ID: 42350385
Title: Intravenous administration of an engineered AAV9-gene-silencing vector suppresses human SOD1 and extends survival in an ALS mouse model.
Abstract: Adeno-associated virus (AAV)-mediated gene silencing offers a promising strategy for achieving durable therapeutic effects with a single administration. Mutations in the human superoxide dismutase 1 (hSOD1) gene, inherited in an autosomal dominant manner, lead to motor neuron degeneration in amyotrophic lateral sclerosis (ALS)-a fatal neurodegenerative disease with no effective treatment. In this study, we employed AAV9 to deliver to the SOD1G93A ALS mouse model artificial microRNAs targeting SOD1, embedded in dual miR-33 scaffolds driven by the promoter of the human survival motor neuron 1 (hSMN1) gene. A single intravenous injection achieved widespread and sustained suppression of SOD1, preserved α-motor neurons, maintained neuromuscular junctions (NMJs), and improved muscle function. These benefits are translated into significantly improved respiratory function, motor performance, and survival. Therapeutic efficacy was observed both when the treatment was administered pre-symptomatically and during symptomatic stages. Compared with previous AAV-based interventions, the survival benefit achieved in this IV delivery approach is unprecedented, supporting its potential for clinical translation in SOD1-linked ALS and other central nervous system (CNS) diseases caused by gain-of-toxicity gene mutations.

ID: 42351313
Title: A rare missense variant impacting NEK1 kinase function is associated with ALS.
Abstract: Heterozygous truncating loss-of-function (LoF) variants in NEK1 are a known cause of amyotrophic lateral sclerosis (ALS). NEK1 encodes the pleiotropic serine/threonine kinase NIMA-related kinase 1, and prior in vitro studies have implicated kinase dysfunction as the principal pathogenic mechanism underlying NEK1-associated ALS. However, bona fide pathogenic missense variants causally linked to ALS have not previously been reported, leaving this hypothesis unconfirmed. Here, we identify a rare NEK1 missense variant, p.N598S, that co-segregates with disease in a familial ALS pedigree and is enriched in European ALS cohorts. This variant exhibits normal protein expression levels, indicating a functional rather than quantitative defect. Using isogenic human motor neurons, we directly compared the effects of p.N598S with those of the ALS-associated truncating variant p.R812* to delineate disease mechanisms. The p.N598S variant induced pathological phenotypes consistent with NEK1 haploinsufficiency, including increased susceptibility to DNA damage, increased apoptosis, ciliary dysmorphia, and nucleocytoplasmic translocation of TDP-43. Importantly, p.N598S impaired NEK1 kinase activity, and pharmacological inhibition of NEK1 recapitulated the cellular phenotypes observed in both p.N598S- and p.R812*-mutant motor neurons. Collectively, these findings provide strong genetic and functional evidence for a disease-causing role of NEK1 kinase disruption in NEK1-ALS. Our findings provide immediate diagnostic and therapeutic implications, particularly for the functional interpretation of missense variants of uncertain significance and the development of targeted treatment strategies.

ID: 42353064
Title: Chronic Diazepam Reveals Excessive Homeostatic Gain in SOD1G93A Mouse Spinal Motoneurons.
Abstract: 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 SOD1G93A 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 SOD1G93A 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 SOD1G93A 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 SOD1G93A 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.

ID: 42353250
Title: Microglial Dysfunction Induced by C9ORF72 Dipeptide Repeat Proteins: Biomarker and Therapeutic Perspectives.
Abstract: 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.

