Search Results (571)

Motor Neuron Diseases (MNDs) such as Amyotrophic Lateral Sclerosis (ALS), Primary Lateral Sclerosis (PLS), Hereditary Spastic Paraplegia (HSP), Spinal Muscular Atrophy with Respiratory Distress Type 1 (SMARD1), Multisystem Proteinopathy (MSP), Spinal and Bulbar Muscular Atrophy (SBMA), and ALS associated to Frontotemporal Dementia (ALS-FTD), have traditionally been studied as distinct entities, each one with unique genetic and clinical characteristics. However, emerging research reveals that these seemingly disparate conditions converge on shared molecular mechanisms that drive progressive neuroaxonal degeneration. This narrative review addresses a critical gap in the field by synthesizing the most recent findings into a comprehensive, cross-disease mechanisms framework. By integrating insights into RNA dysregulation, protein misfolding, mitochondrial dysfunction, DNA damage, kinase signaling, axonal transport failure, and immune activation, we highlight how these converging pathways create a common pathogenic landscape across MNDs. Importantly, this perspective not only reframes MNDs as interconnected neurodegenerative models but also identifies shared therapeutic targets and emerging strategies, including antisense oligonucleotides, autophagy modulators, kinase inhibitors, and immunotherapies that transcend individual disease boundaries. The diagnostic and prognostic potential of Neurofilament Light Chain (NfL) biomarkers is also emphasized. By shifting focus from gene-specific to mechanism-based approaches, this paper offers a much-needed roadmap for advancing both research and clinical management in MNDs, paving the way for cross-disease therapeutic innovations. Full article

Dementia prevention is a global public health priority, and lifestyle interventions, including nutrition, have gained interest for their potential to maintain cognitive health. Among nutritional interventions, omega-3 polyunsaturated fatty acids (n-3 FA), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been widely studied for their potential to support cognitive health. This systematic review evaluated whether n-3 FA supplementation improves global cognition in cognitively unimpaired older adults. Nineteen randomized controlled trials (RCTs) met inclusion criteria, of which five reported significant improvements in global cognition. A random-effects meta-analysis of 11 placebo-controlled RCTs showed no significant effect (SMD = −0.02, 95% CI: −0.07 to 0.04). Heterogeneity in supplement type, dosage, duration, and outcome measures may have contributed to inconsistent findings and limited comparability. Furthermore, methodological quality of the trials was generally low. While current evidence does not demonstrate a significant effect of n-3 FA supplementation on global cognition, future research should prioritize well-powered, longer-duration RCTs that incorporate biomarker monitoring and more appropriate doses. Clarifying the role of n-3 FA in cognitive aging remains essential for informing nutrition-based dementia prevention strategies. Full article

Background: There is growing interest in the potential role of manganese (Mn) in the development of Alzheimer’s Disease and related dementias (ADRD). Methods: In this nested pilot study of a ferroalloy worker cohort, we investigated the impact of chronic occupational Mn exposure on cognitive function through β-amyloid (Aβ) deposition and multi-omics profiling. We evaluated six male Mn-exposed workers (median age 63, exposure duration 31 years) and five historical controls (median age: 60 years), all of whom had undergone brain PET scans. Exposed individuals showed significantly higher Aβ deposition in exposed individuals (p < 0.05). The average annual cumulative respirable Mn was 329.23 ± 516.39 µg/m³ (geometric mean 118.59), and plasma Mn levels were significantly elevated in the exposed group (0.704 ± 0.2 ng/mL) compared to controls (0.397 ± 0.18 in controls). Results: LC-MS/MS-based pathway analyses revealed disruptions in olfactory signaling, mitochondrial fatty acid β-oxidation, biogenic amine synthesis, transmembrane transport, and choline metabolism. Simoa analysis showed notable alterations in ADRD-related plasma biomarkers. Protein microarray revealed significant differences (p < 0.05) in antibodies targeting neuronal and autoimmune proteins, including Aβ (25–35), GFAP, serotonin, NOVA1, and Siglec-1/CD169. Conclusion: These findings suggest Mn exposure is associated with neurodegenerative biomarker alterations and disrupted biological pathways relevant to cognitive decline. Full article

