Amyotrophic Lateral Sclerosis (ALS) and Related Motor Neuron Diseases: An Overview

Expression Changes of miRNAs in Humans and Animal Models of Amyotrophic Lateral Sclerosis and Their Potential Application for Clinical Diagnosis

Amyotrophic lateral sclerosis (ALS) is a severe motor neuron disease. Current detection methods can only confirm the diagnosis at the onset of the disease, missing the critical window for early treatment. Recent studies using animal models have found that detecting changes in miRNA sites can predict the onset and severity of the disease in its early stages, facilitating early diagnosis and treatment. miRNAs show expression changes in motor neurons that connect the brain, spinal cord, and brain stem, as well as in the skeletal muscle in mouse models of ALS. Clinically, expression changes in some miRNAs in patients align with those in mouse models, such as the upregulation of miR-29b in the brain and the upregulation of miR-206 in the skeletal muscle. This study provides an overview of some miRNA study findings in humans as well as in animal models, including SOD1, FUS, TDP-43, and C9orf72 transgenic mice and wobbler mice, highlighting the potential of miRNAs as diagnostic markers for ALS. miR-21 and miR-206 are aberrantly expressed in both mouse model and patient samples, positioning them as key potential diagnostic markers in ALS. Additionally, miR-29a, miR-29b, miR-181a, and miR-142-3p have shown aberrant expression in both types of samples and show promise as clinical targets for ALS. Finally, miR-1197 and miR-486b-5p have been recently identified as aberrantly expressed miRNAs in mouse models for ALS, although further studies are needed to determine their viability as diagnostic targets.

Emerging targets in amyotrophic lateral sclerosis (ALS): The promise of ATP-binding cassette (ABC) transporter modulation

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative primarily affecting motor neurons, leading to disability and neuronal death, and ATP-Binding Cassette (ABC) transporter due to their role in drug efflux and modulation of various cellular pathways contributes to the pathogenesis of ALS. In this article, we extensively investigated various molecular and mechanistic pathways linking ALS transporter to the pathogenesis of ALS; this involves inflammatory pathways such as Mitogen-Activated Protein Kinase (MAPK), Phosphatidylinositol-3-Kinase/Protein Kinase B (PI3K/Akt), Toll-Like Receptor (TLR), Glycogen Synthase Kinase 3β (GSK-3β), Nuclear Factor Kappa-B (NF-κB), and Cyclooxygenase (COX). Oxidative pathways such as Astrocytes, Glutamate, Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), Sirtuin 1 (SIRT-1), Forkhead box protein O (FOXO), Extracellular signal-regulated kinase (ERK). Additionally, we delve into the role of autophagic pathways like TAR DNA-binding protein 43 (TDP-43), AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and lastly, the apoptotic pathways. Furthermore, by understanding these intricate interactions, we aim to develop novel therapeutic strategies targeting ABC transporters, improving drug delivery, and ultimately offering a promising avenue for treating ALS.

Temporal stratification of amyotrophic lateral sclerosis patients using disease progression patterns

Identifying groups of patients with similar disease progression patterns is key to understand disease heterogeneity, guide clinical decisions and improve patient care. In this paper, we propose a data-driven temporal stratification approach, ClusTric, combining triclustering and hierarchical clustering. The proposed approach enables the discovery of complex disease progression patterns not found by univariate temporal analyses. As a case study, we use Amyotrophic Lateral Sclerosis (ALS), a neurodegenerative disease with a non-linear and heterogeneous disease progression. In this context, we applied ClusTric to stratify a hospital-based population (Lisbon ALS Clinic dataset) and validate it in a clinical trial population. The results unravelled four clinically relevant disease progression groups: slow progressors, moderate bulbar and spinal progressors, and fast progressors. We compared ClusTric with a state-of-the-art method, showing its effectiveness in capturing the heterogeneity of ALS disease progression in a lower number of clinically relevant progression groups.

Neuroglia targeting nano-therapeutic approaches to rescue aging and neurodegenerating brain

Despite intense efforts at the bench, the development of successful brain-targeting therapeutics to relieve malicious neural diseases remains primitive. The brain, being a beautifully intricate organ, consists of heterogeneous arrays of neuronal and glial cells. Primarily acting as the support system for neuronal functioning and maturation, glial cells have been observed to be engaged more apparently in the progression and worsening of various neural pathologies. The diseased state is often related to metabolic alterations in glial cells, thereby modulating their physiological homeostasis in conjunction with neuronal dysfunction. A plethora of data indicates the effect of oxidative stress, protein aggregation, and DNA damage in neuroglia impairments. Still, a deeper insight is needed to gain a conflict-free understanding in this arena. As a consequence, glial cells hold the potential to be identified as promising targets for novel therapeutic approaches aimed at brain protection. In this review, we describe the recent strides taken in the direction of understanding the impact of oxidative stress, protein aggregation, and DNA damage on neuroglia impairment and neuroglia-directed nanotherapeutic approaches to mitigate the burden of various neural disorders.