ID: 42362484
Title: Neuropathological and Molecular Features Associated With a Heterozygous DNAJC7 Mutation in Amyotrophic Lateral Sclerosis.
Abstract: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with unclear molecular mechanisms. Heterozygous protein-truncating variants of DNAJC7, which encode a cochaperone involved in Hsp70/90-mediated protein quality control, are potential risk factors for ALS. However, the neuropathological consequences of heterozygous DNAJC7 mutations are unclear. We aimed to clarify the molecular and neuropathological features associated with a heterozygous DNAJC7 mutation in ALS. We genetically screened 39 Japanese patients with ALS and identified a novel heterozygous frameshift mutation in DNAJC7 (c.157_163del, p.Lys53Ter) in one patient that was neuropathologically diagnosed with Kii ALS. We performed biochemical and neuropathological analyses using postmortem tissues from this patient, from cases of ALS without the mutation and from control cases. In the cases of ALS without DNAJC7 mutation, there was elevation of both DNAJC7 mRNA and protein levels compared with controls. The patient with DNAJC7 mutation showed relatively lower DNAJC7 mRNA and protein levels compared with the nonmutated cases of ALS, although mRNA expression remained relatively higher. DNAJC7 may be upregulated as a protective response against ALS pathogenesis, whereas a heterozygous mutation may attenuate this response. Immunohistochemistry and double immunofluorescence demonstrated partial colocalization of DNAJC7 with phospho-TDP-43-positive neuronal cytoplasmic inclusions, which supports a direct role for DNAJC7 in modulating pathological TDP-43 aggregation. These findings provide neuropathological evidence linking heterozygous DNAJC7 mutation to ALS, demonstrating impaired protein expression and suggesting a loss-of-function mechanism that compromises protective responses to TDP-43 pathology. DNAJC7 may represent a key modulator of ALS pathogenesis and potential therapeutic target.

ID: 42363684
Title: FMRP-Mediated Proteasome Regulation: A Novel Mechanism in ALS Pathology.
Abstract: Amyotrophic Lateral Sclerosis (ALS) is a rare and fatal neurodegenerative disease characterized by the hallmark cytoplasmic accumulation and aggregation of TAR DNA binding protein 43 (TDP-43), which impairs proteasome activity through its interaction with Tankyrase (TNKS). Using molecular and imaging techniques, we have identified a novel role for the Fragile X Mental Retardation Protein (FMRP) in regulating the TNKS/PI31-mediated proteasome activation mechanism in co-operation with TDP-43. Our results demonstrate that depletion of FMRP causes nuclear translocation of TDP-43, reducing cytoplasmic TNKS/TDP-43 co-localization, thereby releasing TNKS in the cytoplasm. Free TNKS gets associated with proteasome inhibitor of 31 kDa (PI31), reversing PI31-mediated inhibition of proteasome assembly, trafficking, and activity. Thus, FMRP regulates proteasome activity by modulating the subcellular distribution of TDP-43. Interestingly, FMRP expression is elevated in specific brain regions and spinal cords of TDP-43A315T transgenic ALS mice that helps more TDP-43 to stay in cytoplasm to sequester more TNKS with it, resulting in proteasome dysfunction in ALS disease system. We have demonstrated for the first time that FMRP can act as a disease modifier for ALS. ALS patients with high FMRP expression in the brain and spinal cord may exhibit more severe protein aggregation due to proteasome dysfunction.

ID: 42364760
Title: The impedance mismatch theory: A non-equilibrium thermodynamic framework for a shared energetic stress pathway in neurodegeneration.
Abstract: Current neurobiological models of Amyotrophic Lateral Sclerosis (ALS), Multiple Sclerosis (MS), and Huntington's Disease (HD) utilize multi-omic interactome analyses to map cascades of proteinopathy. While essential, these approaches often overlook the macroscopic thermodynamic limits of the neural substrate as an information processing system. We propose the Impedance Mismatch Theory, a theoretical biophysical model and quantitative framework for the thermodynamic limits of neural computation, positing that these distinct pathologies converge as a shared energetic stress pathway. We introduce the Neurophysiological Load Index (NLI)-a dimensionless parameter quantifying the mismatch between electrical computational drive, topological network impedance, and the local structural and microvascular dissipation capacity. Drawing on the Pennes Bioheat Transfer Equation and insights from multiplex network theory, we hypothesize that pathology initiates as localized thermal runaway, where resistive metabolic heat exceeds convective blood perfusion and thermal conduction, inducing acute decompensation. We outline cross-translational disease-network mechanisms, address the inverse cancer comorbidity paradox via speculative bioelectric attractor states, and propose falsifiable predictions involving high-resolution in vivo proton magnetic resonance spectroscopy thermometry (1H-MRS-t) and phosphorus-31 magnetic resonance spectroscopy (31P-MRS).