Background/Objectives: Neurodegenerative proteinopathies, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and dementia with Lewy bodies (DLB), are increasingly prevalent worldwide mainly due to population aging. These conditions are marked by complex etiologies, overlapping pathologies, and progressive clinical decline, with significant consequences for patients, caregivers, and healthcare systems. This review aims to synthesize evidence on the healthcare complexities of major neurodegenerative proteinopathies to highlight current knowledge gaps, and to inform future care models, policies, and research directions. Methods: We conducted a comprehensive literature search in PubMed/MEDLINE using combinations of MeSH terms and keywords related to neurodegenerative diseases, proteinopathies, diagnosis, sex, management, treatment, caregiver burden, and healthcare delivery. Studies were included if they addressed the clinical, pathophysiological, economic, or care-related complexities of aging-related neurodegenerative proteinopathies. Results: Key themes identified include the following: (1) multifactorial and unclear etiologies with frequent co-pathologies; (2) long prodromal phases with emerging biomarkers; (3) lack of effective disease-modifying therapies; (4) progressive nature requiring ongoing and individualized care; (5) high caregiver burden; (6) escalating healthcare and societal costs; and (7) the critical role of multidisciplinary and multi-domain care models involving specialists, primary care, and allied health professionals. Conclusions: The complexity and cost of neurodegenerative proteinopathies highlight the urgent need for prevention-focused strategies, innovative care models, early interventions, and integrated policies that support patients and caregivers. Prevention through the early identification of risk factors and prodromal signs is critical. Investing in research to develop effective disease-modifying therapies and improve early detection will be essential to reducing the long-term burden of these disorders. Full article

Alzheimer’s Disease and Dementia (ADD) progresses along a continuum of cognitive decline, typically from Subjective Cognitive Impairment (SCI) to Mild Cognitive Impairment (MCI) and eventually to dementia. While many studies have focused on classifying these clinical stages, fewer have examined whether brain connectomes encode this continuum in a low-dimensional, interpretable form. Motivated by the hypothesis that structural brain connectomes undergo complex yet compact changes across cognitive decline, we propose a Graph Neural Network (GNN)-based framework that embeds these connectomes into a two-dimensional manifold to capture the evolving patterns of structural connectivity associated with cognitive deterioration. Using attention-based graph aggregation and Principal Component Analysis (PCA), we find that MCI subjects consistently occupy an intermediate position between SCI and ADD, and that the observed transitions align with known clinical biomarkers of ADD pathology. This hypothesis-driven analysis is further supported by the model’s robust separation performance, with ROC-AUC scores of 0.93 for ADD vs. SCI and 0.81 for ADD vs. MCI. These findings offer an interpretable and neurologically grounded representation of dementia progression, emphasizing structural connectome alterations as potential markers of cognitive decline. Full article

Background: The biological mediators for the epidemiologic overlap between osteoporosis and dementia are unclear. We undertook a scoping review of clinical studies to identify genetic and biological factors linked with these degenerative conditions, exploring the mechanisms and pathways connecting both conditions. Methods: Studies selected (1) involved clinical research investigating genetic factors or biomarkers associated with dementia or osteoporosis, and (2) were published in English in a peer-reviewed journal between July 1993 and March 2025. We searched Medline Ovid, Embase, PsycINFO, the Cochrane Library, the Web of Science databases, Google Scholar, and the reference lists of studies following the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-ScR). Results: Twenty-three studies were included in this review. These explored the role of the APOE polymorphism (n = 2) and the APOE4 allele (n = 13), associations between TREM2 mutation and late onset AD (n = 1), and associations between amyloid beta and bone remodeling (n = 1); bone-related biomarkers like DKK1, OPG, and TRAIL as predictors of cognitive change (n = 2); extracellular vesicles as bone–brain communication pathways (1); and the role of dementia-related genes (n = 1), AD-related CSF biomarkers (n = 1), and parathyroid hormone (PTH) (n = 1) in osteoporosis–dementia pathophysiology. Conclusions: Bone-related biomarkers active in the Wnt/β-Catenin pathway (Dkk1 and sclerostin) and the RANKL/RANK/OPG pathway (OPG/TRAIL ratio) present consistent evidence of involvement in AD and osteoporosis development. Reports proposing APOE4 as a causal genetic link for both osteoporosis and AD in women are not corroborated by newer observational studies. The role of Aβ toxicity in osteoporosis development is unverified in a large clinical study. Full article

