A revision of the El Escorial criteria - 2015

MicroRNA signature of lymphoblasts from amyotrophic lateral sclerosis patients as potential clinical biomarkers

MicroRNAs (miRNAs) are a class of small, non-coding RNAs involved in different cellular functions that have emerged as key regulators of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). ALS is a fatal disease that lacks of not only effective treatments, but also presents delays in its diagnosis, since reliable clinical biomarkers are unavailable. In recent years, advancements in high-throughput sequencing strategies have led to the identification of novel ALS biomarkers, facilitating earlier diagnosis and assessment of treatment efficacy. Since immortalized lymphocytes obtained from peripheral blood are a suitable model to study pathological features of ALS, we employed these samples with the aim of characterize the dysregulated miRNAs in ALS patients. Next-generation sequencing (NGS) was utilized in order to analyze the expression profiles of miRNAs in immortalized lymphocytes from healthy controls, sporadic ALS (sALS), and familial ALS with mutations in superoxide dismutase 1 (SOD1-ALS). The screening analysis of the NGS data identified a set of dysregulated miRNAs, of which nine candidates were selected for qRT-PCR validation, identifying for the first time the possible importance of hsa-miR-6821-5p as a potential ALS biomarker. Furthermore, the up-regulated miRNAs identified are predicted to have direct or indirect interactions with genes closely related to ALS, such as SIGMAR1, HNRNPA1 and TARDBP. Additionally, by Metascape enrichment analysis, we found the VEGFA/VEGFR2 signaling pathway, previously implicated in neuroprotective effects in ALS, as a candidate pathway for further analyses.

Associations between water exposure and the development of amyotrophic lateral sclerosis: a matched case-control study

OBJECTIVE

Previous studies have hinted at an association between water exposure and the development of ALS. However, proximity measures to these water sources have been limited to questionnaires or large buffers due to a lack of fine geospatial measures. They also do not distinguish the various classes of hydrographic features. Thus, we created a robust database to investigate the association between proximity to water bodies at place of residence and the development of ALS.

METHODS

A matched (sex and year of birth) case-control study was conducted in New Brunswick, Canada from January 2003 to February 2021. Study population included 304 ALS patients and 1207 controls with their historical postal codes linked to spatial proximity datasets and air pollution index indicators (proxy measures for contamination by run-off).

RESULTS

Odds of ALS were not significantly associated with proximity to water bodies, even within a 250 m buffer from place of residence (Oceans: 1.10, 0.60-2.00 [95% CI], Reservoirs/Ponds/Lakes: 1.24, 0.47-3.30 [95% CI]). As for interaction models investigating proximity to potentially contaminated water bodies, none of the final fitted models observed an association between proximity to water bodies with indicators of potential run-off sources and the development of ALS.

CONCLUSIONS

No significant association between proximity to water bodies at place of residence and the development of ALS were observed in the current study. Future studies should consider taking direct measurements of water quality or utilize geomaps of spraying activities and cyanobacteria blooms alongside proximity measures. Household water quality is another avenue to explore, particularly well water use.

Cognitive capacity in amyotrophic lateral sclerosis: the value of diagnostic markers in cerebrospinal fluid and the influence of nutrition and pulmonary function

Amyotrophic lateral sclerosis is an incurable neurodegenerative disease that is fatal with a median of 3-4 years. It is characterized by degeneration of the first and second motor neurons. In addition to physical limitations, neuropsychological abnormalities occur in more than 50% of cases. This leads to a rapid loss of autonomy and increases the need for care. An individual prognosis for the course of the disease, in particular the development of cognitive and behavioural abnormalities, is not yet possible As part of our investigations, we focused on cognitive performance and behavioural abnormalities measured by the Edinburgh Cognitive and Behavioural ALS Screen in patients with amyotrophic lateral sclerosis and investigated possible prognostic biomarkers in cerebrospinal fluid as well as modifiable factors such as nutrition and lung function. A retrospective data analysis of 99 patients with amyotrophic lateral sclerosis cases examined between 2018 and 2021 at the Department for Neurodegenerative Diseases and Gerontopsychiatry at the University Hospital of Bonn, using Edinburgh Cognitive and Behavioural ALS Screen, revealed that elevated levels of total tau and phospho-tau 181 were associated with diminished performance of patients with amyotrophic lateral sclerosis on the Edinburgh Cognitive and Behavioural ALS Screen. Additionally, weight loss during the course of the disease has been observed to have a deleterious impact on cognitive performance. Moreover, we were able to demonstrate a previously insufficiently described correlation between abnormalities in the Edinburgh Cognitive and Behavioural ALS Screen and low-normal thiamine levels in serum. The hypothesis that reduced lung function has a negative effect on cognitive performance was not supported by our findings. The initial onset of amyotrophic lateral sclerosis, whether bulbar or spinal, does not appear to affect cognition and behaviour measured using Edinburgh Cognitive and Behavioural ALS Screen. Furthermore, our findings confirm the utility of the Edinburgh Cognitive and Behavioural ALS Screen in identifying a behavioural variant frontotemporal dementia in amyotrophic lateral sclerosis patients who have been previously diagnosed by experienced neurologists using the Rascovsky criteria. This development facilitates a more precise utilization of complex diagnostic instruments. Our results provide insight into the prognosis of patients with amyotrophic lateral sclerosis in terms of cognitive performance and behavioural abnormalities as the disease progresses, as well as potential therapeutic approaches to stabilize and support neuropsychological abnormalities. The importance of total tau as a widely available prognostic marker should be emphasized. Additionally, new avenues of research are emerging, particularly regarding the role of thiamine in amyotrophic lateral sclerosis.

Advances in the early diagnosis of amyotrophic lateral sclerosis

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease. Despite rapid disease progression, diagnostic delay of 10-16 months persists, influenced by disease-specific factors and healthcare systems. Reducing it is crucial for early intervention, multidisciplinary care planning, and patient participation in clinical trials.

AREAS COVERED

The authors review relevant studies identified through PubMed from 1990 to 2024. The article explores factors contributing to diagnostic delay, the importance of early diagnosis, and strategies for improvement, including the role of diagnostic criteria and biomarkers.

EXPERT OPINION

Diagnosis of ALS remains clinical, with clinical expertise as the main modifiable factor in the diagnostic delay. Some biomarkers may be useful to speed up diagnosis at an earlier stage of the disease and in patients with atypical presentations or co-morbidities. However, the use of biomarkers for ALS diagnosis in clinical practice is far from being established and poses considerable challenges, including the lack of disease-specific biomarkers and the potential for delayed results. Until disease-specific biomarkers become available, early referral to ALS specialists, together with physician education programs, will remain the main tools to reduce diagnostic delay in the next years.

SUMO2/3 conjugation of TDP-43 protects against aggregation

Cytosolic aggregation of the RNA binding protein TDP-43 (transactive response DNA-binding protein 43) is a hallmark of amyotrophic lateral sclerosis and frontotemporal dementia. Here, we report that during oxidative stress, TDP-43 becomes SUMO2/3-ylated by the SUMO E3 ligase protein PIAS4 (protein inhibitor of activated STAT 4) and enriches in cytoplasmic stress granules (SGs). Upon pharmacological inhibition of TDP-43 SUMO2/3-ylation or PIAS4 depletion, TDP-43 enrichment in SGs is accompanied by irreversible aggregation. In cells that are unable to assemble SGs, SUMO2/3-ylation of TDP-43 is strongly impaired, supporting the notion that SGs are compartments that promote TDP-43 SUMO2/3-ylation during oxidative stress. Binding of TDP-43 to UG-rich RNA antagonizes PIAS4-mediated SUMO2/3-ylation, while RNA dissociation promotes TDP-43 SUMO2/3-ylation. We conclude that SUMO2/3 protein conjugation is a cellular mechanism to stabilize cytosolic RNA-free TDP-43 against aggregation.

Molecular Biomarkers of Neurodegeneration in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is the most prevalent motor neuron disease. However, definitive diagnosis could be delayed by up to 12 months due to the lack of specific and sensitive biomarkers for ALS. In our study, conducted for the first time on a large cohort of ALS patients (n = 100) within the Russian population, we assessed key biomarkers of neurodegenerative pathology, including β-amyloids (Aβ40 and Aβ42) and tau proteins (Tau-total and Tau-p181), as well as other pathogenetically relevant, promising biomarkers such as FGF-21, Kallikrein-6 (KLK-6), NCAM-1, Neurogranin (NRGN), TDP-43, Apolipoprotein E4, Clusterin (Apo J), Complement Factor H, Fetuin-A, α2-Macroglobulin, Apo AI, Apo CIII, Apo E, Complement C3, GDNF, sRAGE, and S100B protein. Significant differences between the ALS patients and the control group were observed for Aβ40 (p = 0.044), Aβ42 (p < 0.001), FGF-21 (p < 0.001), Tau-total (p = 0.001), Tau-p181 (p = 0.014), Clusterin (p < 0.001), Complement C3 (p = 0.001), and S100B (p = 0.024). A significant direct correlation was found between the ALSFRS-R score and concentrations of Aβ40 and Aβ42. Changes in the complement system (Complement C3 and Complement Factor H) were identified, highlighting critical role of neuroinflammatory processes in ALS pathogenesis. Additionally, increased levels of FGF-21 were observed in the patients with the bulbar onset of ALS. Significant increase in the concentration of the chaperone protein clusterin in the patients with rapid disease progression suggests its potential as a prognostic biomarker for motor neuron disease. Furthermore, its role in maintaining proteostasis could provide novel therapeutic targets.

