Search Results (136)

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

This narrative review examines the effects of caffeine on brain health in older adults, with particular attention to its potential for dependence—an often-overlooked issue in geriatric care. Caffeine acts on central adenosine, dopamine, and glutamate systems, producing both stimulating and rewarding effects that can foster tolerance and habitual use. Age-related pharmacokinetic and pharmacodynamic changes prolong caffeine’s half-life and increase physiological sensitivity in the elderly. While moderate consumption may enhance alertness, attention, and possibly offer neuroprotective effects—especially in Parkinson’s disease and Lewy body dementia—excessive or prolonged use may lead to anxiety, sleep disturbances, and cognitive or motor impairment. Chronic exposure induces neuroadaptive changes, such as adenosine receptor down-regulation, resulting in tolerance and withdrawal symptoms, including headache, irritability, and fatigue. These symptoms, often mistaken for typical aging complaints, may reflect a substance use disorder yet remain under-recognized due to caffeine’s cultural acceptance. The review explores caffeine’s mixed role in neurological disorders, being beneficial in some and potentially harmful in others, such as restless legs syndrome and frontotemporal dementia. Given the variability in individual responses and the underestimated risk of dependence, personalized caffeine intake guidelines are warranted. Future research should focus on the long-term cognitive effects and the clinical significance of caffeine use disorder in older populations. Full article

Background/Objectives: Type 2 diabetes mellitus (T2DM) and Parkinson’s disease (PD) are two highly prevalent chronic conditions that often coexist in older adults. Their interaction may influence clinical outcomes, particularly during external stressors such as the COVID-19 pandemic. This study aimed to assess the prevalence and temporal trends of PD among hospitalized patients with T2DM in Spain (2017–2023), evaluate sex-based differences in clinical characteristics and outcomes, examine the impact of the COVID-19 pandemic, and identify predictors of PD diagnosis and in-hospital mortality (IHM). Methods: We conducted a retrospective, nationwide study using the Spanish National Hospital Discharge Database (RAE-CMBD). Adults aged ≥40 years hospitalized with T2DM were included. PD cases were identified using ICD-10 codes. Joinpoint regression assessed temporal trends, and multivariable logistic regression identified factors associated with PD and IHM. Results: Among 5.1 million T2DM-related hospitalizations, 107,931 (2.41%) involved PD. PD prevalence increased over time, particularly among women. Men accounted for most PD cases and were younger than their female counterparts. Depression and anxiety were more frequent in women and associated with PD in both sexes. IHM peaked at 14.6% in 2020, coinciding with the COVID-19 outbreak. Predictors of IHM included older age, higher comorbidity burden, dementia, and COVID-19 diagnosis. Conclusions: The coexistence of PD and T2DM in hospitalized patients is associated with clinical complexity and increased mortality. Personalized, multidisciplinary care is essential to address sex-specific patterns, psychiatric comorbidities, and vulnerability to systemic stressors. 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

Parkinson’s disease and related synucleinopathies, including dementia with Lewy bodies and multiple system atrophy, are characterised by the pathological aggregation of the α-synuclein (aSyn) protein in neuronal and glial cells, leading to cellular dysfunction and neurodegeneration. This review synthesizes knowledge of aSyn biology, including its structure, aggregation mechanisms, cellular interactions, and systemic influences. We highlight the structural diversity of aSyn aggregates, ranging from oligomers to fibrils, their strain-like properties, and their prion-like propagation. While the role of prion-like mechanisms in disease progression remains a topic of ongoing debate, these processes may contribute to the clinical heterogeneity of synucleinopathies. Dysregulation of protein clearance pathways, including chaperone-mediated autophagy and the ubiquitin–proteasome system, exacerbates aSyn accumulation, while post-translational modifications influence its toxicity and aggregation propensity. Emerging evidence suggests that immune responses and alterations in the gut microbiome are key modulators of aSyn pathology, linking peripheral processes—particularly those of intestinal origin—to central neurodegeneration. Advances in biomarker development, such as cerebrospinal fluid assays, post-translationally modified aSyn, and real-time quaking-induced conversion technology, hold promise for early diagnosis and disease monitoring. Furthermore, positron emission tomography imaging and conformation-specific antibodies offer innovative tools for visualising and targeting aSyn pathology in vivo. Despite significant progress, challenges remain in accurately modelling human synucleinopathies, as existing animal and cellular models capture only specific aspects of the disease. This review underscores the need for more reliable aSyn biomarkers to facilitate the development of effective treatments. Achieving this goal requires an interdisciplinary approach integrating genetic, epigenetic, and environmental insights. Full article