Background: High-density lipoprotein cholesterol (HDL-C) is known for its cardiovascular and neuroprotective effects, but its association with cognitive function remains unclear, particularly in relation to genetic factors such as apolipoprotein E ε4 (APOE4). We aimed to investigate the association between serum HDL-C levels and cognition and to examine the moderating effect of APOE4 on this relationship. Methods: This cross-sectional study included 196 dementia-free older adults (aged 65–90) recruited from a memory clinic and the community. Cognitive function was assessed across multiple domains using the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) battery. Serum HDL-C levels were measured, and APOE4 genotyping was performed. Multiple linear regression analyses were conducted, adjusting for age, sex, APOE4 status, education, diagnosis, vascular risk, nutritional status, physical activity, and blood biomarkers. Results: Higher HDL-C levels were significantly associated with better episodic memory (B = 0.109, 95% confidence interval [CI]: 0.029–0.189, p = 0.008) and global cognition (B = 0.130, 95% CI: 0.001–0.261, p = 0.049). These associations were significantly moderated by APOE4 status. In APOE4-positive individuals, HDL-C was strongly associated with both episodic memory (B = 0.357, 95% CI: 0.138–0.575, p = 0.003) and global cognition (B = 0.519, 95% CI: 0.220–0.818, p = 0.002), but no such associations were observed in APOE4-negative participants. Conclusions: This study indicates a significant association between serum HDL-C levels and cognitive function, particularly in episodic memory and global cognition, with APOE4 status potentially moderating this relationship. While these findings may suggest a protective role of HDL-C in individuals at increased genetic risk due to APOE4, they should be interpreted with caution given the cross-sectional design. Future longitudinal and mechanistic studies are warranted to clarify causality and potential clinical implications. Full article

Mild cognitive impairment represents a transitional phase between healthy ageing and dementia, including Alzheimer’s disease. Early detection is essential for timely clinical intervention. This study explores the viability of smooth pursuit eye movements (SPEM) as a non-invasive biomarker for cognitive impairment. A total of 115 participants—62 with cognitive impairment and 53 cognitively healthy controls—underwent comprehensive neuropsychological assessments followed by an eye-tracking task involving smooth pursuit of horizontally and vertically moving stimuli at three different speeds. Quantitative metrics such as tracking accuracy were extracted from the eye movement recordings. These features were used to train machine learning models to distinguish cognitively impaired individuals from controls. The best-performing model achieved an area under the ROC curve (AUC) of approximately 68 %, suggesting that SPEM-based assessment has potential as part of an ensemble of eye-tracking based screening methods for early cognitive decline. Of course, additional paradigms or task designs are required to enhance diagnostic performance. Full article

Alzheimer’s disease (AD) is one of the primary dementia causes worldwide. For this reason, there is a need for plasma-based diagnostic biomarkers to facilitate the timely diagnosis of AD. This work synthesizes the current evidence concerning the tau protein p-tau phosphorylated at threonine 217 (p-tau217) as an emerging biomarker, emphasizing its utility in preclinical phases and its potential application in Latin American populations. The findings indicate that p-tau217 has superior sensitivity and specificity compared to classical biomarkers such as p-tau181 and Aβ42. Likewise, its plasma concentration regulates neuropathological progression, as studies by Braak have shown, enabling it to identify alterations from the early stages. In Latin America, studies in Peru, Colombia, and Brazil have shown promising results, albeit with methodological limitations. Some of them have small sample sizes or lack neuroimaging confirmation. Additionally, clinical factors common in the region, such as hypertension, diabetes, or chronic kidney disease, may alter the clinical interpretation. In short, p-tau217 represents a potential non-invasive diagnostic resource. More diverse cohorts are needed to confirm its validity in daily clinical practice. Full article

Canine cognitive dysfunction syndrome (CDS) is a progressive neurodegenerative disorder in aging dogs and serves as a natural model for Alzheimer’s disease in humans. This study evaluated blood biomarkers—amyloid-beta (Aβ40, Aβ42), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP)—for diagnosing and staging CDS and assessed whether combining biomarkers with behavioral questionnaires improves diagnostic reliability. Seventy-seven dogs, including healthy controls and CDS cases, were assessed using the Canine Cognitive Dysfunction Rating Scale (CCDR), Canine Dementia Scale (CADES), and Canine Cognitive Assessment Scale (CCAS). Plasma Aβ40, Aβ42, GFAP, and serum NfL levels were measured via ELISA. While Aβ40, Aβ42, and GFAP were not significantly associated with CDS stage, serum NfL levels were elevated (p < 0.05) across all questionnaires. Receiver operating characteristic (ROC) analyses showed areas under the curve (AUCs) of 0.763 (CCDR), 0.722 (CADES), and 0.777 (CCAS), with cut-off values around 18.28–43.13 pg/mL. NfL shows promise as a blood biomarker correlated with CDS severity. Combining serum NfL measurements with questionnaire assessments may enhance diagnostic accuracy for CDS in veterinary practice. Full article