GDF15-GFRAL signaling drives weight loss and lipid metabolism in mouse model of amyotrophic lateral sclerosis

Weight loss is a common early sign in amyotrophic lateral sclerosis (ALS) patients and negatively correlates with survival. In different cancers and metabolic disorders, high levels of serum growth differentiation factor 15 (GDF15) contribute to a decrease of food intake and body weight, acting through GDNF family receptor alpha-like (GFRAL). Here we report that GDF15 is highly expressed in the peripheral blood of ALS patients and in the hSOD1G93A mouse model and that GFRAL is upregulated in the brainstem of hSOD1G93A mice. We demonstrate that the localized GFRAL silencing by shRNA in the area postrema/nucleus tractus solitarius of hSOD1G93A mice induces weight gain, reduces adipose tissue wasting, ameliorates the motor function and muscle atrophy and prolongs the survival time. We report that microglial cells could be involved in mediating these effects because their depletion with PLX5622 reduces brainstem GDF15 expression, weight loss and the expression of lipolytic genes in adipose tissue. Altogether these results reveal a key role of GDF15-GFRAL signaling in regulating weight loss and the alteration of and lipid metabolism in the early phases of ALS.

Early-onset sleep alterations found in patients with amyotrophic lateral sclerosis are ameliorated by orexin antagonist in mouse models

Sleep alterations have been described in several neurodegenerative diseases yet are currently poorly characterized in amyotrophic lateral sclerosis (ALS). This study investigates sleep macroarchitecture and related hypothalamic signaling disruptions in ALS. Using polysomnography, we found that both patients with ALS as well as asymptomatic C9ORF72 and SOD1 mutation carriers exhibited increased wakefulness and reduced non-rapid eye movement sleep. Increased wakefulness correlated with diminished cognitive performance in both clinical cohorts. Similar changes in sleep macroarchitecture were observed in three ALS mouse models (Sod1G86R, FusΔNLS/+, and TDP43Q331K). A single oral administration of a dual-orexin receptor antagonist or intracerebroventricular delivery of melanin-concentrating hormone (MCH) through an osmotic pump over 15 days partially normalized sleep patterns in mouse models. MCH treatment did not extend the survival of Sod1G86R mice but did decrease the loss of lumbar motor neurons. These findings suggest MCH and orexin signaling as potential targets to treat sleep alterations that arise in early stages of the disease.

Tofersen and other antisense oligonucleotides in ALS

The advent of antisense oligonucleotide (ASO) therapies in neurodegenerative disorders is associated with enormous hope. Nusinersen treatment was a breakthrough intervention in the recessive disease spinal muscular atrophy, and superoxide dismutase 1 (SOD1) amyotrophic lateral sclerosis (ALS) seems to be the paradigm disease in dominant degenerative diseases. The results of treatment with the ASO tofersen in SOD1-ALS show that the drug has a convincing beneficial effect on ALS caused by SOD1 mutations, that preclinical studies in rodents predicted the therapeutic effect in the human disease, and that clinical efficacy is associated with a specific sequence of effects of the drug on mechanistic and degenerative biomarkers and, subsequently, functional outcomes such as weight stabilization and ALSFRS-R. Therefore, the enthusiasm seems to be justified; but this should be followed by an attempt to obtain further insights with the goal to improve this therapy. In particular, the following issues are only partially resolved: Which mechanisms are responsible for the clinical effect following the downregulation of SOD1 protein by ASOs? Is long-term downregulation of SOD1 function associated with side effects? Is there an autoimmune response caused by this and other ASO? Is prevention of SOD1-associated ALS possible?

Hypothalamic atrophy in primary lateral sclerosis, assessed by convolutional neural network-based automatic segmentation

Primary lateral sclerosis (PLS) is a motor neuron disease (MND) which mainly affects upper motor neurons. Within the MND spectrum, PLS is much more slowly progressive than amyotrophic laterals sclerosis (ALS). `Classical` ALS is characterized by catabolism and abnormal energy metabolism preceding onset of motor symptoms, and previous studies indicated that the disease progression of ALS involves hypothalamic atrophy. Very limited weight loss is observed in patients with PLS, which raises the question of whether there are also less hypothalamic alterations. The purpose of this study was to quantitatively investigate the hypothalamic volume in a group of PLS patients and to compare it with ALS and controls. Recently, we have introduced automatic hypothalamic quantification method based on the use of convolutional neural network (CNN) to reduce human variability and enhance analysis robustness. This CNN of U-Net architecture was applied for automatic segmentation of the hypothalamus and intracranial volume (ICV) to allow adjustments of the hypothalamic volume between subjects with different head sizes respectively. Automatic segmentation and volumetric analysis were performed in high resolution T1 weighted MRI volumes (acquired on a 1.5 T MRI scanner) of 46 PLS patients in comparison to 107 healthy controls and 411 `classical` ALS patients, respectively. Significant hypothalamic volume reduction was observed in PLS (818 ± 73 mm3) when compared to controls (852 ± 77 mm3); significant hypothalamic volume reduction was also confirmed in ALS (823 ± 84 mm3), in support of previous studies. No significant differences were found in normalized hypothalamic volumes between ALS patients and PLS patients at the group level. This unbiased CNN-based hypothalamus volume quantification study demonstrated similarly reduced hypothalamus volume in PLS and ALS patients, despite the clinical phenotypic differences.

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.

Clinical features and progress in diagnosis and treatment of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of the central nervous system. Despite a large number of studies, the current prognosis of ALS is still not ideal. This article briefly describes the clinical features including epidemiology, genetic structure and clinical manifestations, as well as the progress of new diagnostic criteria and treatment of ALS. Meanwhile, we also discussed further both developments and improvements to enhance understanding and accelerating the introduction of the effective treatments of ALS.

Accessing and Receiving Speech-Language Pathology Services at the Multidisciplinary Amyotrophic Lateral Sclerosis Clinic: An Exploratory Qualitative Study of Patient Experiences and Needs

PURPOSE

This study sought to explore how patients with amyotrophic lateral sclerosis (ALS) presenting with coexisting bulbar and cognitive impairments and their caregivers experienced the speech-language pathologist (SLP) services provided in multidisciplinary ALS clinics in Canada and identified their perceived needs for bulbar symptom management.

METHOD

This qualitative study was informed by interpretive description. Seven interviews were conducted with patients with severe bulbar dysfunction or severe bulbar and cognitive dysfunction due to ALS or ALS-frontotemporal dementia, respectively, and/or their caregivers. Purposive sampling was used to recruit individuals with severe bulbar or bulbar and cognitive disease. Thematic analysis was used to analyze interview data.

RESULTS

Patients and caregivers reported difficulties with accessing and receiving SLP services at the multidisciplinary ALS clinic. These difficulties were further exacerbated in those with severe cognitive disease. Participants expressed a need for more specific (i.e., disease and service-related) information and personalized care to address their changing needs and preferences. Engaging caregivers earlier in SLP appointments was perceived as vital to support care planning and provide in-time caregiver education.

CONCLUSIONS

This study highlighted the challenges experienced by patients and caregivers in accessing and receiving SLP services. There is a pressing need for a more person-centered approach to ALS care and a continuing need for education of SLPs on care provision in cases of complex multisymptom diseases within a multidisciplinary ALS clinic.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24069222.

Diagnostic criteria for amyotrophic lateral sclerosis

PURPOSE OF REVIEW

The present review will discuss the evolution of diagnostic criteria for amyotrophic lateral sclerosis (ALS) and biomarker considerations.

RECENT FINDINGS

To address the limitations of existing ALS diagnostic criteria, a consortium of key stakeholders developed the Gold Coast consensus criteria (GCC). The GCC has similar or greater sensitivity compared with the revised El Escorial (rEEC) and Awaji criteria (AC), particularly for atypical phenotypes, maintained across disease duration, severity, and site of onset. In addition to improving diagnostic sensitivity, using the GCC in clinical trials may promote an increased enrolment of up to 50% of ALS patients who do not currently meet the full diagnostic eligibility requirements of the rEEC. Future inclusion of genetic biomarkers may mitigate some limitations of the GCC, to further improve diagnostic utility. In advance of such a process, validation of these biomarkers will be required before inclusion as additional criteria.

SUMMARY

The GCC are simpler to use than previous consensus criteria, with demonstrated greater sensitivity and, enabling an earlier and more definitive ALS diagnosis, thereby facilitating wider enrolment into clinical trials. Broader implementation of the GCC in clinical trial settings is currently underway, globally.

TBK1 p.Y153Qfs*9 variant may be associated with young-onset, rapidly progressive amyotrophic lateral sclerosis through a haploinsufficiency mechanism

BACKGROUND

TBK1 variants have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia spectrum disorder. The current study elucidated the clinical and molecular genetic features of a novel TBK1 variant identified in a patient with young-onset, rapidly progressive ALS.

METHODS

The coding regions of TBK1 , SOD1 , TARDBP , and FUS were genetically analyzed using Sanger sequencing. Repeat-primed polymerase chain reaction (PCR) was used to survey the GGGGCC repeat in C9ORF72 . The study participant underwent a comprehensive clinical evaluation. The functional effects of the TBK1 variant were analyzed through in vitro transfection studies.

RESULTS

We identified a novel frameshift truncating TBK1 variant, c.456_457delGT (p.Y153Qfs*9), in a man with ALS. The disease initially manifested as right hand weakness at the age of 39 years but progressed rapidly, with the revised ALS Functional Rating Scale score declining at an average monthly rate of 1.92 points in the first year after diagnosis. The patient had no cognitive dysfunction. However, Technetium-99m single photon emission tomography indicated hypoperfusion in his bilateral superior and middle frontal cortices. In vitro studies revealed that the p.Y153Qfs*9 variant resulted in a truncated TBK1 protein product, reduced TBK1 protein expression, loss of kinase function, reduced interaction with optineurin, and impaired dimerization.

CONCLUSION

The heterozygous TBK1 p.Y153Qfs*9 variant may be associated with young-onset, rapidly progressive ALS through a haploinsufficiency mechanism.

Pain in patients with motor neuron disease: Variation of pain and association with disease severity, health-related quality of life and depression - A longitudinal study

OBJECTIVES

To describe levels of pain over time during disease progression in individual patients and for a total sample of patients with motor neuron disease (MND), respectively, and to examine associations between pain, disease severity, health-related quality of life (HRQOL), and depression.