Effects and mechanisms of bisphenols exposure on neurodegenerative diseases risk: A systemic review

Environmental bisphenols (BPs) pose a global threat to human health because of their extensive use as additives in plastic products. BP residues are increasing in various environmental media (i.e., water, soil, and indoor dust) and biological and human samples (i.e., serum and brain). Both epidemiological and animal studies have determined an association between exposure to BPs and an increased risk of neurodegenerative diseases (e.g., Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis), including cognitive abnormalities and behavioral disturbances. Hence, understanding the biological responses to different BPs is essential for prevention, and treatment. This study provides an overview of the underlying pathogenic molecular mechanisms as a valuable basis for understanding neurodegenerative disease responses to BPs, including accumulation of misfolded proteins, reduction of tyrosine hydroxylase and dopamine, abnormal hormone signaling, neuronal death, oxidative stress, calcium homeostasis, and inflammation. These findings provide new insights into the neurotoxic potential of BPs and ultimately contribute to a comprehensive health risk evaluation.

Amyotrophic Lateral Sclerosis and Its Management during the COVID-19 Pandemic: A Qualitative Study with Thematic Analysis of Patients and Caregivers Who Participated in Self-Help Groups

This study employs a qualitative methodology to explore the effects of the pandemic on the lives of ALS patients and their caregivers. It aims to understand whether and how online self-help groups have assisted families dealing with amyotrophic lateral sclerosis (ALS) patients. ALS is a neurodegenerative disease with both physical and psychosocial implications. Consequently, it significantly affects the lives of patients' caregivers. In 2020, the COVID-19 pandemic exacerbated this situation. The results show that the pandemic has had a negative impact on the well-being of ALS caregivers and patients. Furthermore, bereavement and death were dealt with in different ways by the families involved. The pandemic aggravated the health of ALS patients and increased the workload of their caregivers; however, online psychological support was appreciated for its role in providing emotional help and diminishing social isolation.

Synthesis and clinical application of new drugs approved by FDA in 2022

The pharmaceutical industry had a glorious year in 2022, with a total of 37 new drugs including 20 new chemical entities (NCEs) and 17 new biological entities (NBEs) approved by the Food and Drug Administration (FDA). These drugs are mainly concentrated in oncology, central nervous system, antiinfection, hematology, cardiomyopathy, dermatology, digestive system, ophthalmology, MRI enhancer and other therapeutic fields. Of the 37 drugs, 25 (68%) were approved through an expedited review pathway, and 19 (51%) were approved to treat rare diseases. These newly listed drugs have unique structures and new mechanisms of action, which can serve as lead compounds for designing new drugs with similar biological targets and enhancing therapeutic efficacy. This review aims to outline the clinical applications and synthetic methods of 19 NCEs newly approved by the FDA in 2022, but excludes contrast agent (Xenon Xe-129). We believe that an in-depth understanding of the synthetic methods of drug molecules will provide innovative and practical inspiration for the development of new, more effective, and practical synthetic techniques. According to the therapeutic areas of these 2022 FDA-approved drugs, we have classified these 19 NCEs into seven categories and will introduce them in the order of their approval for marketing.

Extracellular Vesicles as Potential Biomarkers in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is described as a fatal and rapidly progressive neurodegenerative disorder caused by the degeneration of upper motor neurons in the primary motor cortex and lower motor neurons of the brainstem and spinal cord. Due to ALS's slowly progressive characteristic, which is often accompanied by other neurological comorbidities, its diagnosis remains challenging. Perturbations in vesicle-mediated transport and autophagy as well as cell-autonomous disease initiation in glutamatergic neurons have been revealed in ALS. The use of extracellular vesicles (EVs) may be key in accessing pathologically relevant tissues for ALS, as EVs can cross the blood-brain barrier and be isolated from the blood. The number and content of EVs may provide indications of the disease pathogenesis, its stage, and prognosis. In this review, we collected a recent study aiming at the identification of EVs as a biomarker of ALS with respect to the size, quantity, and content of EVs in the biological fluids of patients compared to controls.

