Search Results (1,346)

Vitamin D has long been recognized for its role in calcium homeostasis and bone metabolism; however, it is now emerging as an important regulator of central nervous system (CNS) function. Recent evidence suggests that vitamin D signaling contributes to the pathogenesis and progression of several neurodegenerative disorders. Vitamin D exerts neuroprotective effects through multiple mechanisms, including regulation of calcium homeostasis, modulation of immune responses, reduction in oxidative stress, stimulation of neurotrophic factors, and maintenance of blood–brain barrier (BBB) integrity. Vitamin D receptors and metabolizing enzymes are widely distributed across several brain regions, highlighting their direct involvement in neuronal function. This review summarizes the biosynthesis, metabolism, and signaling pathways of vitamin D. It explores its role in neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), stroke, and traumatic brain injury (TBI). Evidence from experimental and clinical studies indicates that vitamin D deficiency is associated with an increased risk and severity of these conditions, while supplementation may provide therapeutic benefits. Full article

Neurodegenerative diseases are characterized by the accumulation of misfolded and aggregation-prone proteins, reflecting a failure of proteostasis. The ubiquitin–proteasome system (UPS), a major pathway for selective intracellular protein degradation, is essential for maintaining neuronal protein homeostasis. Proteasome dysfunction has been implicated in several major neurodegenerative disorders, including Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD), although its extent and mechanisms vary across disease contexts. In this review, we examine current evidence for proteasome dysfunction in neurodegeneration and discuss how disease-associated proteins impair proteasome function through direct inhibition, defective substrate processing, and sequestration into protein aggregates. We also address the contribution of oxidative stress, neuroinflammation, and aging to proteasome dysregulation. Finally, we highlight emerging therapeutic strategies aimed at restoring proteasome function, including pharmacological activation, modulation of proteasome assembly and stability, and targeted protein degradation approaches. Understanding the context-dependent nature of proteasome dysfunction will be important for developing effective proteostasis-based therapies. Full article

Introduction: Vaccination against COVID-19 has been crucial in controlling the pandemic. While side effects are typically mild, rare neurological complications have been reported. This is a case series of ten patients who reported of persistent fasciculations after COVID-19 vaccination. Methods: We describe the clinical presentation and diagnostic work-up of ten patients with new-onset fasciculations in temporal proximity to COVID-19 vaccination. Patients with prior SARS-CoV-2 infection or known alternative causes of fasciculations were excluded. Routine clinical data, including neurological examination, laboratory results, and electrophysiology (electromyography and nerve conduction studies), were analyzed. Results: Ten patients (5 male, 5 female; mean age 42.4 years) reported fasciculations beginning within 6 h to 13 days post-vaccination and persisting for 2–12 months at the time of presentation. Fasciculations were accompanied by additional symptoms such as paresthesia and fatigue. Laboratory results were mostly unremarkable; two patients had positive myositis antibodies without clinical correlates. Electrophysiology was unremarkable in six patients, while fasciculation potentials were detected in four patients. Nine were diagnosed with probable benign fasciculation syndrome (BFS), and one met diagnostic criteria for amyotrophic lateral sclerosis (ALS). Discussion: In this small, retrospective case series, most cases of post-vaccination fasciculations were benign and compatible with BFS. Whether BFS onset was causally linked to vaccination or due to a nocebo effect remains unclear. One patient was diagnosed with ALS, though a causal link remains speculative given the study’s limitations and rarity of similar reports. Larger, prospective studies are needed to validate these observations and explore underlying pathophysiological mechanisms. Full article

The GGGGCC hexanucleotide repeat expansion (HRE) in C9ORF72 was recognized as the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Repeat-associated non-AUG (RAN) translation of the expanded repeat generated dipeptide repeat proteins (DPRs), which disrupted multiple cellular processes and contributed to neurodegeneration. Emerging evidence indicated that disease pathogenesis involved both gain-of-function (GOF) and loss-of-function (LOF) mechanisms. DPR-mediated GOF toxicity induced ribosomal dysfunction, nucleolar stress, proteostatic impairment, and neuronal injury, whereas C9ORF72 LOF disrupted lysosomal and autophagic pathways in microglia, impairing the immune homeostasis. Neuronal injury further promoted the release of damage-associated signals that triggered secondary microglial activations and chronic neuroinflammations. This review summarized current knowledge of DPR biology, microglial dysfunction, and their contributions to disease progression in C9ORF72-associated ALS/FTD. Therapeutic strategies targeting repeated RNA, DPR productions, proteostasis, autophagy, and neuroinflammatory pathways were also discussed. In addition, the potentials of fluid biomarkers, including cerebrospinal fluid poly (GP) and blood neurofilament light chain (NfL), for diagnosis, disease monitoring, and therapeutic assessment were shown. Together, these findings provided important insights into disease mechanisms and potential avenues for improved clinical management. Full article