METHODS

A prospective cohort study was conducted on 68 patients with MND, including data collected on five occasions over a period of 2 years. Pain was assessed using the Brief Pain Inventory - Short Form. Depression was assessed using the Amyotrophic Lateral Sclerosis (ALS)-Depression-Inventory (ADI-12). Disability progression was measured using the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised Version (ALSFRS-R). HRQOL was assessed using the Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-5).

RESULTS

Participants reported great individual variation over time. The median level of pain was 4 (min 0 and max 10). Higher levels of pain during the last 24 h were associated with higher depression scores (ADI-12), poorer quality of life (ALSAQ-5), and lower reporting of fine and gross motor skills (ALSFRS-R). Baseline pain levels did not predict future values of depression and function. Individuals reporting average pain >3 experienced more hopelessness toward the future and reported higher depression scores compared with participants reporting average pain <3.

SIGNIFICANCE OF RESULTS

Great within-individual variation of pain intensity was reported. Pain intensity was associated with depression, function and HRQOL cross-sectionally, but it did not have a strong prognostic value for future depression, function, or HRQOL. Patients with MND should be offered frequent assessment of pain and depressive symptoms in person-centered care, allowing for individualization of treatment.

Assessment of Cerebral White Matter Involvement in Amyotrophic Lateral Sclerosis Patients With Disease Progression and Cognitive Impairment by Fixel-Based Analysis and Neurite Orientation Dispersion and Density Imaging

BACKGROUND

Previous studies using emerging diffusion MRI techniques have revealed damage to the white matter (WM) microstructure in amyotrophic lateral sclerosis (ALS), particularly the influence of crossed fibers, but there is a lack of subgroup analyses.

PURPOSE

To detect WM microstructural changes in ALS patients using fixel-based analysis (FBA) and neurite orientation dispersion and density imaging (NODDI) MRI.

STUDY TYPE

Prospective.

POPULATION

Thirty-six ALS patients (aged 60.50 ± 9.5 years) and 25 healthy controls (HCs) (aged 58.90 ± 8.1 years).

FIELD STRENGTH/SEQUENCE

3 T; NODDI and FBA (b-values = 0, 1000, and 2500 seconds/mm2).

ASSESSMENT

Subgroups were performed according to progression rate and cognition, including fast and slow progression (FP/SP), ALS with and without cognitive impairment (ALS-ci/ALS-nci). Fiber density (FD), fiber-bundle cross-section (FC), combined fiber density and cross-section (FDC), neurite density index (NDI), orientation dispersion index (ODI), isotropic volume fraction (ISO), and fractional anisotropy (FA) were calculated and their correlation with clinical variables examined.

STATISTICAL TESTING

Chi-square test, Mann-Whitney U test, two-sample t test, partial correlation analysis, and false discovery rate (FDR) corrected. A P-value <0.05 was considered significant.

RESULTS

ALS patients had lower FD and FDC values predominantly in the corticospinal tract (CST) and corpus callosum (CC) regions, as well as lower NDI value in the CC, radial crown, and internal capsule compared to HCs. Subgroup analysis based on progression rate and cognitive function showed significant differences in FBA results. The FC in the right CST region was significantly lower in the FP than SP, and the FD in the CC region was significantly lower in the ALS-ci than ALS-nci. Furthermore, a negative correlation was found between the mean FC value and the rate of progression in ALS patients (r = -0.408).

DATA CONCLUSION

FBA is a powerful tool for detecting complex cerebral WM microstructural damage for evaluating ALS cognition and disease progression.

Clinical and genetic factors affecting diagnostic timeline of amyotrophic lateral sclerosis: a 15-year retrospective study

OBJECTIVES

Amyotrophic Lateral Sclerosis (ALS) diagnosis can take 10-16 months from symptom onset, leading to delays in treatment and patient counselling. We studied the impact of clinical and genetic risk factors on the diagnostic timeline of ALS.

METHODS

Baseline characteristics, family history, gene testing, onset location, time from symptom onset to diagnosis, and time from first doctor visit to suspected ALS was collected. We used multiple regression to assess the interaction of these factors on ALS diagnostic timeline. We analysed a subgroup of patients with genetic testing and compared positive or negative tests, sporadic or familial and ALS-related genes to time for diagnosis.

RESULTS

Four hundred and forty-eight patients diagnosed with ALS at the University of Massachusetts Chan Medical Center between January 2007 and December 2021 were analysed. The median time to ALS diagnosis was 12 months and remained unchanged from 2007 to 2021 (p = 0.20). Diagnosis was delayed in patients with sporadic compared with familial ALS (mean months [standard deviation], 16.5[13.5] and 11.2[8.5], p < 0.001); cognitive onset (41[21.26]) had longer time to diagnosis than bulbar (11.9[8.2]), limb (15.9[13.2]), respiratory (19.7[13.9]) and ALS with multiple onset locations (20.77[15.71], p < 0.001). One hundred and thirty-four patients had gene testing and 32 tested positive (23.8%). Gene testing (p = 0.23), a positive genetic test (p = 0.16), different ALS genes (p = 0.25) and sporadic (p = 0.92) or familial (p = 0.85) ALS testing positive for ALS genes did not influence time to diagnosis.

DISCUSSION

Time for ALS diagnosis remained unchanged from 2007 to 2021, bulbar-onset and familial ALS made for faster diagnosis.

Spatial enrichment and genomic analyses reveal the link of NOMO1 with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a severe motor neuron disease with uncertain genetic predisposition in most sporadic cases. The spatial architecture of cell types and gene expression are the basis of cell-cell interactions, biological function and disease pathology, but are not well investigated in the human motor cortex, a key ALS-relevant brain region. Recent studies indicated single nucleus transcriptomic features of motor neuron vulnerability in ALS motor cortex. However, the brain regional vulnerability of ALS-associated genes and the genetic link between region-specific genes and ALS risk remain largely unclear. Here, we developed an entropy-weighted differential gene expression matrix-based tool (SpatialE) to identify the spatial enrichment of gene sets in spatial transcriptomics. We benchmarked SpatialE against another enrichment tool (multimodal intersection analysis) using spatial transcriptomics data from both human and mouse brain tissues. To investigate regional vulnerability, we analysed three human motor cortex and two dorsolateral prefrontal cortex tissues for spatial enrichment of ALS-associated genes. We also used Cell2location to estimate the abundance of cell types in ALS-related cortex layers. To dissect the link of regionally expressed genes and ALS risk, we performed burden analyses of rare loss-of-function variants detected by whole-genome sequencing in ALS patients and controls, then analysed differential gene expression in the TargetALS RNA-sequencing dataset. SpatialE showed more accurate and specific spatial enrichment of regional cell type markers than multimodal intersection analysis in both mouse brain and human dorsolateral prefrontal cortex. Spatial transcriptomic analyses of human motor cortex showed heterogeneous cell types and spatial gene expression profiles. We found that 260 manually curated ALS-associated genes are significantly enriched in layer 5 of the motor cortex, with abundant expression of upper motor neurons and layer 5 excitatory neurons. Burden analyses of rare loss-of-function variants in Layer 5-associated genes nominated NOMO1 as a novel ALS-associated gene in a combined sample set of 6814 ALS patients and 3324 controls (P = 0.029). Gene expression analyses in CNS tissues revealed downregulation of NOMO1 in ALS, which is consistent with a loss-of-function disease mechanism. In conclusion, our integrated spatial transcriptomics and genomic analyses identified regional brain vulnerability in ALS and the association of a layer 5 gene (NOMO1) with ALS risk.

AI-assisted automatic MRI-based tongue volume evaluation in motor neuron disease (MND)

PURPOSE

Motor neuron disease (MND) causes damage to the upper and lower motor neurons including the motor cranial nerves, the latter resulting in bulbar involvement with atrophy of the tongue muscle. To measure tongue atrophy, an operator independent automatic segmentation of the tongue is crucial. The aim of this study was to apply convolutional neural network (CNN) to MRI data in order to determine the volume of the tongue.

METHODS

A single triplanar CNN of U-Net architecture trained on axial, coronal, and sagittal planes was used for the segmentation of the tongue in MRI scans of the head. The 3D volumes were processed slice-wise across the three orientations and the predictions were merged using different voting strategies. This approach was developed using MRI datasets from 20 patients with 'classical' spinal amyotrophic lateral sclerosis (ALS) and 20 healthy controls and, in a pilot study, applied to the tongue volume quantification to 19 controls and 19 ALS patients with the variant progressive bulbar palsy (PBP).

RESULTS

Consensus models with softmax averaging and majority voting achieved highest segmentation accuracy and outperformed predictions on single orientations and consensus models with union and unanimous voting. At the group level, reduction in tongue volume was not observed in classical spinal ALS, but was significant in the PBP group, as compared to controls.

CONCLUSION

Utilizing single U-Net trained on three orthogonal orientations with consequent merging of respective orientations in an optimized consensus model reduces the number of erroneous detections and improves the segmentation of the tongue. The CNN-based automatic segmentation allows for accurate quantification of the tongue volumes in all subjects. The application to the ALS variant PBP showed significant reduction of the tongue volume in these patients and opens the way for unbiased future longitudinal studies in diseases affecting tongue volume.

Clinical spreading of muscle weakness in amyotrophic lateral sclerosis (ALS): a study in 910 patients

BACKGROUND

Neuroanatomical staging of sporadic amyotrophic lateral sclerosis (ALS) indicates that neurodegeneration may spread corticofugally.

METHODS

We conducted an observational study to define the initial sites of disease onset and the clinical progression ('spreading patterns') of motor deficits in a cohort of 910 ALS patients in Germany.

RESULTS

Mean age of ALS onset was 59.0 ± 12.6 years for males and 61.2 ± 10.5 years for females, the mean ALSFRS-R was 35.1 ± 9.2, and 7.7% of the cohort reported a family history. Onset of motor symptoms was bulbar/upper limb in 26.8%/35.9%, the right arm initially being slightly more often affected than the left (18.5% vs.16.3%). Testing on concordance of handedness and onset in the dominant arm did not reach significance. Lower limb onset was observed in 37.3%. Unilateral limb onset patients reported horizontal spreading about three times more often than vertical spreading. 71/244 bulbar onset patients reported spreading pattern to the legs, and 17/339 lumbar onset patients reported spreading secondarily to the bulbar region.

