BACKGROUND:This study aimed at identifying neuropsychological sub-phenotypes in amyotrophic lateral sclerosis (ALS) within the mild cognitive impairment (MCI) and mild behavioral impairment (MBI) frameworks. METHODS:We used individual task-/item-level data from the cognitive and behavioral sections of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS) from 901 non-demented ALS to derive neuropsychological sub-phenotypes pursuant to classical MCI and MBI frameworks and in accordance with an expanded version of Strong's criteria, which also addressed memory and visuo-spatial measures. RESULTS:The prevalence of MCI and MBI was 39% and 37%, respectively in this retrospective review. The following MCI sub-phenotypes were identified: dysexecutive MCI-single- and multiple-domain (dMCI-sd: 63%; dMCI-md: 24%, respectively); non-dysexecutive MCI-single- and multiple-domain (ndMCI-sd: 12%; ndMCI-md: 1%, respectively). MBI was classified as follows: apathetic MBI-single- and multiple-domain (aMBI-sd: 40%; aMBI-md: 20%, respectively); apathetic-disinihibited/perseverative MBI-multiple domain (ad/pMBI-md: 21%); disinihibited/perseverative MBI-multiple domain (d/pMBI-md: 7%); psychotic MBI-single- and multiple-domain (psyMBI-sd: 2%; psyMBI-md: 3%, respectively); unclassifiable MBI-multiple domain (uMBI-md: 1%). 143 (16%) of patients exhibited mild cognitive and behavioral impairment (MCBI). CONCLUSIONS:This study delivers a provisional, ECAS-based classification for the neuropsychological sub-phenotyping of non-demented ALS patients, which, with further validation, might be useful for both research and clinical purposes.

AXL, a receptor tyrosine kinase expressed in neurons and glial cells, involved in neuronal survival, myelination, and regulation of immune responses, can undergo shedding due to the activation of metalloproteases in neuroinflammatory conditions. Indeed, CSF and serum levels of soluble AXL (sAXL) have been correlated with neurodegeneration and cognitive decline in Alzheimer's disease (AD). Based on these observations, we explored whether sAXL is implicated in amyotrophic lateral sclerosis (ALS). sAXL levels were measured in biofluids (CSF and serum) from two biorepositories, totalling 107 ALS patients, 76 healthy controls, 25 AD patients, 22 patients with multiple sclerosis and 51 patients with ALS disease mimicking disorders (i.e. patients that displayed symptoms resembling ALS, in whom eventually ALS was excluded after a thorough clinical examination). Gender and age were considered as covariate in the statistical analyses. Our results provide the first evidence of sAXL alterations in the CSF and serum of ALS patients at diagnosis and demonstrate a significant association between CSF sAXL levels and disease progression, as well as its prognostic value in ALS. While these observations require validation through multicentre studies, they suggest the involvement of the AXL pathway in ALS pathology and pave the way for leveraging CSF sAXL levels as a biomarker to aid ALS disease stratification.

This study aimed to compare different algorithms based on the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) to classify patients with amyotrophic lateral sclerosis (ALS) according to their neuropsychological phenotype to identify possible discrepancies among these systems. ECAS-Cognitive and -Carer Interview (ECAS-C/-CI) scores of N = 901 patients with ALS without a formal diagnosis of dementia were retrospectively retrieved. Patients were classified, pursuant to Strong et al.’s criteria, as cognitively and behaviourally normal (ALScbn), cognitively and/or behaviourally impaired (ALSci/bi/cbi), or Possible ALS-FTD, according the following ECAS-based algorithms: (1) Abrahams’, solely addressing ECAS-C total and ALS-Specific subtotals; (2) Poletti et al.’s, addressing single task-level ECAS-C scores; (3) “Subscale”, addressing ECAS-C subscales (i.e., Language, Executive, Fluency, Memory and Visuospatial). All algorithms relied on single-item-level ECAS-CI scores for behavioural classifications. Whilst agreement rates among these classifications were moderate to high (84–86

