Cerebral Small Vessel Disease, Hypertension, and Vascular Contributions to Cognitive Impairment and Dementia

Association between cardiometabolic diseases and the risk and progression of motor neuron diseases in Sweden: a population-based case-control study

Background

The evidence on the link between cardiometabolic diseases (CMDs) and motor neuron diseases (MNDs) remains inconsistent. We aimed to determine whether there is an association of CMDs, namely, any cardiovascular disease, cardiac arrhythmia, heart failure, thromboembolic disease, hypertension, cerebrovascular disease, ischemic heart disease, diabetes mellitus type 2, and hypercholesterolemia with the risk and progression of MNDs.

Methods

We included 1463 MND patients (amyotrophic lateral sclerosis (ALS), primary lateral sclerosis (PLS), progressive spinal muscular atrophy (PSMA), and unspecified MND) diagnosed from January 1, 2015, to July 1, 2023, in Sweden according to the Swedish Motor Neuron Disease Quality Registry (i.e., cases), up to 5 MND-free population controls per case (N = 7311) who were individually matched to the cases on age and sex, and the full siblings (N = 2002) and spouses (N = 1220) of MND patients (i.e., relative controls). Conditional logistic regression models were used to estimate the risk of MND diagnosis in relation to previous CMDs, through comparing MND patients to population controls or relative controls. MND patients were followed from diagnosis to assess the role of pre-diagnostic CMDs on disease progression. A joint longitudinal-survival model was used to estimate risk of mortality (or use of invasive ventilation) in relation to CMDs after taking into account the longitudinal changes of ALS functional rating scale-revised (ALSFRS-R) in the time-to-event analysis. Hierarchical clustering with the Ward's linkage and a dissimilarity matrix created by Gower's method was used to identify clusters of MND patients with distinct phenotypes.

Findings

Among the CMDs studied, a history of diabetes mellitus type 2 (OR 0.75; 95% CI 0.62, 0.93) or hypercholesterolemia (OR 0.82; 95% CI 0.71, 0.94) more than one year before diagnosis was associated with a lower risk for MNDs. The associations persisted for more than five years before MND diagnosis. MND patients with a history of any cardiovascular disease (HR 1.43; 95% CI 1.13, 1.81), arrhythmia (HR 1.42; 95% CI 1.04, 1.93), heart failure (HR 1.79; 95% CI 1.02, 3.14), hypertension (HR 1.41; 95% CI 1.12, 1.77), or hypercholesterolemia (HR 1.28; 95% CI 1.01, 1.62) had an increased mortality risk, compared to others, after taking into consideration the longitudinal changes in ALSFRS-R. Cluster analysis identified two clusters of MND patients, where one cluster demonstrated higher age, worse functional status, and higher prevalence of CMDs at the time of diagnosis as well as a higher mortality and faster functional decline during follow-up, compared to the ones included in the other cluster.

Interpretation

Diabetes mellitus type 2 and hypercholesterolemia were associated with a lower future risk of MND. On the other hand, most of the CMDs were indicative of a poor disease progression after an MND diagnosis.

Funding

European Research Council, US Center for Disease Control and Prevention, Swedish Research Council.

Proteins Involved in Endothelial Function and Inflammation Are Implicated in Cerebral Small Vessel Disease

BACKGROUND

Endothelial dysfunction and inflammation have been implicated in the pathophysiology of cerebral small vessel disease (SVD). However, whether they are causal, and if so which components of the pathways represent potential treatment targets, remains uncertain.

METHODS

Two-sample Mendelian randomization (MR) was used to test the association between the circulating abundance of 996 proteins involved in endothelial dysfunction and inflammation and SVD. The genetic instruments predicting protein levels were obtained from the Iceland 36K (n=35 892) and the UK Biobank Proteomics (n=34 557) cohorts, both of which were longitudinal studies with follow-up from 2000 to 2023 and 2006 to 2023, respectively. SVD was represented by lacunar stroke (n=6030 cases) and 5 neuroimaging features (white matter hyperintensities [n=55 291], diffusion tensor imaging metrics: mean diffusivity [n=36 460] and fractional anisotropy [n=36 533], extensive white matter perivascular space burden [n=9324 cases], and cerebral microbleeds [n=3556 cases]). Among the proteins supported by causal evidence from the MR, cross-sectional analysis was performed to assess their associations with cognitive performance; survival analysis with Fine-Gray models was applied to examine their associations with incident all-cause dementia and stroke within the UK Biobank Proteomics cohort.

RESULTS

MR suggested COL2A1 (collagen type II α-1 chain) was associated with lacunar stroke (odds ratio, 0.89 [95% CI, 0.86-0.91]; P=5×10-5). Moreover, 12 proteins related to endothelial function and inflammation were associated with neuroimaging features of SVD. Cross-sectional analyses showed 5 of the 13 proteins (EPHA2 [ephrin type-A receptor 2], METAP1D [methionine aminopeptidase 1D, mitochondrial], FLT4 [vascular endothelial growth factor receptor 3], COL2A1, and TIMD4 [T-cell immunoglobulin and mucin domain-containing protein 4]) were associated with cognitive performance with effects concordant with their MR findings. Survival analyses with the Fine-Gray models indicated that 5 of the 13 proteins (EPHA2, METAP1D, FLT4, APOE [apolipoprotein E], and PDE5A [cGMP-specific 3',5'-cyclic phosphodiesterase]) were associated with the risk of all-cause dementia or stroke independent of age and sex, consistent with their MR evidence.

CONCLUSIONS

Our findings suggest that endothelial-platelet activation and complement-mediated regulation of inflammation play roles in SVD and identify potential therapeutic targets and pathways.

The immunology of stroke and dementia

Ischemic stroke and vascular cognitive impairment, caused by a sudden arterial occlusion or more subtle but protracted vascular insufficiency, respectively, are leading causes of morbidity and mortality worldwide with limited therapeutic options. Innate and adaptive immunity have long been implicated in neurovascular injury, but recent advances in methodology and new experimental approaches have shed new light on their contributions. A previously unappreciated dynamic interplay of brain-resident, meningeal, and systemic immune cells with the ischemic brain and its vasculature has emerged, and new insights into the frequent overlap between vascular and Alzheimer pathology have been provided. Here, we critically review these recent findings, place them in the context of current concepts on neurovascular pathologies and Alzheimer's disease, and highlight their impact on recent stroke and Alzheimer therapies.

