Epidemiology of amyotrophic lateral sclerosis: an update of recent literature

Estimating the minimum important difference in the ALSFRS-R-instrument in people living with MND

Objective: The Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) is a commonly used outcome measure in clinical trials for motor neuron disease (MND) therapies. As such, understanding how differences in scores relate to patient perception of their disease status is important when interpreting ALSFRS-R data. Our study sought to estimate the minimal important difference (MID) for the ALSFRS-R, the smallest difference in scores at which patients perceive a change in their quality of life. Methods: Data were collected as part of a longitudinal, observational saliva management study, ProSec3. These included both the ALSFRS-R and a global rating of change question (GRoC), which asked participants to rate how their disease had progressed since the previous visit. Anchor-based and distribution-based methods have been used to estimate the MID of the ALSFRS-R. The MID was estimated using two methods of calculating the total ALSFRS-R score, the original summation scale method and the recently proposed interval scale method. Results: A total of 145 people with MND had longitudinal ALSFRS-R and GRoC data. Different methods estimated the ALSFRS-R MID to be in the range of 2.02-5.43 for the summation scale and 1.23-3.31 for the interval scale method over a 3-month period, the time between study visits. Using anchor-based methods our MID estimates for the ALSFRS-R are 3.8 points and 2 points, respectively. Conclusions: The results of this study can guide clinicians and researchers in the interpretation of ALSFRS-R data. However, further studies are required to more precisely estimate the ALSFRS-R MID.

Care trajectories and adherence to respiratory management recommendations in persons living with amyotrophic lateral sclerosis: a ten-year cohort study in a French tertiary university centre

Objective: This study determined real-life care trajectories before and after initiation of noninvasive ventilation (NIV) in patients with amyotrophic lateral sclerosis (ALS). Caregiver adherence to respiratory management recommendations and the associated survival rate of people with ALS were also assessed. Methods: Data were obtained from a tertiary center prospective ALS database that included 10 years of follow-up data for people with ALS. Results are presented numerically and with graphical time sequence analysis through K clustering (TAK) representation. Kaplan Meier and Cox models were used to determine survival and associated prognostic factors. Results: 109 patients with ALS patients were included; median [interquartile range] follow-up was 25.0 months [15.3-43.3]. During study timeframe patients had a median of 4.0 [2.0-6.0] clinical visits; death occurred in 54.1%. Median time between clinical visits was 3.9 [2.8-6.5] months, between arterial blood gases was 4.3 months [3.0-6.6], between spirometry testing was 5.8 months [4.1-8.2], and between nocturnal oximetry was 4.4 months [3.0-7.8]. Visualization of care trajectories TAK show marked heterogeneity in survival, time to NIV initiation, and time from NIV initiation to death. Mortality was correlated with NIV initiation and arterial carbon dioxide pressure increase. Conclusions: The current framework in ALS guidelines should be adapted to the ALS disease stage and individual patient characteristics. Understanding how subgroups of patients with ALS use healthcare services over time could help to highlight fragility areas and priorities in the allocation of care resources and implementation of best practices.

Mechanistic insights into impaired β-oxidation and its role in mitochondrial dysfunction: A comprehensive review

Mitochondria, also known as the powerhouse of cells, have an important role in cellular metabolism and energy production. However, during Mitochondrial Dysfunction (MD), it is known to generate reactive oxidative species and induce cellular apoptosis. A number of research findings have linked MD to various diseases, highlighting its critical role in maintaining health and contributing to disease development. In this regard, recent research has revealed that disruptions in lipid metabolism, especially in fatty acid oxidation, are significant contributors to MD. However, the precise mechanisms by which these defects lead to disease remain poorly understood. This review explores how disruptions in lipid metabolism are responsible for triggering oxidative stress, inflammation, and cellular damage, leading to impaired mitochondrial function. By examining specific fatty acid oxidation disorders, such as carnitine palmitoyltransferase deficiency, medium-chain acyl-CoA dehydrogenase deficiency, and very long-chain acyl-CoA dehydrogenase deficiency, this review aims to uncover the underlying molecular pathways connecting lipid metabolism to mitochondrial dysfunction. Furthermore, MD is a common underlying mechanism in a wide array of diseases, including neurodegenerative disorders and metabolic syndromes. Understanding the mechanisms behind mitochondrial malfunction may aid in the development of tailored therapies to restore mitochondrial health and treat intricate health conditions.

Muscle strengthening in individuals with Amyotrophic Lateral Sclerosis: a systematic review with meta-analyses

Despite the observed benefits of properly prescribed exercises for people with Amyotrophic Lateral Sclerosis (ALS), the scarcity of studies and lack of consensus on the effects of muscle-strengthening exercises on this population has a negative impact on their rehabilitation. This study aimed to evaluate the effects of muscle-strengthening interventions in individuals with ALS. This systematic review of intervention studies included clinical trials that performed non-respiratory muscle strengthening in people with ALS compared to non-strengthening interventions, usual care, or placebo. Such studies were obtained from the MEDLINE, EMBASE, Cochrane Library, SPORTDiscus, and Physiotherapy Evidence Database databases, with no language or publication date restrictions. The outcomes considered were peripheral muscle strength, functionality, fatigue, and adverse events. The Physiotherapy Evidence Database scale was used to analyze the risk of bias, while the Grading of Recommendations Assessment, Development and Evaluation system was used to evaluate the quality of the evidence. Searches were conducted in October 2023 and eight studies were included, totaling 296 individuals. Seven of the eight studies showed superiority of the experimental intervention over the control, but this was not supported in the meta-analyses. Small sample size and high heterogeneity in the primary studies contributed significantly to the low quality of the evidence. There was no evidence of the superiority of interventions for muscle strengthening compared to interventions not aimed at strengthening, usual care, or placebo in terms of the outcomes analyzed immediately after the intervention. The quality of the evidence ranged from low to very low. Five of the studies evaluated adverse events, without reporting serious events. Interventions for muscle strengthening did not prove to be more effective when compared to the control group in the short term nor seem to produce serious adverse events. The low quality of the evidence indicates the need for studies with greater methodological rigor in this population, to more assertively assess the impacts of this intervention over the short, medium, and long term.

Deficits in taste-guided behaviors and central processing of taste in the transgenic TDP-43Q331K mouse model of frontotemporal dementia

Frontotemporal dementia (FTD) is the second most prevalent form of presenile dementia. Patients with FTD show prominent chemosensory symptoms such as abnormal detection and recognition thresholds for various gustatory stimuli. The chemosensory symptoms of FTD may be related to damage of the gustatory insular cortex (GC) as the insular cortex is one of the primary targets in FTD disease progression. Little is known about how circuitry changes in GC lead to deficits in taste processing in FTD. Here we tested the hypothesis that gustatory deficits are present in a mouse model of FTD, and that they are related to abnormal patterns of neural activity in GC. We behaviorally evaluated a transgenic FTD mouse model overexpressing human TDP-43 with a Q331K mutation (TDP-43Q331K) in a brief access test and a taste-based two alternative forced choice (2AFC) task probing the ability to discriminate sucrose/NaCl mixtures. TDP-43Q331K mice showed abnormal sucrose consumption and an impaired ability to discriminate taste mixtures compared to non-transgenic control mice. To assess deficits in GC taste processing, we relied on electrophysiological recordings using chronically implanted tetrodes in alert TDP-43Q331K and non-transgenic control mice. The proportion of taste-selective neurons in TDP-43Q331K mice decreased over time compared to control mice. Similarly, encoding of chemosensory information and processing of taste palatability were impaired in TDP-43Q331K mice compared to control mice. Overall, these results demonstrate taste-related symptoms in a mouse model of FTD and provide evidence for altered taste processing in GC of TDP-43Q331K mice compared to control mice.

Headache types and characteristics in patients with Amyotrophic Lateral Sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder associated with progressive loss of motor neurons, this result in muscle denervation, atrophy and consequently death takes place due to respiratory failure within 3-5 years of onset of symptoms.

OUR AIM

Was to investigate types and frequency of headache in ALS patients.

METHODS

This is cross sectional hospital based study. Clinically definite 100 ALS Patients (diagnosed according to El Escorial revised criteria) were recruited out of 137 ALS patients presented to the Neuromuscular Clinic in Ain Shams university Hospital from February 2022 to June 2024. Patients were screened for headache types and symptoms diagnosed according to International Headache Society criteria (IHS). Headache severity and impact were assessed using Arabic versions of Headache Impact Test (HIT) and Migraine Disability Assessment (MIDAS). Depression was also assessed via Arabic version of Beck's Depression Inventory (BDI). ALS symptoms severity was assessed via Arabic version of Amyotrophic Lateral Sclerosis Functional Rating Scale Revised (ALSFRS-R). Cognitive functions were assessed via the Egyptian version of the Edinburgh Cognitive and Behavioral Amyotrophic Lateral Sclerosis Screen (ECAS‑EG). Demographic data and ALS related parameters were collected.