Variants in the GBA1 gene, encoding the lysosomal enzyme glucosylceramidase beta 1 (GCase), are linked to Parkinson’s disease (PD) and Gaucher disease (GD). Heterozygous variants increase PD risk, while homozygous variants lead to GD, a lysosomal storage disorder. Some GBA1 variants impair GCase maturation in the endoplasmic reticulum, blocking lysosomal transport and causing glucosylceramide accumulation, which disrupts lysosomal function. This study explores therapeutic strategies to address these dysfunctions. Using Site-directed Enzyme Enhancement Therapy (SEE-Tx^®), two structurally targeted allosteric regulators (STARs), GT-02287 and GT-02329, were developed and tested in GD patient-derived fibroblasts with relevant GCase variants. Treatment with GT-02287 and GT-02329 improved the folding of mutant GCase, protected the GCase_Leu444Pro variant from degradation, and facilitated the delivery of active GCase to lysosomes. This enhanced lysosomal function and reduced cellular stress. These findings validate the STARs’ mechanism of action and highlight their therapeutic potential for GCase-related disorders, including GD, PD, and Dementia with Lewy Bodies. Full article

Hemerocallis citrina is an herbaceous perennial plant used in Asian cuisine and Traditional Chinese Medicine. Here, we tested the therapeutic potential of extracts (HCE30%, HCE50%, and HCN) in vivo, using models of two human genetic neurodegenerative diseases—Machado–Joseph Disease/Spinocerebellar Ataxia type 3 (MJD/SCA3) and Frontotemporal Dementia with Parkinsonism associated to chromosome 17 (FTDP-17). Chronic treatment with HCE30% extract ameliorated the motor deficits typically observed in these models. Interestingly, we found that the effect on the motor phenotype of the MJD/SCA3 model was dependent on serotonergic signaling and on the action of the HLH-30/TFEB transcription factor, known to regulate the cellular response to amino acid starvation, the autophagy and mitophagy pathways, lysosome localization and biogenesis, exocytosis, and mitochondrial biogenesis. Altogether, our findings reinforce the idea that phytochemicals act through the modulation of serotonergic neurotransmission and introduce a novel layer to the HLH-30/TFEB regulatory network. Thus, it also strengthens the use of these pathways as therapeutic targets for protein-related neurodegenerative disorders and confirms the utility of medicinal plants as a source of innovation in the quest for new therapeutic agents. Full article

Homocysteine, a sulfur-containing amino acid, is an intermediate product during the metabolism of methionine, a vital amino acid. An elevated concentration of homocysteine in the plasma, named hyperhomocysteinemia, has been significantly related to the onset of several diseases, including diabetes, multiple sclerosis, osteoporosis, cancer, and neurodegenerative disorders such as dementia, Alzheimer’s and Parkinson’s diseases. An interaction between metabolic pathways of homocysteine and gut microbiota has been reported, and specific microbial signatures have been found in individuals experiencing hyperhomocysteinemia. Furthermore, some evidence suggests that gut microbial modulation may exert an influence on homocysteine levels and related disease progression. Conventional approaches for managing hyperhomocysteinemia typically involve dietary interventions alongside the administration of supplements such as B vitamins and betaine. The present review aims to synthesize recent advancements in understanding interventions targeted at mitigating hyperhomocysteinemia, with a particular emphasis on the role of gut microbiota in these strategies. The emerging therapeutic potential of gut microbiota has been reported for several diseases. Indeed, a better understanding of the complex interaction between microbial species and homocysteine metabolism may help in finding novel therapeutic strategies to counteract hyperhomocysteinemia. Full article

Sidransky syndrome represents a distinct variant of Parkinson’s disease (PD) that is linked to pathogenic variants in the glucocerebrosidase (GBA1) gene. This disorder exhibits an earlier onset, a more severe course, and a higher dementia prevalence compared to idiopathic PD. While the pathogenesis remains debated between loss-of-function and gain-of-function mechanisms, targeted therapies are emerging. Pharmacological chaperones (PCs), like high-dose Ambroxol, aim to mitigate enzyme misfolding—a primary driver of this disorder—rather than addressing metabolic deficiencies seen in Gaucher disease. Despite failed trials of substrate reduction therapies, current clinical trials with Ambroxol and other PCs highlight promising avenues for disease modification. This commentary advocates for increased awareness of Sidransky syndrome to advance diagnostic strategies, promote genetic testing, and refine targeted treatments, with the potential to transform care for GBA1-related PD and prodromal stages of the disease. Full article