The relationship between postoperative cognitive dysfunction and cerebral small vessel disease: A comprehensive review

Postoperative cognitive dysfunction (POCD) is a common complication in elderly patients, and cerebral small vessel disease (CSVD) has been suggested as a potential risk factor. This review examines the relationship between POCD and CSVD from epidemiological, pathophysiological, and clinical perspectives, while also considering the role of Alzheimer's disease (AD) pathology. We conducted a comprehensive literature search of major databases, supplemented by reference list checking, to ensure a thorough review of studies published between 2000 and 2023 on the relationship between POCD and CSVD. Epidemiological studies have shown that POCD and CSVD are associated in terms of common risk factors, including advanced age, vascular comorbidities, impaired baseline cognitive function, and certain population characteristics. Animal studies have revealed that CSVD and POCD share similar neuropathological changes, including abnormal cerebral hypoperfusion, inflammatory responses, and blood-brain barrier disruption. Furthermore, recent research suggests a complex interplay between CSVD, AD pathology, and POCD, with potential synergistic effects on cognitive decline. Neuroimaging studies have further demonstrated that preoperative CSVD burden and postoperative CSVD progression are associated with the development of POCD, and the presence of both CSVD and AD markers may increase the risk of cognitive decline. The association between CSVD and POCD has important implications for the perioperative management of elderly patients, including preoperative assessment, choice of anesthesia and surgical methods, intraoperative management, postoperative care, and long-term follow-up. A better understanding of the relationship between CSVD and POCD will guide evidence-based strategies to prevent and manage this debilitating complication in the aging population.

Biological brain age and resilience in cognitively unimpaired 70-year-old individuals

INTRODUCTION

This study investigated the associations of brain age gap (BAG)-a biological marker of brain resilience-with life exposures, neuroimaging measures, biological processes, and cognitive function.

METHODS

We derived BAG by subtracting predicted brain age from chronological age in 739 septuagenarians without dementia or neurological disorders. Robust linear regression models assessed BAG associations with life exposures, plasma inflammatory and metabolic biomarkers, magnetic resonance imaging, and cerebrospinal fluid biomarkers of neurodegeneration and vascular brain injury, and cognitive performance.

RESULTS

Greater BAG (older-looking brains) was associated with physical inactivity, diabetes, and stroke, while prediabetes was related to lower BAG, that is, younger-looking brains. Physical activity mitigated the link between obesity and BAG. Greater BAG was associated with greater small vessel disease burden, white-matter alterations, inflammation, high glucose, poorer vascular-related cognitive domains. Sex-specific associations were identified.

DISCUSSION

Vascular-related lifestyles and health shape brain appearance. Inflammation and insulin-related processes may be keys to understanding vascular cognitive disorders.

HIGHLIGHTS

BAG, reflecting deviations from CA, can indicate resilience. Diabetes, stroke, and low physical activity link to "older" brains (greater BAG). Physical activity yielded to "younger" brains in septuagenarians with obesity. High cerebrovascular burden, inflammation, and glucose associate with "older" brains. Sex differences were detected in all BAG-associated factors.

Cerebrovascular regulation in patients with active tumors and an acute ischemic stroke: a retrospective analysis

Introduction

Ischemic stroke in patients with a systemic tumor disease or cancer not in remission (active tumors) is less well understood. Some aspects of such paraneoplastic strokes remind on a generalized cerebrovascular disorder. We hypothesized that cerebrovascular regulation in active tumor patients with a stroke is different from other patients with stroke who have no active tumor disease.

Methods

Within the first 72 h after the acute ischemic stroke, cerebral blood flow regulation was analyzed by means of transfer function analysis between middle cerebral artery blood flow velocity and blood pressure with estimation of coherence, gain and phase in the very low (0.02-0.07 Hz), low (0.07-0.20 Hz) and high frequencies (0.20-0.5 Hz) in four stroke groups: active tumors, inactive tumors (untreated and in remission), hypertensive lacunar stroke (LS), and non-hypertensive embolic stroke (NHES).

Results

The 4 groups did not differ regarding age, sex distribution, and brain infarct size on magnet resonance imaging Between the four stroke groups, phase was not different in any frequency range in both hemispheres. Gain was highest (either significant or by trend) in the active tumor group in the HF range in comparison to all other stroke subgroups, it was also higher in the LF range in the stroke affected hemisphere when compared to the LS group. The HF gain findings were independent of end-tidal CO2 levels but exhibited some dependency of coherence.

Discussion

The high gain can be interpreted as a generalized high vascular resistance. The cerebrovascular regulation in active tumor patients seems to exhibit some analogy to hypertensive patients with lacunar stroke.

Clinical Trial Registration

clinicaltrials.gov, identifier NCT04611672.

Single-nucleus RNA sequencing of human periventricular white matter in vascular dementia

Vascular dementia (VaD) refers to a variety of dementias driven by cerebrovascular disease and is the second leading cause of dementia globally. VaD may be caused by ischemic strokes, intracerebral hemorrhage, and/or cerebral small vessel disease, commonly identified as white matter hyperintensities on MRI. The mechanisms underlying these white matter lesions in the periventricular brain are poorly understood. In this study we perform an extensive transcriptomic analysis on human postmortem periventricular white matter lesions in patients with VaD with the goal of identifying molecular pathways in the disease. We find increased cellular stress responses in astrocytes, oligodendrocytes, and oligodendrocyte precursor cells as well as transcriptional and translational repression in microglia in our dataset. We show that several genes identified by GWAS as being associated with white matter disease are differentially expressed in cells in VaD. Finally, we compare our dataset to an independent snRNAseq dataset of PVWM in VaD and a scRNAseq dataset on human iPSC-derived microglia exposed to oxygen glucose deprivation (OGD). We identify the increase of the heat shock protein response as a conserved feature of VaD across celltypes and show that this increase is not linked to OGD exposure. Overall, our study is the first to show that increased heat shock protein responses are a common feature of lesioned PVWM in VaD and may represent a potential therapeutic target.

The Level of Fibrinogen-to-Albumin Ratio Was Associated with the Severity of Cerebral Small Vessel Disease in Patients with Transient Ischemic Attack

Purpose

Inflammation plays a role in cerebral small vessel disease (CSVD) pathophysiology. This study aimed to explore the association of the fibrinogen-to-albumin ratio (FAR), a novel inflammatory marker, with CSVD burden in patients with transient ischemic attack (TIA).

Patients and Methods

From October 1, 2022, to November 30, 2023, continuous patients with TIA were recruited in the study. The total CSVD burden score and modified total CSVD burden score were used to assess the severity of CSVD. Multivariable regression analysis was used to explore the correlation between the FAR and CSVD in TIA patients.

Results

A total of 455 participants were recruited, of whom 225 (48.35%), according to the total CSVD burden score, and 181 (40.67%), according to the modified CSVD burden score were finally identified as moderate-severe CSVD. Spearman correlation analysis showed that levels of FAR correlated with the total CSVD (r=0.392, P<0.001) and the modified total CSVD burden scores (r=0.379, P<0.001). Multivariable logistic regression analysis showed that FAR was independently associated with moderate-severe CSVD, both as a continuous variable and as a tertile variable (P<0.001).

Conclusion

The level of FAR on admission was independently associated with the severity of CSVD in patients with TIA.

Medial intracranial carotid artery calcifications and hematoma expansion in deep intracerebral hemorrhage

BACKGROUND

Medial intracranial carotid artery calcifications (ICAC) are associated with impaired vascular physiology, increased arterial stiffness and pulse pressure. Their presence might therefore be associated with increased risk of intracerebral hemorrhage (ICH) expansion, according to the avalanche model. We explored the association between ICAC presence and pattern and hematoma expansion (HE).