Study on the Applicability of Digital Twins for Home Remote Motor Rehabilitation

The COVID-19 pandemic created the need for telerehabilitation development, while Industry 4.0 brought the key technology. As motor therapy often requires the physical support of a patient's motion, combining robot-aided workouts with remote control is a promising solution. This may be realised with the use of the device's digital twin, so as to give it an immersive operation. This paper presents an extensive overview of this technology's applications within the fields of industry and health. It is followed by the in-depth analysis of needs in rehabilitation based on questionnaire research and bibliography review. As a result of these sections, the original concept of controlling a rehabilitation exoskeleton via its digital twin in the virtual reality is presented. The idea is assessed in terms of benefits and significant challenges regarding its application in real life. The presented aspects prove that it may be potentially used for manual remote kinesiotherapy, combined with the safety systems predicting potentially harmful situations. The concept is universally applicable to rehabilitation robots.

The incidence and prevalence of motor neurone disease in South Australia

Background: Motor neurone disease (MND) is a neurodegenerative disease that leads to significant morbidity and mortality. The Global Burden of Disease (GBD) project estimated the MND all-age global prevalence is 4.5 (95% confidence interval (CI)=4.1-5.0) per 100,000 persons and the all-age incidence of 0.78 (95% CI = 0.71-0.86) per 100,000 person-years. Whether the prevalence and incidence of MND within South Australia using registry data is in keeping with these global estimates has not been studied. Objective: To describe the prevalence and annual incidence rates (IRs) of MND in South Australia between 2017 and 2019. Methods: A retrospective cohort study calculating the point prevalence of MND on 31 December 2017, 2018 and 2019 utilizing data from the Australasian Motor Neurone Disease Registry (AMNDR). The annual IRs between 2017 and 2019 were calculated using population data reported in the 2016 Australian census and age-standardized rates utilized the world population from the United Nations Population Division's World Population Prospects. Results: A total of 256 MND patients were identified, of whom 114 were alive on 31 December 2019. Based on the 2016 population of 1,676,653 persons, the estimated prevalence was 6.79 per 100,000 persons. The crude IR for the all-age South Australian population was 3.34 per 100,000 person-years (95% CI, 2.85-3.88). The estimated annual IRs based on those ≥20 yo were 4.98 (3.84-6.35), 3.68 (2.71-4.88), and 4.21 (3.17-5.49) per 100,000 person-years for 2017, 2018, and 2019, respectively. Conclusion: The crude prevalence and incidence of MND in South Australia were considerably higher than global estimates. This may reflect higher rates of the disease or higher rates of case ascertainment compared to the GBD project.

Misdiagnoses in a Brazilian population with amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects the upper and lower motor neurons. The correct diagnosis at the onset of the disease is sometimes very difficult, due to the symptoms being very similar to those of other neurological syndromes.

OBJECTIVE

This study aimed to analyze the initial manifestations, the specialty of the first physician visited due the initial complaint, the misdiagnoses, as well as the unnecessary surgical interventions in a new ALS Brazilian population.

METHODS

The medical records of 173 patients with typical ALS were reviewed.

RESULTS

The present study demonstrated that other symptoms, besides weakness, were very frequent as initial presentation of ALS, and orthopedics was the medical specialty most sought by patients at the onset of symptoms. Our frequency of misdiagnoses was 69.7%, and in 7.1% of them, an unnecessary surgical intervention was performed.

CONCLUSIONS

Amyotrophic lateral sclerosis presents a very large pool of signs and symptoms; therefore, there is an urgent need of increasing the disease awareness to other specialties due to the high frequency of misdiagnoses observed in clinical practice.

A Review of the Common Neurodegenerative Disorders: Current Therapeutic Approaches and the Potential Role of Nanotherapeutics

Neurodegenerative disorders are primarily characterized by neuron loss. The most common neurodegenerative disorders include Alzheimer’s and Parkinson’s disease. Although there are several medicines currently approved for managing neurodegenerative disorders, a large majority of them only help with associated symptoms. This lack of pathogenesis-targeting therapies is primarily due to the restrictive effects of the blood–brain barrier (BBB), which keeps close to 99% of all “foreign substances” out of the brain. Since their discovery, nanoparticles have been successfully used for targeted delivery into many organs, including the brain. This review briefly describes the pathophysiology of Alzheimer’s, Parkinson’s disease, and amyotrophic lateral sclerosis, and their current management approaches. We then highlight the major challenges of brain-drug delivery, followed by the role of nanotherapeutics for the diagnosis and treatment of various neurological disorders.

