with a positive effect on somatic disorders and results of antihypertensive therapy. Taken together, they enhance adherence to treatment and, consequently, reduce the cardiovascular risk.

Can Blood Oxygenation Level Dependent Functional Magnetic Resonance Imaging Be Used Accurately to Compare Older and Younger Populations? A Mini Literature Review

A wealth of research has investigated the aging brain using blood oxygenation level dependent functional MRI [Blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI)]. However, many studies do not consider the aging of the cerebrovascular system, which can influence the BOLD signal independently from neural activity, limiting what can be inferred when comparing age groups. Here, we discuss the ways in which the aging neurovascular system can impact BOLD fMRI, the consequences for age-group comparisons and possible strategies for mitigation. While BOLD fMRI is a valuable tool in this context, this review highlights the importance of consideration of vascular confounds.