RESULTS

Among 100 patients with clinically definite ALS, 79 patients reported headaches, 62 of them had primary headaches; with tension-type headache being the most commonly reported in 46 patients, Migraine in 16 patients. Fifteen ALS patients had secondary headaches; among them 12 had headache secondary to respiratory insufficiency and 3 patients developed headache after the initiation of Riluzole therapy. Two patients had non specific headache. Mean age for the patients at ALS presentation was 43.9 ± 13.8, Mean ALSFRS-R score 33.3 ± 9.04. The relationships between headache and clinical features of ALS were also investigated.

IN CONCLUSION

ALS patients should be evaluated for Headache; Not only headache secondary to respiratory compromise and hypercapnea, but also primary headaches which can be overlooked in patients with ALS.

Persistent high levels of perceived fatigue are not associated with hypermetabolism in patients with amyotrophic lateral sclerosis

Objective: Fatigue is a common symptom in amyotrophic lateral sclerosis (ALS). Little is known about factors that contribute to fatigue, and whether levels of fatigue change throughout disease course. We aimed to determine associations between self-reported perceived fatigue and metabolic and clinical features of ALS, and perceived fatigue over the course of disease. Methods: This prospective study was conducted between July 2017 and March 2024. Baseline measures of self-reported perceived fatigue, metabolic rate, and clinical measures of disease were assessed in 117 participants with clinically definite or probable ALS. For comparison, fatigue and metabolic rate were collected from 107 control participants. Perceived fatigue was determined using the Fatigue Severity Scale (FSS). Metabolic rate was assessed using indirect calorimetry. Functional capacity and clinical progression were assessed using the ALS Functional Rating Scale-Revised (ALSFRS-R). Results: Baseline levels of perceived fatigue were greater in people living with ALS (plwALS) when compared to controls (5.44 vs. 2.55; p < 0.01). Perceived fatigue was higher in plwALS with lower ALSFRS-R scores and was not associated with measures of metabolism. For most plwALS, perceived fatigue remained high as functional capacity worsened. Conclusion: Our findings confirm higher prevalence of perceived fatigue in plwALS, with persistently high FSS scores reported by most patients during follow-up. High levels of fatigue were not associated with hypermetabolism, suggesting that metabolic rate is unlikely to be a primary contributor. Results highlight a need for further research to identify factors that contribute to fatigue in ALS, and options for improved fatigue management.

Clinical and epidemiological characteristics of amyotrophic lateral sclerosis in an Egyptian cohort

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder associated with progressive loss of motor neurons. It is a growing and underestimated disease, prompting this epidemiological study to describe the characteristics of ALS in Egyptian patients.

METHODS

This is a prospective hospital based study. ALS patients were recruited consecutively from Neuromuscular Unit in Ain Shams university Hospital from December 2018 to June 2023. Demographic data and disease related parameters were recorded.

RESULTS

203 ALS patients had a mean age of onset equal 39 years and an inter quartile range IQR of (28.00-51.00). 76% of the cases were spinal onset ALS. Median disease duration was 2 years with IQR of (1-4 years); male to female ratio was 2.5:1; 18% of patients were familial ALS (FALS), while 19% were Juvenile ALS (JALS). Median diagnostic delay was 12 ± (6-36) months. Median Amyotrophic Lateral Sclerosis Functional Rating Scale Revised scores (ALSFRS-R) at presentation was 34.5 IQR of (26.00-40.00). Also, the mean rate of disease progression ALSFRS-R decline [points/month] was 0.76 ± 0.51.

CONCLUSION

Our cohort was characterized by a younger age of onset, male predominance, more familial cases, within average Initial ALSFRS-R scores as well as diagnostic delay. Juvenile ALS patients were much more common in our population. These findings suggest an influential presence of genetic and epigenetic factors affecting the clinical phenotype of Egyptian ALS patients.

A Comprehensive Review on Utilizing Human Brain Organoids to Study Neuroinflammation in Neurological Disorders

Most current information about neurological disorders and diseases is derived from direct patient and animal studies. However, patient studies in many cases do not allow replication of the early stages of the disease and, therefore, offer limited opportunities to understand disease progression. On the other hand, although the use of animal models allows us to study the mechanisms of the disease, they present significant limitations in developing drugs for humans. Recently, 3D-cultured in vitro models derived from human pluripotent stem cells have surfaced as a promising system. They offer the potential to connect findings from patient studies with those from animal models. In this comprehensive review, we discuss their application in modeling neurodevelopmental conditions such as Down Syndrome or Autism, neurodegenerative diseases such as Alzheimer's or Parkinson's, and viral diseases like Zika virus or HIV. Furthermore, we will discuss the different models used to study prenatal exposure to drugs of abuse, as well as the limitations and challenges that must be met to transform the landscape of research on human brain disorders.

Self-assessment of amyotrophic lateral sclerosis functional rating scale on the patient's smartphone proves to be non-inferior to clinic data capture

OBJECTIVE

To investigate self-assessment of the amyotrophic lateral sclerosis functional rating scale-revised (ALSFRS-R) using the patient's smartphone and to analyze non-inferiority to clinic assessment.

METHODS

In an observational study, ALSFRS-R data being remotely collected on a mobile application (App-ALSFRS-R) were compared to ALSFRS-R captured during clinic visits (clinic-ALSFRS-R). ALS progression rate (ALSPR)-as calculated by the monthly decline of ALSFRS-R-and its intrasubject variability (ALSPR-ISV) between ratings were used to compare both cohorts. To investigate non-inferiority of App-ALSFRS-R data, a non-inferiority margin was determined.

RESULTS

A total of 691 ALS patients using the ALS-App and 1895 patients with clinic assessments were included. Clinical characteristics for the App-ALSFRS-R and clinic-ALSFRS-R cohorts were as follows: Mean age 60.45 (SD 10.43) and 63.69 (SD 11.30) years (p < 0.001), disease duration 38.7 (SD 37.68) and 56.75 (SD 54.34) months (p < 0.001) and ALSPR 0.72 and 0.59 (p < 0.001), respectively. A paired sample analysis of ALSPR-ISV was applicable for 398 patients with clinic as well as app assessments and did not show a significant difference (IQR 0.12 [CI 0.11, 0.14] vs 0.12 [CI 0.11, 0.14], p = 0.24; Cohen's d = 0.06). CI of IQR for App-ALSFRS-R was below the predefined non-inferiority margin of 0.15 IQR, demonstrating non-inferiority.

CONCLUSIONS

Patients using a mobile application for remote digital self-assessment of the ALSFRS-R revealed younger age, earlier disease course, and faster ALS progression. The finding of non-inferiority of App-ALSFRS-R assessments underscores, that data collection using the ALS-App on the patient's smartphone can serve as additional source of ALSFRS-R in ALS research and clinical practice.

Association Between Early-Life and Premorbid Measurements of Body Composition and Risk of Motor Neuron Disease: A Prospective Cohort Study in the UK Biobank

OBJECTIVE

The objective of this study was to investigate the association between developmental and premorbid body composition measurements and the risk of motor neuron disease (MND).

METHODS

We performed a cohort study in the UK Biobank to assess the association of developmental body metrics and premorbid body composition measures (using 28 measurements and 7 patterns of body composition) with the risk of MND. Among participants with longitudinal measures, we compared the changes in body composition over time between individuals who later developed MND and those who remained free of MND.

RESULTS

Among the 412,691 individuals included in this study, 549 people received an MND diagnosis during the follow-up visit. Higher birth weight was associated with an increased risk of MND among individuals born over 4 kg (hazard ratio [HR] per kg increase = 2.21, 95% confidence interval [CI] = 1.38-3.55), and taller adult height was associated with an increased risk of MND (HR per 5 cm increase = 1.10, 95% CI = 1.03-1.17). We observed that measures of elevated fat mass were associated with a lower risk of MND more than 5 years before diagnosis. A higher "leg-dominant fat distribution" pattern was associated with an increased risk whereas higher "muscle strength" was associated with a reduced risk of MND 5 years before diagnosis. Longitudinal analyses indicated a faster decline in measures of fat mass and muscle strength, as well as a shift in fat distribution from arm to leg dominant, among individuals who later developed MND, compared with others.

INTERPRETATION

Body composition at early and middle age may be indicative of the risk of MND development. ANN NEUROL 2025;97:259-269.

Occupational lead exposure and amyotrophic lateral sclerosis survival in the Danish National Patient Registry

OBJECTIVES

We investigated the relationship between occupational lead exposure and amyotrophic lateral sclerosis (ALS) survival in Denmark.