Objective: to investigate the association between long-term exposure to fine particulate matter (PM2.5) and nitrogen oxides (NOx) with ALS risk, progression, and survival. Methods: We conducted a population-based study in Lombardy, Italy. A case-control analysis included 161 incident ALS cases (2011-2014) and 161 age-, sex-, and province-matched controls. Average residential exposures to PM2.5 and NOx over the 20 years before diagnosis were estimated using European Monitoring and Evaluation Programme data and analysed with conditional logistic regression. A retrospective cohort of 135 ALS cases was used to assess associations with disease progression (ΔFS) and mortality using logistic and Cox regression models, adjusting for demographic and lifestyle factors. Results: Higher PM2.5 exposure in the 20 years preceding diagnosis was associated with increased ALS risk (adjusted OR per 5 µg/m³ increase 1.19; 95% CI 1.01-1.40), with consistent findings across sensitivity analyses. NOx was not associated with ALS incidence. In contrast, NOx exposure in the 5 years before diagnosis was marginally associated with increased mortality (adjusted HR 1.12; 95% CI 1.00-1.26), whereas PM2.5 was not. Neither pollutant was significantly associated with disease progression rate. Conclusions: Long-term PM2.5 exposure was associated with higher ALS risk, while NOx showed a modest association with mortality. These findings support a role of air pollution in ALS susceptibility and highlight the need for integrated environmental prevention strategies to mitigate the burden of neurodegenerative diseases.

Tofersen is a gene-targeted therapy for superoxide dismutase 1 (SOD1)-associated amyotrophic lateral sclerosis (ALS), but neurofilament light chain (NfL) may not fully capture the biological response to treatment. We performed a multicentre retrospective longitudinal study including 24 patients with SOD1-ALS treated with intrathecal tofersen at four Italian referral centres between 2022 and 2025. Cerebrospinal fluid (CSF) and serum biomarkers were assessed at baseline, month 3, month 6, and last available administration using single-molecule array assays to quantify NfL, glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase L1 (UCHL-1), and total Tau. NfL decreased after treatment initiation in both CSF and serum, providing the clearest pharmacodynamic signal. In contrast, CSF GFAP increased progressively over follow-up, while CSF total Tau and UCHL-1 rose mainly at later timepoints; serum GFAP, total Tau, and UCHL-1 also showed increases during follow-up. ALS Functional Rating Scale-Revised trajectories were broadly stable, whereas disease progression rate was lower at last follow-up than at baseline. Greater reductions in CSF NfL were observed in pathogenic versus uncertain SOD1 variants, and early serum NfL and UCHL-1 changes were associated with longer-term changes in disease progression. These findings suggest that longitudinal multi-analyte profiling may refine biological response stratification beyond NfL alone in tofersen-treated SOD1-ALS.

Understanding the multiple mechanisms underlying peripheral nerve regeneration in humans is crucial for developing effective therapies for peripheral axonal neuropathies. Although in vitro and in vivo studies have provided significant insights, human studies exploring the composition of proteome remain limited. The ECM plays a crucial role in nerve regeneration, influencing cell adhesion, proliferation, migration, and finally differentiation. In this study, we used a high-sensitivity, label-free liquid chromatography-mass spectrometry (LC-MS) method to investigate the global proteomic profile of human sural nerves aiming to identify molecular dynamics that promote or hinder nerve regeneration in well-characterized cohorts of patients with acute axonal injury, regenerating axonal neuropathy, and non-regenerating axonal neuropathy. Overall, 149 proteins were identified, of which 68 showed significant modulation across the groups. Proteins over-represented in regenerating nerves highlighted the multifactorial nature of regeneration, including immune modulation, debris clearance, cytoskeletal reorganization, axonal extension, and lipid transport. Conversely, structural myelin and neuronal proteins were significantly downregulated in non-regenerating nerves. Among the differentially expressed proteins, functional enrichment analysis revealed a significant overrepresentation of ECM-related components, providing compelling evidence that the ECM is not merely a passive scaffold, but an active driver of peripheral nerve regeneration. ECM remodeling contribute to / influence regenerative outcomes in human axonal neuropathies. Acutely injured nerves display enrichment in wound-response proteins, consistent with blood–nerve barrier disruption, and formation of a fibrin/fibronectin-rich ECM that supports repair. Regenerating nerves exhibit a dynamic ECM and a proteomic profile similar to those of controls, reflecting the restoration of a permissive regenerative environment. Non-regenerating nerves exhibit ECM accumulation and reduced levels of neuronal/myelin structural proteins, consistent with chronic regenerative failure.