DISCUSSION

Our results indicate that, although the phenotype of so-called 'spinal' or 'intraspinal' spreading predominated, we also observed an additional clinical spreading pattern: 29.1% of patients with bulbar onset experienced spreading clinically to the legs (vice versa in 5.0% of lumbar onset patients). For obvious neuroanatomical reasons, this pattern hardly can be explained solely by a 'spinal' or an 'intraspinal' pattern of spreading. Instead, these findings complement insights from previous clinical and clinicopathological studies supporting a cortical initiation of ALS.

Relationship between pulmonary, cough, and swallowing functions in individuals with amyotrophic lateral sclerosis

INTRODUCTION/AIMS

Evaluations of pulmonary, cough, and swallow function are frequently performed to assess disease progression in amyotrophic lateral sclerosis (ALS), yet the relationship between these functions remains unknown. We therefore aimed to determine relationships between these measures in individuals with ALS.

METHODS

One hundred individuals with ALS underwent standardized tests: forced vital capacity (FVC), maximum expiratory/inspiratory pressure (MEP, MIP), voluntary cough peak expiratory flow (PEF), and videofluoroscopic swallow evaluation (VF). Duplicate raters completed independent, blinded ratings using the Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) scale. Descriptives, Spearman's Rho correlations, Kruskal-Wallis analyses, and Pearson's chi-squared tests were completed.

RESULTS

Mean and standard deviation across pulmonary and cough measures were FVC: 74.2% predicted (± 22.6), MEP: 91.6 cmH2O (± 46.4), MIP cmH2O: 61.1 (± 28.9), voluntary PEF: 352.7 L/min (± 141.6). DIGEST grades included: 0 (normal swallowing): 31%, 1 (mild dysphagia): 48%, 2 (moderate dysphagia): 10%, 3 (severe dysphagia): 10%, and 4 (life-threatening dysphagia): 1%. Positive correlations were observed: MEP-MIP: r = .76, MIP-PEF: r = .68, MEP-PEF: r = .61, MIP-FVC: r = .60, PEF-FVC: r = .49, and MEP-FVC: r = .46, p < .0001. MEP (p = .009) and PEF (p = .04) differed across DIGEST safety grades. Post hoc analyses revealed significant between group differences in MEP and PEF across DIGEST safety grades 0 versus 1 and grades 0 versus 3, (p < .05).

DISCUSSION

In this cohort of individuals with ALS, pulmonary function, and voluntary cough were associated. Expiratory metrics (MEP, PEF) were diminished in individuals with unsafe swallowing, increasing their risk for effectively defending the airway.

Screening instruments of cognition: The relation of the mini-mental state examination to the Edinburgh cognitive and behavioural ALS screen in amyotrophic lateral sclerosis

OBJECTIVE

The Edinburgh Cognitive and Behavioural ALS Screen (ECAS) is an established cognitive screening instrument for patients with amyotrophic lateral sclerosis (ALS). Different from tools like the Mini-Mental State Examination (MMSE), it is adjusted for motor impairment, yet, the latter remains one of the most widely used screening instruments, also in ALS studies. Thus, it is of utmost importance to relate outcome scores of both instruments to allow for comparison in ALS patients. This study reports on the performance of ALS patients in both tests with regard to incidence and degree of cognitive impairment, and the correspondence of both, ECAS and MMSE scores.

METHODS

We examined N = 84 ALS patients with the German versions of the ECAS and the MMSE. Performance in both tests regarding incidence and degree of cognitive impairment, and correspondence of frequency of cognitive impairment according to both tests was examined. The relationship between ECAS and MMSE scores was modelled with a non-linear regression model.

RESULTS

All ALS patients were able to complete the ECAS, 89.3% (N = 75) were capable to complete the MMSE. Prevalence of cognitive impairment was in both tests 22.7%, however agreement was only 52.9%. Despite, regression analyses yielded a strong positive relationship (adjusted R2 = .68) between the ECAS total score and the MMSE total score. Both tests were able to identify all patients with dementia.

CONCLUSION

These results suggest that the MMSE is not ideal for cognitive screening in early-stage ALS patients. However, a rough translation of MMSE scores in ECAS scores is possible to estimate the cognitive performance level of patients, with the ECAS being more discriminative in the lower range of cognitive dysfunction (ECAS score: 80-136), for which the MMSE does not define cognitive impairment (corresponding MMSE score: 27-30).

Plasma extracellular vesicle tau and TDP-43 as diagnostic biomarkers in FTD and ALS

Minimally invasive biomarkers are urgently needed to detect molecular pathology in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Here, we show that plasma extracellular vesicles (EVs) contain quantifiable amounts of TDP-43 and full-length tau, which allow the quantification of 3-repeat (3R) and 4-repeat (4R) tau isoforms. Plasma EV TDP-43 levels and EV 3R/4R tau ratios were determined in a cohort of 704 patients, including 37 genetically and 31 neuropathologically proven cases. Diagnostic groups comprised patients with TDP-43 proteinopathy ALS, 4R tauopathy progressive supranuclear palsy, behavior variant FTD (bvFTD) as a group with either tau or TDP-43 pathology, and healthy controls. EV tau ratios were low in progressive supranuclear palsy and high in bvFTD with tau pathology. EV TDP-43 levels were high in ALS and in bvFTD with TDP-43 pathology. Both markers discriminated between the diagnostic groups with area under the curve values >0.9, and between TDP-43 and tau pathology in bvFTD. Both markers strongly correlated with neurodegeneration, and clinical and neuropsychological markers of disease severity. Findings were replicated in an independent validation cohort of 292 patients including 34 genetically confirmed cases. Taken together, the combination of EV TDP-43 levels and EV 3R/4R tau ratios may aid the molecular diagnosis of FTD, FTD spectrum disorders and ALS, providing a potential biomarker to monitor disease progression and target engagement in clinical trials.

The Miami Framework for ALS and related neurodegenerative disorders: an integrated view of phenotype and biology

Increasing appreciation of the phenotypic and biological overlap between amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, alongside evolving biomarker evidence for a pre-symptomatic stage of disease and observations that this stage of disease might not always be clinically silent, is challenging traditional views of these disorders. These advances have highlighted the need to adapt ingrained notions of these clinical syndromes to include both the full phenotypic continuum - from clinically silent, to prodromal, to clinically manifest - and the expanded phenotypic spectrum that includes ALS, frontotemporal dementia and some movement disorders. The updated clinical paradigms should also align with our understanding of the biology of these disorders, reflected in measurable biomarkers. The Miami Framework, emerging from discussions at the Second International Pre-Symptomatic ALS Workshop in Miami (February 2023; a full list of attendees and their affiliations appears in the Supplementary Information) proposes a classification system built on: first, three parallel phenotypic axes - motor neuron, frontotemporal and extrapyramidal - rather than the unitary approach of combining all phenotypic elements into a single clinical entity; and second, biomarkers that reflect different aspects of the underlying pathology and biology of neurodegeneration. This framework decouples clinical syndromes from biomarker evidence of disease and builds on experiences from other neurodegenerative diseases to offer a unified approach to specifying the pleiotropic clinical manifestations of disease and describing the trajectory of emergent biomarkers.

Skin innervation across amyotrophic lateral sclerosis clinical stages: new prognostic biomarkers

Over recent decades, peripheral sensory abnormalities, including the evidence of cutaneous denervation, have been reported among the non-motor manifestations in amyotrophic lateral sclerosis (ALS). However, a correlation between cutaneous innervation and clinical features has not been found. The aims of this study were to assess sensory involvement by applying a morpho-functional approach to a large population of ALS patients stratified according to King's stages and correlate these findings with the severity and prognosis of the disease. We recruited 149 ALS patients and 41 healthy controls. Patients undertook clinical questionnaires for small fibre neuropathy symptoms (Small Fiber Neuropathy Symptoms Inventory Questionnaire) and underwent nerve conductions studies (NCS) and 3-mm punch skin biopsies from leg, thigh and fingertip. We assessed intraepidermal nerve fibre (IENF) and Meissner corpuscle (MC) density by applying an indirect immunofluorescence technique. Moreover, a subset of 65 ALS patients underwent a longitudinal study with repeat biopsies from the thigh at 6- and 12-month follow-ups. Serum NfL levels were measured in 40 patients. Sensory symptoms and sensory NCS abnormalities were present in 32.2% and 24% of patients, respectively, and increased across clinical stages. Analogously, we observed a progressive reduction in amplitude of the sensory and motor ulnar nerve potential from stage 1 to stage 4. Skin biopsy showed a significant loss of IENFs and MCs in ALS compared with healthy controls (all P < 0.001). Across the clinical stages, we found a progressive reduction in MCs (P = 0.004) and an increase in IENFs (all P < 0.027). The increase in IENFs was confirmed by the longitudinal study. Interestingly, the MC density inversely correlated with NfL level (r = -0.424, P = 0.012), and survival analysis revealed that low MC density, higher NfL levels and increasing IENF density over time were associated with a poorer prognosis (all P < 0.024). To summarize, in patients with ALS, peripheral sensory involvement worsens in parallel with motor disability. Furthermore, the correlation between skin innervation and disease activity may suggest the use of skin innervation as a putative prognostic biomarker.

Coping as a resource to allow for psychosocial adjustment in fatal disease: results from patients with amyotrophic lateral sclerosis

Background

Amyotrophic lateral sclerosis (ALS) is a fatal disorder, which imposes a severe emotional burden on patients. Appropriate coping mechanisms may alleviate this burden and facilitate wellbeing, with social support known to be a successful coping strategy. This observational study aimed to determine the interplay of general coping traits of hope for success and fear of failure, coping behavior of social activity, and patients' wellbeing.