METHODS

We identified 2,161 ALS cases diagnosed from 1982 to 2013 with at least 5 years of employment history before ALS diagnosis, via the Danish National Patient Registry. Cases were followed until March 2017. We defined lead exposure as never employed in a lead job, ever employed in a lead job, and ever employed in a lead job by exposure probability (<50% vs. ≥50%), excluding jobs held in the 5 years before diagnosis in main analyses. Survival was evaluated using Cox proportional hazards models and stratified by sex and age of diagnosis.

RESULTS

Median age of diagnosis was 63.5 years, and individuals in lead-exposed jobs were diagnosed at a younger age. Adjusted hazard ratios (aHR) were slightly decreased for men ever lead-exposed (aHR:0.92, 95%CI: 0.80, 1.05) and more so among those diagnosed at age 60-69 (lead ≥ 50% aHR: 0.66, 95%CI: 0.45, 0.98), but reversed for men diagnosed at age 70 and later (aHR: 2.03, 95%CI: 1.13, 3.64). No apparent pattern was observed among women.

CONCLUSIONS

Occupational lead exposure contributed to shorter survival among men diagnosed at older ages. The inverse associations observed for men diagnosed earlier could relate to possible healthy worker hire effect or health advantages of working in lead-exposed jobs. Our results are consistent with an adverse impact of lead exposure on ALS survival at older ages, with the age at which lead's effects on survival worsen later on among those in lead-exposed jobs.

HIV associated motor neuron disease (MND): A case series with systematic review of literature

Human immunodeficiency virus (HIV) associated motor neuron disease (MND) is very rare. HIV infection can cause an MND-like syndrome due to central nervous system (CNS) involvement de novo or during antiretroviral therapy (ART) due to CNS escape. We present two cases: one with a classic amyotrophic lateral sclerosis (ALS) phenotype, which was the manifestation of symptomatic CNS escape from ART, and the second with a primary lateral sclerosis (PLS) phenotype associated with underlying HIV infection. A systematic review of published literature of people living with HIV (PLHIV) who developed ALS/ MND was conducted using the PubMed, Embase, and Lilacs databases. A total of 91 cases were found, 89 of which were obtained from 37 articles, and two were included from our own case series. In patients with HIV-associated MND, 63 patients reviewed had a classic ALS phenotype followed by progressive muscular atrophy variant (12), progressive bulbar palsy (8), PLS (7) and bulbar onset ALS (1). Neuroimaging, electrophysiology, cerebrospinal fluid (CSF) analysis, CSF and serum HIV viral load, and CD4 count investigations were used for diagnosis. Following the initiation or modification of antiretroviral therapy (ART), approximately 70% exhibited an improvement or a stable disease course. HIV-associated MND is a rare condition that can occur in both ART-naive individuals and those on treatment. A proportion of cases (~ 70%) show improvement with ART. Accurate diagnosis requires the exclusion of opportunistic infections, which remains a critical yet challenging aspect of managing this condition.

Fighting Amyotrophic Lateral Sclerosis by Protecting the Liver? A Prospective Cohort Study

BACKGROUND

Previous studies have observed liver abnormalities in amyotrophic lateral sclerosis (ALS) patients. This study aimed to investigate whether early signs of liver disease, measured by magnetic resonance imaging-derived iron-corrected T1-mapping (cT1), are risk factors for developing ALS.

METHODS

cT1 and proton density fat fraction were measured and automatically analyzed using LiverMultiScan® software. The Fibrosis-4 index was calculated using an established formula based on age and blood markers. Cox proportional hazard models were used to examine the relationship between liver disease, liver biomarkers, and incident ALS.

RESULTS

In a cohort of 533,707 individuals from UK Biobank, 24 ALS cases were identified among 28,328 participants with liver disease during the follow-up period. Among a total of 33,959 individuals with complete liver imaging data, 15 incident ALS cases were observed during a median follow-up period of 5.6 years. Individuals with liver disease had a higher risk of developing ALS, with an adjusted hazard ratio of 7.35 (95% CI 4.47-12.09; p < 0.001). An increase in cT1 was also associated with a higher risk of ALS. After adjusting for age, sex, Townsend deprivation index, smoking status, alcohol intake frequency, body mass index, proton density fat fraction, Fibrosis-4, and metabolic syndrome, an increase in cT1 remained significantly associated with a higher risk of ALS, with an adjusted hazard ratio of 3.15 (95% CI 1.79-5.55) per 1-SD increase. Sensitivity analyses confirmed these robust results.

INTERPRETATION

Liver disease activity, indicated by cT1, increases the risk of developing ALS, independent of metabolic syndrome, liver fat, or fibrosis. ANN NEUROL 2025;97:270-280.

Epigenetic Biomarkers Driven by Environmental Toxins Associated with Alzheimer's Disease, Parkinson's Disease, and Amyotrophic Lateral Sclerosis in the United States: A Systematic Review

Environmental toxins and epigenetic changes have been linked to neurodegenerative diseases, including Alzheimer's Disease (AD), Parkinson's Disease (PD), and amyotrophic lateral sclerosis (ALS). This paper aimed to (i) identify environmental toxins associated with AD, PD, and ALS, (ii) locate potential industrial sources of toxins in the United States (U.S.), and (iii) assess epigenetic changes driven by exposure to toxins reported by patients. Environmental factors and epigenetic biomarkers of neurodegeneration were compiled from 69 studies in the literature using Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) and geographic information system approaches. Some 127 environmental toxins have been associated or putatively associated with AD, PD, or ALS, with four toxic metals (As, Cd, Mn, and Hg) common to all three of these neurodegenerative diseases. Environmental toxins associated with epigenetic changes (e.g., DNA methylation) in patients include air pollutants, metals, and organic chemicals (e.g., pesticides, mycotoxins, and cyanotoxins). Geographic analysis showed that study locations (e.g., U.S., Europe, and East Asia) were selected by researchers based on convenience of access rather than exposure risk and disease prevalence. We conclude that several toxins and epigenetic markers shared among neurodegenerative diseases could serve as attractive future targets guiding environmental quality improvements and aiding in early disease detection.

From Cell Architecture to Mitochondrial Signaling: Role of Intermediate Filaments in Health, Aging, and Disease

The coordination of cytoskeletal proteins shapes cell architectures and functions. Age-related changes in cellular mechanical properties have been linked to decreased cellular and tissue dysfunction. Studies have also found a relationship between mitochondrial function and the cytoskeleton. Cytoskeleton inhibitors impact mitochondrial quality and function, including motility and morphology, membrane potential, and respiration. The regulatory properties of the cytoskeleton on mitochondrial functions are involved in the pathogenesis of several diseases. Disassembly of the axon's cytoskeleton and the release of neurofilament fragments have been documented during neurodegeneration. However, these changes can also be related to mitochondrial impairments, spanning from reduced mitochondrial quality to altered bioenergetics. Herein, we discuss recent research highlighting some of the pathophysiological roles of cytoskeleton disassembly in aging, neurodegeneration, and neuromuscular diseases, with a focus on studies that explored the relationship between intermediate filaments and mitochondrial signaling as relevant contributors to cellular health and disease.

Epigenetic Mechanisms Underlying Sex Differences in Neurodegenerative Diseases

Neurodegenerative diseases are characterized by profound differences between females and males in terms of incidence, clinical presentation, and disease progression. Furthermore, there is evidence suggesting that differences in sensitivity to medical treatments may exist between the two sexes. Although the role of sex hormones and sex chromosomes in driving differential susceptibility to these diseases is well-established, the molecular alterations underlying these differences remain poorly understood. Epigenetic mechanisms, including DNA methylation, histone tail modifications, and the activity of non-coding RNAs, are strongly implicated in the pathogenesis of neurodegenerative diseases. While it is known that epigenetic mechanisms play a crucial role in sexual differentiation and that distinct epigenetic patterns characterize females and males, sex-specific epigenetic patterns have been largely overlooked in studies aiming to identify epigenetic alterations associated with neurodegenerative diseases. This review aims to provide an overview of sex differences in epigenetic mechanisms, the role of sex-specific epigenetic processes in the central nervous system, and the main evidence of sex-specific epigenetic alterations in three neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Understanding the sex-related differences of these diseases is essential for developing personalized treatments and interventions that account for the unique epigenetic landscapes of each sex.