BACKGROUND:Respiratory failure is the main cause of death in Amyotrophic lateral sclerosis (ALS), in which the physiological sigh reflex is impaired due to inspiratory muscle weakness. Aim of this study is to assess the tolerability, safety, and effectiveness of adding a sigh cycle to non-invasive mechanical ventilation (NIMV) settings in ALS patients. METHODS:In this randomized, blind-controlled proof-of concept study, 44 consecutive ALS patients with indication for NIMV were randomized to: Group I: NIMV with Sigh cycles; Group II: NIMV without Sigh. The primary outcome was the reduction in the Oxygen Desaturation Index (ODI); secondary outcomes included: Overnight Oximetry (OvOx), Arterial blood gas (ABG), and Visual Analog Scale (VAS; 0-10) scores to assess sleep quality, symptom intensity, mask interface, and NIMV tolerance. Assessments were conducted at baseline, after NIMV adaptation (T1) and at 1-month follow-up (T2). RESULTS:The Sigh cycle was safe and well tolerated. No significant group differences were observed at T1 or T2 in the primary outcome ODI (median ΔODI: Group A:-4.2; Group B:-4.6: p = 0.54), as well as in the OvOx parameters and pO2 and pCO2 ABG values. At T2, secondary analysis showed a significant difference in HCO₃- in favor of the Sigh arm (ΔHCO3 -: -1.60 vs. 1.35 mmol/L, p = 0.042). Exploratory Cox-regression models suggested a potential independent effect of SIGH on survival. CONCLUSIONS:Sigh is safe, well tolerated in ALS patients. Although this study did not reach the primary outcome, we also cannot rule out that sigh doesn't benefit the patient.

IntroductionPercutaneous endoscopic gastrostomy (PEG) is commonly used to manage dysphagia and nutritional failure, which are among the most frequent and severe complications of amyotrophic lateral sclerosis (ALS). While several studies assessed PEG indications, outcomes, and prognostic factors, there is no evidence regarding ALS patients’ perspectives and health-related quality of life (HRQoL) associated with PEG.MethodsThis study included 48 consecutive ALS patients. At the 1-month follow-up after PEG, patients and their caregivers completed a PEG satisfaction questionnaire regarding their decision to proceed with the PEG-tube placement. HRQoL was assessed using the Gastrointestinal Quality of Life Index (GIQLI) and the Short Form-36 (SF-36).ResultsIn total, 77.1% of patients and 88.9% of caregivers confirmed that they would prefer to have a PEG tube placed again if required (p > 0.001); 93.8% of patients felt that PEG made feeding easier, exerting a positive effect on overall wellbeing (83.3%) and increasing survival rates (93.8%) (p > 0.001); 54.2% felt that PEG was cosmetically acceptable. Consistent positive rates were reported by caregivers. The GIQLI digestion subscale values significantly improved from baseline (28.3; SD = 6.6) to discharge (30.97, SD = 5.84) and were maintained at 1-month follow-up (30.21, SD = 6.7; p = 0.014). Conversely, in follow-up assessments, we observed a significant reduction in the SF-36 physical component summary (PCS) subscale (baseline = 33.3; 1-month follow-up = 28.61; p = 0.032), which was accompanied by a significant worsening in the GIQLI physical dimension subscale (baseline = 9.63; 1-month follow-up = 7.38; p = 0.044).DiscussionThis study provides preliminary evidence that ALS patients have a positive perspective on PEG positioning, which may also have a beneficial effect on HRQoL related to gastrointestinal function.