ID: 42371122
Title: Quantification of amyotrophic lateral sclerosis (ALS) disease accumulation with T1-weighted high-resolution magnetic resonance imaging: validation in an independent cohort.
Abstract: Amyotrophic Lateral Sclerosis (ALS) is a progressive neuromuscular disease with multifaceted phenotypic presentation thus obstructing objective disease staging. The D50 disease progression model is a framework to comprehensively dissect biomarker-signals towards their relevance regarding disease accumulation/phase (rD50), or disease aggressiveness (D50). Based on previous findings using 1.5-Tesla Magnetic-Resonance-Imaging (MRI), this study hypothesized that high-resolution MRI markers of Grey-Matter (GM) structural integrity would enable quantification of disease accumulation, independent of aggressiveness. A separate cohort of 75 patients with ALS and 73 Healthy Controls (HC) underwent T1-weighted 3-Tesla MRI. Voxel-Based-Morphometry measured GM and White-Matter (WM) density and Surface-Based-Morphometry assessed Cortical Thickness (CT). Non-parametric Threshold-Free-Cluster-Enhancement with 5000 permutations was applied for inter-group and regression contrasts, whilst correcting for possibly interfering co-variates and applying Family-Wise-Error-adjustment. Compared with HC, the ALS cohort showed widespread decreases of CT and GM/WM density (p < 0.001). These case-control effects were driven by patients scanned during rD50-defined disease Phase 2 (p < 0.001). Within the ALS-cohort, direct Phase 2 versus Phase 1 contrasts revealed spatially-distributed decreases, reflecting higher disease accumulation (p < 0.05). These were independent of disease aggressiveness (and onset-region), as corrected for in the models. Accordingly, all contrasts assessing aggressiveness did not yield significant results. These semi-automated analyses of T1-weighted-images captured disease accumulation related GM structural integrity-loss in this cohort scanned with 3-Tesla MRI, independent of the underlying disease aggressiveness. This principle was validated across different scanners and field strengths, supporting its application for objective and non-invasive staging of patients with ALS, whereby true longitudinal studies are necessary.

ID: 42373582
Title: Unravelling the Significance of Cystatin C and Bunina Bodies in Amyotrophic Lateral Sclerosis Pathogenesis.
Abstract: Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND), is a fatal neurodegenerative disease primarily affecting motor neurons. Two key protein inclusions found in lower motor neurons serve as neuropathological hallmarks of the disease in human tissue: the TDP43-positive inclusion and the cystatin C-positive Bunina body. Despite their diagnostic specificity and presence in most sporadic and familial ALS cases, Bunina bodies remain poorly understood, and their true prevalence is likely underestimated. The co-occurrence of the Bunina body and the TDP43 inclusion may provide valuable insights into the development of TDP43 pathology in ALS. Thorough characterisation of the Bunina body is needed to understand this interplay and the broader pathomechanisms of disease. This review examines our current knowledge of Bunina bodies and the biochemical properties of cystatin C that may promote its aggregation. Sequestration and aggregation of cystatin C into Bunina bodies may diminish its neuroprotective functions, including cysteine protease inhibition, autophagy induction and anti-amyloidogenic activity, thereby contributing to ALS pathogenesis. This review also evaluates findings from human post-mortem tissue and ALS disease models, discussing the value and limitations of these models in the context of Bunina bodies and TDP43 pathology. Finally, we discuss cystatin C's use as a biomarker and its therapeutic potential. A deeper understanding of cystatin C biology, its relationship with TDP43 pathology and improved ALS models will be essential for determining whether targeting cystatin C could provide a viable avenue for future ALS therapies.