Near-Infrared Spectroscopy (NIRS) is a non-invasive technique that measures the oxygenation variations of brain tissue in response to different stimuli. It has many advantages such as being easy to use, portable, and non-invasive. Several studies over the years have demonstrated the usefulness of NIRS in neurological and neurodegenerative diseases. NIRS remains relatively underutilized in clinical practice. The aim of this brief review was to describe the use of NIRS in neurological and neurodegenerative diseases and how its use can modify clinical, therapeutic, and rehabilitative approaches. A total of 54 relevant articles were selected from the PUBMED research database related to the diagnostic and prognostic role of fNIRS in the main neurological and neurodegenerative diseases; significant outcomes have been reported in a descriptive form with careful considerations. In addition, we excluded studies using fNIRS in co-registration with other neurophysiological techniques. The use of NIRS should be applied even in the field of neurological and neurodegenerative diseases; in dementia, NIRS can aid in differential diagnosis and predict possible evolutions from Mild Cognitive Impairment (MCI) to Alzheimer’s Disease (AD) stage; in stroke, it plays an important role especially in the post-acute phase, giving information about the patient’s chances of recovery; in Parkinson’s Disease (PD), the results showed the important role of cognitive aspects; in epilepsy, NIRS can localize the epileptic focus or potentially predict seizure onset. Full article

Neurodegenerative diseases comprise a group of chronic, usually age-related, disorders characterized by progressive neuronal loss, deformation of neuronal structure, or loss of neuronal function, leading to a substantially reduced quality of life. They remain a significant focus of scientific and clinical interest due to their increasing medical and social importance. Most neurodegenerative diseases present intracellular protein aggregation or their extracellular deposition (plaques), such as α-synuclein in Parkinson’s disease and amyloid beta (Aβ)/tau aggregates in Alzheimer’s. Conventional treatments for neurodegenerative conditions incur high costs and are related to the development of several adverse effects. In addition, many patients are irresponsive to them. For these reasons, there is a growing tendency to find new therapeutic approaches to help patients. This review intends to investigate some phytocompounds’ effects on neurodegenerative diseases. These conditions are generally related to increased oxidative stress and inflammation, so phytocompounds can help prevent or treat neurodegenerative diseases. To achieve our aim to provide a critical assessment of the current literature about phytochemicals targeting neurodegeneration, we reviewed reputable databases, including PubMed, EMBASE, and COCHRANE, seeking clinical trials that utilized phytochemicals against neurodegenerative conditions. A few clinical trials investigated the effects of phytocompounds in humans, and after screening, 13 clinical trials were ultimately included following PRISMA guidelines. These compounds include polyphenols (flavonoids such as luteolin and quercetin, phenolic acids such as rosmarinic acid, ferulic acid, and caffeic acid, and other polyphenols like resveratrol), alkaloids (such as berberine, huperzine A, and caffeine), and terpenoids (such as ginkgolides and limonene). The gathered evidence underscores that quercetin, caffeine, ginkgolides, and other phytochemicals are primarily anti-inflammatory, antioxidant, and neuroprotective, counteracting neuroinflammation, neuronal oxidation, and synaptic dysfunctions, which are crucial aspects of neurodegenerative disease intervention in various included conditions, such as Alzheimer’s and other dementias, depression, and neuropsychiatric disorders. In summary, they show that the use of these compounds is related to significant improvements in cognition, memory, disinhibition, irritability/lability, aberrant behavior, hallucinations, and mood disorders. Full article

Depositions of protein aggregates are typical pathological hallmarks of various neurodegenerative diseases (NDs). For example, amyloid-beta (Aβ) and tau aggregates are present in the brain and plasma of patients with Alzheimer’s disease (AD); α-synuclein in Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA); mutant huntingtin protein (Htt) in Huntington’s disease (HD); and DNA-binding protein 43 kD (TDP-43) in amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and limbic-predominant age-related TDP-43 encephalopathy (LATE). The same misfolded proteins can be present in multiple diseases in the form of mixed proteinopathies. Since there is no cure for all these diseases, understanding the mechanisms of protein aggregation becomes imperative in modern medicine, especially for developing diagnostics and therapeutics. A Multimer Detection System (MDS) was designed to distinguish and quantify the multimeric/oligomeric forms from the monomeric form of aggregated proteins. As the unique epitope of the monomer is already occupied by capturing or detecting antibodies, the aggregated proteins with multiple epitopes would be accessible to both capturing and detecting antibodies simultaneously, and signals will be generated from the oligomers rather than the monomers. Hence, MDS could present a simple solution for measuring various conformations of aggregated proteins with high sensitivity and specificity, which may help to explore diagnostic and treatment strategies for developing anti-aggregation therapeutics. Full article