METHODS

Retrospective analysis of a monocentric, prospectively collected cohort of ICH patients admitted between June 2017 and October 2023. ICAC pattern was determined by Kockelkoren's rating scale on admission CT; medial ICAC were defined with a >6 points cutoff. A follow-up CT scan was performed within 72 h. HE was analyzed as a dichotomous (≥6 mL and/or ≥33%) and as a categorical (none/mild/moderate/severe) variable, and its predictors were explored with logistic and ordinal regression respectively, accounting for baseline volume, onset-to-CT time, and anticoagulation. All the analyses were stratified by ICH location (supratentorial deep vs lobar ICH).

RESULTS

A total of 201 patients were included (median age 78, 42% females, 59% deep ICH). Medial ICAC were significantly more common in deep ICH with HE compared with non-expanders (72% vs 49%, p = 0.03), whereas there was no association between ICAC and HE in lobar ICH (53% vs 52%, p = 0.85). This association between medial ICAC and HE in deep ICH remained significant in logistic (aOR 3.11, 95% CI [1.19-9.06], p = 0.03) and ordinal regression (acOR 2.42, 95% CI [1.19-4.99], p = 0.01).

INTERPRETATION

Ipsilateral medial ICAC are associated with higher odds of HE in deep ICH. Our findings are best interpreted as hypothesis generating, requiring prospective validation and further research to characterize the underlying biological mechanisms.

Medin, a link between vascular pathology and dementia?

Medin is a protein fragment derived from milk fat globule epidermal growth factor VIII (MFG-E8). Medin aggregates are present in the vessel wall of most subjects over 50 years of age. In this narrative review, we focus on the consequences of medin aggregation in relation to the development of dementia. Recent literature revealed medin as biomarker for dementia in CSF, specifically of a vascular subtype. Preclinical work showed that medin is associated with aging-related cerebral vascular dysfunction, vascular stiffening, hypertension, and. vascular amyloid β deposition. These findings position medin as a potential mechanistic link between aging, vascular pathology and dementia.

Brain endothelial cell activation and dysfunction associate with and contribute to the development of enlarged perivascular spaces and cerebral small vessel disease

Multiple injurious stimuli to the brain's endothelium results in brain endothelial cell activation and dysfunction (BECact/dys) with upregulation of inflammatory signaling cascades and a decrease in bioavailable nitric oxide respectively. These injurious stimuli initiate a brain injury and a response to injury wound healing genetically programed cascade of events, which result in cellular remodeling of the neurovascular unit and blood-brain barrier with increased inflammation and permeability. These remodeling changes also include the perivascular spaces that become dilated to form enlarged perivascular spaces (EPVS) that may be identified noninvasively by magnetic resonance imaging. These EPVS are associated with and considered to be a biomarker for cerebral small vessel disease (SVD) and a dysfunctional glymphatic system with impaired removal of neurotoxic waste, which ultimately results in neurodegeneration with impaired cognition and dementia. The penultimate section discusses the understudied role of venous cerebral circulation in relation to EPVS, SVD, and the vascular contribution to cognitive impairment (VCID). The focus of this review will be primarily on BECact/dys that associates with and contributes to the development of EPVS, SVD, and impaired glymphatic system efflux. Importantly, BECact/dys may be a key piece of the puzzle to unlock this complicated story of EPVS and SVD. Multiple transmission electron micrographs and illustrations will be utilized to depict anatomical ultrastructure and allow for the discussion of multiple functional molecular cascades.

Linking peripheral atherosclerosis to blood-brain barrier disruption: elucidating its role as a manifestation of cerebral small vessel disease in vascular cognitive impairment

Aging plays a pivotal role in the pathogenesis of cerebral small vessel disease (CSVD), contributing to the onset and progression of vascular cognitive impairment and dementia (VCID). In older adults, CSVD often leads to significant pathological outcomes, including blood-brain barrier (BBB) disruption, which in turn triggers neuroinflammation and white matter damage. This damage is frequently observed as white matter hyperintensities (WMHs) in neuroimaging studies. There is mounting evidence that older adults with atherosclerotic vascular diseases, such as peripheral artery disease, ischemic heart disease, and carotid artery stenosis, face a heightened risk of developing CSVD and VCID. This review explores the complex relationship between peripheral atherosclerosis, the pathogenesis of CSVD, and BBB disruption. It explores the continuum of vascular aging, emphasizing the shared pathomechanisms that underlie atherosclerosis in large arteries and BBB disruption in the cerebral microcirculation, exacerbating both CSVD and VCID. By reviewing current evidence, this paper discusses the impact of endothelial dysfunction, cellular senescence, inflammation, and oxidative stress on vascular and neurovascular health. This review aims to enhance understanding of these complex interactions and advocate for integrated approaches to manage vascular health, thereby mitigating the risk and progression of CSVD and VCID.

MRI in older patients-A focused review

MRI has considerably increased our pathophysiological knowledge of age-related brain abnormalities. Brain abnormalities regularly seen on MRI of older adults are atrophy, and changes related to small vessel disease (SVD). SVD-related changes include white matter hyperintensities (WMH), lacunes, microbleeds, microinfarcts and perivascular spaces. While atrophy, WMH and lacunes are recognized as important contributors to cognitive decline and dementia, relationships are less clear for microbleeds, microinfarcts and perivascular spaces. Vascular risk factors are considered critical in the development of these changes and being potentially modifiable have become increasingly interesting to researchers and clinicians alike. Managing vascular risk early, particularly hypertension, is a key factor in slowing down the evolution of age-related brain abnormalities and decelerate their detrimental cognitive consequences. Cognition and visible brain abnormalities have a complex relationship, which reaches far beyond what we can understand using standard MRI. Remote effects of lesions and associated- as well as independent network changes likely explain much of the different cognitive trajectories observed with aging. Because of the versatility of MRI in the diagnostic of various diseases, including epilepsy, incident signs of brain aging will be encountered ever more frequently on standard MRI of older adults. To facilitate understanding and ultimately reporting these changes to patients, this review will give a brief overview of MRI findings encountered on MRI of older people. We will discuss their pathology, risk factors, and relationships with cognition. Special emphasis will be given to more recent developments, including remote effects of lesions, and effects on the structural brain network. Relationships between MRI findings in older people and epilepsy will be discussed as well.

Exploring the global impact of obesity and diet on dementia burden: the role of national policies and sex differences

Obesity is a significant modifiable risk factor for dementia. This study aims to quantify the global impact of obesity on dementia burden and examine how national strategies for managing overweight/obesity and dietary factors influence dementia prevalence and mortality, with a focus on sex-specific differences. We used data from the Global Burden of Disease (GBD) and World Health Organization (WHO) to evaluate the association between obesity age-standardized prevalence rate (ASPR) and dementia age-standardized mortality rate (ASMR) and ASPR across 161 countries. A two-step multivariate analysis adjusted for socioeconomic and lifestyle factors was performed. Temporal trends in dementia were analyzed based on the presence of national obesity management strategies and varying dietary scores. A 1% increase in national obesity prevalence was associated with a 0.36% increase in dementia mortality (OR: 1.0036; 95% CI: 1.0028-1.0045) in males and 0.12% in females (OR: 1.0012; 95% CI: 1.0007-1.0018). A 1% increase in national obesity ASPR was associated with an increase in ASPR of dementia by 0.26% for males (OR: 1.0026, 95% CI: 1.0024-1.0028) and 0.05% for females (OR: 1.0005, 95% CI: 1.0004-1.0006). Males exhibited a higher susceptibility to obesity-related dementia. Countries with national obesity management strategies showed a significantly greater reduction in dementia mortality, particularly among females (P = 0.025). Higher dietary scores were associated with a more significant decrease in dementia prevalence across both sexes. Rising obesity prevalence is linked to increased dementia burden globally, with males being more vulnerable to this relationship. National management of overweight/obesity and healthier dietary habits may help mitigate the dementia burden, emphasizing the need for integrated public health interventions.