Background/Objectives: Cognitive impairment often occurs in various parkinsonian syndromes. The course of deficits in cognitive functions ranges from mild cognitive decline to severe deterioration. Affected cognitive domains are also variable. The genetic background of patients exhibiting parkinsonism with concomitant cognitive decline is still elusive. A significant part of current research in Parkinson’s disease and other parkinsonian syndromes is targeted towards the genetic aspects of these disorders. The aim of the present review was to summarize existing studies focusing on the investigation of the interplay between genetic data in parkinsonism and associated cognitive symptoms. Methods: A review of English-language articles published between 2000 and 2024 was conducted, focusing on genetic studies of Parkinson’s disease and atypical parkinsonian syndromes with cognitive decline, using the databases PUBMED, SCOPUS, and EMBASE. Results: We have selected a clinical phenotype-wise assessment of parkinsonian conditions with cognitive deficits, including typical or early-onset Parkinson’s disease, dementia with Lewy bodies, Corticobasal Syndrome, Progressive Supranuclear Palsy, and frontotemporal dementia with parkinsonism. Both typical and atypical parkinsonian syndromes with concomitant cognitive decline were explored. Conclusions: Genetic background likely contributes to the heterogeneity of cognitive impairment in parkinsonian syndromes, with specific mutations linked to distinct cognitive symptoms. The integration of genetic data and a more thorough neuropsychological assessment with clinical, imaging, and biomarkers may enhance diagnosis and enable personalized therapies. Full article

This pilot study explored whether the ceruloplasmin (CP) and ferritin (FT) levels in ocular fluids could serve as biomarkers for early neurodegenerative diseases (Alzheimer’s, Parkinson’s, and other dementias). CP and FT are known to modulate neurodegenerative tissue responses. We analysed aqueous and vitreous samples from 26 patients (8M/18F, aged 60–85) who were undergoing elective vitreoretinal (VR) surgery. Of these, 14 had idiopathic epiretinal membranes (ERMs), 6 had idiopathic macular holes (MH), and 6 were patients with Alzheimer’s disease (AD) who presented with VR disorders (VRDs). CP, FT, and selected neuroinflammatory mediators such as interferon γ (IFN-γ), interleukin (IL-6), vascular endothelial growth factor (VEGF), nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) were quantified. Odds ratio analysis was applied to assess the CP/FT ratio’s association with subretinal drusen. We found distinct CP and FT profiles in VRD samples. In aqueous fluid, the CP increased and the FT decreased in early-stage ERM, which reduced the CP/FT ratio. Similar patterns were observed in vitreous fluid. The CP levels correlated with the VEGF (aqueous), IL-4 (vitreous), NGF, and BDNF levels; FT correlated with IL-6 and NGF. A higher CP/FT ratio was associated with increased risk for neurodegenerative conditions. Our findings support the quantification of CP and FT in ocular fluids as a promising approach for identifying early neurodegenerative changes and suggest that the CP/FT ratio may be linked to drusen imaging and clinical neurodegenerative history. Full article

Background: Research concerning the genetic risk for dementia has recently been headed towards new directions. Novel findings from genome-wide association studies have highlighted the association of Alzheimer’s disease incidence with many gene polymorphisms, apart from the Apolipoprotein-E genotype. The identification of additional genetic risk factors has led to the construction of specific genetic risk scores for dementia, considering many different genetic factors and specific biological pathways related to Alzheimer’s disease. Methods: We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis method, summarizing existing data regarding genetic risk scores for Alzheimer’s disease and dementia, in order to improve the current understanding of the genetic underpinnings of dementia. In specific, five databases (PubMed/MEDLINE, Embase, Scopus, Web of science, and Cochrane Central) were searched using the keywords “genetic risk score”, “Alzheimer’s disease”, and “dementia” with specific inclusion and exclusion criteria. Results: From the 552 articles identified, we finally included 20 studies for the qualitative analysis. These reports were classified in three different categories of genetic scores: “polygenic risk scores (PRSs)” (including 11 studies), “pathway specific polygenic risk scores (p-PRSs)” (5 studies), and “complex genetic risk scores” (4 studies). Conclusions: Existing genetic risk scores have contributed to better dementia prediction and a better understanding of the underlying pathology. Novel approaches integrating multiple polygenic risk scores might ameliorate the accuracy of genetic risk scores. The combination of polygenic risk scores that are specific to related biological pathways or relevant biomarkers is of utmost importance to achieve a better predictive ability. Full article

