Search Results (328)

The focal “hot spot” neuropathologies in COVID-19 infection are revealing footprints of a hidden underlying collapse of a novel ultrafast ultradian Piezo2 signaling system within the nervous system. Paradoxically, the same initiating pathophysiology may underpin the systemic findings in COVID-19 infection, namely the multiorgan SARS-CoV-2 infection-induced vascular pathologies and brain–body-wide systemic pro-inflammatory signaling, depending on the concentration and exposure to infecting SARS-CoV-2 viruses. This common initiating microdamage is suggested to be the primary damage or the acquired channelopathy of the Piezo2 ion channel, leading to a principal gateway to pathophysiology. This Piezo2 channelopathy-induced neural switch could not only explain the initiation of disrupted cell–cell interactions, metabolic failure, microglial dysfunction, mitochondrial injury, glutamatergic synapse loss, inflammation and neurological states with the central involvement of the hippocampus and the medulla, but also the initiating pathophysiology without SARS-CoV-2 viral intracellular entry into neurons as well. Therefore, the impairment of the proposed Piezo2-induced quantum mechanical free-energy-stimulated ultrafast proton-coupled tunneling seems to be the principal and critical underlying COVID-19 infection-induced primary damage along the brain axes, depending on the loci of SARS-CoV-2 viral infection and intracellular entry. Moreover, this initiating Piezo2 channelopathy may also explain resultant autonomic dysregulation involving the medulla, hippocampus and heart rate regulation, not to mention sleep disturbance with altered rapid eye movement sleep and cognitive deficit in the short term, and even as a consequence of long COVID. The current opinion piece aims to promote future angles of science and research in order to further elucidate the not entirely known initiating pathophysiology of SARS-CoV-2 infection. Full article

Background: People with post-stroke cognitive impairment (PSCI) are at increased risk of recurrent stroke, dementia, and accelerated cognitive decline. Objective: To examine the feasibility, safety, acceptability, and suitability of a virtually-delivered vascular risk reduction intervention that integrates tailored cognitive strategy training for people with executive function (EF) impairments post-stroke. Methods: This case series included eight participants who completed up to ten virtual sessions focused on vascular risk reduction and metacognitive strategy training. Sessions averaged 40 min over a 4–5-week period. Results: The intervention was found to be feasible, safe, and acceptable. The recruitment rate was 66.7%, and the retention rate was 87.5% (7 of 8 completed the training). No serious adverse events were reported. Most participants demonstrated improvements on the Canadian Occupational Performance Measure (COPM), with mean performance and satisfaction change scores of 1.22 ± 0.87 and 1.18 ± 0.83, respectively. Conclusions: This technology-enabled intervention was feasible and acceptable for individuals with post-stroke EF impairments. Virtual delivery was a key factor in its accessibility and success. The results are promising for improving self-management of vascular risk factors, warranting further study in larger trials. Full article

Alzheimer’s disease (AD) is associated with an abnormal accumulation of amyloid β (Aβ) fibrils in the brain parenchyma and cerebrovasculature, which leads to cognitive impairment and cerebrovascular dysfunction. Cerebrovascular endothelial cells play a crucial role in regulating cerebral blood flow, vascular permeability, and neurovascular function. Reactive oxygen species (ROS), particularly those generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), contribute to vascular dysfunction and amyloid deposition in the Alzheimer’s disease (AD) brain. However, the role of the NOX4 isoform in AD pathogenesis remains to be examined. In the present study, we found that NOX4 among the NOX isoforms is predominantly expressed in bEnd.3 mouse brain endothelial cells. Treatment with Aβ₄₀ significantly enhanced the release of H₂O₂ and NO, and increased the endothelial cell viability. To test the involvement of NOX4 in Aβ₄₀-induced H₂O₂ production, we utilized pharmacological inhibitors of NOX isoforms. Aβ₄₀-induced H₂O₂ production was attenuated in the presence of the pan-NOX inhibitor, apocynin, or the NOX1/4-selective inhibitors, setanaxib and GKT136901. Since only the NOX4 isoform is expressed in bEnd.3 cells, these results indicate that NOX4 is responsible for the release of H₂O₂ stimulated by Aβ₄₀. Taken together, the present study demonstrated that Aβ₄₀ peptide exerts beneficial effects in bEnd.3 endothelial cells via the NOX4-dependent mechanism. Full article