Assessing stroke recurrence in sICAS: a study on mCSVD score and culprit plaque magnetic resonance characteristics

Background

Recurrent ischemic stroke in patients with symptomatic intracranial atherosclerotic stenosis (sICAS) can be attributed to two main causes: intracranial atherosclerotic stenosis (ICAS) and cerebral small vessel disease (CSVD). This study investigates the potential associations between stroke recurrence and the modified cerebral small vessel disease (mCSVD) burden score, as well as the characteristics of culprit plaques related to intracranial artery high-resolution vessel wall imaging (HR-VWI).

Methods

A total of 145 patients presenting sICAS underwent intracranial artery HR-VWI and routine cranial MRI at two large Chinese hospitals from December 2019-2022 were participants of this retrospective analysis. Standard MRI scans were used to calculate the mCSVD score. Following a 12-month observation period, the patients were categorized into two distinct groups depending on whether or not they experienced a subsequent stroke.

Results

Within 12 months, 32 patients experienced stroke recurrence. The recurrence group's mCSVD score was higher compared to the non-recurrence group (p < 0.001). Their luminal stenosis and culprit plaque thickness and burden were also higher (p < 0.05). Additionally, higher rates of diabetes, T1WI hyperintensity of culprit plaques, and significant plaque enhancement were observed in the recurrence group (p < 0.05). The adjusted Cox regression model indicated that the mCSVD score (HR = 1.730, 95% CI 1.021-2.933, p = 0.042) and T1WI hyperintensity of the culprit plaque (HR = 6.568, 95% CI 1.104-39.059, p = 0.039) remained significantly independent risk variables. The combination of the mCSVD score and T1WI hyperintensity of the culprit plaque demonstrated the highest efficacy in predicting stroke recurrence (z = 2.678, p < 0.05).

Conclusion

The mCSVD score, associated with T1WI hyperintensity of culprit plaque, effectively predicts stroke recurrence and can be easily obtained, offering high clinical value.

The brain and hypertension: how the brain regulates and suffers from blood pressure

The brain plays several roles in the relationship between blood pressure (BP) and the brain: it acts as the control center for BP regulation, a target organ in hypertension, and a crucial component for cognitive function. This mini-review introduces recent findings on "brain and hypertension" from Hypertension Research and other journals. Activation of the angiotensin II type 1 receptor (AT1R) signaling pathway in the brain causes sympathoexcitation and hypertension. AT1R-associated protein and β-arrestin promote AT1R internalization and suppress AT1R signaling, with brain-specific roles in BP regulation. The brain receives various inputs from the peripheral system, including the heart and kidneys, and controls central sympathetic outflow. The brain mechanism involved in the enhanced cardiac sympathetic afferent reflex and the beneficial effects of renal denervation have been demonstrated. The brain's vulnerability in hypertension includes stroke, with cerebral small vessel disease (SVD) contributing to stroke risk and brain changes. Sex differences and the age of hypertension onset influence these outcomes. High salt intake exacerbates hypertension and stroke risk, with central mechanisms like sympathoexcitation implicated. Hypertension significantly impacts cognitive function, linking to cerebral SVD and cognitive decline. Orthostatic BP regulation abnormalities also emerge as early risk markers for dementia. Improved BP control in hypertensive individuals can significantly reduce the risk of stroke and cognitive decline, as well as cardiovascular disease, enhancing overall brain health and quality of life. Further understanding the brain's role in BP regulation and the pathogenesis of hypertension will facilitate the development of novel hypertension treatments and prevention strategies.

Associations between carotid plaques and white matter hyperintensities in cerebral small vessel disease

BACKGROUND

Cerebral small vessel disease (CSVD) can lead to stroke and cognitive impairment. Small vessels cannot be visualized by neuroimaging directly, and CSVD can only be evaluated by cerebral parenchymal changes in MRI. Therefore, a convenient screening method for identifying high-risk and susceptible patients is needed. Recently, some studies found that CSVD was related to large atherosclerosis, and atherosclerosis was an essential pathological feature of CSVD. Therefore, we aimed to investigate the association between carotid plaque size characteristics and white matter hyperintensities (WMHs) in patients with CSVD.

METHODS

We continuously enrolled patients with CSVD. Carotid plaque features were evaluated using carotid ultrasound, and WMHs were evaluated using brain magnetic resonance imaging. Plaque characteristics were compared between patients with no/mild WMHs and those with severe WMHs. Associations between the plaque characteristics and WMH severity were analyzed using logistic regression.

RESULTS

In total, 180 patients were recruited, of whom 92 had severe WMHs. The severe WMHs group had a higher sum of the bilateral maximum intima-media thickness (4.15 mm vs. 3.30 mm), longer maximum plaque length (17.20 mm vs. 13.90 mm), thicker plaques (2.70 mm vs. 2.30 mm), and more plaques (3 vs. 2) than the no/mild WMHs group. Adjusted logistic regression analyses revealed that maximum plaque length and thickness were associated with WMHs.

CONCLUSIONS

Carotid atherosclerotic plaque features, such as plaque length and thickness, were associated with the severity of WMHs, which suggested that carotid atherosclerotic plaque characteristics measured using ultrasound might be helpful indicators for identifying high-risk patients with CSVD.

Unveiling the theranostic potential of SPIONs in Alzheimer's disease management

Alzheimer's disease (AD) is a devastating kind of dementia that is becoming more common worldwide. Toxic amyloid-beta (Aβ) aggregates are the primary cause of AD onset and development. Superparamagnetic iron oxide nanoparticles (SPIONs) have received a lot of interest in AD therapy over the last decade because of their ability to redirect the Aβ fibrillation process and improve associated brain dysfunction. The potential diagnostic application of SPIONs in AD has dramatically increased this interest. Furthermore, surface-modified engineered SPIONs function as drug carriers to improve the efficacy of current therapies. Various preclinical and clinical studies on the role of SPIONs in AD pathology have produced encouraging results. However, due to their physicochemical properties (e.g., size, surface charge, and particle concentration) in the biological milieu, SPIONs may play the role of a preventive or accelerative agent in AD. Even though SPIONs are potential therapeutic and diagnostic options in AD, significant efforts are still needed to overcome the inconsistencies and safety concerns. This review evaluated the current understanding of how various SPIONs interact with AD models and explored the discrepancies in their efficacy and safety.