ID: 42383305
Title: TDP-43 proteinopathy as a biomarker and therapeutic target in amyotrophic lateral sclerosis.
Abstract: Amyotrophic lateral sclerosis (ALS) is the most common form of adult-onset motor neuron disease, characterised by the degeneration of upper and lower motor neurons. The cytoplasmic aggregation of TDP-43 (TAR DNA-binding protein 43), an RNA-binding protein, is considered a hallmark of ALS pathology, found in nearly all postmortem cases of ALS. TDP-43 is normally primarily nuclear, where it has a widespread role in gene regulation. Mutations, extrinsic stressors, and alterations in RNA homeostasis in ALS lead to nuclear depletion of TDP-43 and the formation of cytosolic TDP-43 aggregates. This causes multiple downstream effects on neuronal function and degeneration as well as gene expression. TDP-43 is a promising target as a biomarker, as it is found to be elevated in the biofluids of ALS patients, and its cytoplasmic aggregation can also be observed in peripheral tissues; however, methodological variability and technical limitations currently preclude the establishment of TDP-43 as a standalone biomarker. There are also promising therapeutic strategies in development targeting TDP-43 pathology, but a critical challenge that remains is achieving a balance between eliminating toxic aggregates and preserving the essential functions of TDP-43. In summary, with further research, considering TDP-43 pathology in ALS gives hope for finding future novel diagnostics and therapeutics for ALS.

ID: 42384233
Title: Genome-wide spectrum of coding DNA variations in Indian patients with amyotrophic lateral sclerosis.
Abstract: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with limited therapies, emphasizing the need for deeper understanding of disease pathogenesis. While more than 40 ALS-associated genes have been identified, their contribution varies significantly across populations and the data from the Indian population remains scarce. We aimed to comprehensively characterize the spectrum of coding DNA variations in ALS-associated genes and identify novel genetic contributors in an Indian cohort. Whole-exome sequencing on 761 ALS patients and 917 in-house healthy controls and repeat-primed PCR for expansions (C9orf72, ATXN2, NOTCH2NLC, NOP56) were performed. Variants were classified using ACMG guidelines, and rare variant association testing was conducted. Overall diagnostic yield was 15.90%, with pathogenic/likely pathogenic variants. Familial ALS showed higher diagnostic yield (36.95%) than sporadic ALS (12.96%). SOD1 dominated familial cases (53.85%), while OPTN, SOD1 and FIG4 were prevalent in sporadic cases. Homozygous SOD1 variants in six patients correlated with juvenile/young onset (< 30 years). C9orf72 expansions (4%) and ATXN2 repeats (1.7%) were identified at frequencies comparable with Asian cohorts. Rare variant analysis identified JAK2 as a novel genome-wide significant signal (FDR = 3.5 × 10-5). This first large-scale genomic survey of Indian ALS patients showed SOD1 being the predominant cause of fALS, while OPTN, FIG4, and other genes drive disease amidst low C9orf72 frequency. The novel JAK2 association suggests a potential neuroinflammatory mechanism, highlighting the importance of studying diverse populations to uncover distinct genetic etiologies.

ID: 42397462
Title: A case study of comprehensive association analysis and risk prediction of amyotrophic lateral sclerosis in a Chinese population.
Abstract: Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease with significant genetic heterogeneity. While large-scale studies have characterized its genetic architecture in European populations, the genetic basis of ALS in the Chinese population remains under-explored. To address this gap, we conducted a comprehensive genetic analysis on a cohort of 40 Chinese individuals (32 ALS patients and 8 controls) using whole genome sequencing. We employed the Phenotype-Covariate Genetic Correlation method to estimate SNP-based heritability on the liability scale and utilized LDAK-KVIK for gene-based association analysis. Our analysis revealed a SNP-based heritability (h2SNP) of approximately 25.1% in this Chinese cohort, with a positive correlation between minor allele frequency and heritability, highlighting the substantial contribution of common variants. Gene-based analysis prioritized candidate risk genes, including MIB1, TMED2, and DOC2B, which implicate ubiquitin-mediated protein degradation and intracellular vesicle trafficking in ALS pathogenesis. In risk prediction models, the BOLT-LMM approach achieved a robust mean Area Under the Curve (AUC) of 0.883. This study provides the first comprehensive estimate of SNP-based heritability in a sequenced Chinese ALS cohort and supports the "polygenic background" hypothesis. The identification of candidate risk genes and the preliminary validation of polygenic risk scoring highlight the potential for future genetic stratification in Chinese patients.