(1) Background: In the absence of locally validated tools, the CHA2DS2-VA score has been suggested as a substitute for the CHA2DS2-VASc score. This study compared the potential discrepancies between these scores. (2) Methods: The observational, retrospective, and community-based study included a cohort of 3370 patients with a new diagnosis of atrial fibrillation (AF) between 1 January 2015 and 31 December 2024. (3) Results: AF prevalence was 8.4%, which was significantly higher in men. The mean age was 80.1 (SD ± 6.24) years. Women (42.8%) were older (80.9 SD ± 6.1 vs. 79.5 SD ± 6.23; p < 0.001). Men had more instances of diabetes mellitus, peripheral vascular disease, coronary artery disease, and chronic obstructive pulmonary disease, as well as a higher Charlson Comorbidity Index. Conversely, women exhibited a higher proportion ≥75 years, including cognitive impairment, dyslipidemia, and higher stroke risk, as assessed by the CHA2DS2-VASc score (p < 0.001) but not by the CHA2DS2-VA score (p = 0.071). The CHA2DS2-VA score reduced the sex-based risk stratification differences, and only 3.2% of women were reclassified as being at very low risk (CHA2DS2-VA < 2). (4) Conclusions: The CHA2DS2-VA score notably redefined sex-based thromboembolic risk stratification profiles, with no sex-based disparities in the selection of OAC treatment modality. The clinical utility of CHA2DS2-VA remains a subject of ongoing debate. Full article

Background: Primary aldosteronism is characterized by elevated aldosterone levels, leading to adverse effects such as hypertension, hypokalaemia and increased risk for cardiovascular and cerebrovascular events. Aldosterone impacts the central nervous system by promoting vascular remodelling and oxidative stress, potentially impairing cognitive function. The presence of mineralocorticoid receptors in the hippocampus, a key region for cognition, further suggest a link between primary aldosteronism and cognitive dysfunction. This study aims to further explore the association between hyperaldosteronism and cognitive impairment. Methods: In this pilot study we examined 15 individuals with primary aldosteronism and arterial hypertension alongside 15 age- and sex-matched controls with essential hypertension, all free of previous cerebrovascular events. Clinical and archival laboratory data were obtained. Cognitive function was assessed using the Mini-Mental State Examination and Montreal Cognitive Assessment. Results: Participants with primary aldosteronism had higher blood pressure values, longer duration of hypertension, lower serum potassium levels and higher 24 h urine albumin excretion rate compared to controls. Comorbidities, other characteristics and laboratory values were comparable across the two groups. No differences were observed in Mini-Mental State Examination scores, but Montreal Cognitive Assessment scores were significantly lower in the primary aldosteronism group (25.1 ± 2.2 vs. 27.1 ± 2.2, p = 0.021). Trends of poorer performance in language and attention/executive function domains were noted in primary aldosteronism individuals, as well as a higher number of pathological Montreal Cognitive Assessment scores (7 vs. 3). No significant correlations were found between cognitive test results and aldosterone concentrations or blood pressure in primary aldosteronism group. However, importantly, multiple regression analysis showed that aldosterone levels have a significant impact on Montreal Cognitive Assessment test, independent of blood pressure or duration of hypertension. Conclusions: This study supports an association between hyperaldosteronism and cognitive dysfunction, underscoring the need for more active detection and targeted treatment of primary aldosteronism. These findings warrant further research in larger cohorts to better elucidate this relationship. Full article

Background: Type 2 diabetes is linked to impaired cognitive function, but the underlying mechanisms remain poorly understood. As white matter hyperintensities (WMHs) are common in diabetes and associated with vascular brain injury, we investigated whether WMH burden mediates the relationship between hemoglobin A1c (HbA1c) levels and cognition. Methods: We quantified WMH load using the Fazekas scale and conducted a mediation analysis with HbA1c as the independent variable, Fazekas scale as the mediator, and MoCA scores as the outcome variable. Results: WMHs partially mediated the relationship between HbA1c levels and MoCA scores (indirect effect = −0.224, 95% CI = −0.619 to −0.050, p = 0.001), accounting for approximately 15.6% of the total effect. Conclusions: This study suggests that WMHs partially mediate the association between chronically elevated blood glucose levels and cognitive impairment in neurologically healthy adults, supporting a potential microvascular mechanism in diabetes-related cognitive impairment. Full article