The panoramic view of amyotrophic lateral sclerosis: A fatal intricate neurological disorder

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurological disease affecting both upper and lower motor neurons. In the United States alone, there are 16,000-20,000 established cases of ALS. The early disease diagnosis is challenging due to many overlapping pathophysiologies with other neurological diseases. The etiology of ALS is unknown; however, it is divided into two categories: familial ALS (fALS) which occurs due to gene mutations & contributes to 5-10% of ALS, and sporadic ALS (sALS) which is due to environmental factors & contributes to 90-95% of ALS. There is still no curative treatment for ALS: palliative care and symptomatic treatment are therefore essential components in the management of these patients. In this review, we provide a panoramic view of ALS, which includes epidemiology, risk factors, pathophysiologies, biomarkers, diagnosis, therapeutics (natural, synthetic, gene-based, pharmacological, stem cell, extracellular vesicles, and physical therapy), controversies (in the clinical trials of ALS), the scope of nanomedicine in ALS, and future perspectives.

Challenges of caregiving to neurological patients

A substantial number of neurological diseases lead to chronic impairment of activities of daily living (ADL) and physical or mental dependence. In Austria, homecare is provided mostly by female family members. Moreover, mainly female personnel, in the majority from southern and eastern European countries, contributes to care. Dependence and need for care vary between neurological diagnoses and accompanying diseases. Caregiver burden (CB) depends on patient- and caregiver-related and external factors, such as integrity of a family network, spatial resources, and socioeconomic factors. Depending on the neurological diagnosis, disease severity, and behavioral impairment and psychiatric symptoms, caregivers (CG) are at a significant risk of mental and somatic health problems because of limitations in personal needs, occupational and social obligations, financial burden, and restricted family life and leisure. Subjective and objective CB needs to be assessed in time and support should be provided on an individual basis. Recently, COVID-19 has caused additional multifactorial distress to dependent patients and informal and professional CG.

Mapping of critical events in disease progression through binary classification: Application to amyotrophic lateral sclerosis

BACKGROUND

The progression of many degenerative diseases is tracked periodically using scales evaluating functionality in daily activities. Although estimating the timing of critical events (i.e., disease tollgates) during degenerative disease progression is desirable, the necessary data may not be readily available in scale records. Further, analysis of disease progression poses data challenges, such as censoring and misclassification errors, which need to be addressed to provide meaningful research findings and inform patients.

METHODS

We developed a novel binary classification approach to map scale scores into disease tollgates to describe disease progression leveraging standard/modified Kaplan-Meier analyses. The approach is demonstrated by estimating progression pathways in amyotrophic lateral sclerosis (ALS). Tollgate-based ALS Staging System (TASS) specifies the critical events (i.e., tollgates) in ALS progression. We first developed a binary classification predicting whether each TASS tollgate was passed given the itemized ALSFRS-R scores using 514 ALS patients' data from Mayo Clinic-Rochester. Then, we utilized the binary classification to translate/map the ALSFRS-R data of 3,264 patients from the PRO-ACT database into TASS. We derived the time trajectories of ALS progression through tollgates from the augmented PRO-ACT data using Kaplan-Meier analyses. The effects of misclassification errors, condition-dependent dropouts, and censored data in trajectory estimations were evaluated with Interval Censored Kaplan Meier Analysis and Multistate Model for Panel Data.

RESULTS

The approach using Mayo Clinic data accurately estimated tollgate-passed states of patients given their itemized ALSFRS-R scores (AUCs > 0.90). The tollgate time trajectories derived from the augmented PRO-ACT dataset provide valuable insights; we predicted that the majority of the ALS patients would have modified arm function (67%) and require assistive devices for walking (53%) by the second year after ALS onset. By the third year, most (74%) ALS patients would occasionally use a wheelchair, while 48% of the ALS patients would be wheelchair-dependent by the fourth year. Assistive speech devices and feeding tubes were needed in 49% and 30% of the patients by the third year after ALS onset, respectively. The onset body region alters some tollgate passage time estimations by 1-2 years.

CONCLUSIONS

The estimated tollgate-based time trajectories inform patients and clinicians about prospective assistive device needs and life changes. More research is needed to personalize these estimations according to prognostic factors. Further, the approach can be leveraged in the progression of other diseases.