Microglial upregulation of CD109 expression in spinal cord of amyotrophic lateral sclerosis mouse model and its role in modulating inflammation and TGFβ/SMAD pathway

CD109 is a multifunctional coreceptor, whose function has been widely studied in tumor progression and metastasis. One of the reported primary roles of CD109 involves down-regulating TGFβ signaling. However, the role of CD109 in central nervous system, especially neurodegenerative disease, is barely known. Here, we examined the expression changes and cellular location of CD109 and TGFβ/SMAD pathway molecules in lumbar spinal cord of SOD1-G93A mice, and explored the role and mechanism of CD109 on LPS-treated BV2 microglia and primary microglia derived from SOD1-G93A mice. Our results showed an increased expression of CD109 and TGFβ/SMAD pathway molecules in lumbar spinal cord of SOD1-G93A mice. Further cellular localization analysis demonstrated that proliferating microglia contributed mainly to the upregulation of CD109 and TGFβ1. Moreover, CD109 intervention in vitro partially reduced inflammatory response and TGFβ/SMAD pathway activation in both LPS-treated BV2 microglia and primary SOD1-G93A microglia. Thus, CD109 was involved in pathogenesis of ALS mice, and interventions targeting on CD109 modulation could be a potential therapeutic strategy for ALS.

Olfactory dysfunction as potential biomarker in neurodegenerative diseases: a narrative review

Neurodegenerative diseases represent a group of disorders characterized by progressive degeneration of neurons in the central nervous system, leading to a range of cognitive, motor, and sensory impairments. In recent years, there has been growing interest in the association between neurodegenerative diseases and olfactory dysfunction (OD). Characterized by a decline in the ability to detect or identify odors, OD has been observed in various conditions, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and Amyotrophic Lateral Sclerosis (ALS). This phenomenon often precedes the onset of other clinical symptoms, suggesting its potential utility as an early marker or prodromal symptom of neurodegenerative diseases. This review provides a vast literature overview on the current knowledge of OD in PD, AD, ALS, and HD in order to evaluate its potential as a biomarker, particularly in the early and prodromal stages of these diseases. We summarize the most common methods used to measure olfactory function and delve into neuropathological correlations and the alterations in neurotransmitter systems associated with OD in those neurodegenerative diseases, including differences in genetic variants if applicable, and cater to current pitfalls and shortcomings in the research.

Neuroglia in neurodegeneration: Amyotrophic lateral sclerosis and frontotemporal dementia

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are devastating neurodegenerative diseases sharing significant pathologic and genetic overlap, leading to consider these diseases as a continuum in the spectrum of their pathologic features. Although FTD compromises only specific brain districts, while ALS involves both the nervous system and the skeletal muscles, several neurocentric mechanisms are in common between ALS and FTD. Also, recent research has revealed the significant involvement of nonneuronal cells, particularly glial cells such as astrocytes, oligodendrocytes, microglia, and peripheral immune cells, in disease pathology. This chapter aims to provide an extensive overview of the current understanding of the role of glia in the onset and advancement of ALS and FTD, highlighting the recent implications in terms of prognosis and future treatment options.

Association between motor neuron disease and HIV infection: A systematic review of case reports

BACKGROUND

Motor neuron disease (MND) is a well-known group of neurodegenerative diseases, with amyotrophic lateral sclerosis (ALS) being the most common form. Since 1985, a possible association between MND/ALS and HIV infection has been described.

METHODS

We performed a systematic review of case reports and case series involving people living with HIV with MND/ALS through PubMed, Bireme, Embase, and Lilacs databases. The risk of bias was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Tool for Case Reports.

RESULTS

We analyzed 36 articles presenting 88 cases. The mean age was 41.6 years. Antiretroviral therapy (ART) was used by 89.8% and riluzole by 16.9%. First signs and symptoms were similarly present on cervical/upper (25%) and lumbosacral/lower limbs (23.9%), mostly with fasciculations (69.8%) and hyperreflexia (58.8%). MND had a progressive course in 32.9% patients and a clinical improve in 54.6% following ART. The mean survival of the 32 patients who died was 12.3 months and the mean survival of the living patients was 62 months. Respiratory failure was the main cause of death (35.7%).

CONCLUSIONS

MND/ALS may present differently in the people living with HIV as a rapidly progressive disease in younger people but with the potential to improve weakness and survival through antiretroviral therapy.

Nrf2 and Ferroptosis: Exploring Translational Avenues for Therapeutic Approaches to Neurological Diseases

Nrf2, a crucial protein involved in defense mechanisms, particularly oxidative stress, plays a significant role in neurological diseases (NDs) by reducing oxidative stress and inflammation. NDs, including Alzheimer's, Parkinson's, Huntington's, amyotrophic lateral sclerosis, stroke, epilepsy, schizophrenia, depression, and autism, exhibit ferroptosis, iron-dependent regulated cell death resulting from lipid and iron-dependent reactive oxygen species (ROS) accumulation. Nrf2 has been shown to play a critical role in regulating ferroptosis in NDs. Age-related decline in Nrf2 expression and its target genes (HO-1, Nqo-1, and Trx) coincides with increased iron-mediated cell death, leading to ND onset. The modulation of iron-dependent cell death and ferroptosis by Nrf2 through various cellular and molecular mechanisms offers a potential therapeutic pathway for understanding the pathological processes underlying these NDs. This review emphasizes the mechanistic role of Nrf2 and ferroptosis in multiple NDs, providing valuable insights for future research and therapeutic approaches.

Surface-based Analyses of Diffusional Kurtosis Imaging in Amyotrophic Lateral Sclerosis: Relationship with Onset Subtypes

PURPOSE

Here, we aimed to characterize the cortical and subcortical microstructural alterations in the brains of patients with amyotrophic lateral sclerosis (ALS). In particular, we compared these features between bulbar-onset ALS (b-ALS) and limb-onset ALS (l-ALS).

METHODS

Diffusion MRI data (b = 0, 700, 2000 ms/mm2, 1.7-mm isotropic voxel) from 28 patients with ALS (9 b-ALS and 19 l-ALS) and 17 healthy control subjects (HCs) were analyzed. Diffusional kurtosis imaging (DKI) metrics were sampled at the mid-cortical and subcortical surfaces. We used permutation testing with a nonparametric combination of mean diffusivity (MD), fractional anisotropy (FA), and mean kurtosis (MK) to assess intergroup differences over the cerebrum. We also carried out an atlas-based analysis focusing on Brodmann Area 4 and 6 (primary motor and premotor areas) and investigated the correlation between MRI metrics and clinical parameters.

RESULTS

At both the mid-cortical and subcortical surfaces, b-ALS was associated with significantly greater MD, smaller FA, and smaller MK in the motor and premotor areas than HC. In contrast, the patients with l-ALS showed relatively moderate differences relative to HCs. The ALS Functional Rating Scale-Revised bulbar subscore was significantly correlated with the diffusion metrics in Brodmann Area 4.

CONCLUSION

The distribution of abnormalities over the cerebral hemispheres and the more severe microstructural alteration in b-ALS compared to l-ALS were in good agreement with findings from postmortem histology. Our results suggest the feasibility of surface-based DKI analyses for exploring brain microstructural pathologies in ALS. The observed differences between b-ALS and l-ALS and their correlations with functional bulbar impairment support the clinical relevance of DKI measurement in the cortical and juxtacortical regions of patients with ALS.

Genetic epidemiology of amyotrophic lateral sclerosis in Cyprus: a population-based study

Amyotrophic lateral sclerosis (ALS) is a devastating, uniformly lethal degenerative disease of motor neurons, presenting with relentlessly progressive muscle atrophy and weakness. More than fifty genes carrying causative or disease-modifying variants have been identified since the 1990s, when the first ALS-associated variant in the gene SOD1 was discovered. The most commonly mutated ALS genes in the European populations include the C9orf72, SOD1, TARDBP and FUS. Understanding the genetic causes of ALS within a population is becoming more significant, especially in light of the possible development of personalized medicine. Here, we provide clinical and genetic data on familial and sporadic ALS patients in a Greek-Cypriot population-based cohort. Eighty-nine ALS patients, including 21 familial ALS (fALS) (23.6%) and 68 sporadic ALS (sALS) (76.4%), provided the cohort for variant screening of the most common ALS-associated genes. Moreover, next-generation sequencing (NGS) was also performed to identify rare ALS variants, and in silico prediction tools were applied to predict the downstream effect of the variants detected in our study. The pathogenic hexanucleotide G4C2 repeat expansion in C9orf72 was the predominant genetic cause (22.47%) of ALS in our population, while variants in six additional ALS-associated genes were identified, including ALS2, TARDBP, FIG4, TBK1, GLT8D1, and BICD2.