Background/Objectives: Gamma oscillations (30–100 Hz), which are essential for memory, attention, and cortical synchronization, remain underexplored in Alzheimer’s disease (AD) research. While resting-state EEG studies have predominantly examined lower frequency bands (delta to beta), gamma activity may more accurately reflect early synaptic dysfunction and other mechanisms relevant to AD pathophysiology. AD is a common age-related neurodegenerative disorder frequently associated with altered resting-state EEG (rEEG) patterns. This study analyzed gamma power spectral density (PSD) during eyes-open (EOR) and eyes-closed (ECR) resting-state EEG in AD patients compared to cognitively normal (CN) individuals. Methods: rEEG data from 534 participants (269 CN, 265 AD) aged 40–90 were analyzed. Quantitative EEG (qEEG) analysis focused on the gamma band (30–100 Hz) using PSD estimation with the Welch method, coherence matrices, and coherence-based functional connectivity. Data preprocessing and analysis were performed using EEGLAB and Brainstorm in MATLAB R2024b. Group comparisons were conducted using ANOVA for unadjusted models and linear regression with age adjustment using log₁₀-transformed PSD values in Python (version 3.13.2, 2025). Results: AD patients exhibited significantly elevated gamma PSD in frontal and temporal regions during EOR and ECR states compared to CN. During ECR, gamma PSD was markedly higher in the AD group (Mean = 0.0860 ± 0.0590) than CN (Mean = 0.0042 ± 0.0010), with a large effect size (Cohen’s d = 1.960, p < 0.001). Conversely, after adjusting for age, the group difference was no longer statistically significant (β = −0.0047, SE = 0.0054, p = 0.391), while age remained a significant predictor of gamma power (β = −0.0008, p = 0.019). Pairwise coherence matrix and coherence-based functional connectivity were increased in AD during ECR but decreased in EOR relative to CN. Conclusions: Gamma oscillatory activity in the 30–100 Hz range differed significantly between AD and CN individuals during resting-state EEG, particularly under ECR conditions. However, age-adjusted analyses revealed that these differences are not AD-specific, suggesting that gamma band changes may reflect aging-related processes more than disease effects. These findings contribute to the evolving understanding of gamma dynamics in dementia and support further investigation of gamma PSD as a potential, age-sensitive biomarker. Full article

Background/Objectives: We previously demonstrated that nilotinib can sufficiently enter the brain to pharmacologically inhibit discoidin domain receptors (DDR)-1 in patients with Parkinson’s and Alzheimer’s disease. We primarily hypothesized that nilotinib is safe, and may alter disease-related biomarkers to improve, motor, cognitive and/or behavioral features in dementia with Lewy bodies (DLB). Methods: Forty-three participants were randomized 1:1 into nilotinib, 200 mg, or matching placebo in a single-center, phase 2, randomized, double-blind study. Study drug was taken orally once daily for 6 months followed by one-month wash-out. Results: Of 43 individuals enrolled, 14 were women (33%); age (mean ± SD) was 73 ± 8.5 years. Nilotinib was safe and well-tolerated, and more adverse events were noted in the placebo (74) vs. nilotinib (37) groups (p = 0.054). The number of falls were reduced in the nilotinib (six) compared to placebo (21) group (p = 0.006). Cerebrospinal fluid homovanillic acid, a biomarker of dopamine levels, was increased (p = 0.004), while the ratio of pTau181/Aβ42 was reduced (p = 0.034). The Alzheimer’s Disease Assessment Scale—cognition 14 improved by 2.8 pts (p = 0.037), and no differences were observed in Movement Disorders Society–Unified Parkinson’s Disease Rating Scale parts II and III. However, part I (cognition) improved (p = 0.044) in nilotinib compared to placebo. Conclusions: Nilotinib demonstrates favorable safety, biomarkers, and efficacy outcomes in patients with DLB supporting further trials in DLB or advanced Parkinson’s disease with dementia. Full article