Intracranial Aneurysms and Cerebral Small Vessel Disease: Is There an Association between Large- and Small-Artery Diseases?

Background/Objectives: Intracranial aneurysms (IAs) may be connected to interactions between large and small intracranial vessels. We aimed to investigate the association between IAs and cerebral small-vessel disease (CSVD) and assess CSVD impact on IA patient management. Methods: This retrospective study analyzed clinical data and MRI features of CSVD in 192 subarachnoid hemorrhage (SAH) patients: 136 with incidental IA, 147 with severe CSVD without SAH/IA, and 50 controls without SAH, IA, or severe CSVD. MRI assessments followed the Standards for Reporting Vascular Changes on Neuroimaging (STRIVE), with a total burden of small-vessel disease (TBSVD) score calculated. Statistical analyses included forward selection and binary logistic regression. Results: TBSVD differed significantly across groups (p < 0.001), except between SAH and IA groups (p = 0.8). Controls had the lowest TBSVD (1.00; 1.22 ± 0.996), followed by SAH (2.00; 2.08 ± 1.013) and IA groups (2.00; 2.04 ± 1.141), with the highest in the CSVD group (1.00; 1.22 ± 0.996). White-matter hyperintensity (WMH) patterns varied with IA rupture status (p = 0.044); type A was prevalent in SAH patients and type D in the IA group. Incorporating MRI CSVD features and TBSVD into risk assessments did not enhance IA prediction or outcome models. Conclusions: IA patients exhibit a higher CSVD burden than controls, suggesting a link between small and large intracranial vessels. WMH patterns distinguish between ruptured and unruptured IA patients, offering potential markers for IA rupture risk assessment and signaling a paradigm shift in understanding IAs and CSVD.

Atherosclerotic burden and cerebral small vessel disease: exploring the link through microvascular aging and cerebral microhemorrhages

Cerebral microhemorrhages (CMHs, also known as cerebral microbleeds) are a critical but frequently underestimated aspect of cerebral small vessel disease (CSVD), bearing substantial clinical consequences. Detectable through sensitive neuroimaging techniques, CMHs reveal an extensive pathological landscape. They are prevalent in the aging population, with multiple CMHs often being observed in a given individual. CMHs are closely associated with accelerated cognitive decline and are increasingly recognized as key contributors to the pathogenesis of vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). This review paper delves into the hypothesis that atherosclerosis, a prevalent age-related large vessel disease, extends its pathological influence into the cerebral microcirculation, thereby contributing to the development and progression of CSVD, with a specific focus on CMHs. We explore the concept of vascular aging as a continuum, bridging macrovascular pathologies like atherosclerosis with microvascular abnormalities characteristic of CSVD. We posit that the same risk factors precipitating accelerated aging in large vessels (i.e., atherogenesis), primarily through oxidative stress and inflammatory pathways, similarly instigate accelerated microvascular aging. Accelerated microvascular aging leads to increased microvascular fragility, which in turn predisposes to the formation of CMHs. The presence of hypertension and amyloid pathology further intensifies this process. We comprehensively overview the current body of evidence supporting this interconnected vascular hypothesis. Our review includes an examination of epidemiological data, which provides insights into the prevalence and impact of CMHs in the context of atherosclerosis and CSVD. Furthermore, we explore the shared mechanisms between large vessel aging, atherogenesis, microvascular aging, and CSVD, particularly focusing on how these intertwined processes contribute to the genesis of CMHs. By highlighting the role of vascular aging in the pathophysiology of CMHs, this review seeks to enhance the understanding of CSVD and its links to systemic vascular disorders. Our aim is to provide insights that could inform future therapeutic approaches and research directions in the realm of neurovascular health.

Utility of cerebrovascular imaging biomarkers to detect cerebral amyloidosis

INTRODUCTION

The relationship between cerebrovascular disease (CVD) and amyloid beta (Aβ) in Alzheimer's disease (AD) is understudied. We hypothesized that magnetic resonance imaging (MRI)-based CVD biomarkers-including cerebral microbleeds (CMBs), lacunar infarction, and white matter hyperintensities (WMHs)-would correlate with Aβ positivity on positron emission tomography (Aβ-PET).

METHODS

We cross-sectionally analyzed data from the Alzheimer's Disease Neuroimaging Initiative (ADNI, N = 1352). Logistic regression was used to calculate odds ratios (ORs), with Aβ-PET positivity as the standard-of-truth.

RESULTS

Following adjustment, WMHs (OR = 1.25) and superficial CMBs (OR = 1.45) remained positively associated with Aβ-PET positivity (p < 0.001). Deep CMBs and lacunes exhibited a varied relationship with Aβ-PET in cognitive subgroups. The combined diagnostic model, which included CVD biomarkers and other accessible measures, significantly predicted Aβ-PET (pseudo-R2 = 0.41).

DISCUSSION

The study highlights the translational value of CVD biomarkers in diagnosing AD, and underscores the need for more research on their inclusion in diagnostic criteria.

CLINICALTRIALS

gov: ADNI-2 (NCT01231971), ADNI-3 (NCT02854033).

HIGHLIGHTS

Cerebrovascular biomarkers linked to amyloid beta (Aβ) in Alzheimer's disease (AD). White matter hyperintensities and cerebral microbleeds reliably predict Aβ-PET positivity. Relationships with Aβ-PET vary by cognitive stage. Novel accessible model predicts Aβ-PET status. Study supports multimodal diagnostic approaches.

The vasoprotective role of IGF-1 signaling in the cerebral microcirculation: prevention of cerebral microhemorrhages in aging

Aging is closely associated with various cerebrovascular pathologies that significantly impact brain function, with cerebral small vessel disease (CSVD) being a major contributor to cognitive decline in the elderly. Consequences of CSVD include cerebral microhemorrhages (CMH), which are small intracerebral bleeds resulting from the rupture of microvessels. CMHs are prevalent in aging populations, affecting approximately 50% of individuals over 80, and are linked to increased risks of vascular cognitive impairment and dementia (VCID). Hypertension is a primary risk factor for CMHs. Vascular smooth muscle cells (VSMCs) adapt to hypertension by undergoing hypertrophy and producing extracellular matrix (ECM) components, which reinforce vessel walls. Myogenic autoregulation, which involves pressure-induced constriction, helps prevent excessive pressure from damaging the vulnerable microvasculature. However, aging impairs these adaptive mechanisms, weakening vessel walls and increasing susceptibility to damage. Insulin-like Growth Factor 1 (IGF-1) is crucial for vascular health, promoting VSMC hypertrophy, ECM production, and maintaining normal myogenic protection. IGF-1 also prevents microvascular senescence, reduces reactive oxygen species (ROS) production, and regulates matrix metalloproteinase (MMP) activity, which is vital for ECM remodeling and stabilization. IGF-1 deficiency, common in aging, compromises these protective mechanisms, increasing the risk of CMHs. This review explores the vasoprotective role of IGF-1 signaling in the cerebral microcirculation and its implications for preventing hypertension-induced CMHs in aging. Understanding and addressing the decline in IGF-1 signaling with age are crucial for maintaining cerebrovascular health and preventing hypertension-related vascular injuries in the aging population.