Involvement of the left uncinate fasciculus in the amyotrophic lateral sclerosis: an exploratory longitudinal multi-modal neuroimaging and neuropsychological study

To investigate the microstructural integrity, tract volume analysis, and functional connectivity (FC) alterations of the left uncinate fasciculus (UF) in patients with amyotrophic lateral sclerosis (ALS) compared to healthy controls (HCs). Fourteen limb-onset ALS patients were recruited at baseline and ten at follow-up, along with 14 HCs. All participants underwent 3D T1-weighted, diffusion tensor imaging and kurtosis imaging (DTI/DKI), and resting-state functional MRI (rs-fMRI) using a 3 Tesla scanner with 64-channel coils. Eight metrics of diffusion, rs-FC of the left UF, and graph theory analyses were extracted. Statistical group comparisons and correlation analysis for significant diffusion metrics were also conducted. Significantly lower radial kurtosis (RK), mean kurtosis (MK), and higher DTI diffusivity metrics were observed in the left UF of ALS patients than in HCs. RK and MK were correlated with various cognitive scores, particularly executive function and visuospatial ability. The volume of the left UF was positively correlated only with RK and MK at follow-up. While rs-FC analysis did not reveal group differences, a negative functional link between the left UF and cerebellum was observed in HCs but not in patients. Graph theory analysis suggested decreased connectivity in baseline patients and potential compensatory effects during the follow-up. Our study reveals microstructural abnormalities and potential network changes in left UF. DKI metrics, especially RK and MK, may be more sensitive biomarkers than DTI metrics, particularly longitudinally. Diffusion changes appear to precede volume and functional connectivity alterations, suggesting diffusion as a potential early biomarker.

Exploring the Role of Axons in ALS from Multiple Perspectives

Amyotrophic lateral sclerosis (ALS), commonly known as motor neuron disease, is a neurodegenerative disorder characterized by the progressive degeneration of both upper and lower motor neurons. This pathological process results in muscle weakness and can culminate in paralysis. To date, the precise etiology of ALS remains unclear. However, a burgeoning body of research indicates that axonal dysfunction is a pivotal element in the pathogenesis of ALS and significantly influences the progression of disease. Dysfunction of axons in ALS can result in impediments to nerve impulse transmission, leading to motor impairment, muscle atrophy, and other associated complications that severely compromise patients' quality of life and survival prognosis. In this review, we concentrate on several key areas: the ultrastructure of axons, the mechanisms of axonal degeneration in ALS, the impact of impaired axonal transport on disease progression in ALS, and the potential for axonal regeneration within the central nervous system (CNS). Our objective is to achieve a more holistic and profound understanding of the multifaceted role that axons play in ALS, thereby offering a more intricate and refined perspective on targeted axonal therapeutic interventions.

Unveiling the veil of adipokines: A meta-analysis and systematic review in amyotrophic lateral sclerosis

BACKGROUND

Adipokines are proposed to be associated with ALS progression through assorted pathways. Therefore, The present meta-analysis explored the link between various adipokines and ALS progression.

METHOD

International database like PubMed, Scopus, and Web of Science databases were searched to achieve eligible papers published before December 2023. The following PICO structure was utilized: Population (patients with ALS); Intervention (serum concentrations of ghrelin, leptin, and adiponectin), Comparison (with or without controls), and Outcome (ALS progression). the risk of bias of selected papers was assessed through the Newcastle-Ottawa Scale (NOS) tool.

RESULTS

11 out of 240 papers were selected for this study which were published between 2010 and 2024. Lower serum leptin concentrations were detected in the ALS compared to control groups (WMD: -0.91, 95% CI:-1.77, -0.05). Serum concentrations of adiponectin were higher in ALS compared to control groups (WMD: 0.41, 95% CI:-0.7, 0.89). Ultimately, The serum concentrations of ghrelin in the ALS groups were lower than control groups (WMD: -1.21, 95% CI: -2.95, 0.53).

CONCLUSION

Our findings revealed that serum concentrations of ghrelin and leptin were higher in ALS patients compared to control, unlike adiponectin.

Survival Prognostic Factors of Non-Invasive Ventilation in Amyotrophic Lateral Sclerosis: A Systematic Review

OBJECTIVE

Amyotrophic lateral sclerosis is a neurodegenerative disease with high rates of disability and mortality. Non-invasive ventilation (NIV) is an effective method of treating patients, increasing life expectancy, but currently, predictors available to determine the best outcome of therapy in this category of patients are unknown. This systematic review aimed to determine the impact of prognostic factors on benefits from NIV application compared with non-NIV tools of treatment (invasive ventilation and standard care) in case of survival of ALS patients.

METHOD

We systematically sought relevant longitudinal cohort and case-control studies published in PubMed, CINAHL/EMBASE, Cochrane library, and Scopus.

RESULTS

We included seven prospective studies, published in 2010-2020, in the analysis. According to the evidence base available to date, NIV favors survival compared to non-NIV in patients with bulbar onset ALS. We obtained conflicting data on the significance of spinal onset and bulbar function. Survival depending on patient age, and also for spinal, cervical, and flail limb phenotypes during NIV therapy has not been sufficiently studied and needs further investigation.

CONCLUSIONS

The studies analyzed in this review allow us to state with confidence that NIV is effective in bulbar onset ALS, taking into account recommendations for duration of ventilation and the use of the full range of symptomatic therapy, including mechanically assisted coughing. The effectiveness of NIV on severe bulbar symptoms requires further research.

Incidence and mortality of ALS: a 42-year population-based nationwide study

BACKGROUND AND AIM

Recent studies have suggested that the incidence rate (IR) and the rate of death (MR) of amyotrophic lateral sclerosis (ALS) are increasing. Still, it remains unclear whether this is due to improved case ascertainment or represents a true increase. We examined the development in the incidence and mortality of ALS in Denmark for 42 years.

METHODS

We retrieved individual-level data of all patients aged above 18 years with first-time ALS diagnosed at any Danish department of neurology. The IR and MR were calculated based on data from 1980 to 2021, stratified by gender and age.

RESULTS

We identified 5,943 patients with ALS and identified a total of 5,069 deaths in the nationwide population. Overall, the IR was 3.4 per 100,000 persons per year (95% CI 3.4-3.5). ALS incidence rose gradually during the study period, and the IR was 2.8 times higher (95% CI 2.4-3.2) when comparing the latest period (2018-2021) with the first (1980-1983). Parallel to the IR, the MR increased over time and was associated with male gender and rose with age at diagnosis, peaking in the 70-79-year age group.

CONCLUSION

In Denmark, the IR and MR of ALS increased threefold from 1980 to 2021, with steadily increasing risk related to male gender and in particular to higher age. Considering our aging societies, the number of elderly patients with ALS can be expected to increase considerably.

Effect of fecal microbiota transplantation on patients with sporadic amyotrophic lateral sclerosis: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder marked by the progressive loss of motor neurons. Recent insights into ALS pathogenesis underscore the pivotal role of the gut microbiome, prompting an investigation into the potential therapeutic impact of fecal microbiota transplantation (FMT) on sporadic ALS patients.

METHODS

Conducted as a double-blind, placebo-controlled, parallel-group, randomized clinical trial, the study enrolled 27 participants from October 2022 to April 2023. The participants were followed up for 6 months from February 2023 to October 2023, during in-person visits at baseline, week 15, week 23, and week 35. The participants, evenly randomized, received either healthy donor FMT (FMT, n = 14) or a mixture of 0.9% saline and food coloring (E150c) as sham transplantation (placebo, n = 13). The primary outcome measured the change in the ALS Functional Rating Scale-Revised (ALSFRS-R) total score from baseline to week 35. Secondary outcomes included changes in gastrointestinal and respiratory functions, muscle strength, autonomic function, cognition, quality of life, intestinal microbiome composition, and plasm neurofilament light chain protein (NFL). Efficacy and safety outcomes were assessed in the intention-to-treat population.

RESULTS

A total of 27 randomized patients (47% women; mean age, 67.2 years), 24 participants completed the entire study. Notably, ALSFRS-R score changes exhibited no significant differences between FMT (6.1 [SD, 3.11]) and placebo (6.41[SD, 2.73]) groups from baseline to week 35. Secondary efficacy outcomes, encompassing respiratory function, muscle strength, autonomic function, cognition, quality of life, and plasm NFL, showed no significant differences. Nevertheless, the FMT group exhibited improvements in constipation, depression, and anxiety symptoms. FMT induced a shift in gut microbiome community composition, marked by increased abundance of Bifidobacterium, which persisted until week 15 (95% CI, 0.04 to 0.28; p = 0.01). Gastrointestinal adverse events were the primary manifestations of FMT-related side effects.

CONCLUSIONS

In this clinical trial involving 27 sporadic ALS patients, FMT did not significantly slow the decline in ALSFRS-R score. Larger multicenter trials are needed to confirm the efficacy of FMT in sporadic ALS patients and to explore the underlying biological mechanisms.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR 2200064504.