Background: With an aging population, dementia prevalence is increasing in Korea. Vascular dementia (VaD), often caused by cerebrovascular disease (CVD), is more common in Korea compared to Western countries. Hwanhon decoction, a traditional medicine containing Ephedrae Herba, Armeniacae Semen, and Glycyrrhizae Radix et Rhizoma, is traditionally used for CVD-related loss of consciousness. This study aimed to assess the cognitive improvement and anti-inflammatory effects of Hwanhon decoction extract (HHex) in a mouse model of VaD caused by chronic cerebral hypoperfusion (CCH). Methods: Key pharmacologically active ingredients of Hwanhon decoction were identified using network pharmacology analysis. VaD was induced in C57Bl/6 male mice through bilateral common carotid artery stenosis (BCAS). Mice were divided into sham surgery, BCAS control, low-dose HHex (L-HHex), and high-dose HHex (H-HHex) groups (n = 5/group). After CCH induction, L-HHex or H-HHex was administered thrice weekly for six weeks. Cognitive function, inflammatory markers, and RNA sequencing data were analyzed. Results: HHex administration reduced cognitive impairment and mitigated CCH-induced astrocyte activation. Inflammatory responses mediated by reactive astrocytes were suppressed, and network pharmacology predicted central proteins influencing HHex’s activity. Conclusions: HHex alleviated cognitive dysfunction and reduced inflammation in a VaD mouse model, suggesting its potential as a therapeutic agent for vascular dementia associated with impaired cerebral blood flow. Full article

Rhamnan sulfate (RS), extracted from the seaweed Monostroma nitidum, suppresses vascular endothelial inflammation and arteriosclerosis, decreases blood glucose levels, and improves blood lipid metabolism and the intestinal environment. We examined whether RS improves hyperglycemia-induced cognitive decline in a hyperglycemic mouse model pretreated with nicotinamide and streptozotocin and then orally administered a high-fat diet and maltodextrin (MD) for 4 months. RS was administered in an MD solution at doses of 75, 225, and 750 mg/kg of mouse body weight. Administration of RS to hyperglycemic mice significantly reduced blood glucose levels and tended to improve memory function in behavioral pharmacological tests using spontaneous locomotor activity, rotarod test, and eight-way-maze test, although the results were not significant. Brain histopathological analysis showed that RS significantly reduced atrophy of neuronal layers in each region of the hippocampus compared with untreated hyperglycemic controls. RS also significantly suppressed TNF-α expression and microglial activation in the brain. These results suggest that RS intake suppresses inflammation in the brain and alleviates the cognitive impairment associated with hyperglycemic diabetes. Full article

SARS-CoV-2 can cause neurological issues, including cognitive dysfunction in COVID-19 survivors. Endothelial dysfunction, a key mechanism in COVID-19, is also a risk factor for vascular dementia (VaD). Reduced nitric oxide (NO) bioavailability is a pathogenic factor of endothelial dysfunction and platelet aggregation in COVID-19 patients, and endothelial NO synthase (eNOS) levels decline with advancing age, a risk factor for both COVID-19 morbidity and VaD. SARS-CoV-2 also induces cellular senescence and senescence-associated secretory phenotype (SASP). We hypothesized that eNOS deficiency would worsen neuroinflammation, senescence, blood–brain barrier (BBB) permeability, and hypercoagulability in eNOS-deficient mice. Six-month-old eNOS^+/− (pre-cognitively impaired experimental VaD) and wild-type (WT) male mice were infected with mouse-adapted (MA10) SARS-CoV-2. Mice were evaluated for weight loss, viral load, and markers of inflammation and senescence 3 days post-infection. eNOS^+/− mice showed more weight loss (~15%) compared to WT mice (~5%) and increased inflammatory markers (Ccl2, Cxcl9, Cxcl10, IL-1β, and IL-6) and senescence markers (p53 and p21). They also exhibited higher microglial activation (Iba1) and increased plasma coagulation and BBB permeability, despite comparable lung viral loads and absence of virus in the brain. This is the first experimental evidence demonstrating that eNOS deficiency exacerbates SARS-CoV-2-induced morbidity, neuroinflammation, and brain senescence, linking eNOS to COVID-19-related neuropathology. Full article