Patients with neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) frequently lose the ability to communicate through speech or writing. However, their cognitive and sensory functions are often relatively preserved. In Japan, the traditional method known as kuchimoji (mouth-based character communication) enables character-by-character communication using mouth shapes. This method relies heavily on caregiver skill and is challenging to implement consistently. This study introduces KUCHIMOJI, a Japanese text input system that uses mouth-shape recognition to support independent augmentative and alternative communication (AAC) without caregiver assistance. The system employs a lightweight convolutional neural network (MobileNetV2) to classify six mouth shapes. These shapes correspond to five vowels and a closed-lip state. To accommodate diverse user conditions, a multimodal input framework is designed. It supports three operation modes: facial-image-based signal input, button-based input, and key-based direct input. As an initial feasibility study, experiments with ten healthy participants were conducted to evaluate text entry performance in terms of text entry speed (TES) and miss entry rate (MER). Results indicate that the system achieves average input speeds of 3.86, 5.32, and 11.35 characters per minute (cpm) for the facial-image, button, and key-based modes, respectively. It maintains low error rates (2.96–5.05%). These findings suggest that the system offers a flexible trade-off between speed and accuracy depending on the input modality. The proposed approach provides a practical, low-cost, non-contact communication solution. This underscores its potential forpractical assistive communication applications. Full article

Amyotrophic lateral sclerosis (ALS) remains an intractable motor neuron (MN) disease with a growing patient population and few effective treatments. Here, we review how extracellular phosphoglycerate kinase 1 (ePgk1) improves neurite outgrowth of MNs (NOMN) and axonal growth, both in vitro and in vivo. Our group first elucidated a novel non-canonical function of ePgk1 as a cross-tissue mediator between nerve and muscle tissues. We then discovered that neural membranous Enolase 2 (Eno2) serves as a receptor of ligand ePgk1 and that ePgk1-Eno2 interaction suppresses the Rac1-GTP/p-Pak1-T423/p-P38-T180/pMK2-T334/p-Limk1-S323 axis, reducing p-Cofilin and promoting NOMN and axonal growth, finally suggesting that the 419th aspartic acid residue of Eno2 mediates this interaction. In a crucial preclinical step, we truncated two short 16-amino-acid derivatives from Pgk1, FD-1/-2, each mediating neuroprotection comparable to that of full-length 417-amino-acid Pgk1 in ALS animal models, in terms of improvements of innervated neuromuscular junction, MN cell bodies, motor performance, and endpoint prolongation. In this context, we also discuss the opposite function driven by Eno1-plasminogen interaction and by Eno2-ePgk1 interaction; the latter results in unfavorable for tumorigenesis. Unlike intracellular Pgk1 roles, ePgk1 is an extracellular factor with anti-angiogenic properties, further positioning ePgk1 and its FD-1/-2 as promising protein/peptide drugs for ALS treatment. Full article

Motoneurons are under strong pressure to maintain stable motor output throughout an individual life, through homeostatic regulation of their electrical properties. Dysregulated spinal motoneuron excitability has long been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). Recent work in SOD1^G93A mice suggests that the homeostatic response of motoneurons becomes dysregulated as cellular processes are disrupted by the disease, causing fluctuations in motoneuron electrical properties. Yet, few studies directly test whether ALS motoneurons respond differently than wild-type motoneurons to a common chronic perturbation. Here, we used in vivo electrophysiology to test whether motoneurons from pre-symptomatic SOD1^G93A mice modulate excitability differently than wild-type motoneurons in response to the same homeostatic perturbation: chronic inhibition exerted by the benzodiazepine diazepam. Using linear mixed-effects statistical models, we assessed whether diazepam treatment differentially modulated passive properties, firing behavior, spike properties, and/or synaptic inputs in SOD1^G93A versus wild-type motoneurons. We identified a significant genotype × treatment interaction effect selectively for properties related to passive membrane integration and spike initiation, including membrane time constant, peak input resistance, and recruitment current. In contrast, firing gain, spike waveform characteristics, and synaptic inputs were largely unaffected. These findings indicate that sustained inhibitory perturbation selectively triggered overactive intrinsic compensatory mechanisms in SOD1^G93A motoneurons rather than inducing widespread changes in firing or synaptic transmission. Together, our results provide direct evidence for over-active homeostatic control of motoneuron excitability and support a view of motoneuron dysfunction in ALS as a problem of altered feedback regulation rather than simply hyper- or hypo-excitability. Full article