Background: As the global population ages, the prevalence of neurodegenerative conditions, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), dementia with Lewy bodies, and frontotemporal dementia, continues to rise. Understanding the impact of aging on striatal glucose metabolism is pivotal in identifying potential biomarkers for the early detection of these disorders. Methods: We investigated age-related changes in striatal glucose metabolism using both region of interest (ROI)-based and voxel-wise correlation analyses. Additionally, we employed a normative modeling approach to establish age-related metabolic trajectories and assess individual deviations from these normative patterns. In vivo cerebral glucose metabolism was quantified using a molecular neuroimaging technique, ¹⁸F-FDG PET. Results: Our results revealed significant negative correlations between age and glucose metabolism in the bilateral caudate. Furthermore, the normative modeling demonstrated a clear, progressive decline in caudate metabolism with advancing age, and the most pronounced reductions were observed in older individuals. Conclusions: These findings suggest that metabolic reductions in the caudate may serve as a sensitive biomarker for normal aging and offer valuable insights into the early stages of neurodegenerative diseases. Moreover, by establishing age-specific reference values for caudate glucose metabolism, the normative model provides a framework for detecting deviations from expected metabolic patterns, which may facilitate the early identification of metabolic alterations that could precede clinical symptoms of neurodegenerative processes. Full article

The microvessel neurovascular unit, with its brain endothelial cells (BEC) and blood–brain barrier remodeling, is important in the development of impaired cognition in sporadic or late-onset Alzheimer’s disease (LOAD), which is associated with aging and is highly prevalent in older populations (≥65 years of age). It is also linked with vascular dementia and vascular contributions to cognitive impairment and dementia, including cerebral amyloid angiopathy in neurodegeneration. LOAD is considered to be the number one cause of dementia globally; however, when one considers the role of mixed dementia (MD)—the combination of both the amyloid cascade hypothesis and the vascular hypothesis of LOAD—it becomes apparent that MD is the number one cause. Microvessel BECs are the first cells in the brain to be exposed to peripheral neurotoxins from the systemic circulation and are therefore the brain cells at the highest risk for early and chronic injury. Therefore, these cells are the first to undergo injury, followed by excessive and recurrent wound healing and remodeling processes in aging and other age-related diseases such as cerebrocardiovascular disease, hypertension, type 2 diabetes mellitus, and Parkinson’s disease. This narrative review explores the intricate relationship between microvessel remodeling, cerebral small vessel disease (SVD), and neurodegeneration in LOAD. It also discusses the current understanding of how microvessel dysfunction, disruption, and pathology contribute to the pathogenesis of LOAD and highlights potential avenues for therapeutic intervention. Full article

Alpha-synuclein (α-syn) is a 140-amino-acid, intrinsically disordered, soluble protein that is abundantly present in the brain. It plays a crucial role in maintaining cellular structures and organelle functions, particularly in supporting synaptic plasticity and regulating neurotransmitter turnover. However, for reasons not yet fully understood, α-syn can lose its physiological role and begin to aggregate. This altered α-syn disrupts dopaminergic transmission and causes both presynaptic and postsynaptic dysfunction, ultimately leading to cell death. A group of neurodegenerative diseases known as α-synucleinopathies is characterized by the intracellular accumulation of α-syn deposits in specific neuronal and glial cells within certain brain regions. In addition to Parkinson’s disease (PD), these conditions include dementia with Lewy bodies (DLBs), multiple system atrophy (MSA), pure autonomic failure (PAF), and REM sleep behavior disorder (RBD). Given that these disorders are associated with α-syn-related neuroinflammation—and considering that SARS-CoV-2 infection has been shown to affect the nervous system, with COVID-19 patients experiencing neurological symptoms—it has been proposed that COVID-19 may contribute to neurodegeneration in PD and other α-synucleinopathies by promoting α-syn misfolding and aggregation. In this review, we focus on whether SARS-CoV-2 could act as an environmental trigger that facilitates the onset or progression of α-synucleinopathies. Specifically, we present new evidence on the potential role of SARS-CoV-2 in modulating α-syn function and discuss the causal relationship between SARS-CoV-2 infection and the development of parkinsonism-like symptoms. Full article