Awaji criteria for the diagnosis of amyotrophic lateral sclerosis in Hanoi, Vietnam

The aim of the article was to evaluate the role of electromyography and the value of Awaji criteria for the diagnosis of ALS in the early stage. The study involves 48 patients (27 male and 21 females from 41 to 84 years old) who went to Bach Mai Hospital and Dong Do Clinic in Hanoi and were diagnosed with ALS according to Awaji criteria. All patients underwent clinical examination for ALS. The patients were examined for nerve conduction (motor and sensory conduction) using needle electromyography (EMG). Upper motor neuron (UMN) signs and lower motor neuron (LMN) signs were most common in the cervical region (89.58%), the lumbosacral region (70.83%), and the bulbar region (56.25%). The sensory nerve conduction was normal. The spontaneous activities (fasciculation, fibrillation, positive wave) accounted for more than 50% in all 4 regions: bulbar, cervical, thoracic, and lumbosacral regions. The abnormality of both clinical and electrodiagnosis was seen in the cervical region (87.5%) and lumbosacral one (70.83%) while the bulbar region and thoracic one usually had abnormal electrodiagnosis before clinical. There were 60.42% of patients with "definite ALS" by Awaji criteria. It allowed to make an earlier diagnosis cause the sensitivity of Awaji criteria (93.75%) was higher than the revised El Escorial criteria (85.42%) (p < 0.05). The needle EMG makes it possible to detect the early-stage symptoms of ALS in a situation where there are no clinical manifestations, especially in bulbar and thoracic regions.

Defective Oligodendroglial Lineage and Demyelination in Amyotrophic Lateral Sclerosis

Motor neurons and their axons reaching the skeletal muscle have long been considered as the best characterized targets of the degenerative process observed in amyotrophic lateral sclerosis (ALS). However, the involvement of glial cells was also more recently reported. Although oligodendrocytes have been underestimated for a longer time than other cells, they are presently considered as critically involved in axonal injury and also conversely constitute a target for the toxic effects of the degenerative neurons. In the present review, we highlight the recent advances regarding oligodendroglial cell involvement in the pathogenesis of ALS. First, we present the oligodendroglial cells, the process of myelination, and the tight relationship between axons and myelin. The histological abnormalities observed in ALS and animal models of the disease are described, including myelin defects and oligodendroglial accumulation of pathological protein aggregates. Then, we present data that establish the existence of dysfunctional and degenerating oligodendroglial cells, the chain of events resulting in oligodendrocyte degeneration, and the most recent molecular mechanisms supporting oligodendrocyte death and dysfunction. Finally, we review the arguments in support of the primary versus secondary involvement of oligodendrocytes in the disease and discuss the therapeutic perspectives related to oligodendrocyte implication in ALS pathogenesis.

The illness experience for people with amyotrophic lateral sclerosis: A qualitative study

Aims and objectives

This study aims to gain a comprehensive understanding of the illness experience of amyotrophic lateral sclerosis (ALS) patients in China and the meaning they attach to those experiences.

Background

ALS is a progressive and fatal neurodegenerative disorder that significantly impacts individuals and families. There is a large number of patients with ALS in China. However, little is known about how they live with ALS.

Design

Phenomenological qualitative research was performed among twenty people with ALS from the neurology department of a tertiary hospital in China. Colaizzi's method was used to analyse the participants’ data. The Consolidated Criteria for Reporting Qualitative Research (COREQ) was used as a guideline to secure accurate and complete reporting of the study.

Results

We proposed three themes and eight subthemes on the illness experience of participants: (1) life countdown: ‘my body was frozen’ (body out of control and inward suffering); (2) family self‐help: ‘we kept an eye on each other’ (family warmth and hardship, and supporting the supporter); and (3) reconstruction of life: ‘what was the meaning of my life’ (learning to accept, rebuilding self‐worth, resetting the priority list and living in the moment).

Conclusions

In the family self‐help model, patients are prompted to turn from negative mentalities to search for meaning in life actively. Healthcare providers need to attach importance to the family self‐help model to alleviate the pressure on medical resources.

Relevance to clinical practice

Healthcare providers should encourage patients to play a supportive role in the family and provide more care support and professional care knowledge guidance to caregivers, to promote the formation of the family self‐help model which might help to improve the experience of patients and families.