Extracellular vesicles (EVs) have emerged as key mediators of intercellular communication in the brain, with glial cell-derived EVs increasingly recognized for their roles in maintaining brain homeostasis and contributing to the progression of neurodegenerative diseases. By transferring a diverse cargo of bioactive molecules, including proteins, RNAs, and organelles, EVs influence recipient cell behavior and overall brain function. In neurodegenerative conditions, glial EVs can either propagate pathogenic signals or deliver neuroprotective and regenerative cues, depending on their cellular origin and molecular composition. This context-dependent heterogeneity highlights the need for physiologically relevant human models to investigate EVs biology. Human induced pluripotent stem cell (iPSC)-derived glial models provide a disease-relevant platform, as they recapitulate key pathological features of Alzheimer’s disease (AD), Parkinson’s disease (PD) and amyotrophic lateral sclerosis (ALS). When further integrated with brain organoid platforms, these iPSC-based systems enable the generation of three-dimensional environments that closely resemble in vivo EVs dynamics. Importantly, glial EVs can modulate cellular pathways involved in neuronal survival and function. Indeed, their potential to interact with and, under specific experimental conditions, traverse the blood–brain barrier (BBB) has contributed to growing interest in their application for biomarker discovery and therapeutic development. Engineered and patient-specific EVs derived from iPSCs are emerging as promising tools for targeted, cell type-specific, therapeutic approaches, although their clinical applicability still requires further validation. This review discusses the emerging evidence supporting the dual role of iPSC-derived glial EVs in health and disease, underscores the translational potential of iPSC-based platforms for mechanistic studies, and outlines their promise as precision medicine tools for diagnostics and therapy. Full article

Background and Objectives: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease frequently associated with dysphagia and aspiration risk. This study aimed to investigate the relationship between clinical dysphagia assessment tools (EAT-10, GUSS, RSST, and sialorrhea severity) and videofluoroscopic swallowing study (VFSS) findings in patients with ALS. Materials and Methods: This retrospective observational study included 60 patients with ALS classified as spinal-onset (n = 38) or bulbar-onset (n = 22). Relationships between clinical assessments and VFSS findings were analysed using Spearman correlation analysis. Exploratory multivariable regression and receiver operating characteristic (ROC) analyses were performed to evaluate associations and aspiration risk discrimination. Results: Strong negative correlations were observed between PAS–Liquid and RSST and GUSS scores, whereas EAT-10 showed a strong positive correlation (all p < 0.001). ROC analyses demonstrated good discriminative ability for aspiration risk for GUSS (AUC = 0.89), RSST (AUC = 0.88), and EAT-10 (AUC = 0.82). Patients with bulbar-onset ALS demonstrated higher penetration–aspiration severity and lower functional oral intake. Conclusions: Clinical dysphagia assessment tools showed significant associations with instrumental swallowing findings in ALS. GUSS and RSST demonstrated good discriminative ability for aspiration risk and may be clinically useful bedside screening tools. However, instrumental swallowing assessment remains essential whenever feasible. Full article