Exploring amyotrophic lateral sclerosis through the visual system: A systematic review

BACKGROUND AND PURPOSE

The human visual system relies on neural networks throughout the brain that are easily accessible for tests exploring eye structures and movements. Over the past two decades, investigations have been carried out on both afferent and efferent components of the visual system in people with amyotrophic lateral sclerosis (ALS). This approach might represent an innovative biomarker research strategy to better characterise the phenotypic variability of ALS. The purpose of this review was to determine whether exploring the visual system of patients with ALS (pwALS) is an effective strategy.

METHODS

The Medline and Web of science databases were searched for studies with terms relating to ALS and vision. Of 1146 references identified, 43 articles were included.

RESULTS

In this review article, both afferent and efferent components of the visual system were found to be impaired in pwALS in the absence of visual complaint, thereby contributing to the hypothesis that ALS is a multisystem disease with sensory involvement. Of note, some areas of the eye remain unexplored (i.e., tears, and retinal function using electroretinography).

CONCLUSIONS

According to the findings available in the literature, investigating the oculomotor system and exploring the ocular surface could represent two key promising strategies to identify new diagnostic biomarkers in pwALS. Further longitudinal studies are needed to identify relevant indicators of disease progression and response to therapeutic intervention.

Diaphragm pacing compared with mechanical ventilation in patients with chronic respiratory failure caused by diaphragmatic dysfunction: a systematic review and meta-analysis

BACKGROUND

The effectiveness of diaphragmatic electrical stimulation (DES) compared to mechanical ventilation (MV) in improving clinical outcomes such as quality-of-life (QOL) and hospital stay remains inconsistent.

METHODS

We conducted a systematic review and meta-analysis by searching PubMed, Scopus, Google Scholar, LILACS, and IEEE Xplore. We included comparative studies (randomized controlled trials and observational studies) of DES administered via the phrenic nerve or intramuscular electrodes, compared with MV in adults with diaphragmatic paralysis or paresis. Two authors independently extracted data and assessed bias, with discrepancies resolved by a senior author. Results were pooled using the inverse variance method.

RESULTS

Out of 1,290 articles, nine were included in the systematic review, totaling 852 subjects. In spinal cord injury (SCI), one study reported lower mortality with DES, while three found no difference compared to MV. In these patients, DES was associated with shorter hospital stay, similar QOL, and heterogeneous results on respiratory infections. In amyotrophic lateral sclerosis (ALS), DES was associated with higher mortality and similar QOL compared to MV. Most SCI studies had a serious risk of bias.

CONCLUSION

DES shows potential in reducing hospital stay and respiratory infections in SCI but is associated with higher mortality in ALS.

From suspicion to diagnosis: exploration strategy for suspected amyotrophic lateral sclerosis

The diagnosis of amyotrophic lateral sclerosis (ALS) is based on evidence of upper and lower motor neuron degeneration in the bulbar, cervical, thoracic, and lumbar regions in a patient with progressive motor weakness, in the absence of differential diagnosis. Despite these well-defined criteria, ALS can be difficult to diagnose, given the wide variety of clinical phenotypes. Indeed, the central or peripheral location of the disease varies with a spectrum ranging from predominantly central to exclusively peripheral, symptoms can be extensive or limited to the limbs, bulbar area or respiratory muscles, and the duration of the disease may range from a few months to several decades. In the absence of a specific test, the diagnostic strategy relies on clinical, electrophysiological, biological and radiological investigations to confirm the disease and exclude ALS mimics. The main challenge is to establish a diagnosis based on robust clinical and paraclinical evidence without delaying treatment initiation by increasing the number of additional tests. This approach requires a thorough knowledge of the phenotypes of ALS and its main differential diagnoses.

A bibliometric analysis of gene editing and amyotrophic lateral sclerosis (from 2004 to 2024)

Objective

To learn more about gene editing and ALS, and to provide a comprehensive view of gene editing for further treatment of amyotrophic lateral sclerosis.

Methods

We searched 1981 records from Web of Science core collection and Pubmed, Scopus, of which 1,292 records were obtained after exclusion. We then scientifically and metrologically analyzed these records for spatial and temporal distribution, author distribution, subject categories, subject distribution, references, and keywords using R, software CiteSpace and VOSviewer.

Results

Our analysis provides basic information about research in the field, suggests that the field has stabilized over the past decade, and identifies potential partners for interested researchers. Current research in this area is focused on inflammatory mechanisms, immune mechanisms, related diseases, and associated cytokines in ALS.

Conclusion

RNA Editing, Antisense Bligonucleotide, and Glycine Receptor are cutting-edge research topics in this field, which is undergoing rapid development. We hope that this work will provide new ideas for advancing the scientific research and clinical application of ALS.

Epigenetic Explorations of Neurological Disorders, the Identification Methods, and Therapeutic Avenues

Neurodegenerative disorders are major health concerns globally, especially in aging societies. The exploration of brain epigenomes, which consist of multiple forms of DNA methylation and covalent histone modifications, offers new and unanticipated perspective into the mechanisms of aging and neurodegenerative diseases. Initially, chromatin defects in the brain were thought to be static abnormalities from early development associated with rare genetic syndromes. However, it is now evident that mutations and the dysregulation of the epigenetic machinery extend across a broader spectrum, encompassing adult-onset neurodegenerative diseases. Hence, it is crucial to develop methodologies that can enhance epigenetic research. Several approaches have been created to investigate alterations in epigenetics on a spectrum of scales-ranging from low to high-with a particular focus on detecting DNA methylation and histone modifications. This article explores the burgeoning realm of neuroepigenetics, emphasizing its role in enhancing our mechanistic comprehension of neurodegenerative disorders and elucidating the predominant techniques employed for detecting modifications in the epigenome. Additionally, we ponder the potential influence of these advancements on shaping future therapeutic approaches.

Exposure to Metals, Pesticides, and Air Pollutants: Focus on Resulting DNA Methylation Changes in Neurodegenerative Diseases

Individuals affected by neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS), are dramatically increasing worldwide. Thus, several efforts are being made to develop strategies for stopping or slowing the spread of these illnesses. Although causative genetic variants linked to the onset of these diseases are known, they can explain only a small portion of cases. The etiopathology underlying the neurodegenerative process in most of the patients is likely due to the interplay between predisposing genetic variants and environmental factors. Epigenetic mechanisms, including DNA methylation, are central candidates in translating the effects of environmental factors in genome modulation, and they play a critical role in the etiology of AD, PD, and ALS. Among the main environmental exposures that have been linked to an increased risk for these diseases, accumulating evidence points to the role of heavy metals, pesticides, and air pollutants. These compounds could trigger neurodegeneration through different mechanisms, mainly neuroinflammation and the induction of oxidative stress. However, increasing evidence suggests that they are also capable of inducing epigenetic alterations in neurons. In this article, we review the available literature linking exposure to metals, pesticides, and air pollutants to DNA methylation changes relevant to neurodegeneration.

Phrenic Nerve Sonography Alterations in Patients with ALS: Insight with Clinical and Neurophysiological Findings

Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder, and although the diagnosis is primarily based on clinical criteria, ENMG, as the "gold standard", does not always show detectable changes. Therefore, our study suggests that alterations in echogenicity and heterogeneity of the phrenic nerve (PN) may serve as potential additional diagnostic tools for ALS. Methods: Our study included 32 patients in the ALS group and 64 individuals in the control group. Each participant underwent an interview and completed questionnaires to collect clinical and demographic data, including age, gender, height, body mass index (BMI), hip and waist circumference, duration of illness, ALS-FRS-R score, comorbidities, and medication use. Ultrasound examinations of the PN were performed by two authors using a high-resolution "Philips EPIQ 7" ultrasound machine equipped with a linear 4-18 MHz transducer. The ALS group participants underwent PN sonography and conduction examinations, arterial blood gas (ABG) analysis, respiratory function tests (RFT), and electroneuromyography (ENMG). Results: The study demonstrated that the phrenic nerve is significantly smaller on both sides in patients with ALS compared to the control group (p < 0.01). Changes in the homogeneity and echogenicity of the PN were also observed on both sides. On the right side, 43.8% of the nerves showed heterogeneity, 40.6% were isoechoic, and 21.9% were hyperechoic. On the left side, 59.4% of the nerves exhibited heterogeneity, 34.4% were isoechoic, and 28.1% were hyperechoic. Moreover, sonography on both sides showed significant correlation with ALS-FRS-R, COMPASS-31, and ENMG results. Conclusions: Our study highlights the importance of phrenic nerve ultrasound as a promising supplementary diagnostic tool for ALS. The significant differences in phrenic nerve size, echogenicity, and homogeneity between patients with ALS and the control group demonstrate that ultrasound imaging can detect morphological changes in the phrenic nerve. Incorporating phrenic nerve ultrasound into routine diagnostic protocols could improve early detection, enhance disease monitoring, and offer a more comprehensive understanding of the neurodegenerative processes in ALS.