Vascular Impairment, Muscle Atrophy, and Cognitive Decline: Critical Age-Related Conditions

The triad of vascular impairment, muscle atrophy, and cognitive decline represents critical age-related conditions that significantly impact health. Vascular impairment disrupts blood flow, precipitating the muscle mass reduction seen in sarcopenia and the decline in neuronal function characteristic of neurodegeneration. Our limited understanding of the intricate relationships within this triad hinders accurate diagnosis and effective treatment strategies. This review analyzes the interrelated mechanisms that contribute to these conditions, with a specific focus on oxidative stress, chronic inflammation, and impaired nutrient delivery. The aim is to understand the common pathways involved and to suggest comprehensive therapeutic approaches. Vascular dysfunctions hinder the circulation of blood and the transportation of nutrients, resulting in sarcopenia characterized by muscle atrophy and weakness. Vascular dysfunction and sarcopenia have a negative impact on physical function and quality of life. Neurodegenerative diseases exhibit comparable pathophysiological mechanisms that affect cognitive and motor functions. Preventive and therapeutic approaches encompass lifestyle adjustments, addressing oxidative stress, inflammation, and integrated therapies that focus on improving vascular and muscular well-being. Better understanding of these links can refine therapeutic strategies and yield better patient outcomes. This study emphasizes the complex interplay between vascular dysfunction, muscle degeneration, and cognitive decline, highlighting the necessity for multidisciplinary treatment approaches. Advances in this domain promise improved diagnostic accuracy, more effective therapeutic options, and enhanced preventive measures, all contributing to a higher quality of life for the elderly population.

Asymptomatic carotid artery stenosis is associated with increased Alzheimer's disease and non-Alzheimer's disease dementia risk

BACKGROUND

In the absence of a cerebrovascular accident, whether asymptomatic extracranial carotid atherosclerotic disease (aECAD) affects Alzheimer's disease (AD) and non-AD dementia risk is not clear. Understanding whether aECAD is associated with an increased risk for AD is important as it is present in roughly 10% of the population over 60 and could represent a modifiable risk factor for AD and non-AD dementia.

METHODS

This retrospective cohort study analysed Mariner insurance claims. Enrolment criteria included patients aged 55 years or older with at least 5 years of data and no initial dementia diagnosis. Subjects with and without aECAD were evaluated for subsequent AD and non-AD dementia diagnoses. Propensity score matching was performed using confounding factors identified by logistic regression. χ2 tests and Kaplan-Meier survival curves were used to evaluate the impact of aECAD diagnosis on AD and non-AD dementia risk over time.

RESULTS

767 354 patients met enrolment criteria. After propensity score matching, 62 963 subjects with aECAD and 62 963 subjects without ECAD were followed through data records. The aECAD cohort exhibited an increased relative risk of 1.22 (95% CI 1.15 to 1.29, p<0.001) for AD and 1.48 (95% CI 1.38 to 1.59, p<0.001) for non-AD dementias compared with the propensity score-matched cohort without aECAD. The increased AD risk associated with aECAD was evident in patients younger than 75 years old and was less apparent in patients over 75 years of age.

CONCLUSIONS

aECAD is associated with an increased risk of developing AD and non-AD dementias. These findings underscore the need for further prospective evaluation of interactions between aECAD and dementia, with potential implications for change of clinical care in both of these large patient populations.

Association between the incident hypertension duration and cognitive performance in older adults: data from the NHANES 2011-2014

BACKGROUND

Established evidences have demonstrated that hypertension was associated with the cognitive impairment. But the associations between the duration of hypertension exposure and cognitive performance are still inconclusive.

OBJECTIVES

The objective of this study was to assess the association between the duration of hypertension diagnosis and cognitive performance in older adults by the National Health and Nutrition Examination Survey (2011-2014).

METHODS

To evaluate the relationship between the hypertension duration and cognitive performance, we conducted the logistic regression analysis. Furthermore, we also performed the Restricted cubic spline (RCS) analysis to assess the nonlinear relationship between the duration of exposure to hypertension and cognitive performance.

RESULTS

Initially, total 19,931 participants were included in this study, and 2928 individuals were enrolled. With the increase of hypertension duration, more risk of cognitive impairment was observed in the Digit Symbol Substitution test (DSST) (OR = 1.012, 1.006-1.019), and a similar trend was observed in Animal Fluency test (AFT) (OR = 1.009,1.003-1.016). The RCS results showed that the hypertension duration pattern was linear associated with the risk of cognitive impairment in DDST (P for non-linearity = 0.758). Meanwhile, subgroups analysis of midlife hypertension, we revealed that linear association with the risk of cognitive impairment in DSST (P for non-linearity = 0.391) and CERAD (P for non-linearity = 0.849) among hypertension diagnose < 55 years populations.

CONCLUSION

Collectively, our finding indicates that longer duration of exposure to hypertension worsens the cognition performance, especially for middle-aged hypertension.

Interplay of mitochondrial calcium signalling and reactive oxygen species production in the brain

Intracellular communication and regulation in brain cells is controlled by the ubiquitous Ca2+ and by redox signalling. Both of these independent signalling systems regulate most of the processes in cells including the cell surviving mechanism or cell death. In physiology Ca2+ can regulate and trigger reactive oxygen species (ROS) production by various enzymes and in mitochondria but ROS could also transmit redox signal to calcium levels via modification of calcium channels or phospholipase activity. Changes in calcium or redox signalling could lead to severe pathology resulting in excitotoxicity or oxidative stress. Interaction of the calcium and ROS is essential to trigger opening of mitochondrial permeability transition pore - the initial step of apoptosis, Ca2+ and ROS-induced oxidative stress involved in necrosis and ferroptosis. Here we review the role of redox signalling and Ca2+ in cytosol and mitochondria in the physiology of brain cells - neurons and astrocytes and how this integration can lead to pathology, including ischaemia injury and neurodegeneration.

The promise of molecular science in brain health. What breakthroughs are anticipated in the next 20 years?

Brain health means optimal physiological brain function across the normal life-course. It encompasses not only healthy brain aging but also brain diseases, their diagnosis and treatment. In all these areas, molecular science has advanced our understanding. This multi-disciplinary review combines viewpoints from laboratory science, clinical medicine and the bioscience industry. First, we review the advances that molecular science has brought to brain health in the past twenty years. These include therapeutic antibodies for CNS diseases (multiple sclerosis, Alzheimer disease) and the dramatic introduction of RNA-targeted therapeutics. Second, we highlight areas where greater molecular understanding is needed. Salient examples are the relation of brain structure to cognitive symptoms, and molecular biomarkers for diagnosis, target discovery and testing of interventions. Finally, we speculate on aspects of molecular science that are likely to advance brain health in the next twenty years. These include: cell senescence and chronobiology; gene editing (notably, CRISPR) and RNA targeting (RNA interference, miRNA manipulation); brain-immune interactions; novel drug targets (AQP4, HIF1, Toll-like receptors); and novel chemistry to make new drugs (molecular machines, quantum molecular modelling and "click" chemistry). Early testing of the relationships between molecular pathways and clinical manifestations will drive much-needed breakthroughs in neurology and psychiatry.