BACKGROUND AND PURPOSE:Recent studies suggest that primary lateral sclerosis (PLS) may have a genetic component. In this work, we performed a next-generation sequencing (NGS) analysis in order to explore the genetic architecture of PLS in a cohort of Italian patients. METHODS:NGS was conducted to analyze 228 genes associated with amyotrophic lateral sclerosis (ALS), hereditary spastic paraplegia (HSP), and parkinsonian syndromes (PS) in a cohort of PLS patients diagnosed between 2003 and 2021 at our center. All patients were also screened for C9orf72 hexanucleotide repeat expansion (C9orf72-HRE) by repeat-primed PCR. Genetic variants were classified according to the ACMG criteria. RESULTS:In our study, including 47 PLS patients, we detected 22 rare variants in 17 patients, including 8 likely pathogenic or pathogenic variants and 14 variants of uncertain significance. Four patients carried more than one variant. Among the variants identified, 18 (81.8%) were found in ALS-associated genes. Variants in TBK1 were associated with extra-motor involvement. CONCLUSIONS:Although the majority of the PLS patients in our cohort tested negative for an expanded panel of genes associated with ALS, HSP and PS, in 36.2% of the cases, a genetic variant was identified and it mostly belongs to genes associated with ALS, including a C9orf72 expansion and a rare SOD1 variant. Based on these results, we emphasize the need for genetic screening in PLS patients. Further studies on the genetic background are necessary to better understand the complex pathomechanism of each phenotype within the MND-FTD spectrum disorder.

BACKGROUND:Emotional lability (EL), also known as pathological laughter and crying, is a common but understudied symptom in motor neuron diseases (MND): amyotrophic lateral sclerosis and primary lateral sclerosis. This study aimed to investigate the prevalence of EL in MND and to explore the independent frequency components of laughter and crying in relation to motor, cognitive, neuropsychiatric, and neuroimaging factors. METHODS:A total of 198 incident MND patients were enrolled. The Centre of Neurological Study-Lability Scale was used to measure EL. Associations between EL and motor function, mood, neuropsychological variables, and structural MRI were examined, with cortical thinning measured on a subset of 48 patients. RESULTS:EL was identified in 36% of patients showing more severe motor functional disabilities, heightened depressive and anxiety symptoms and behavioral changes than those without EL. Women exhibited more severe EL and altered mood with frequent crying episodes than men. EL was strongly correlated with bulbar involvement. Crying episodes were associated with mood disorders, while laughter correlated with disinhibition and emotional regulation difficulties. EL had a specific association with the thinning of frontal regions, including the right pars orbitalis, which was also linked to altered emotional and behavioral regulation. CONCLUSION:These findings underscore the role of corticobulbar and frontal pathways in EL pathophysiology. The study highlights the distinct mechanisms underlying pathological crying and laughter and their independency from general cognitive decline. It emphasizes the need for clinicians to recognize EL as an independent symptom, necessitating targeted management strategies to improve patient outcomes and support caregivers.

BACKGROUND:This study aimed to determine whether educational attainment-a common proxy of cognitive reserve (CR)-influences the association between motor and cognitive/behavioural outcomes in a large cohort of ALS patients without dementia. METHODS:N = 726 ALS patients without FTD were assessed for motor (ALSFRS-R), cognitive (Edinburgh Cognitive and Behavioural ALS Screen, ECAS) and behavioural outcomes (ECAS-Carer Interview, ECAS-CI). CR was operationalized via educational attainment (in years). Moderation models were run on each subscale of the cognitive section of the ECAS and on the ECAS-CI by addressing ALSFRS-R as the predictor and education as the moderator. RESULTS:Education was associated with both the ALSFRS-R and all the cognitive subscales of the ECAS, while not with the ECAS-CI. As to moderation models, a significant Education*ALSFRS-R interaction was detected solely with regard to the ECAS-Executive-with its simple slope-based decomposition revealing that higher ALSFRS-R scores were associated with higher scores on the ECAS-Executive for patients with low (p < 0.001) and average (p = 0.007), while not high, levels of education. DISCUSSION:Education seems to moderate the association between motor involvement and executive status in ALS patients without dementia, thus possibly exerting a protective role towards both motor function and cognition in this population.