Prolonged distal latency of the median motor nerve is associated with poor prognosis in amyotrophic lateral sclerosis

A nerve conduction study (NCS) is routinely undertaken for the differential diagnosis of amyotrophic lateral sclerosis (ALS). Prolonged median motor distal latency (MMDL) has been reported in a subset of patients with ALS. This study aimed to investigate the clinical importance of NCS characteristics in patients with ALS. A total of 75 patients who underwent NCS were enrolled in this study. The frequency of ALS patients with prolonged motor DL was higher in the median than ulnar NCS. The multivariate analysis revealed that shorter diagnostic latency, prolonged MMDL, and higher disease progression rate were significantly associated with poor prognosis. When ALS patients were divided into two groups according to the cut-off value (4.2 ms) of the MMDL, the group with prolonged MMDL had lower ALS functional rating scale and frontal assessment battery scores, upper limbs subscore, and shorter survival time than the group with shorter MMDL. In conclusion, patients with ALS that have prolonged MMDL may have upper limb dysfunction and shorter survival. MMDL can be a useful prognostic marker for patients with ALS. Abbreviations: ADM = abductor digiti minimi; APB = abductor pollicis brevis; ALS = amyotrophic lateral sclerosis; ALSFRS-R = revised ALS Functional Rating Scale; CI = confidence interval; CMAP = compound muscle action potential; CTS = carpal tunnel syndrome; DL = distal latency; ΔFS = disease progression rate; FAB = frontal assessment battery; FVC = forced vital capacity; HR = hazard ratio; MCV = motor nerve conduction velocity; MMDL = median motor distal latency; MMSE = mini-mental state examination; NCS = nerve conduction study; PaCO₂ = partial pressure of arterial carbon dioxide; SBMA = spinal and bulbar muscular atrophy; SCV = sensory nerve conduction velocity; SD = standard deviation; SMA = spinal muscular atrophy; SNAP = sensory nerve action potential; SOD1 = superoxide dismutase 1; UMDL = ulnar motor distal latency.

Quality of life and functional independence in amyotrophic lateral sclerosis: A systematic review

Amyotrophic Lateral Sclerosis (ALS) leads to functional capacity decline, generating great impact in quality of life. Quality of life is directly related to physical integrity and functional independence. This systematic review aimed to analyze treatment protocols and their outcomes from clinical trials with focus on ALS rehabilitation that evaluated the effects on quality of life and functional independence from their intervention process. A literature search was conducted through MEDLINE-PubMed, Science Direct, Web of Science and Scopus databases. A total of 3630 articles were identified. Eleven studies met the inclusion criteria. They focused on different aspects of quality of life or functional independence, which are: respiratory care, mental health, communication skills and exercises. Use of bipap and inspiratory muscle training, anxiety and depression, communication devices implementation and exercises safety and tolerability were considered as key points. However, the drastic evolution of the disease is a limiting factor to the perception of quality of life improvement by patients. Further studies should be done to validate the benefits on patients' quality of life.

Tollgate-based progression pathways of ALS patients

OBJECTIVE

To capture ALS progression in arm, leg, speech, swallowing, and breathing segments using a disease-specific staging system, namely tollgate-based ALS staging system (TASS), where tollgates refer to a set of critical clinical events including having slight weakness in arms, needing a wheelchair, needing a feeding tube, etc. METHODS: We compiled a longitudinal dataset from medical records including free-text clinical notes of 514 ALS patients from Mayo Clinic, Rochester-MN. We derived tollgate-based progression pathways of patients up to a 1-year period starting from the first clinic visit. We conducted Kaplan-Meier analyses to estimate the probability of passing each tollgate over time for each functional segment.

RESULTS

At their first clinic visit, 93%, 77%, and 60% of patients displayed some level of limb, bulbar, and breathing weakness, respectively. The proportion of patients at milder tollgate levels (tollgate level < 2) was smaller for arm and leg segments (38% and 46%, respectively) compared to others (> 65%). Patients showed non-uniform TASS pathways, i.e., the likelihood of passing a tollgate differed based on the affected segments at the initial visit. For instance, stratified by impaired segments at the initial visit, patients with limb and breathing impairment were more likely (62%) to use bi-level positive airway pressure device in a year compared to those with bulbar and breathing impairment (26%).

CONCLUSION

Using TASS, clinicians can inform ALS patients about their individualized likelihood of having critical disabilities and assistive-device needs (e.g., being dependent on wheelchair/ventilation, needing walker/wheelchair or communication devices), and help them better prepare for future.