Methods

In this cross-sectional study, patients with ALS from a clinical-epidemiological registry in Southwestern Germany were interviewed regarding coping traits (achievement-motivated behavior: hope for success and fear of failure), coping behavior of social activity, and psychosocial adjustment, determined using measures of depressiveness, anxiety [both measured by Hospital Anxiety and Depression Scale (HADS)], and quality of life [Anamnestic Comparative Self-Assessment (ACSA)]. Demographics, clinical [ALS Functional Rating Scale revised version (ALSFRS-R)], and survival data were recorded.

Results

A total of 868 patients [60.70% male patients, mean age: 64.70 (±10.83) years, mean ALSFRS-R: 37.36 ± 7.07] were interviewed. Anxiety in patients was found to be associated with a high fear of failure. In contrast, a generally positive attitude in patients exemplified in high hopes for success was associated with better wellbeing. Finally, coping behavior of social activity explained up to 65% of the variance of depressiveness among the patients with ALS.

Conclusion

In this study, we present evidence that the wellbeing of patients with ALS is not an immediate fatalistic consequence of physical degradation but rather determined by coping traits and behavior, which may be trained to substantially increase the wellbeing of patients with ALS.

Non-Pharmacological Interventions on Pain in Amyotrophic Lateral Sclerosis Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder affecting upper and lower motor neurons. Some ALS patients exhibit concomitant nonmotor signs; thus, ALS is considered a multisystemic disorder. Pain is an important nonmotor symptom. Observational and case-control studies report high frequency of pain in ALS patients and it has been correlated with depression and quality of life. There are no specific scales for the assessment of pain and no randomized controlled trials (RCTs) regarding the drug management of pain in ALS.

AIM

To systematically review the evidence for the nonpharmacological interventions (NPIs) in relieving pain in ALS, on March 2024, we searched the following databases: Pubmed, Scopus, Web of Science, and Cochrane. We also checked the bibliographies of trials identified to include further published or unpublished trials.

MAIN RESULTS

A total of 1003 records were identified. Finally, five RCTs including 131 patients (64 in the intervention group and 67 in the control group) were included for meta-analysis. The interventions of the included RCTs consisted of muscle exercise, combined aerobics-strength intervention, and osteopathic manual treatment. The meta-analysis did not find a statistically significant difference in favor of NPIs for alleviating pain in ALS patients.

CONCLUSIONS

ALS has a fulminant course and irreversibly leads to death. Pain in ALS patients, although a common nonmotor symptom, is often unrecognized and undertreated, and this is underlined by the lack of any RCTs on drug therapy for pain. Albeit NPIs are considered safe, as adverse effects are rarely reported, this systematic review did not provide sufficient evidence for a beneficial effect on pain. The scarceness of relevant literature highlights the need for future studies, with larger samples, more homogeneous in terms of interventions and population characteristics (stage of disease), and better choice of measurement scales to further investigate the efficacy, if any, of various pain interventions in ALS patients.

Chronic respiratory failure negatively affects speech function in patients with bulbar and spinal onset amyotrophic lateral sclerosis: retrospective data from a tertiary referral center

Background: Although dysarthria and respiratory failure are widely described in literature as part of the natural history of Amyotrophic lateral sclerosis (ALS), the specific interaction between them has been little explored.Aim: To investigate the relationship between chronic respiratory failure and the speech of ALS patients.Materials and methods: In this cross-sectional retrospective study we reviewed the medical records of all patients diagnosed with ALS that were accompanied by a tertiary referral center. In order to determine the presence and degree of speech impairment, the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRS-R) speech sub-scale was used. Respiratory function was assessed through spirometry and through venous blood gasometry obtained from a morning peripheral venous sample. To determine whether differences among groups classified by speech function were significant, maximum and mean spirometry values of participants were compared using multivariate analysis of variance (MANOVA) with Tukey's post hoc test.Results: Seventy-five cases were selected, of which 73.3% presented speech impairment and 70.7% respiratory impairment. Respiratory and speech functions were moderately correlated (seated FVC r = 0.64; supine FVC r = 0.60; seated FEV1 r = 0.59 and supine FEV1 r = 0.54, p < .001). Multivariable logistic regression revealed that the following variables were significantly associated with the presence of speech impairment after adjusting for other risk factors: seated FVC (odds ratio [OR] = 0.862) and seated FEV1 (OR = 1.106). The final model was 81.1% predictive of speech impairment. The presence of daytime hypercapnia was not correlated to increasing speech impairment.Conclusion: The restrictive pattern developed by ALS patients negatively influences speech function. Speech is a complex and multifactorial process, and lung volume presents a pivotal role in its function. Thus, we were able to find that lung volumes presented a significant correlation to speech function, especially in those with bulbar onset and respiratory impairment. Neurobiological and physiological aspects of this relationship should be explored in further studies with the ALS population.

Parkinson-ALS with a novel MAPT variant

The mutations on microtubule associated protein tau (MAPT) gene manifest clinically with behavioural frontotemporal dementia (FTD), parkinsonism, such as progressive supranuclear palsy and corticobasal degeneration, and rarely with amyotrophic lateral sclerosis (ALS). FTD-parkinsonism and FTD-ALS are clinical overlaps included in the spectrum of MAPT mutation's phenotypes. The mutations on MAPT gene cause the dysfunction of tau protein determining its accumulation in neurofibrillary tangles. Recent data describe frequently the co-occurrence of the aggregation of tau protein and α-synuclein in patients with parkinsonism and Parkinson disease (PD), suggesting an interaction of the two proteins in determining neurodegenerative process. The sporadic description of PD-ALS clinical complex, known as Brait-Fahn-Schwarz disease, supports the hypothesis of common neuropathological pathways between different disorders. Here we report the case of a 54-year-old Italian woman with idiopathic PD later complicated by ALS carrying a novel MAPT variant (Pro494Leu). The variant is characterized by an amino acid substitution and is classified as damaging for MAPT functions. The case supports the hypothesis of tau dysfunction as the basis of multiple neurodegenerative disorders.

Healthcare Utilization and Supportive Care Timing in South Korean People Living With Amyotrophic Lateral Sclerosis: A Single-Center Retrospective Study

BACKGROUND AND PURPOSE

Despite the growing demands and challenges faced by patients with amyotrophic lateral sclerosis (ALS) in accessing healthcare services, our understanding of this access remains poor. This study aimed to investigate the healthcare utilization patterns and timing of nutritional and respiration support in patients with ALS in South Korea.

METHODS

A retrospective cohort study was conducted on patients diagnosed with ALS at a single tertiary hospital between 2016 and 2019 and followed up for 2 years. We evaluated patient characteristics, healthcare utilization (hospital admissions, outpatient visits, and emergency department [ED] visits), and the timing of nutritional and respiration support (noninvasive positive pressure ventilation [NIPPV], tracheostomy, gastrostomy, and nasogastric tube) at 6-month intervals from the first outpatient visit.

RESULTS

Among the 143 included patients, 73.4% were admitted at least once, 18.9% experienced unplanned admissions, and 30.1% visited the ED at least once during the study period. The most-common reason for ED visits was neurological symptoms during the first 6 months (59.1%), followed by respiratory symptoms. One fifth of patients who visited the ED underwent tracheostomy (20.9%) or NIPPV (20.9%). Two years after the first visit, 32.2% used a ventilator, and 13.3%, 26.6%, and 6.3% had undergone tracheostomy, gastrostomy, and nasogastric tube insertion, respectively.

CONCLUSIONS

During the 2 years following their first outpatient visit, 20% of patients with ALS experienced unplanned admissions and 30% visited the ED. An active and prompt supportive-care program should be implemented to ensure timely functional support in order to reduce these risks of unplanned admissions.

Sodium Phenylbutyrate and Taurursodiol: A New Therapeutic Option for the Treatment of Amyotrophic Lateral Sclerosis

OBJECTIVE

To review the safety and efficacy of sodium phenylbutyrate and taurursodiol (SP + T) in slowing progression of amyotrophic lateral sclerosis (ALS) compared with pre-existing therapies.

DATA SOURCES

A PubMed (from January 1, 2009, to April 13, 2023) and ClinicalTrials.gov search conducted using sodium phenylbutyrate, taurursodiol, AMX0035, riluzole, and edaravone. Additional articles were identified by hand from references.

DATA SELECTION AND DATA EXTRACTION

This included English-language articles evaluating SP + T efficacy or safety in humans for decreasing neuronal death and slowing the progression of ALS.

DATA SYNTHESIS

In one phase II clinical trial that encompassed an open-label extension phase, disease severity, assessed by the rate of decline in overall score on the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised with higher scores indicating more functional ability, was -1.24 points per month with active drug and -1.66 points per month with placebo (difference, 0.42 points per month; 95% CI, 0.03-0.81; P = 0.03). Post hoc analysis found survival benefit of median 4.8 months with active medication compared with placebo.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON WITH EXISTING DRUGS

SP + T is a new US Food and Drug Administration-approved oral suspension for the treatment of ALS. Patients who received active medication through the phase II trial showed decreased rates of disease progression. Overall, SP + T could be considered a potential agent for the treatment of ALS which has a high unmet need.

CONCLUSION

SP + T is an option for the treatment of ALS; however, additional data regarding efficacy in phase III trials with long-term safety profile considerations, as well as trials to compare current therapy with SP + T, are needed.

Biochemical parameters as a tool to assess the nutritional status of patients with amyotrophic lateral sclerosis

Background

The research aimed to analyze blood biochemical parameters in patients with amyotrophic lateral sclerosis and to determine whether they can be used to assess their nutritional status.

Methods

The study included 45 patients diagnosed with amyotrophic lateral sclerosis (ALS): 28 (62.2%) were men and 17 (37.8%) were women. The mean age of the study participants was 50.69 ± 7.24 years. The control group consisted of 30 practically healthy individuals.