Neurodegenerative disorders, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), and amyotrophic lateral sclerosis (ALS), arise from highly interconnected molecular and cellular abnormalities that progressively lead to neuronal dysfunction, synaptic failure, and cell death. This review provides a unified framework to understand the interrelated molecular mechanisms driving these diseases, with a focus on identifying key disease-specific intervention nodes. Core contributors include oxidative stress, mitochondrial dysfunction, protein aggregation, neuroinflammation, and emerging roles of peroxisomal dysfunction in redox imbalance, lipid dysregulation, and inflammatory amplification. Single-target therapies often show limited efficacy due to the complex, interconnected nature of these pathways. In contrast, polypharmacology, which targets multiple disease-relevant mechanisms simultaneously, offers a more promising therapeutic strategy. This review critically examines how pathway crosstalk drives neurodegenerative progression, with particular emphasis on mitochondrial–ROS–inflammatory signaling, aggregation–proteostasis failure, synaptic–neuroimmune dysfunction, and gut–brain communication. It evaluates various multi-node intervention strategies, including multi-target-directed ligands (MTDLs), molecular hybrids, natural products, drug repurposing, and nanocarrier-based delivery systems. Advances in network pharmacology, artificial intelligence (AI), bioinformatics, and multi-omics have enhanced the identification of actionable therapeutic nodes, candidate compounds, and brain-targeted delivery platforms. Notably, the NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome and cyclic GMP–AMP synthase (cGAS)—stimulator of interferon genes (STING) pathways—play distinct roles in neuroinflammation, amplifying neuronal damage by releasing inflammatory cytokines and inducing mitochondrial dysfunction. However, successful translation into clinical practice remains constrained by challenges such as blood–brain barrier penetration, patient heterogeneity, and biomarker limitations. The review advocates for a shift towards mechanism-informed, patient-stratified polypharmacological strategies to better address the network pathology of neurodegeneration, despite significant translational hurdles. Full article

Background/Objectives: Amyotrophic Lateral Sclerosis (ALS) is a rare, neurodegenerative disease with complex genetic and environmental determinants. The MTHFR C677T (rs1801133) variant, known for reducing enzymatic activity in the folate cycle, has been implicated in ALS risk, though findings remain inconsistent across diverse populations. Methods: A population-based case–control study was conducted in 248 age-matched individuals to investigate the MTHFR C677T (rs1801133) and ALS susceptibility. Molecular analysis was performed using the polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP). Genetic associations were evaluated under multiple inheritance models, while survival analysis utilized the Kaplan–Meier method to assess the relationship between MTHFR genotypes and patient prognosis. Results: The C677T variant showed a significant association under the codominant and recessive models, suggesting involvement in ALS risk (OR = 4.63; p = 0.01 and OR = 3.92; p = 0.02), respectively. However, stratification by sex demonstrated an association predominantly in women (OR = 7.10, p = 0.02; OR = 5.87, p = 0.04). Additionally, Kaplan–Meier analysis revealed a numerically shorter mean survival time for the mutant genotype compared with wild-type and heterozygous carriers, without statistical significance. Conclusions: Notably, we identified a significant association between the MTHFR C677T (rs1801133) variant and ALS risk, particularly among women. These findings suggest that the mutant (T/T) genotype showed a stronger association, potentially reflecting postmenopausal hormonal influences on one-carbon metabolism and related susceptibility pathways. Full article

Background/Objectives: Weight loss and hypermetabolism are negative prognostic factors in amyotrophic lateral sclerosis (ALS). Ketone bodies (β-hydroxybutyrate, βHB) as high-energy substrates may compensate for this energy deficit, since a ketogenic diet (KD) has been shown to increase survival and stabilize body weight in the SOD1 mouse model. In this case series, we tested exogenous ketone salts (KS), ketone esters (KE), and a KD, in patients with ALS and in healthy subjects to identify novel therapeutic interventions for subsequent clinical studies. Methods: KS (KetoForce^® (KetoSports, Frisco, TX, USA)) were tested in healthy subjects (11.7 g and 15.6 g βHB) and patients (15.6 g βHB 3×/day over 3 days). KE (KE4^® (KetoneAid, Falls Church, VA, USA)) containing 10.0 g βHB were applied in healthy subjects (once) and in patients (3×/day over 2 days). For the KD, KetoCal^® 2.5:1 LQ MCT MF Vanilla (Nutricia, Frankfurt, Germany) was applied via percutaneous endoscopic gastrostomy over four weeks. Regular capillary βHB measurements were conducted, and adverse events were recorded. Results: Between January 2021 and March 2025, we treated nine patients with ALS and two healthy subjects at the Department of Neurology of Ulm University, Germany. KE and KS increased βHB temporarily. However, the elevation was more pronounced following KE (maximum 2.2–2.7 mmol/L vs. 0.8–1.2 mmol/L). The KD increased βHB levels continuously with nighttime fluctuations. No adverse events occurred under KE. KS caused diarrhea in 3/5 patients and 1/2 healthy subjects. The KD was well tolerated, with mild gastrointestinal symptoms occurring in all patients. Conclusions: All ketogenic approaches increased βHB blood levels. While the KD and KE provided good tolerability, KS caused significant gastrointestinal side effects. KD seems to be an interesting candidate for future clinical studies, as it prompted a long-term increase in βHB while providing satisfying tolerability. Since maintaining a KD long-term is difficult for oral-feeding patients, KE may constitute a feasible alternative. Full article

Neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS; Lou Gehrig’s disease), represent a growing global health burden characterized by progressive neuronal loss and functional decline. Despite decades of intensive research, effective disease-modifying therapies remain limited, underscoring the urgent need for innovative therapeutic strategies. This review highlights recent advances in the understanding of disease etiology and emerging treatment approaches, with a particular focus on modalities with translational potential. We discussed novel disease-modifying interventions, including gene and cell therapies, RNA-targeting strategies, and immunotherapies aimed at clearing misfolded proteins such as amyloid-β, tau, and α-synuclein. In parallel, we examined the evolving recognition of neuroinflammation and mitochondrial dysfunction as actionable therapeutic targets, alongside progress in precision medicine and biomarker-guided approaches that enable early diagnosis and individualized treatment. Additionally, we summarized developments in repurposed pharmacological agents, neuroprotective compounds, and lifestyle interventions, emphasizing the importance of integrative, multimodal strategies. Across AD, PD, and ALS, convergent molecular mechanisms, including protein misfolding, oxidative stress, and disrupted proteostasis, present opportunities for cross-disease therapeutic targeting. Finally, we addressed key challenges and future directions, including translating preclinical efficacy into clinical success, optimizing CNS-targeted delivery systems, and navigating ethical considerations surrounding gene editing and stem cell therapies. Full article

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease characterized by progressive loss of motor neurons in the brain and spinal cord. While most cases are sporadic, around 10% are familial. Recent genetic studies show that many apparently isolated cases carry pathogenic mutations, highlighting the importance of penetrance, the probability that a causal mutation manifests clinically. This review focuses on mutation penetrance in ALS (C9orf72, SOD1, TARDBP, FUS genes), its variability across genes, age, and environmental or genetic modifiers, and its implications for genetic counseling. Identification of pathogenic mutations informs the monitoring of relatives and, in some cases, gives access to targeted therapies or clinical trials. Counseling of asymptomatic relatives must consider incomplete penetrance, which can lead to delayed or absent disease manifestation. ALS exists on a clinical and genetic continuum including related disorders, such as frontotemporal dementia, further influencing risk interpretation. Advances in panel, whole-exome and whole-genome sequencing refine our understanding of penetrance and enable precise diagnostics, and potential tailored therapies. Understanding penetrance is therefore essential to translate mutation discovery into informed clinical decisions and genetic counseling in ALS. Full article

Neuromuscular and neurodegenerative (NMND) disorders are diseases that cause progressive damage to the central nervous system leaving patients with symptoms that negatively affect everyday living with death almost inevitable. These include amyotrophic lateral sclerosis (ALS), Lewy body dementia (LBD), and Parkinson’s disease (PD) with cases expected to increase in the future. Intranasally administered stem cell-derived exosomes/secretome have been seen as potential therapeutic options for these disorders in preclinical animal models. This study sought to observe the efficacy of mesenchymal stem cell-derived exosomes/secretome in patients with ALS, LBD, and PD. Based off these preclinical studies, we conducted a case-controlled series experiment with 86 patients with ALS, LBD, or PD, with the independent variable being the treatment and the dependent variable being the clinical response. These patients were recruited and given intranasal instillations of various MSC-derived exosome/secretome products. Subsequent treatments were given to patients who did not have a response to one product. Patients were followed up at one week, one, two, three, and six months post-treatment. Historical external controls were used for comparison to clinical outcomes. There were no serious adverse events in any patient. A total of 67 of 86 (77%) patients showed a positive clinical response to at least one product. Outcomes were strongly associated with greater treatment frequency for ALS and LBD. Intranasal administration of MSC-derived exosome/secretome products were safe, and most patients showed overall improvement with at least one product. Some patients also saw a substantial decrease in the rate of decline compared to historical controls. These results also give rise to the hypothesis: do MSC-derived exosomes/secretome treatments show efficacy in other NMND disorders? The primary limitation of this study is the 6-month follow-up. Full article