Learning Discriminative Spatiospectral Features of ERPs for Accurate Brain-Computer Interfaces

Constructing accurate predictive models is at the heart of brain-computer interfaces (BCIs) because these models can ultimately translate brain activities into communication and control commands. The majority of the previous work in BCI use spatial, temporal, or spatiotemporal features of event-related potentials (ERPs). In this study, we examined the discriminatory effect of their spatiospectral features to capture the most relevant set of neural activities from electroencephalographic recordings that represent users' mental intent. In this regard, we model ERP waveforms using a sum of sinusoids with unknown amplitudes, frequencies, and phases. The effect of this signal modeling step is to represent high-dimensional ERP waveforms in a substantially lower dimensionality space, which includes their dominant power spectral contents. We found that the most discriminative frequencies for accurate decoding of visual attention modulated ERPs lie in a spectral range less than 6.4 Hz. This was empirically verified by treating dominant frequency contents of ERP waveforms as feature vectors in the state-of-the-art machine learning techniques used herein. The constructed predictive models achieved remarkable performance, which for some subjects was as high as 94% as measured by the area under curve. Using these spectral contents, we further studied the discriminatory effect of each channel and proposed an efficient strategy to choose subject-specific subsets of channels that generally led to classifiers with comparable performance.

The frequency of the C9orf72 expansion in a Brazilian population

G₄C₂ hexanucleotide repeat expansions in the C9orf72 gene seem to be the cause of numerous cases of amyotrophic lateral sclerosis (ALS) and/or frontotemporal dementia (FTD). In this study, we investigated the presence of the G₄C₂ repeat expansion in 463 Brazilian probands, of whom 404 had ALS/motor neuron disease and 67 FTD, and in 63 healthy controls in the southeastern region of Brazil. The highest frequencies of the C9orf72 mutation were in the ALS-FTD group (50% of familial and 17.6% of sporadic cases), although it was also present in 5% of pure ALS/motor neuron disease patients (11.8% of familial and 3.6% of sporadic cases) and in 7.1% of pure familial FTD. Among G₄C₂ repeat mutation carriers, 68.8% of the subjects who developed dementia symptoms were females. This frequency was significantly higher than the percentage reached by men with C9orf72 expansion who had this phenotype (p = 0.047). No abnormal repeat expansion was found in control groups. Inclusion of the C9orf72 genetic test in the molecular panels for Brazilian populations with these neurodegenerative diseases should be strongly considered.

Implications of white matter damage in amyotrophic lateral sclerosis (Review)

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, which involves the progressive degeneration of motor neurons. ALS has long been considered a disease of the grey matter; however, pathological alterations of the white matter (WM), including axonal loss, axonal demyelination and oligodendrocyte death, have been reported in patients with ALS. The present review examined motor neuron death as the primary cause of ALS and evaluated the associated WM damage that is guided by neuronal‑glial interactions. Previous studies have suggested that WM damage may occur prior to the death of motor neurons, and thus may be considered an early indicator for the diagnosis and prognosis of ALS. However, the exact molecular mechanisms underlying early‑onset WM damage in ALS have yet to be elucidated. The present review explored the detailed anatomy of WM and identified several pathological mechanisms that may be implicated in WM damage in ALS. In addition, it associated the pathophysiological alterations of WM, which may contribute to motor neuron death in ALS, with similar mechanisms of WM damage that are involved in multiple sclerosis (MS). Furthermore, the early detection of WM damage in ALS, using neuroimaging techniques, may lead to earlier therapeutic intervention, using immunomodulatory treatment strategies similar to those used in relapsing‑remitting MS, aimed at delaying WM damage in ALS. Early therapeutic approaches may have the potential to delay motor neuron damage and thus prolong the survival of patients with ALS. The therapeutic interventions that are currently available for ALS are only marginally effective. However, early intervention with immunomodulatory drugs may slow the progression of WM damage in the early stages of ALS, thus delaying motor neuron death and increasing the life expectancy of patients with ALS.

Lack of association between the P413L variant of chromogranin B and ALS risk or age at onset: a meta-analysis

BACKGROUND

Amyotrophic lateral sclerosis (ALS), the most common motor neuron disease, is thought to result from interaction of genetic and environmental risk factors. Whether the potentially functional exonic P413L variant in the chromogranin B gene influences ALS risk and age at onset is controversial.

METHOD

We meta-analysed or other studies assessing the association between the P413L variant and ALS risk or age at ALS onset indexed in Web of Science, PubMed, Embase, Chinese National Knowledge Infrastructure, Wanfang, and SinoMed databases.

RESULTS

Five case-control studies were analysed, involving 2639 patients with sporadic ALS, 201 with familial ALS and 3381 controls. No association was detected between risk of either ALS type and the CT + TT genotype or T-allele of the P413L variant. Age at ALS onset was similar between carriers and non-carriers of the T-allele.