Results

Compared with practically healthy individuals, patients with ALS had significantly lower blood parameters, including total lymphocyte count (1.49 ± 0.11 vs. 2.86 ± 0.25, p < 0.05), total protein (60.55 ± 2.38 vs. 77.80 ± 4.41, p < 0.05), albumin (33.70 ± 2.03 vs. 46.49 ± 3.22, p < 0.05), urea (3.09 ± 0.36 vs. 5.37 ± 0.50, p < 0.05), creatinine (51.28 ± 4.42 vs. 70.91 ± 5.13, p < 0.05), and transferrin (1.84 ± 0.12 vs. 2.32 ± 0.10, p < 0.05). These parameters correspond to first-degree malnutrition. There were direct correlations between anthropometric and biochemical parameters in the ALS group. BMI correlated with the blood levels of total protein (r = 0.22, p < 0.05), albumin (r = 0.27, p < 0.05), urea (r = 0.33, p < 0.05), creatinine (r = 0.30, p < 0.05), transferrin (r = 0.18, p < 0.05), and total lymphocyte count (r = 0.20, p < 0.05). PNI correlated with the blood levels of total protein (r = 0.53, p < 0.05), albumin (r = 0.87, p < 0.05), total cholesterol (r = 0.34, p < 0.05), transferrin (r = 0.40, p < 0.05), total lymphocyte count (r = 0.79, p < 0.05), urea (r = 0, 37, p < 0.05), and creatinine (r = 0.32, p < 0.05).

Conclusion

The study presents compelling evidence supporting the utilization of biochemical parameters, including total protein, albumin, urea, creatinine, transferrin, and total lymphocyte count, for potentially evaluating the nutritional status of individuals diagnosed with ALS.

[Lower motor neuron disease with MRI «snake eyes» pattern]

Motor neuron disease with isolated or predominant lesion of the lower motor neuron at one level of the pyramidal tract is a rare diagnostic finding. In the article, we analyze the case of a patient with asymmetric lesion of the inferior motor neuron at the cervical level: clinical manifestations, results of additional studies and dynamic observation of the patient. Special attention is paid to the MRI picture of changes in the pyramidal tracts in the cervical region, which have been called the «snake eyes» in the literature, and the impact of this finding on the diagnosis and prognosis of the disease.

Functional network dynamics revealed by EEG microstates reflect cognitive decline in amyotrophic lateral sclerosis

Recent electroencephalography (EEG) studies have shown that patterns of brain activity can be used to differentiate amyotrophic lateral sclerosis (ALS) and control groups. These differences can be interrogated by examining EEG microstates, which are distinct, reoccurring topographies of the scalp's electrical potentials. Quantifying the temporal properties of the four canonical microstates can elucidate how the dynamics of functional brain networks are altered in neurological conditions. Here we have analysed the properties of microstates to detect and quantify signal-based abnormality in ALS. High-density resting-state EEG data from 129 people with ALS and 78 HC were recorded longitudinally over a 24-month period. EEG topographies were extracted at instances of peak global field power to identify four microstate classes (labelled A-D) using K-means clustering. Each EEG topography was retrospectively associated with a microstate class based on global map dissimilarity. Changes in microstate properties over the course of the disease were assessed in people with ALS and compared with changes in clinical scores. The topographies of microstate classes remained consistent across participants and conditions. Differences were observed in coverage, occurrence, duration, and transition probabilities between ALS and control groups. The duration of microstate class B and coverage of microstate class C correlated with lower limb functional decline. The transition probabilities A to D, C to B and C to B also correlated with cognitive decline (total ECAS) in those with cognitive and behavioural impairments. Microstate characteristics also significantly changed over the course of the disease. Examining the temporal dependencies in the sequences of microstates revealed that the symmetry and stationarity of transition matrices were increased in people with late-stage ALS. These alterations in the properties of EEG microstates in ALS may reflect abnormalities within the sensory network and higher-order networks. Microstate properties could also prospectively predict symptom progression in those with cognitive impairments.

Mutation and clinical analysis of the CLCC1 gene in amyotrophic lateral sclerosis patients from Central South China

INTRODUCTION

Recently, chloride channel CLIC-like 1 (CLCC1) was reported to be a novel ALS-related gene. We aimed to screen CLCC1 variants in our ALS cohort and further explore the genotype-phenotype correlation of CLCC1-related ALS.

METHODS

We screened rare damaging variants in CLCC1 from our cohorts of 1005 ALS patients and 1224 healthy controls with whole-exome sequencing in Central South China. Fisher's exact test was conducted for association analysis at the entire gene level and single variant level.

RESULTS

In total, four heterozygous missense variants in CLCC1 were identified from four unrelated sporadic ALS patients and predicted to be putative pathogenic by in silico tools and protein model prediction, accounting for 0.40% of all patients (4/1005). The four variants were c.A275C (p.Q92P), c.G1139A (p.R380K), c.C1244T (p.T415M), and c.G1328A (p.R443Q), respectively, which had not been reported in ALS patients previously. Three of four variants were located in exon 10. Patients harboring CLCC1 variants seemed to share a group of similar clinical features, including earlier age at onset, rapid progression, spinal onset, and vulnerable cognitive status. Statistically, we did not find CLCC1 to be associated with the risk of ALS at the entire gene level or single variant level.

CONCLUSION

Our findings further expanded the genetic and clinical spectrum of CLCC1-related ALS and provided more genetic evidence for anion channel involvement in the pathogenesis of ALS, but further investigations are needed to verify our findings.

Impairment of oculomotor functions in patients with early to advanced amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) can result into an incomplete locked in state (iLIS), in which communication depends on eye tracking computer devices. Oculomotor function impairments in ALS have been reported, but there is little research, particularly with respect to patients in iLIS. In the present study, we compared reflexive and executive oculomotor function by means of an eye tracking test battery between three groups: advanced ALS patients in iLIS (n = 22), patients in early to middle ALS stages (n = 44) and healthy subjects (n = 32). Patients with ALS showed significant deteriorations in oculomotor functions, with stronger impairments in iLIS. More specifically, ALS patients produced visually guided prosaccades with longer latencies and more frequent hypometria compared to healthy subjects. Longest latencies were obtained in iLIS patients, with a stronger prolongation for vertical than for horizontal prosaccades. ALS patients made more antisaccade errors and generated antisaccades with longer latencies. Smooth pursuit was also impaired in ALS. In the earlier ALS stages, bulbar onset patients presented stronger antisaccade and smooth pursuit deficits than spinal onset patients. Our findings reveal a relevant deterioration of important oculomotor functions in ALS, which increases in iLIS. It includes impairments of reflexive eye movements to loss of executive inhibitory control, indicating a progressing pathological involvement of prefrontal, midbrain and brainstem areas. The assessment of oculomotor functions may therefore provide clinically relevant bio- and progression marker, particularly in advanced ALS.

Genetic Landscape of Amyotrophic Lateral Sclerosis in Czech Patients

Background

Genetic factors are involved in the pathogenesis of familial and sporadic amyotrophic lateral sclerosis (ALS) and constitute a link to its association with frontotemporal dementia (FTD). Gene-targeted therapies for some forms of ALS (C9orf72, SOD1) have recently gained momentum. Genetic architecture in Czech ALS patients has not been comprehensively assessed so far.

Objective

We aimed to deliver pilot data on the genetic landscape of ALS in our country.

Methods

A cohort of patients with ALS (n = 88), recruited from two Czech Neuromuscular Centers, was assessed for hexanucleotide repeat expansion (HRE) in C9orf72 and also for genetic variations in other 36 ALS-linked genes via next-generation sequencing (NGS). Nine patients (10.1%) had a familial ALS. Further, we analyzed two subgroups of sporadic patients - with concomitant FTD (n = 7) and with young-onset of the disease (n = 22).

Results

We detected the pathogenic HRE in C9orf72 in 12 patients (13.5%) and three other pathogenic variants in FUS, TARDBP and TBK1, each in one patient. Additional 7 novel and 9 rare known variants with uncertain causal significance have been detected in 15 patients. Three sporadic patients with FTD (42.9%) were harbouring a pathogenic variant (all HRE in C9orf72). Surprisingly, none of the young-onset sporadic patients harboured a pathogenic variant and we detected no pathogenic SOD1 variant in our cohort.

Conclusion

Our findings resemble those from other European populations, with the highest prevalence of HRE in the C9orf72 gene. Further, our findings suggest a possibility of a missing genetic variability among young-onset patients.

Amyotrophic lateral sclerosis with upper motor neuron predominance: diagnostic accuracy of qualitative and quantitative susceptibility metrics in the precentral gyrus

OBJECTIVE

The study aims at comparing the diagnostic accuracy of qualitative and quantitative assessment of the susceptibility in the precentral gyrus in detecting amyotrophic lateral sclerosis (ALS) with predominance of upper motor neuron (UMN) impairment.

METHODS

We retrospectively collected clinical and 3T MRI data of 47 ALS patients, of whom 12 with UMN predominance (UMN-ALS). We further enrolled 23 healthy controls (HC) and 15 ALS Mimics (ALS-Mim). The Motor Cortex Susceptibility (MCS) score was qualitatively assessed on the susceptibility-weighted images (SWI) and automatic metrics were extracted from the quantitative susceptibility mapping (QSM) in the precentral gyrus. MCS scores and QSM-based metrics were tested for correlation, and ROC analyses.

RESULTS

The correlation of MCS score and susceptibility skewness was significant (Rho = 0.55, p < 0.001). The susceptibility SD showed an AUC of 0.809 with a specificity and positive predictive value of 100% in differentiating ALS and ALS Mim versus HC, significantly higher than MCS (Z = -3.384, p-value = 0.00071). The susceptibility skewness value of -0.017 showed specificity of 92.3% and predictive positive value of 91.7% in differentiating UMN-ALS versus ALS mimics, even if the performance was not significantly better than MCS (Z = 0.81, p = 0.21).

CONCLUSION

The MCS and susceptibility skewness of the precentral gyrus show high diagnostic accuracy in differentiating UMN-ALS from ALS-mimics subjects. The quantitative assessment might be preferred being an automatic measure unbiased by the reader.

CLINICAL RELEVANCE STATEMENT

The clinical diagnostic evaluation of ALS patients might benefit from the qualitative and/or quantitative assessment of the susceptibility in the precentral gyrus as imaging marker of upper motor neuron predominance.