INTRODUCTION:Seed amplification assays (SAAs) have shown promising results in detecting misfolded transactive response (TAR) DNA-binding protein 43 (TDP-43) in cerebrospinal fluid (CSF) of genetic frontotemporal dementia (FTD). To date, the use of SAA has yet to be evaluated in presymptomatic individuals. METHODS:Thirty patients carrying GRN or C9orf72 mutations, 2 microtubule-associated protein tau (MAPT) carriers, 14 presymptomatic subjects, and 27 controls underwent CSF collection. We used SAA for detecting misfolded TDP-43 (TDP-43_SAA) and single molecule array (SIMOA) technology for neurofilament light chain (NfL) dosage. RESULTS:TDP-43 seeding activity was detected in 67% of TDP-43-linked symptomatic patients, with a specificity of 93%. Almost half of presymptomatic subjects tested positive, mostly GRN carriers. Interestingly, among TDP-43_SAA positive presymptomatic individuals, two GRN carriers underwent phenoconversion. DISCUSSION:TDP-43_SAA can also detect misfolded TDP-43 in the CSF of presymptomatic individuals. A possible link exists between positive TDP-43_SAA and conversion to the symptomatic phase. HIGHLIGHTS:Seed amplification assay of transactive response (TAR) DNA-binding protein 43 (TDP-43_SAA) can detect misfolded TDP-43 in the cerebrospinal fluid (CSF) of patients with genetic frontotemporal dementia (FTD), linked to GRN and C9orf72 mutations. TDP-43_SAA can detect misfolded TDP-43 also in the CSF of presymptomatic individuals. In both groups, most TDP-43_SAA positive cases were carriers of GRN mutation. Two GRN carriers that resulted TDP-43_SAA positive converted to the symptomatic phase of the disease.

In recent years, the seed amplification assay (SAA) has enabled the identification of pathological TDP-43 in the cerebrospinal fluid (CSF) and olfactory mucosa (OM) of patients with genetic forms of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Here, we investigated the seeding activity of TDP-43 in OM samples collected from patients with sporadic ALS. OM samples were collected from patients with (a) sporadic motor neuron diseases (MND), including spinal ALS (n = 35), bulbar ALS (n = 18), primary lateral sclerosis (n = 10), and facial onset sensory and motor neuronopathy (n = 2); (b) genetic MND, including carriers of C9orf72exp (n = 6), TARDBP (n = 4), SQSTM1 (n = 3), C9orf72exp + SQSTM1 (n = 1), OPTN (n = 1), GLE1 (n = 1), FUS (n = 1) and SOD1 (n = 4) mutations; (c) other neurodegenerative disorders (OND), including Alzheimer’s disease (n = 3), dementia with Lewy bodies (n = 8) and multiple system atrophy (n = 6); and (d) control subjects (n = 22). All samples were subjected to SAA analysis for TDP-43 (TDP-43_SAA). Plasmatic levels of TDP-43 and neurofilament-light chain (NfL) were also assessed in a selected number of patients. TDP-43_SAA was positive in 29/65 patients with sporadic MND, 9/21 patients with genetic MND, 6/17 OND patients and 3/22 controls. Surprisingly, one presymptomatic individual also tested positive. As expected, OM of genetic non-TDP-43-related MND tested negative. Interestingly, fluorescence values from non-MND samples that tested positive were consistently and significantly lower than those obtained with sporadic and genetic MND. Furthermore, among TDP-43-positive samples, the lag phase observed in MND patients was significantly longer than that in non-MND patients. Plasma TDP-43 levels were significantly higher in sporadic MND patients compared to controls and decreased as the disease progressed. Similarly, plasma NfL levels were higher in both sporadic and genetic MND patients and positively correlated with disease progression rate (ΔFS). No significant correlations were detected between TDP-43_SAA findings and the biological, clinical, or neuropsychological parameters considered. The OM of a subset of patients with sporadic MND can trigger seeding activity for TDP-43, as previously observed in genetic MND. Thus, TDP-43_SAA analysis of OM can improve the clinical characterization of ALS across different phenotypes and enhance our understanding of these diseases. Finally, plasma TDP-43 could serve as a potential biomarker for monitoring disease progression. However, further research is needed to confirm and expand these findings.