Background: Toxic oil syndrome (TOS) was a major food-borne epidemic that occurred in Spain in May 1981, caused by the ingestion of rapeseed oil adulterated with aniline. While the somatic sequelae of TOS have been well documented, its long-term cognitive consequences remain poorly understood more than four decades after exposure. Methods: In this case-control study, 50 individuals with clinically confirmed TOS were compared to 50 healthy controls matched for age, sex, and education. All participants completed a comprehensive neuropsychological assessment, along with questionnaires evaluating fatigue, anxiety, depression, and health-related quality of life. Multivariate regression models were adjusted for demographic and vascular risk factors, as well as for mood symptoms, fatigue, and use of central nervous system-acting medications. Structural equation modeling was used to explore the potential mediating effects of affective and fatigue symptoms on cognitive performance. Results: TOS survivors showed significantly poorer performance than controls in attention, executive function, processing speed, and global cognition after adjusting for demographic and vascular risk factors. However, these differences were no longer statistically significant after additional adjustment for fatigue, depression, anxiety, and central nervous system-acting medications. Structural equation modeling analyses revealed that affective symptoms—particularly fatigue—substantially mediated the relationship between TOS and cognitive performance. Conclusions: The cognitive profile observed mirrors that of disorders characterized by subcortical dysfunction and impaired neural connectivity, such as multiple sclerosis and vascular cognitive impairment. Although early postmortem studies in TOS did not demonstrate overt white matter lesions, our findings raise the possibility of long-lasting alterations involving both white and gray matter networks. These results emphasize the need to consider mood and fatigue symptoms when evaluating cognition in TOS survivors and point to the potential for widespread, enduring neurobiological effects stemming from the original toxic exposure. Full article

Cognitive dysfunction represents one of the most persistent and disabling features of Long COVID, yet its molecular underpinnings remain incompletely understood. This narrative review synthesizes current evidence on the pathophysiological mechanisms linking SARS-CoV-2 infection to long-term neurocognitive sequelae. Key processes include persistent neuroinflammation, blood–brain barrier (BBB) disruption, endothelial dysfunction, immune dysregulation, and neuroendocrine imbalance. Microglial activation and cytokine release (e.g., IL-6, TNF-α) promote synaptic dysfunction and neuronal injury, while activation of inflammasomes such as NLRP3 amplifies CNS inflammation. Vascular abnormalities, including microthrombosis and BBB leakage, facilitate the infiltration of peripheral immune cells and neurotoxic mediators. Hypothalamic–pituitary–adrenal axis dysfunction and reduced vagal tone further exacerbate systemic inflammation and autonomic imbalance. Biomarkers such as GFAP, NFL, IL-6, and S100B have been associated with both neuroinflammation and cognitive symptoms. Notably, transcriptomic signatures in Long COVID overlap with those observed in Alzheimer’s disease, highlighting shared pathways involving tau dysregulation, oxidative stress, and glial reactivity. Understanding these mechanisms is critical for identifying at-risk individuals and developing targeted therapeutic strategies. This review underscores the need for longitudinal research and integrative biomarker analysis to elucidate the molecular trajectory of cognitive impairment in Long COVID. Full article

Background/Objectives: Glaucoma and Alzheimer’s disease (AD) are neurodegenerative conditions with vascular underpinnings. This study aimed to explore the relationship between blood pressure parameters such as mean arterial pressure (MAP), pulse pressure (PP), and cerebral perfusion pressure (CPP) and cognitive performance in patients with AD, normal-tension glaucoma (NTG), and healthy controls. We hypothesized that NTG patients, like those with mild cognitive impairment (MCI), may experience subtle cognitive changes related to vascular dysregulation. Methods: Ninety-eight participants (35 NTG, 17 AD, 46 controls) were assessed for CPP, MAP, OPP, and cognitive performance. Statistical analyses compared groups and examined correlations. Results: AD patients showed lower CPP and MAP (p < 0.001), indicating systemic vascular dysfunction, while NTG patients had higher ocular perfusion pressure (OPP) (p = 0.008), suggesting compensatory mechanisms. CPP correlated with visuospatial abilities in AD (r = 0.492, p = 0.045). MAP correlated with the Clock drawing test (CDT) scores in the NTG group (r = 0.378, p = 0.025). PP negatively correlated with cognition in AD (r = −0.527, p = 0.016 for CDT scores) and controls (r = −0.440, p = 0.002 for verbal fluency and r = −0.348, p = 0.019 for total ACE scores). Conclusions: The study highlights distinct hemodynamic profiles: systemic dysfunction in AD and localized dysregulation in NTG. These findings emphasize the role of vascular dysregulation in neurodegeneration, with implications for personalized treatment approaches targeting vascular health in neurodegenerative conditions. Full article