ID: 42407013
Title: Role of the Upper Motor Neuron in the Generation of Fasciculations in Early Disease Stages of Amyotrophic Lateral Sclerosis.
Abstract: The origin of fasciculation potentials (FPs) in the early stages of amyotrophic lateral sclerosis (ALS) remains a subject of debate. We investigated the role of the motor cortex in FP generation by comparing resting FP frequency in the first dorsal interosseous (FDI) muscle before and after motor cortex inhibition induced by continuous theta-burst stimulation (cTBS). We studied patients with early-stage ALS (G1) and a disease-control group (G2) comprising individuals with chronic lower motor neuron (LMN) disorders or benign fasciculation syndrome without upper motor neuron (UMN) involvement. Inclusion required a right FDI strength of MRC grade 4+ or 5. At baseline, we recorded FP frequency and amplitude in the right FDI (3 replicates) and the motor evoked potential (MEP) amplitude. These measures were repeated immediately after cTBS-induced corticomotor inhibition. Statistical significance was set at p < 0.05. Twenty-two patients with ALS (14 men; median age 65.5 years; 72.7% spinal onset) were included, with a median disease duration of 6.4 months and a mean ALSFRS-R score of 44. The control group (G2) consisted of 11 participants. Notably, 50% of the ALS cohort showed no neurogenic features on needle EMG of the right FDI at enrollment. Baseline peripheral and cortical amplitudes and left hemisphere motor thresholds were comparable between groups. After cTBS, MEP amplitudes decreased significantly in both G1 (0.93 vs 0.50 mV, p = 0.02) and G2 (1.23 vs 0.38 mV, p = 0.02). However, a significant reduction in FP frequency (39.5%) occurred only in the ALS group (0.43 vs 0.26 Hz, p < 0.001), whereas no change was observed in G2 (0.60 vs 0.77 Hz, p = 0.14). Patients with ALS with a normal FDI EMG demonstrated an even greater reduction in FP frequency (54.5%). FP amplitudes remained stable across both groups after cTBS. Our findings indicate that in early ALS, LMN excitability is significantly modulated by descending corticospinal input. The reduction in FP frequency after cortical inhibition suggests that FPs in early ALS are driven by a combination of both UMN and LMN hyperexcitability, distinguishing them from fasciculations in other neurogenic disorders.

ID: 42411482
Title: Amyotrophic Lateral Sclerosis as a Systemic Disease: Why Integrative and Microbiome-Focused Approaches Deserve Re-Evaluation.
Abstract: Despite decades of intensive research, therapeutic advances in amyotrophic lateral sclerosis (ALS) remain limited. Increasing evidence suggests that ALS is a multisystem disorder involving motor neuron degeneration, immune dysregulation, skeletal muscle pathology, and gastrointestinal dysfunction, thereby challenging the adequacy of current therapeutic strategies. Complementary and alternative medicine (CAM) approaches are widely used by patients with ALS. However, their efficacy remains controversial owing to limited clinical evidence and methodological limitations. The multicomponent herbal medicine and system-level characteristics of CAM conceptually align with the emerging view of ALS as a multisystemic disease. The involvement of gut microbiome dysbiosis in the pathophysiology of ALS has provided a unifying biological framework linking the peripheral, metabolic, and neuroinflammatory processes. These findings suggest that the combination of CAM and conventional therapy may serve as a potential integrative approach to target gut-brain-muscle interactions and systemic disease pathways. This article highlights critical gaps in the existing evidence and proposes that microbiome-focused, biomarker-driven clinical trials are essential to thoroughly evaluate CAM-based interventions in ALS. Embracing a system-oriented therapeutic framework may help address the complexity of ALS beyond traditional neuron-centered approaches.