A Review: Visuospatial Dysfunction in Patients with the Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) impairs visuospatial function, and this is one of the most obvious areas of cognitive impairment in CSVD. So, recognizing, monitoring, and treating visuospatial dysfunction are all important to the prognosis of CSVD. This review discussed the anatomical and pathological mechanisms, clinical recognition (scales, imaging, and biomarkers), and treatment of cognitive impairment especially visuospatial dysfunction in CSVD.

Saponin components in Polygala tenuifolia as potential candidate drugs for treating dementia

Objective

This study aims to elucidate the intervention effects of saponin components from Polygala tenuifolia Willd (Polygalaceae) on dementia, providing experimental evidence and new insights for the research and application of saponins in the field of dementia.

Materials and Methods

This review is based on a search of the PubMed, NCBI, and Google Scholar databases from their inception to 13 May 2024, using terms such as "P. tenuifolia," "P. tenuifolia and saponins," "toxicity," "dementia," "Alzheimer's disease," "Parkinson's disease dementia," and "vascular dementia." The article summarizes the saponin components of P. tenuifolia, including tenuigenin, tenuifolin, polygalasaponins XXXII, and onjisaponin B, as well as the pathophysiological mechanisms of dementia. Importantly, it highlights the potential mechanisms by which the active components of P. tenuifolia prevent and treat diseases and relevant clinical studies.

Results

The saponin components of P. tenuifolia can reduce β-amyloid accumulation, exhibit antioxidant effects, regulate neurotransmitters, improve synaptic function, possess anti-inflammatory properties, inhibit neuronal apoptosis, and modulate autophagy. Therefore, P. tenuifolia may play a role in the prevention and treatment of dementia.

Conclusion

The saponin components of P. tenuifolia have shown certain therapeutic effects on dementia. They can prevent and treat dementia through various mechanisms.

The pharmacology of antiplatelet agents for primary, secondary, and tertiary prevention of ischemic stroke

INTRODUCTION

Ischemic etiology accounts for two thirds of all strokes in which platelet activation and aggregation play a major role. A variety of antiplatelet therapies have been tested for primary, secondary, and tertiary prevention, with certain patient subtypes benefiting more than others from a specific regimen.

AREAS COVERED

This review aims at synthetizing current evidence on pharmacology of antiplatelet agents approved for primary, secondary, and tertiary stroke prevention and their application among possible patient subtypes that may benefit more from their administration.

EXPERT OPINION

Management of ischemic stroke has largely evolved over the past decades. A better understanding of stroke pathophysiology has allowed to identify patients who can benefit most from antiplatelet therapies, with varying degrees of benefit depending on whether these agents are being used for primary, secondary, or tertiary prevention. Importantly, the antiplatelet treatment regimens currently available have expanded and no longer limited to aspirin but include other drugs such as P2Y12 and phosphodiesterase inhibitors, also used in combination, as well as precision medicine approaches using genetic testing aiming at optimizing the safety and efficacy in this population.

Development and validation of a nomogram predictive model for cognitive impairment in cerebral small vessel disease: a comprehensive retrospective analysis

Background

Cerebral small vessel disease (CSVD) is a common neurodegenerative condition in the elderly, closely associated with cognitive impairment. Early identification of individuals with CSVD who are at a higher risk of developing cognitive impairment is crucial for timely intervention and improving patient outcomes.

Objective

The aim of this study is to construct a predictive model utilizing LASSO regression and binary logistic regression, with the objective of precisely forecasting the risk of cognitive impairment in patients with CSVD.

Methods

The study utilized LASSO regression for feature selection and logistic regression for model construction in a cohort of CSVD patients. The model's validity was assessed through calibration curves and decision curve analysis (DCA).

Results

A nomogram was developed to predict cognitive impairment, incorporating hypertension, CSVD burden, apolipoprotein A1 (ApoA1) levels, and age. The model exhibited high accuracy with AUC values of 0.866 and 0.852 for the training and validation sets, respectively. Calibration curves confirmed the model's reliability, and DCA highlighted its clinical utility. The model's sensitivity and specificity were 75.3 and 79.7% for the training set, and 76.9 and 74.0% for the validation set.

Conclusion

This study successfully demonstrates the application of machine learning in developing a reliable predictive model for cognitive impairment in CSVD. The model's high accuracy and robust predictive capability provide a crucial tool for the early detection and intervention of cognitive impairment in patients with CSVD, potentially improving outcomes for this specific condition.

Utility of cerebrovascular imaging biomarkers to detect cerebral amyloidosis

INTRODUCTION

The relationship between cerebrovascular disease (CVD) and amyloid-β (Aβ) in Alzheimer disease (AD) is understudied. We hypothesized that magnetic resonance imaging (MRI)-based CVD biomarkers, including cerebral microbleeds (CMBs), ischemic infarction, and white matter hyperintensities (WMH), would correlate with Aβ positivity on positron emission tomography (Aβ-PET).

METHODS

We cross-sectionally analyzed data from the Alzheimer's Disease Neuroimaging Initiative (ADNI, N=1,352). Logistic regression was used to calculate odds ratios (ORs), with Aβ-PET positivity as the standard-of-truth.

RESULTS

Following adjustment, WMH (OR=1.25) and superficial CMBs (OR=1.45) remained positively associated with Aβ-PET positivity (p<.001). Deep CMBs and infarcts exhibited a varied relationship with Aβ-PET in cognitive subgroups. The combined diagnostic model, which included CVD biomarkers and other accessible measures, significantly predicted Aβ-PET (pseudo-R 2 =.41).

DISCUSSION

The study highlights the translational value of CVD biomarkers in diagnosing AD, and underscores the need for more research on their inclusion in diagnostic criteria. ClinicalTrials.gov: ADNI-2 ( NCT01231971 ), ADNI-3 ( NCT02854033 ).

Seasonal variability of lesions distribution in acute ischemic stroke: A retrospective study

Seasonal variability could have an impact on the incidence and outcome of stroke. However, little is known about the correlation between seasonal variability and location of acute cerebral infarction. This study aimed to explore the relationship between onset season and the lesions distribution of acute ischemic stroke (AIS). We retrospectively analysis data from 1488 AIS patients admitted to the Second Hospital of Tianjin Medical University from 2018 to 2022. All subjects completed head magnetic resonance imaging examination (MRI) and were divided into four groups according to the onset seasons. The lesions distribution of AIS was evaluated for anterior/posterior/double circulation infarction (DCI), unilateral/bilateral infarctions, and single/multiple cerebral infarctions based on MRI. Logistic regression models were employed to assess the association of season with lesions distribution of AIS. Subgroup analysis was performed in different stroke subtypes. Of 1488 patients, 387 (26.0%) AIS occurred in spring, 425 (28.6%) in summer, 331 (22.2%) in autumn and 345 (23.2%) in winter. Multivariate logistic regression demonstrated that the winter group had 2.15 times (95% CI:1.44-3.21) risk of multiple infarctions, 2.69 times (95% CI:1.80-4.02) of bilateral infarctions and 1.54 times (95% CI:1.05-2.26) of DCI compared with summer group, respectively. Subgroup analysis showed an increased risk of multiple (p < 0.01) or bilateral infarctions (p < 0.01) in small-artery occlusion (SAO) subtype, and higher risk of bilateral infarctions (p < 0.01) or DCI (p < 0.05) in large artery atherosclerosis (LAA) subtype during winter. No significant associations of season with lesions distribution in cardioembolism subtype. Our study highlighted a prominent seasonal variability in the lesions distribution of AIS, particularly in LAA and SAO subtypes. The findings could help to formulating meteorological risk warning strategies for different subtypes.