CSF and blood levels of Neurofilaments, T-Tau, P-Tau, and Abeta-42 in amyotrophic lateral sclerosis: a systematic review and meta-analysis

Recent literature suggests that markers of neuroaxonal damage, such as neurofilaments and tau protein, might serve as potential biomarkers for ALS. We conducted this systematic review and meta-analysis study to compare cerebrospinal fluid (CSF) and blood levels of total tau (t-tau), phosphorylated tau (p-tau), amyloid beta peptide 42 (Abeta-42), and neurofilaments in ALS patients and controls. A systematic search of Cochrane Library, PubMed, Embase, and ISI Web of Science was conducted on March 18, 2022, and updated on January 26, 2023. Observational studies that compared the concentrations of neurofilament light chain (NfL), neurofilament heavy chain (NFH), t-tau, p-tau, or Abeta-42 in CSF or peripheral blood of ALS patients and controls were included. Data from relevant studies were independently extracted and screened for quality using a standard tool, by at least two authors. Meta-analysis was conducted when a minimum of 3 studies reported the same biomarker within the same biofluid. A total of 100 studies were eligible for at least one meta-analysis. CSF and blood levels of NfL (standardized mean difference (SMD) [95% CI]; CSF: 1.46 [1.25-1.68]; blood: 1.35 [1.09-1.60]) and NFH (CSF: 1.32 [1.13-1.50], blood: 0.90 [0.58-1.22]) were significantly higher in ALS patients compared with controls. The pooled differences between ALS patients and controls were not significant for CSF t-tau, blood t-tau, and CSF Abeta-42, but CSF p-tau was lower in ALS patients (-0.27 [-0.47- -0.07]). Significantly decreased p-tau/t-tau ratios were found in ALS patients compared with controls (-0.84 [-1.16- -0.53]). Heterogeneity was considerable in most of our meta-analyses. CSF and blood neurofilament levels, as well as the CSF p-tau/t-tau ratio, might be potential candidates for improving ALS diagnosis. Further research is warranted to better understand the underlying mechanisms and the clinical implications of these biomarker alterations.

Perceived Pain in People Living with Amyotrophic Lateral Sclerosis-A Scoping Review

(1) Background: Pain is a common symptom in patients with Amyotrophic Lateral Sclerosis (ALS). There are no evidence-based pharmacological treatments for pain in ALS; recommendations are based on guidelines for chronic non-oncological pain and clinical experience. The aim is to map the literature on how people with ALS experience pain, and how this affects their daily activities and social relationships. (2) Methods: This scoping review included studies concerning patients with spinal/bulbar ALS aged ≥ 18 years who experience pain, focusing on perception, characteristics, treatment, and impact on quality of life. Temporal and linguistic criteria were applied when searching the MEDLINE, CINAHL, and SCOPUS databases. (3) Results: The management of pain in these patients is complex and involves the use of anti-inflammatory drugs, analgesics, and opioids. Pain is associated with other conditions such as depression and anxiety, which contribute to a deterioration in the quality of life. Moreover, pain may also negatively influence patient compliance with prescribed treatment regimens and the quality of care they perceive themselves to be receiving. (4) Conclusions: It is of the most importance to identify effective ways to assess and treat this issue, with health care professionals taking an active role in this process.

The Neuroprotective Role of Cyanobacteria with Focus on the Anti-Inflammatory and Antioxidant Potential: Current Status and Perspectives

Neurodegenerative diseases are linked to the process of neurodegeneration. This can be caused by several mechanisms, including inflammation and accumulation of reactive oxygen species. Despite their high incidence, there is still no effective treatment or cure for these diseases. Cyanobacteria have been seen as a possible source for new compounds with anti-inflammatory and antioxidant potential, such as polysaccharides (sacran), phycobiliproteins (phycocyanin) and lipopeptides (honaucins and malyngamides), which can be interesting to combat neurodegeneration. As a promising case of success, Arthrospira (formerly Spirulina) has revealed a high potential for preventing neurodegeneration. Additionally, advantageous culture conditions and sustainable production of cyanobacteria, which are allied to the development of genetic, metabolic, and biochemical engineering, are promising. The aim of this review is to compile and highlight research on the anti-inflammatory and antioxidant potential of cyanobacteria with focus on the application as neuroprotective agents. Also, a major goal is to address essential features that brand cyanobacteria as an ecoefficient and economically viable option, linking health to sustainability.

Unveiling the double-edged sword: SOD1 trimers possess tissue-selective toxicity and bind septin-7 in motor neuron-like cells

Misfolded species of superoxide dismutase 1 (SOD1) are associated with increased death in amyotrophic lateral sclerosis (ALS) models compared to insoluble protein aggregates. The mechanism by which structurally independent SOD1 trimers cause cellular toxicity is unknown but may drive disease pathology. Here, we uncovered the SOD1 trimer interactome-a map of potential tissue-selective protein-binding partners in the brain, spinal cord, and skeletal muscle. We identified binding partners and key pathways associated with SOD1 trimers and found that trimers may affect normal cellular functions such as dendritic spine morphogenesis and synaptic function in the central nervous system and cellular metabolism in skeletal muscle. We discovered SOD1 trimer-selective enrichment of genes. We performed detailed computational and biochemical characterization of SOD1 trimer protein binding for septin-7. Our investigation highlights key proteins and pathways within distinct tissues, revealing a plausible intersection of genetic and pathophysiological mechanisms in ALS through interactions involving SOD1 trimers.

Differentially expressed lncRNAs in SOD1G93A mice skeletal muscle: H19, Myhas and Neat1 as potential biomarkers in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neuromuscular disease characterized by progressive motor function and muscle mass loss. Despite extensive research in the field, the underlying causes of ALS remain incompletely understood, contributing to the absence of specific diagnostic and prognostic biomarkers and effective therapies. This study investigates the expression of long-non-coding RNAs (lncRNAs) in skeletal muscle as a potential source of biomarkers and therapeutic targets for the disease. The expression profiles of 12 lncRNAs, selected from the literature, were evaluated across different disease stages in tissue and muscle biopsies from the SOD1G93A transgenic mouse model of ALS. Nine out of the 12 lncRNAs were differentially expressed, with Pvt1, H19 and Neat1 showing notable increases in the symptomatic stages of the disease, and suggesting their potential as candidate biomarkers to support diagnosis and key players in muscle pathophysiology in ALS. Furthermore, the progression of Myhas and H19 RNA levels across disease stages correlated with longevity in the SOD1G93A animal model, effectively discriminating between long- and short-term survival individuals, thereby highlighting their potential as prognostic indicators. These findings underscore the involvement of lncRNAs, especially H19 and Myhas, in ALS pathophysiology, offering novel insights for diagnostic, prognostic and therapeutic targets.

Ultra-high dose methylcobalamin and other emerging therapies for amyotrophic lateral sclerosis

PURPOSE OF REVIEW

Recent development in understanding the pathophysiology of amyotrophic lateral sclerosis (ALS) has led to increasing number of promising test drugs in the pipeline along with the existing ones. We will review these agents focusing on ultra-high dose methylcobalamin, which is pending approval in Japan. Clinical trial design best suited for ALS will also be discussed.

RECENT FINDINGS

The most recent phase 3 trial (JETALS) of ultra-high dose methylcobalamin demonstrated significant slowing of ALSFRSR changes (0.5/month), with marked reduction of serum homocysteine levels in the initial double-blind period. The post hoc analysis of the previous phase 2/3 study (E761 trial; Eisai) showed that it prolonged survival of ALS patients, if started within 1 year of onset, but the previous studies suggested its efficacy even in later stages, depending upon the rate of progression. Phase 3 trial of AMX0035 or Relyvrio on the other hand showed negative results despite the promising phase 2 data. The latter did not adjust the disease progression rate before entry.

SUMMARY

Ultra-high dose methylcobalamin is not a vitamin supplement but a novel disease-modifying therapy for ALS, and it emphasizes homocysteine as a key factor in the disease process. Clinical trial design must include entering patients early and with similar rates of progression using pretrial observation periods for meaningful results, since ALS is a chronologically heterogenous condition with similar phenotypes.

Metabolomics of basal tears in amyotrophic lateral sclerosis: A cross-sectional study

PURPOSE

Amyotrophic lateral sclerosis (ALS) clinical variability, along with the lack of conclusive diagnostic instruments, result in average diagnosis delays of 9 months. This study aimed to assess whether metabolomic profiling of basal tears in ALS patients could act as a biological marker for diagnosing ALS, predicting prognosis, and discriminating between endophenotypes.

METHODS

A single-center prospective case-control study was conducted in France from September 2021 to March 2023 including patients with ALS according to the revised EI Escorial criteria. Two microliters of basal tears were collected using microcapillary glass tubes and analyzed with ultra-high performance liquid chromatography coupled with mass spectrometry. Both univariate and multivariate analyses were performed.