CONCLUSION

The available evidence suggests that the P413L variant of chromogranin B is not associated with ALS risk or age at ALS onset. These results should be validated in large, well-designed studies.

Emergencies in motoneuron disease

Genetic and acquired motor-neuron-disorders (MNDs) may undergo acute deterioration resulting in various emergency situations. This literature review aims at summarising and discussing current knowledge about emergencies in MNDs. Emergencies that have been reported in MND patients include: respiratory, bulbar, cardiac, septic, epileptic, psychiatric, pain-related, and traumatic emergencies. Emergencies due to respiratory insufficiency have the strongest impact on morbidity and mortality in MNDs. To optimise the management of emergencies in MNDs, it is recommended to discuss these topics with the patient prior to their occurrence. After informed consent, patients may indicate their decision by signing an advance directive as to how such emergencies should be managed in case they arise. Generally, treatment of emergencies in MNDs is not at variance from treatment of similar emergencies due to other causes, but some peculiarities need to be pointed out. It is concluded that patients with MNDs may experience various emergencies during the disease course. Management of these conditions should be discussed with the patient prior to their appearance. Management of these emergencies follows general guidelines, which widely vary between countries, and depend on the availability of a patient's advance directive.

Early Cognitive/Social Deficits and Late Motor Phenotype in Conditional Wild-Type TDP-43 Transgenic Mice

Frontotemporal Dementia (FTD) and amyotrophic lateral sclerosis (ALS) are two neurodegenerative diseases associated to mislocalization and aggregation of TAR DNA-binding protein 43 (TDP-43). To investigate in depth the behavioral phenotype associated with this proteinopathy, we used as a model transgenic (Tg) mice conditionally overexpressing human wild-type TDP 43 protein (hTDP-43-WT) in forebrain neurons. We previously characterized these mice at the neuropathological level and found progressive neurodegeneration and other features that evoke human TDP-43 proteinopathies of the FTD/ALS spectrum. In the present study we analyzed the behavior of mice at multiple domains, including motor, social and cognitive performance. Our results indicate that young hTDP-43-WT Tg mice (1 month after post-weaning transgene induction) present a normal motor phenotype compared to control littermates, as assessed by accelerated rotarod performance, spontaneous locomotor activity in the open field test and a mild degree of spasticity shown by a clasping phenotype. Analysis of social and cognitive behavior showed a rapid installment of deficits in social interaction, working memory (Y-maze test) and recognition memory (novel object recognition test) in the absence of overt motor abnormalities. To investigate if the motor phenotype worsen with age, we analyzed the behavior of mice after long-term (up to 12 months) transgene induction. Our results reveal a decreased performance on the rotarod test and in the hanging wire test, indicating a motor phenotype that was absent in younger mice. In addition, long-term hTDP-43-WT expression led to hyperlocomotion in the open field test. In sum, these results demonstrate a time-dependent emergence of a motor phenotype in older hTDP-43-WT Tg mice, recapitulating aspects of clinical FTD presentations with motor involvement in human patients, and providing a complementary animal model for studying TDP-43 proteinopathies.

An emerging role for eotaxins in neurodegenerative disease

Eotaxins are C-C motif chemokines first identified as potent eosinophil chemoattractants. They facilitate eosinophil recruitment to sites of inflammation in response to parasitic infections as well as allergic and autoimmune diseases such as asthma, atopic dermatitis, and inflammatory bowel disease. The eotaxin family currently includes three members: eotaxin-1 (CCL11), eotaxin-2 (CCL24), and eotaxin-3 (CCL26). Despite having only ~30% sequence homology to one another, each was identified based on its ability to bind the chemokine receptor, CCR3. Beyond their role in innate immunity, recent studies have shown that CCL11 and related molecules may directly contribute to degenerative processes in the central nervous system (CNS). CCL11 levels increase in the plasma and cerebrospinal fluid of both mice and humans as part of normal aging. In mice, these increases are associated with declining neurogenesis and impaired cognition and memory. In humans, elevated plasma levels of CCL11 have been observed in Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease, and secondary progressive multiple sclerosis when compared to age-matched, healthy controls. Since CCL11 is capable of crossing the blood-brain barrier of normal mice, it is plausible that eotaxins generated in the periphery may exert physiological and pathological actions in the CNS. Here, we briefly review known functions of eotaxin family members during innate immunity, and then focus on whether and how these molecules might participate in the progression of neurodegenerative diseases.