ID: 42419740
Title: TOP1MT rs2293925 is an enhancer-active regulatory SNP that shapes mitochondrial R-loop dynamics.
Abstract: Mitochondrial topoisomerase 1 (TOP1MT) regulates mitochondrial DNA (mtDNA) topology during transcription and replication. Perturbed mtDNA maintenance and RNA metabolism have been implicated in neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). Here we show that the common TOP1MT variant rs2293925 (R525W) has enhancer-like activity and is associated with increased mitochondrial R-loops (RNA : DNA hybrids). Tissue-dependent expression, quantitative trait locus analysis, chromatin-state annotation, reporter assays, and allele-specific DNA-protein binding assays support a transcriptional regulatory role for rs2293925. In isogenic cell models, rs2293925 increased TOP1MT mRNA and protein abundance, and this was accompanied by increased mitochondrial R-loop signal. TOP1MT trapping with lamellarin D supported increased TOP1MT-R525W occupancy at mitochondrial control region sites together with enhanced R-loops, consistent with altered TOP1MT-mtDNA interaction and/or increased TOP1MT abundance. Elevated mitochondrial R-loop signal was also detected in a pilot cohort of sporadic ALS samples carrying rs2293925 and in neural stem cells derived from C9orf72-positive ALS patients. These data support a dual-effect model in which rs2293925 increases TOP1MT expression and is associated with altered mitochondrial R-loop dynamics, linking common genetic variation to mitochondrial nucleic acid stress in disease-relevant contexts.

ID: 42430317
Title: Preliminary Investigation of Myoelectric Control of an Assistive Neck Exoskeleton by Individuals with Amyotrophic Lateral Sclerosis.
Abstract: Neck weakness limits head control and quality of life for individuals with Amyotrophic Lateral Sclerosis (ALS). The Utah Neck Exoskeleton can restore neck motion, but current control methods-joystick and gaze tracking-have limited accessibility and reliability. These preliminary offline analyses investigate neck electromyography (EMG) as an alternative control modality from ALS patients. EMG signals were recorded from four male participants with ALS while performing neck flexion/extension, axial rotation, and lateral deviation. The resulting dataset was used to train convolutional neural networks (CNNs) per patient to classify either head position or movement direction from EMG features offline. Position classification significantly outperformed direction classification, with a mean accuracy of 82.5% ± 0.010 across participants. Performance was consistent when controlling one, two, or all three neck degrees of freedom. A subset of participants with sufficient residual motor function also completed neck movements while talking or chewing. Classification accuracy decreased during talking and chewing, although these effects were not statistically significant. Importantly however, training CNNs with diverse data that included periods of talking and chewing improved algorithm robustness across all conditions. These findings suggest that neck EMG signals can reliably predict intended head movements in ALS, even in the presence of weak and often confounding muscle activity. Offline accuracy and real-time computational speed suggest the approach is feasible for future online user-in-the-loop studies. Altogether, this pilot work advances EMG-based assistive technology for individuals with severe motor impairments, laying the groundwork for clinically viable, intuitive control systems.