KEY POINTS

• Amyotrophic lateral sclerosis diagnostic work-up lacks biomarkers able to identify upper motor neuron involvement. • Susceptibility-weighted imaging/quantitative susceptibility mapping-based measures showed good diagnostic accuracy in discriminating amyotrophic lateral sclerosis with predominant upper motor neuron impairment from patients with suspected motor neuron disorder. • Susceptibility-weighted imaging/quantitative susceptibility mapping-based assessment of the magnetic susceptibility provides a diagnostic marker for amyotrophic lateral sclerosis with upper motor neuron predominance.

Investigation of a Fused in Sarcoma Splicing Mutation in a Chinese Amyotrophic Lateral Sclerosis Patient

OBJECTIVE

Genetic mutations of fused in sarcoma (FUS) causing amyotrophic lateral sclerosis (ALS) may disrupt mRNA splicing events. For example, the FUS c.1394-2delA variant was reported in two western ALS patients, but its molecular mechanism is unclear. In this study, we aim to investigate FUS splice site mutations in Chinese ALS patients.

METHODS

Sanger sequencing was used to identify FUS splicing mutations in Chinese ALS patients. We combined a deep learning tool (SpliceAI), RNA sequencing, and RT-PCR/RT-qPCR to analyze the effect of FUS c.1394-2delA mutation on RNA splicing and expression. AlphaFold was used to predict the protein structure of mutant FUS. In transfected cell lines, we used immunofluorescence to assess cytoplasmic mislocalization of mutant FUS protein.

RESULTS

We identified a de novo FUS splice acceptor site mutation (c.1394-2delA, p. Gly466Valfs*14) in one Chinese sporadic ALS patient, which is linked to exon 14 skipping, and upregulated total FUS mRNA expression. The FUS splice site mutation was predicted to be translated into a truncated protein product at C-terminal. In vitro studies revealed that the FUS mutation increased cytoplasmic mislocalization in both HEK293T and SH-SY5Y cells.

CONCLUSIONS

We identified a de novo FUS splicing mutation (c.1394-2delA, p. Gly466Valfs*14) in 1 out of 233 Chinese ALS patients. It caused abnormal RNA splicing, upregulated gene expression, truncated FUS translation, and cytosolic mislocalization. Our findings suggested that FUS splice site mutation is rare in Chinese ALS patients and extended our knowledge of molecular mechanisms of the FUS c.1394-2delA mutation.

Effects of Acetyl-L-Carnitine on Oxidative Stress in Amyotrophic Lateral Sclerosis Patients: Evaluation on Plasma Markers and Members of the Neurovascular Unit

Oxidative stress, the alteration of mitochondrial function, and the neurovascular unit (NVU), play a role in Amyotrophic Lateral Sclerosis (ALS) pathogenesis. We aimed to demonstrate the changes in the plasma redox system and nitric oxide (NO) in 32 new ALS-diagnosed patients in treatment with Acetyl-L-Carnitine (ALCAR) compared to healthy controls. We also evaluated the effects of plasma on human umbilical cord-derived endothelial vascular cells (HUVEC) and astrocytes. The analyses were performed at the baseline (T0), after three months (T1), and after six months (T2). In ALS patients at T0/T1, the plasma markers of lipid peroxidation, thiobarbituric acid reactive substances (TBARS) and 4-hydroxy nonenal (4-HNE) were higher, whereas the antioxidants, glutathione (GSH) and the glutathione peroxidase (GPx) activity were lower than in healthy controls. At T2, plasma TBARS and 4-HNE decreased, whereas plasma GSH and the GPx activity increased in ALS patients. As regards NO, the plasma levels were firmly lower at T0-T2 than those of healthy controls. Cell viability, and mitochondrial membrane potential in HUVEC/astrocytes treated with the plasma of ALS patients at T0-T2 were reduced, while the oxidant release increased. Those results, which confirmed the fundamental role of oxidative stress, mitochondrial function, and of the NVU in ALS pathogenesis, can have a double meaning, acting as disease markers at baseline and potential markers of drug effects in clinical practice and during clinical trials.

Profiling Number of Swallows per Bolus and Residue in Individuals With Amyotrophic Lateral Sclerosis

PURPOSE

Swallowing efficiency impairments are the most prevalent and earliest manifestation of dysphagia in people with amyotrophic lateral sclerosis (pALS). We aimed to profile number of swallows elicited in pALS across thin liquid, moderately thick liquid, extremely thick liquid, and crackers compared to expected healthy reference data and to determine relationships between degree of pharyngeal residue, number of elicited swallows, and swallowing safety.

METHOD

pALS underwent standardized videofluoroscopic swallowing studies of 10 bolus trials. Trained raters performed duplicate, independent, and blinded ratings to derive Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) efficiency and safety grades and Analysis of Swallowing Physiology: Events, Kinematics, and Timing (ASPEKT) percent total pharyngeal residue. Number of swallows per bolus was quantified (1 = typical, 2 = atypically high, 3 = extremely high). Kruskal-Wallis, Pearson chi-square, and odds ratio analyses were performed at bolus and participant levels.

KEY RESULTS

At the bolus level (N = 2,523), number of swallows per bolus was observed to be, in rank order, as follows: atypically high (49.1%), extremely high (28.5%), and typical (22.4%). Mean number of swallows significantly differed by International Dysphagia Diet Standardisation Initiative level (p < .0001), with a higher number of swallows elicited in pALS for moderately thick versus thin liquids, extremely thick liquids, and crackers, p < .0001. Number of swallows per bolus increased with increasing DIGEST efficiency grades (p < .0001). Positive correlations were observed between ASPEKT percent residue and number of swallows for thin (r = .24) and moderately thick (r = .16) liquids, p < .05. DIGEST efficiency and safety grades were not significantly associated (p > .05).

CONCLUSION AND INFERENCES

pALS demonstrated a higher number of swallows per bolus compared to healthy reference data that may represent a compensation for reductions in swallowing efficiency to clear pharyngeal residue.

Structural and microstructural neuroimaging signature of C9orf72-associated ALS: A multiparametric MRI study

BACKGROUND

ALS patients with hexanucleotide expansion in C9orf72 are characterized by a specific clinical phenotype, including more aggressive disease course and cognitive decline. Computerized multiparametric MRI with gray matter volumetry and diffusion tensor imaging (DTI) to analyze white matter structural connectivity is a potential in vivo biomarker.

OBJECTIVE

The objective of this study was to develop a multiparametric MRI signature in a large cohort of ALS patients with C9orf72 mutations. The aim was to investigate how morphological features of C9orf72-associated ALS differ in structural MRI and DTI compared to healthy controls and ALS patients without C9orf72 mutations.

METHODS

Atlas-based volumetry (ABV) and whole brain-based DTI-based analyses were performed in a cohort of n = 51 ALS patients with C9orf72 mutations and compared with both n = 51 matched healthy controls and n = 51 C9orf72 negative ALS patients, respectively. Subsequently, Spearman correlation analysis of C9orf72 ALS patients' data with clinical parameters (age of onset, sex, ALS-FRS-R, progression rate, survival) as well as ECAS and p-NfH in CSF was performed.

RESULTS

The whole brain voxel-by-voxel comparison of fractional anisotropy (FA) maps between C9orf72 ALS patients and controls showed significant bilateral alterations in axonal structures of the white matter at group level, primarily along the corticospinal tracts and in fibers projecting to the frontal lobes. For the frontal lobes, these alterations were also significant between C9orf72 positive and C9orf72 negative ALS patients. In ABV, patients with C9orf72 mutations showed lower volumes of the frontal, temporal, and parietal lobe, with the lowest values in the gray matter of the superior frontal and the precentral gyrus, but also in hippocampi and amygdala. Compared to C9orf72 negative ALS, the differences were shown to be significant for cerebral gray matter (p = 0.04), especially in the frontal (p = 0.01) and parietal lobe (p = 0.01), and in the thalamus (p = 0.004). A correlation analysis between ECAS and averaged regional FA values revealed significant correlations between cognitive performance in ECAS and frontal association fibers. Lower FA values in the frontal lobes were associated with worse performance in all cognitive domains measured (language, verbal fluency, executive functions, memory and spatial perception). In addition, there were significant negative correlations between age of onset and atlas-based volumetry results for gray matter.

CONCLUSIONS

This study demonstrates a distinct pattern of DTI alterations of the white matter and ubiquitous volume reductions of the gray matter early in the disease course of C9orf72-associated ALS. Alterations were closely linked to a more aggressive cognitive phenotype. These results are in line with an expected pTDP43 propagation pattern of cortical affection and thus strengthen the hypothesis that an underlying developmental disorder is present in ALS with C9orf72 expansions. Thus, multiparametric MRI could contribute to the assessment of the disease as an in vivo biomarker even in the early phase of the disease.

Altered Gaze Control During Emotional Face Exploration in Patients With Amyotrophic Lateral Sclerosis

OBJECTIVES

Up to 50% of patients with amyotrophic lateral sclerosis (ALS) present with cognitive problems and behavioral dysfunctions including recognition of human faces presenting different emotions. We investigated whether impaired processing of emotional faces is associated with abnormal scan paths during visual exploration.

METHODS

Cognitively unimpaired patients with ALS (n = 45) and matched healthy controls (n = 37) underwent neuropsychological assessment and video-based eye tracking. Eye movements were recorded while participants visually explored faces expressing different emotions (neutral, disgusted, happy, fearful, and sad) and houses mimicking faces.

RESULTS

Compared with controls, patients with ALS fixated significantly longer to regions which are not relevant for emotional information when faces expressed fear (p = 0.007) and disgust (p = 0.006), whereas the eyes received less attention in faces expressing disgust (p = 0.041). Fixation duration in any area of interest was not significantly associated with the cognitive state or clinical symptoms of disease severity.