Background: Post-stroke cognitive impairment (PSCI) remains under-recognized in Sub-Saharan Africa (SSA), in part due to the lack of validated cognitive screening tools adapted to low-literacy populations. We aimed to validate the Identification of Dementia in Elderly Africans (IDEA) cognitive screen in SSA and assess its utility for detecting PSCI in Guinea and Cameroon. Methods: Normative IDEA scores were derived from a control cohort of healthy older adults in Conakry (Guinea) and Bafoussam (Cameroon). The tool was then applied to consecutive stroke patients from the same hospitals within one month of stroke onset. Demographic, clinical, and vascular risk profiles were collected. Between-group comparisons were performed using Welch’s t-tests and chi-square tests. Results: Among 91 healthy controls (median age: 64), the mean IDEA score was 12 ± 2.4. A cut-off of ≤7 (2 standard deviations below the mean) was defined for cognitive impairment. Among 111 stroke patients (median age: 65; mean NIHSS: 9.9 ± 5.8), the mean IDEA score was 9.6 ± 3.2, and 31 patients (28%) had scores ≤ 7. Stroke patients had significantly higher rates of hypertension and diabetes compared to controls. Conclusions: The IDEA screen appears to be a feasible and effective tool for detecting PSCI in SSA clinical settings. The 28% prevalence of cognitive impairment aligns with data from high-income countries, supporting the broader use of the IDEA to strengthen cognitive care pathways in SSA stroke populations. Full article

Background/Objectives: The interplay between the gut microbiome (GMB) and neurovascular function in neurodegeneration is unclear. The goal of this proof-of-concept, cross-sectional study is to identify relationships between the GMB, neurovascular functioning, and cognition in amnestic mild cognitive impairment (aMCI), the prototypical prodromal symptomatic stage of Alzheimer’s disease (AD). Methods: Participants (n = 14 aMCI and 10 controls) provided fecal samples for GMB sequencing (16S and shotgun metagenomics), underwent MRI, and completed cognitive testing. Cerebral vascular reactivity (CVR), cerebral blood flow (CBF), and arterial transit time (ATT) were assessed. Statistical analyses evaluated the relationships between discriminatory taxa, cerebrovascular metrics, and cognition. Results: Sequencing revealed differentially abundant bacterial and viral taxa distinguishing aMCI from controls. Spearman correlations revealed that bacteria known to induce inflammation were negatively associated with CVR, CBF, and cognition, and positively associated with ATT. A reciprocal pattern emerged for the association of taxa with gut health. Conclusions: Our results provide preliminary evidence that pro-inflammatory gut bacterial and viral taxa are associated with neurovascular dysfunction and cognitive impairment in prodromal AD, highlighting their potential as candidate microbial biomarkers and targets for early intervention. Full article

Objectives: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) comprises rare systemic vasculitides that can present with cognitive dysfunction. However, data on the screening and characterization of cognitive dysfunction in AAV remain limited. Methods: Cognitive complaints in AAV patients were screened using self-report questionnaires. Objective cognitive impairment was assessed with a standardized neurocognitive test battery. Results were compared with clinical evaluations, brain MRI findings, treatment history, and neuropsychiatric symptoms. All test results were standardized for the overall population. Results: Twelve patients (five women, seven men) with a median [IQR] age of 68 [59–71] and a median [IQR] disease duration of 92 months [55–127] were included. None of the patients showed evidence of vasculitis activity on brain MRI. Cognition was assessed using a standardized neurocognitive test battery in all patients except one. Four patients (36%) were found to have cognitive impairment, defined as three or more altered tests. The most affected functions were attentional and executive, with the d2-R (4/4), Rey–Osterrieth Complex Figure Delayed Recall (3/4), and Trail Making Test Part B (3/4) showing the most frequent deficiencies. Objective cognitive disorders were not associated with self-reported cognitive complaints. No significant association was found between cognitive impairment and vasculitis activity or sequelae, corticosteroid and immunosuppressive treatments, or neuropsychiatric symptoms. Conclusions: This study highlights the presence of cognitive impairments in AAV, predominantly affecting attentional and executive functions, which may reflect vascular involvement. Early and tailored approaches to cognitive screening and management are essential to improve patient care and quality of life. Full article