ID: 42432671
Title: The role of AI-assisted drug repurposing in neurological disorders: a systematic review of validation strategies, challenges and opportunities.
Abstract: Neurological disorders refer to a diverse group of conditions that affect the brain, peripheral nerves, and spinal cord and impair socioemotional, cognitive, motor, and sensory functions. Alzheimer's disease (AD), Multiple Sclerosis (MS), Parkinson's disease (PD), Huntington's disease (HD), and Amyotrophic Lateral Sclerosis (ALS) are some of the well-known neurodegenerative diseases that affect millions of people worldwide. Despite the advanced technologies and nano-drug delivery systems, the success rate of developing drugs for neurological disorders is significantly low. Among several constraints, including gastrointestinal irritation, rapid metabolism, and low stability, the blood-brain barrier (BBB) emerges as one of the key challenges in the development and application of drugs against neurological disorders. These challenges necessitate innovative approaches to develop cost-effective therapeutic strategies. Drug repurposing, the discovery of new therapeutic benefits of existing drugs, is a promising drug discovery approach for discovering potential treatment options for complex neurological disorders. This review aims to explore the advanced and significant progress in drug repurposing for major neurological disorders, including MS, AD, PD, ALS, HD, stroke, and neuropsychiatric conditions. It places an explicit emphasis on discussing the potential role of artificial intelligence (AI)-assisted drug repurposing and understanding of the biological mechanisms in discovering new drugs for these neurological conditions. This also examines current challenges in drug repurposing and provides a critical review of the available opportunities and limitations in AI-assisted drug repurposing.

ID: 42434198
Title: Quantifying motor unit loss prior to functional impairment in muscles affected by amyotrophic lateral sclerosis.
Abstract: The compound muscle action potential (CMAP) scan is a non-invasive method for deriving motor unit number estimates (MUNE) to track disease progression in muscles affected by amyotrophic lateral sclerosis (ALS). It remains to be established whether and how long motor unit loss precedes functional impairment. In 56 patients with ALS, we compared the longitudinal trajectories of MUNE derived from thenar CMAP scans, and fine motor function (FMF) using a functional rating scale. Linear and sigmoidal disease trajectories were modelled from which time differences were estimated between these measures to reach their half-maximum scores. The normalized linear decline per month was 0.02 (95% CI 0.01 to 0.03) for FMF and 0.03 (95% CI 0.03 to 0.04) for MUNE. Half-maximum of FMF was reached after 26.3 months (95% CI 18.9 to 35.1) for the linear model, while MUNE had a shorter time required to reach 50% of its maximum with 13.0 months (95% CI 10.3 to 16.4). The head-to-head comparison between FMF and MUNE showed that MUNE values reached 50% of its maximum 13.1 months (95% CI 7.0-20.8) earlier. Results were similar for sigmoidal disease trajectories. Simulated disease trajectories of MUNE values derived from CMAP scans in muscles affected by ALS indicated that MUNE may reach 50% of its maximum in approximately 60% of the time compared to functional impairment. These explorative findings underscore how neurophysiological measures may be of use for early disease monitoring, with relevance for both care and research settings.

ID: 42436431
Title: "Straddling two worlds": complexities of spousal caregiving in amyotrophic lateral sclerosis during younger middle age.
Abstract: Family support is central to amyotrophic lateral sclerosis (ALS) care. Spouses often assume the role of primary caregiver, facing daily challenges as their partner's needs progressively increase. Younger ALS caregivers appear to have distinct experiences and needs, yet age- or life-stage variations and processes of caregiving are seldom considered in studies of ALS family caregiver experience. We undertook a qualitative study, guided by constructivist grounded theory methodology, to explore the dynamics of family caregiving following an ALS diagnosis in a younger middle-aged family member (≤55 years). Data were coded to identify psychosocial processes, including how family caregivers engage in caregiving. In-depth interviews were conducted with ten spousal caregivers between August 2023 and August 2025. Overall, our theoretical understanding of spousal caregiving for younger middle-aged adults with ALS (YMAs) was captured by the core category 'straddling two worlds,' reflecting how caregivers navigated multiple interconnected dichotomies: present and future, familiar and new norms, current and anticipated losses, and the worlds of the living and the dying. To contend with an uncertain future, caregivers anchored themselves in the present as they navigated a shifting sense of normalcy. Middle age expectations and social norms shaped how caregivers engaged in caregiving and experienced losses that were often unending and ambiguous. Caregiving for a spouse with ALS in younger middle age involves temporal, practical, emotional, and existential processes. Caregivers of YMAs may benefit from interventions that help them tolerate uncertainty, stay grounded in the present, maintain normalcy, and grieve losses throughout the caregiving trajectory.