DISCUSSION

In cognitively unimpaired patients with ALS, altered gaze patterns while visually exploring faces expressing different emotions might derive from impaired top-down attentional control with possible involvement of subliminal frontotemporal areas. This may account for indistinctness in emotion recognition reported in previous studies because nonsalient features retrieve more attention compared with salient areas. Current findings may indicate distinct emotion processing dysfunction of ALS pathology, which may be different from, for example, executive dysfunction.

Biomarkers in cerebrospinal fluid for amyotrophic lateral sclerosis phenotypes

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving both upper and lower motor neurons. The motor phenotypes of ALS are highly clinically heterogeneous, and the underlying mechanisms are poorly understood.

METHODS

A comparative proteomic analysis was performed in the cerebrospinal fluid (CSF) of bulbar-onset (BO) and spinal-onset (SO) ALS patients and controls (n = 14). Five biomarker candidates were selected from a differentially regulated protein pool, and further validation was performed in a larger independent cohort (n = 92) using enzyme-linked immunosorbent assay (ELISA).

RESULTS

A total of 1732 CSF proteins were identified, and 78 differentially expressed proteins were found among BO-ALS patients, SO-ALS patients, and controls. Five promising biomarker candidates were selected for further validation, and lipopolysaccharide-binding protein (LBP) and HLA class II histocompatibility antigen, DR alpha chain (HLA-DRA) were validated. CSF LBP levels were increased in ALS patients compared with controls and higher in BO-ALS versus SO-ALS. The increased CSF LBP levels were correlated with the revised ALS Functional Scale (ALSFRS-R) score. CSF HLA-DRA levels were specifically elevated in BO-ALS patients, and there was no significant difference between SO-ALS patients and controls. Increased HLA-DRA expression was correlated with decreased survival.

INTERPRETATION

Our data shows that elevated CSF LBP is a good biomarker for ALS and correlates with clinical severity, and increased HLA-DRA is a specific biomarker for BO-ALS and may predict short survival. It also suggests that the microglial pathway and HLA-II-related adaptive immunity may be differentially involved in ALS phenotypes and may be new therapeutic targets for ALS.

PROSA-a multicenter prospective observational study to develop low-burden digital speech biomarkers in ALS and FTD

Objective: There is a need for novel biomarkers that can indicate disease state, project disease progression, or assess response to treatment for amyotrophic lateral sclerosis (ALS) and associated neurodegenerative diseases such as frontotemporal dementia (FTD). Digital biomarkers are especially promising as they can be collected non-invasively and at low burden for patients. Speech biomarkers have the potential to objectively measure cognitive, motor as well as respiratory symptoms at low-cost and in a remote fashion using widely available technology such as telephone calls. Methods: The PROSA study aims to develop and evaluate low-burden frequent prognostic digital speech biomarkers. The main goal is to create a single, easy-to-perform battery that serves as a valid and reliable proxy for cognitive, respiratory, and motor domains in ALS and FTD. The study will be a multicenter 12-months observational study aiming to include 75 ALS and 75 FTD patients as well as 50 healthy controls and build on three established longitudinal cohorts: DANCER, DESCRIBE-ALS and DESCRIBE-FTD. In addition to the extensive clinical phenotyping in DESCRIBE, PROSA collects a comprehensive speech protocol in fully remote and automated fashion over the telephone at four time points. This longitudinal speech data, together with gold standard measures, will allow advanced speech analysis using artificial intelligence for the development of speech-based phenotypes of ALS and FTD patients measuring cognitive, motor and respiratory symptoms. Conclusion: Speech-based phenotypes can be used to develop diagnostic and prognostic models predicting clinical change. Results are expected to have implications for future clinical trial stratification as well as supporting innovative trial designs in ALS and FTD.

Patterns of synaptic loss in human amyotrophic lateral sclerosis spinal cord: a clinicopathological study

Amyotrophic Lateral Sclerosis (ALS) is mainly characterized by the degeneration of corticospinal neurons and spinal α-motoneurons; vulnerable cells display prominent pTDP-43 inclusions. Evidence gathered from genetics, murine models, and iPSC-derived neurons point to the early involvement of synapses in the disease course and their crucial role in the pathogenic cascade. However, pathology studies, with specimens from large post-mortem cohorts, mapping the pattern of synaptic disturbances over clinical and neuropathological hallmarks of disease progression, are currently not available. Thus, the appearance and progression of synaptic degeneration in human ALS patients are currently not known, preventing a full validation of the murine and in vitro models. Here, we investigated the loss of synaptophysin-positive terminals in cervical, thoracic, and lumbar spinal cord samples from a retrospective cohort of n = 33 ALS patients and n = 8 healthy controls, and we correlated the loss of synapses against clinicodemographic features and neuropathological ALS stage. We found that, although dorsal and intermediate spinal cord laminae do not lose synapses, ALS patients displayed a substantial but variable loss of synapses in the ventral horn of lumbar and cervical spinal cord. The amount of synaptic loss was predicted by disease duration, by the clinical site of onset, and by the loss of α-motoneurons, although not by the fraction of pTDP-43-immunopositive α-motoneurons. Taken together, our findings validate the synaptic pathology observed in other models and suggest that pathogenic pathways unfolding in the spinal microenvironment are critical to the progressive disassembly of local synaptic connectivity.

Case report: Asp194Ala variant in MFN2 is associated with ALS-FTD in an Italian family

Background: MFN2 gene encodes the protein Mitofusin 2, involved in essential mitochondrial functions such as fusion, trafficking, turnover, and cellular interactions. We describe a family carrying a novel MFN2 mutation associated with ALS-frontotemporal dementia (FTD) clinical phenotype in the mother and Charcot-Marie-Tooth disease type 2A (CMT2A) in her son. Case presentation: The mother, a 67-year-old woman, referred to us for a three year-history of mood disturbance and gait impairment, and a more recent hypophonia, dysarthria, dysphagia, and diffuse muscle wasting. Family history was positive for psychiatric disorders and gait disturbances. Brain 18F-FDG PET showed severe hypometabolism in the fronto-temporal brain cortex bilaterally. Electrodiagnostic studies (EDX) showed severe motor axonopathy in the bulbar, cervical and lumbosacral districts. Her 41-year-old son had a history of mood depression and sensory disturbances in the limbs, along with mild muscle wasting, weakness, and reduced reflexes. Nerve conduction studies revealed a moderate sensory-motor polyneuropathy, while brain MRI was normal. Whole exome sequencing of the patients' DNA identified the novel MFN2 (NM_014874.4) variant c.581A>C p.(Asp194Ala). Conclusion: Our findings provide evidence of heterogenous clinical manifestations in family members sharing the same MFN2 molecular defect. Additionally, we present the first documented case of ASL-FTD associated with an MFN2 mutation, thereby expanding the range of MFN-related disorders. Further research involving larger cohorts of patients will be needed to better understand the role of MFN2 as a contributing gene in the development of ALS-FTD.

Loss of PML nuclear bodies in familial amyotrophic lateral sclerosis-frontotemporal dementia

Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD) are two neurodegenerative disorders that share genetic causes and pathogenic mechanisms. The critical genetic players of ALS and FTD are the TARDBP, FUS and C9orf72 genes, whose protein products, TDP-43, FUS and the C9orf72-dipeptide repeat proteins, accumulate in form of cytoplasmic inclusions. The majority of the studies focus on the understanding of how cells control TDP-43 and FUS aggregation in the cytoplasm, overlooking how dysfunctions occurring at the nuclear level may influence the maintenance of protein solubility outside of the nucleus. However, protein quality control (PQC) systems that maintain protein homeostasis comprise a cytoplasmic and a nuclear arm that are interconnected and share key players. It is thus conceivable that impairment of the nuclear arm of the PQC may have a negative impact on the cytoplasmic arm of the PQC, contributing to the formation of the cytoplasmic pathological inclusions. Here we focused on two stress-inducible condensates that act as transient deposition sites for misfolding-prone proteins: Promyelocytic leukemia protein (PML) nuclear bodies (PML-NBs) and cytoplasmic stress granules (SGs). Upon stress, PML-NBs compartmentalize misfolded proteins, including defective ribosomal products (DRiPs), and recruit chaperones and proteasomes to promote their nuclear clearance. SGs transiently sequester aggregation-prone RNA-binding proteins linked to ALS-FTD and mRNAs to attenuate their translation. We report that PML assembly is impaired in the human brain and spinal cord of familial C9orf72 and FUS ALS-FTD cases. We also show that defective PML-NB assembly impairs the compartmentalization of DRiPs in the nucleus, leading to their accumulation inside cytoplasmic SGs, negatively influencing SG dynamics. Although it is currently unclear what causes the decrease of PML-NBs in ALS-FTD, our data highlight the existence of a cross-talk between the cytoplasmic and nuclear PQC systems, whose alteration can contribute to SG accumulation and cytoplasmic protein aggregation in ALS-FTD.

Guideline "Motor neuron diseases" of the German Society of Neurology (Deutsche Gesellschaft für Neurologie)

INTRODUCTION

In 2021, the Deutsche Gesellschaft für Neurology published a new guideline on diagnosis and therapy of motor neuron disorders. Motor neuron disorders affect upper motor neurons in the primary motor cortex and/or lower motor neurons in the brain stem and spinal cord. The most frequent motor neuron disease amyotrophic lateral sclerosis (ALS) is a rapidly progressive disease with an average life expectancy of 2-4 years with a yearly incidence of 3.1/100,000 in Central Europe (Rosenbohm et al. in J Neurol 264(4):749-757, 2017. https://doi.org/10.1007/s00415-017-8413-3 ). It is considered a rare disease mainly due to its low prevalence as a consequence of short disease duration.

RECOMMENDATIONS

These guidelines comprise recommendations regarding differential diagnosis, neuroprotective therapies and multidisciplinary palliative care including management of respiration and nutrition as well as provision of assistive devices and end-of-life situations.

CONCLUSION

Diagnostic and therapeutic guidelines are necessary due the comparatively high number of cases and the aggressive disease course. Given the low prevalence and the severe impairment of patients, it is often impossible to generate evidence-based data so that ALS guidelines are partially dependent on expert opinion.