Vascular defects are common in Amyotrophic Lateral Sclerosis (ALS). The prevailing view is that breakdown of the blood–brain and blood–spinal cord barriers contributes to neurodegeneration. Here, we reveal that selective and early vulnerability of peripheral nerve endothelium —manifested as endothelial cell activation and interlinked blood–nerve barrier dysfunction— constitutes a core feature of ALS pathogenesis, arising before vascular alterations in the central nervous system (CNS) and motor neuron pathology. Vascular changes in ALS patients have been largely studied in postmortem samples, limiting insight into their onset, causes, and pathogenic role. Surveying diagnostic motor nerve samples from ALS patients across clinical stages, we observed endothelial damage that preceded axonal loss and demyelination, marking vascular dysfunction as an early disease event. Similar ultrastructural abnormalities were detected in pre-symptomatic ALS mouse models ( SOD1 and TARDBP mutants). Notably, endothelial cells became dysfunctional even when not carrying mutant TDP-43, indicating they respond to non-cell autonomous disease signals. Transcriptional, histological, and functional analyses revealed that these alterations were largely confined to peripheral nerves, while spinal cord vessels exhibited delayed and more focal changes. Single-cell sequencing identified ALS-susceptible endothelial cell subsets prone to a pro-inflammatory phenotype and impaired blood–nerve barrier function, increasing permeability via the transcellular route. These changes coincided with reactivity of nerve-resident macrophages and neutrophil infiltration. Neutrophil depletion attenuated endothelial activation and barrier leakiness, mitigating axonopathy in ALS mice. Our work unmasks the greater susceptibility of the peripheral nerve vasculature in ALS relative to the CNS. The early activation of peripheral nerve endothelium, combined with its potential reversibility, identifies a therapeutic window and suggests strategies for targeting the vascular–immune axis to protect the motor system. ### Competing Interest Statement The authors have declared no competing interest. AriSLA Foundation pilot grant (NeVALS) Italian Ministry of Health, GR-2016-02364327 Giovanni Armenise-Harvard Foundation, https://ror.org/04q644746

BACKGROUND:Amyotrophic lateral sclerosis (ALS) lacks biomarkers for diagnosis, prognostic stratification, and evaluation of response to potential treatments. Previous research supported the role of serum osteopontin (OPN) levels as a potential biomarker in ALS. However, the associations of OPN serum levels with clinical features and their trend over the disease course have not been explored yet. METHODS:We measured OPN serum levels in a retrospective cohort of 110 well-characterized patients with ALS, using a commercial ELISA kit, and analyzed their association with demographic and clinical features, as well as with other serum biomarkers. For a subset of patients, longitudinal measurements were available. RESULTS:OPN serum levels differed significantly between patients with ALS and a cohort of 45 age and sex-matched healthy controls. However, when considering potential differential diagnoses, elevated OPN serum levels were not specific for ALS. Patients with an advanced disease stage (King's stage 3 or 4) exhibited significantly higher OPN serum levels compared to patients at earlier disease stages, whereas we did not observe any correlation with ALSFRS-R and progression rate. We observed an inverse correlation between OPN serum levels and BMI at diagnosis. Higher OPN serum levels predicted a shorter survival time and a shorter time to King's stage 4. No significant association between serum OPN and serum neurofilament light or glial fibrillary acid protein levels was observed. OPN serum levels were substantially stable over a 9-month observation time. CONCLUSION:Our findings indicate that serum OPN is an informative biomarker in ALS, providing valuable prognostic insights, potentially reflecting the extent of disease, and demonstrating potential applications in clinical trials.

Amyotrophic lateral sclerosis (ALS) is characterized by neuromuscular junction (NMJ) disruption and neurodegeneration. Recent findings highlight a pivotal role for TAR DNA-binding protein 43 (TDP-43) in forming axonal pathological condensates and facilitating NMJ disruption through inhibition of local protein synthesis. However, the mechanisms that drive local TDP-43 accumulation remain unknown. Here we identify that the TDP-43 axonal accumulation in peripheral nerves of SOD1 patients and mice stems from its aberrant local synthesis. This is a non-cell-autonomous process driven by muscle-derived miR-126a-5p extracellular vesicles (EVs). Inhibiting muscle secretion of miR-126a-5p prompts presynaptic TDP-43 synthesis and accumulation, which disrupts axonal translation and causes NMJ degeneration. Introducing miR-126 to SOD1G93A mice, primary co-cultures and human induced pluripotent stem cell (iPSC)-derived co-cultures with ALS mutations exhibits neuroprotective effects and delays motor decline. These findings identify a transcellular communication axis between muscles and motor neurons that regulates axonal local synthesis and NMJ maintenance, offering insights into ALS onset and progression.