RESULTS

Twenty-five patients with ALS and 30 controls were included. No significant differences in metabolite levels were found between ALS and control groups (p > 0.05). The basal tear metabolome significantly discriminated bulbar and spinal forms of ALS based on 6 metabolites, among which 5 were decreased (aniline, trigonelline, caffeine, theophylline and methyl beta-D-galactoside) in the bulbar form and 1 was decreased in the spinal form (dodecanedioic acid).

CONCLUSION

This study represents the first prospective analysis of basal tear metabolomics in individuals with ALS. Despite the inability to distinguish between ALS patients and controls based on metabolic signatures, these findings could contribute to understanding the phenotypic diversity of ALS. Notably, distinct metabolic profiles were identified that differentiate between the bulbar and spinal forms of the disease.

Prognostic Factors and Epidemiology of Amyotrophic Lateral Sclerosis in Southeastern United States

Objective

To assess the performance of known survival predictors and evaluate their stratification capability in patients with amyotrophic lateral sclerosis (ALS).

Patients and Methods

We analyzed demographic and clinical variables collected at the Mayo Clinic, Florida ALS center during the first clinical visit of 1442 (100%) patients with ALS.

Results

Our cohort had a median (interquartile range [IQR]) age at diagnosis of 64.8 (57-72) years; 1350 (92%) were non-Hispanic White; and 771 (53.5%) were male. The median (IQR) diagnostic delay was 10.1 (6-18) months, body mass index was 25.4 (23-49), and forced vital capacity was 72% (52%-87%). Approximately 12% of patients tested carried a pathologic C9orf72 hexanucleotide repeat expansion. Median (IQR) ALS functional rating scale-revised score was 35 (29-40) and ALS cognitive behavioral screen score was 15 (12-17). The median (IQR) survival after diagnosis was 17.2 (9-31) months, and survival from symptom onset was 30 (20-48) months. We found that older age decreased forced vital capacity, and fast-progressing ALS functional rating scale-revised scores significantly (P<.0001) influence survival curves and associated hazard risk.

Conclusion

Although results obtained from our cohort are consistent with other reports (eg, men with spinal onset experience a longer survival than women with bulbar onset), they remind us of the complexity of the disease's natural history and the limited prognostic power of the most common clinical predictors.

Improving prediction models of amyotrophic lateral sclerosis (ALS) using polygenic, pre-existing conditions, and survey-based risk scores in the UK Biobank

BACKGROUND AND OBJECTIVES

Amyotrophic lateral sclerosis (ALS) causes profound impairments in neurological function, and a cure for this devastating disease remains elusive. This study aimed to identify pre-disposing genetic, phenotypic, and exposure-related factors for amyotrophic lateral sclerosis using multi-modal data and assess their joint predictive potential.

METHODS

Utilizing data from the UK (United Kingdom) Biobank, we analyzed an unrelated set of 292 ALS cases and 408,831 controls of European descent. Two polygenic risk scores (PRS) are constructed: "GWAS Hits PRS" and "PRS-CS," reflecting oligogenic and polygenic ALS risk profiles, respectively. Time-restricted phenome-wide association studies (PheWAS) were performed to identify pre-existing conditions increasing ALS risk, integrated into phenotypic risk scores (PheRS). A poly-exposure score ("PXS") captures the influence of environmental exposures measured through survey questionnaires. We evaluate the performance of these scores for predicting ALS incidence and stratifying risk, adjusting for baseline demographic covariates.

RESULTS

Both PRSs modestly predicted ALS diagnosis but with increased predictive power when combined (covariate-adjusted receiver operating characteristic [AAUC] = 0.584 [0.525, 0.639]). PheRS incorporated diagnoses 1 year before ALS onset (PheRS1) modestly discriminated cases from controls (AAUC = 0.515 [0.472, 0.564]). The "PXS" did not significantly predict ALS. However, a model incorporating PRSs and PheRS1 improved the prediction of ALS (AAUC = 0.604 [0.547, 0.667]), outperforming a model combining all risk scores. This combined risk score identified the top 10% of risk score distribution with a fourfold higher ALS risk (95% CI [2.04, 7.73]) versus those in the 40%-60% range.

DISCUSSION

By leveraging UK Biobank data, our study uncovers pre-disposing ALS factors, highlighting the improved effectiveness of multi-factorial prediction models to identify individuals at highest risk for ALS.

Gut microbiota immune cross-talk in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by the loss of motor neurons. While there has been significant progress in defining the genetic contributions to ALS, greater than 90 ​% of cases are sporadic, which suggests an environmental component. The gut microbiota is altered in ALS and is an ecological factor that contributes to disease by modulating immunologic, metabolic, and neuronal signaling. Depleting the microbiome worsens disease in the SOD1 ALS animal model, while it ameliorates disease in the C9orf72 model of ALS, indicating critical subtype-specific interactions. Furthermore, administering beneficial microbiota or microbial metabolites can slow disease progression in animal models. This review discusses the current state of microbiome research in ALS, including interactions with different ALS subtypes, evidence in animal models and human studies, key immunologic and metabolomic mediators, and a path toward microbiome-based therapies for ALS.

Native State Stabilization of Amyloidogenic Proteins by Kinetic Stabilizers: Inhibition of Protein Aggregation and Clinical Relevance

Proteinopathies or amyloidoses are a group of life-threatening disorders that result from misfolding of proteins and aggregation into toxic insoluble amyloid aggregates. Amyloid aggregates have low clearance from the body due to the insoluble nature, leading to their deposition in various organs and consequent organ dysfunction. While amyloid deposition in the central nervous system leads to neurodegenerative diseases that mostly cause dementia and difficulty in movement, several other organs, including heart, liver and kidney are also affected by systemic amyloidoses. Regardless of the site of amyloid deposition, misfolding and structural alteration of the precursor proteins play the central role in amyloid formation. Kinetic stabilizers are an emerging class of drugs, which act like pharmacological chaperones to stabilize the native state structure of amyloidogenic proteins and to increase the activation energy barrier that is required for adopting a misfolded structure or conformation, ultimately leading to the inhibition of protein aggregation. In this review, we discuss the kinetic stabilizers that stabilize the native quaternary structure of transthyretin, immunoglobulin light chain and superoxide dismutase 1 that cause transthyretin amyloidoses, light chain amyloidosis and familial amyotrophic lateral sclerosis, respectively.

Evidence for the potential role of m6A modification in regulating autophagy in models of amyotrophic lateral sclerosis

Objective

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease. Research indicates that N6-methyladenosine (m6A) modification plays a crucial role in cellular autophagy during ALS development. This study investigates the role of autophagy in ALS, with a focus on the effect of messenger ribonucleic acid m6A methylation modification on disease progression.

Material and Methods

We compared m6A levels and regulatory molecule expressions in transgenic superoxide dismutase (SOD1)-G93A and non-transgenic mice, categorized into end-stage and control groups, using quantitative polymerase chain reaction and Western blotting. The NSC-34 cell line, which was modified to model ALS, enabled the investigation of apoptosis, autophagy, and autophagy disruption through terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling assays, Western blotting, and fluorescent staining.

Results

Our findings indicate significantly elevated m6A methylation levels in ALS mice (0.262 ± 0.005) compared with the controls (0.231 ± 0.003) and in the ALS model cells (0.242±0.005) relative to those belonging to the wild-type control group (0.183 ± 0.007). Furthermore, the proteins involved in m6A RNA modification differed between groups, which suggest impaired autophagy flux in the ALS models.

Conclusion

These results suggest that m6A methylation may accelerate ALS progression through the disruption of autophagic processes. Our study underscores the role of m6A methylation in the pathology of ALS and proposes the targeting of m6A methylation as a potential therapeutic strategy for disease treatment. Although this study primarily used transgenic SOD1-G93A mice and NSC-34 cell models to investigate ALS pathology, potential differences in disease mechanisms between animal models and humans must be considered. Although a correlation was detected between m6A methylation levels and autophagy disruption in ALS, the study primarily established an association rather than provided detailed mechanistic insights.

Tofersen for SOD1 ALS

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative condition affecting the motor system. The heterogenous nature of ALS complicates trial design. Genetic forms of ALS present an opportunity to intervene in a less heterogeneous population. ALS associated with gain of function mutations in SOD1 make 'knock-down' strategies an attractive therapeutic approach. Tofersen, an antisense oligonucleotide that reduces expression of SOD1 via RNAase mediated degradation of SOD1 mRNA, has shown robust effects on ALS biomarkers. While a Phase III trial of tofersen failed to meet its primary end point, open label extension data suggests that tofersen slows progression of SOD1 ALS.