Limbic-predominant age-related TDP-43 encephalopathy (LATE-NC): Co-pathologies and genetic risk factors provide clues about pathogenesis

Limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) is detectable at autopsy in more than one-third of people beyond age 85 years and is robustly associated with dementia independent of other pathologies. Although LATE-NC has a large impact on public health, there remain uncertainties about the underlying biologic mechanisms. Here, we review the literature from human studies that may shed light on pathogenetic mechanisms. It is increasingly clear that certain combinations of pathologic changes tend to coexist in aging brains. Although "pure" LATE-NC is not rare, LATE-NC often coexists in the same brains with Alzheimer disease neuropathologic change, brain arteriolosclerosis, hippocampal sclerosis of aging, and/or age-related tau astrogliopathy (ARTAG). The patterns of pathologic comorbidities provide circumstantial evidence of mechanistic interactions ("synergies") between the pathologies, and also suggest common upstream influences. As to primary mediators of vulnerability to neuropathologic changes, genetics may play key roles. Genes associated with LATE-NC include TMEM106B, GRN, APOE, SORL1, ABCC9, and others. Although the anatomic distribution of TDP-43 pathology defines the condition, important cofactors for LATE-NC may include Tau pathology, endolysosomal pathways, and blood-brain barrier dysfunction. A review of the human phenomenology offers insights into disease-driving mechanisms, and may provide clues for diagnostic and therapeutic targets.

Hypertension, Neurodegeneration, and Cognitive Decline

Elevated blood pressure is a well-established risk factor for age-related cognitive decline. Long linked to cognitive impairment on vascular bases, increasing evidence suggests a potential association of hypertension with the neurodegenerative pathology underlying Alzheimer disease. Hypertension is well known to disrupt the structural and functional integrity of the cerebral vasculature. However, the mechanisms by which these alterations lead to brain damage, enhance Alzheimer pathology, and promote cognitive impairment remain to be established. Furthermore, critical questions concerning whether lowering blood pressure by antihypertensive medications prevents cognitive impairment have not been answered. Recent developments in neurovascular biology, brain imaging, and epidemiology, as well as new clinical trials, have provided insights into these critical issues. In particular, clinical and basic findings on the link between neurovascular dysfunction and the pathobiology of neurodegeneration have shed new light on the overlap between vascular and Alzheimer pathology. In this review, we will examine the progress made in the relationship between hypertension and cognitive impairment and, after a critical evaluation of the evidence, attempt to identify remaining knowledge gaps and future research directions that may advance our understanding of one of the leading health challenges of our time.

Low Functional network integrity in cognitively unimpaired and MCI subjects with depressive symptoms: results from a multi-center fMRI study

Evidence suggests that depressive symptomatology is a consequence of network dysfunction rather than lesion pathology. We studied whole-brain functional connectivity using a Minimum Spanning Tree as a graph-theoretical approach. Furthermore, we examined functional connectivity in the Default Mode Network, the Frontolimbic Network (FLN), the Salience Network, and the Cognitive Control Network. All 183 elderly subjects underwent a comprehensive neuropsychological evaluation and a 3 Tesla brain MRI scan. To assess the potential presence of depressive symptoms, the 13-item version of the Beck Depression Inventory (BDI) or the Geriatric Depression Scale (GDS) was utilized. Participants were assigned into three groups based on their cognitive status: amnestic mild cognitive impairment (MCI), non-amnestic MCI, and healthy controls. Regarding affective symptoms, subjects were categorized into depressed and non-depressed groups. An increased mean eccentricity and network diameter were found in patients with depressive symptoms relative to non-depressed ones, and both measures showed correlations with depressive symptom severity. In patients with depressive symptoms, a functional hypoconnectivity was detected between the Anterior Cingulate Cortex (ACC) and the right amygdala in the FLN, which impairment correlated with depressive symptom severity. While no structural difference was found in subjects with depressive symptoms, the volume of the hippocampus and the thickness of the precuneus and the entorhinal cortex were decreased in subjects with MCI, especially in amnestic MCI. The increase in eccentricity and diameter indicates a more path-like functional network configuration that may lead to an impaired functional integration in depression, a possible cause of depressive symptomatology in the elderly.

Vascular dementia: From pathobiology to emerging perspectives

Vascular dementia (VaD) is the second most common type of dementia. VaD is synonymous with ageing, and its symptoms place a significant burden on the health and wellbeing of older people. Despite the identification of a substantial number of risk factors for VaD, the pathological mechanisms underpinning this disease remain to be fully elucidated. Consequently, a biogerontological imperative exists to highlight the modifiable lifestyle factors which can mitigate against the risk of developing VaD. This review will critically examine some of the factors which have been revealed to modulate VaD risk. The survey commences by providing an overview of the putative mechanisms which are associated with the pathobiology of VaD. Next, the factors which influence the risk of developing VaD are examined. Finally, emerging treatment avenues including epigenetics, the gut microbiome, and pro-longevity pharmaceuticals are discussed. By drawing this key evidence together, it is our hope that it can be used to inform future experimental investigations in this field.

Association Between Statin Use and Dementia, and Related Mechanisms: A Bibliometric Analysis from 2007 to 2023

Background

Emerging evidence suggests the potential of hydroxymethylglutaryl-coenzyme A (HMG-CoA, statins) as a therapeutic option for dementia.

Objective

The primary objective of this study is to assess the current state of research on statins use in dementia, with a focus on identifying pivotal questions within the field.

Methods

A systemic search for publications on statin use in dementia between 2007 and 2023 was conducted, utilizing the Web of Science Core Collection. The scientific output was analyzed from various perspectives through VOSviewer, CiteSpace, and the bibliometrics website (https://bibliometric.com/).

Results

560 articles authored by 2,977 individuals and 999 institutions across 58 countries were included, which were published in 295 periodicals and cited 21,176 references from 16,424 authors. The annual publication output remained steady, while the number of citations increased consistently. The U.S. and Mayo Clinic emerged as the most significant country and institution, respectively. B. McGuinness and D.L. Sparks were the most eminent authors. Journal of Alzheimer's Disease was the most influential journal. Three sets of keywords and the top 10 references were identified, suggesting pivotal questions within the field.

Conclusions

While statins show promising potential as a treatment option for dementia, their use remains uncertain due to the reported short-term cognitive impairment events and questionable long-term protective effects against dementia. The pivotal question is to ascertain the association between statins and cognition. The mechanisms underlying the effects of statins on cognition are multifaceted. This study provides insights into the current status within the field of statin use in dementia.