Respiratory measures in amyotrophic lateral sclerosis

Mouth-controlled mouse for quadriplegic disabled people: System design and validation

Disabled people with a high cervical cord injury or quadriplegia face difficulties when controlling a computer. This study presents a digital mouth-controlled mouse-control aid called the bite-press mouth-controlled mouse (BPMCM) to replace the traditional computer mouse. The BPMCM is equipped with a joystick and micro switch, and the disabled person uses neck and head movements to push the joystick and control the cursor position while the three mouse functions (i.e., left-click, right-click, and drag) are activated by bite-pressing for different time intervals. The proposed design eliminates the sip-and-puff technique and the need to recite orders for reduced adaptation time and increased convenience. Furthermore, this design supports plug-and-play and hot plugging in modern mainstream operating systems that can often be directly operated via mouse functions. Experimental results demonstrated that disabled people using a BPMCM were as capable as healthy participants in operating a computer, with both experiments completed within 5 min, and voluntary disabled people immediately adapted to the BPMCM. The proposed design is expected to allow disabled people to operate computers at the same level as healthy participants. The BPMCM also required only half the physical exertion of other mouth-controlled mouse-control aids that require orders to be recited.

Use of the combination of spirometry, arterial blood gas analysis and overnight oximetry to predict the outcomes of patients affected by motor neuron disease: The Milan-Torin respiratory score (Mi-To-RS)

BACKGROUND AND PURPOSE

The use of multiple tests, including spirometry, arterial blood gas (ABG) analysis and overnight oximetry (OvOx), is highly recommended to monitor the respiratory function of patients with motor neuron disease (MND). In this study, we propose a composite score to simplify the respiratory management of MND patients and better stratify their prognosis.

MATERIALS AND METHODS

We screened the clinical charts of 471 non-ventilated MND patients referred to the Neuro-rehabilitation Unit of the San Raffaele Scientific Institute of Milan (January 2001-December 2019), collecting spirometric, ABG and OvOx parameters. To evaluate the prognostic role of each measurement, univariate Cox regression for death/tracheostomy was performed, and the variables associated with survival were selected to design a scoring system. Univariate and multivariate Cox regression analyses were then carried out to evaluate the prognostic role of the score. Finally, results were replicated in an independent cohort from the Turin ALS Center.

RESULTS

The study population included 450 patients. Six measurements were found to be significantly associated with survival and were selected to design a scoring system (maximum score = 8 points). Kaplan-Meier analysis showed significant stratification of survival and time to non-invasive mechanical ventilation adaptation according to score values, and multivariate analysis confirmed the independent effect of the respiratory score on survival of each cohort.

CONCLUSION

Forced vital capacity, ABG and OvOx parameters provide complementary information for the respiratory management and prognosis of MND patients and the combination of these parameters into a single score might help neurologists predict prognosis and guide decisions on the timing of the implementation of different diagnostic or therapeutic approaches.

Assessing pulmonary function in ALS using electrical impedance tomography

OBJECTIVE

We sought to determine whether thoracic electrical impedance tomography (EIT) could characterize pulmonary function in amyotrophic lateral sclerosis (ALS) patients, including those with facial weakness. Thoracic EIT is a noninvasive, technology in which a multi-electrode belt is placed across the chest, producing real-time impedance imaging of the chest during breathing.

METHODS

We enrolled 32 ALS patients and 32 age- and sex-matched healthy controls (HCs) without underlying lung disease. All participants had EIT measurements performed simultaneously with standard pulmonary function tests (PFTs), including slow and forced vital capacity (SVC and FVC) in upright and supine positions and maximal inspiratory and expiratory pressures (MIPs and MEPs, respectively). Intraclass correlation coefficients (ICCs) were calculated to assess the immediate reproducibility of EIT measurements and Pearson's correlations were used to explore the relationships between EIT and PFT values.

RESULTS

Data from 30 ALS patients and 27 HCs were analyzed. Immediate upright SVC reproducibility was very high (ICC 0.98). Correlations were generally strongest between EIT and spirometry measures, with R values ranging from 0.64 to 0.82 (p < 0.001) in the ALS cohort. There were less robust correlations between EIT values and both MIPs and MEPs in the ALS patients, with R values ranging from 0.33 to 0.44. There was no significant difference for patients with and without facial weakness. There were no reported adverse events.

CONCLUSION

EIT-based pulmonary measures hold the promise of providing an alternative approach for lung function assessment in ALS patients. Based on these early results, further development and study of this technology are warranted.

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.

Factors associated with adherence to noninvasive positive pressure ventilation in amyotrophic lateral sclerosis

INTRODUCTION

This cohort study aimed to investigate the factors associated with noninvasive positive pressure ventilation adherence and assess the long-term effects of noninvasive positive pressure ventilation adherence in patients with amyotrophic lateral sclerosis (ALS).

METHODS

The medical records of patients with ALS admitted to a tertiary hospital for noninvasive positive pressure ventilation initiation were retrospectively reviewed. Pulmonary function parameters, variables of blood gas analysis, the site of symptom onset, the time from onset and diagnosis to noninvasive positive pressure ventilation application, ALS Functional Rating Scale-Revised, neurophysiological index, and the length of hospital stay were evaluated. The adherence to noninvasive positive pressure ventilation was defined as the use of noninvasive positive pressure ventilation for ≥ 2 h/day or ≥ 4 h/day. The correlations between noninvasive positive pressure ventilation adherence or length of hospital stay and other clinical parameters were analyzed.

RESULTS

Fifty-one patients with ALS were included in the study. The time from onset and diagnosis to NIPPV application was reduced by 16 months in the adherent group than that in the non-adherent group; however, the parameters of blood gas analysis and pulmonary function tests did not differ significantly between the groups. Furthermore, the neurophysiological index of the abductor digiti minimi muscle was higher by 4.05 in the adherent group than that in the non-adherent group. The adherence to noninvasive positive pressure ventilation prolonged tracheostomy-free survival compared to that of non-adherence. Desaturation events, lower forced vital capacity, last pCO2, bicarbonate, and base excess, and higher differences in pCO2, were associated with an increase in the length of hospital stay.

CONCLUSIONS

Noninvasive positive pressure ventilation application shortly after symptom onset and ALS diagnosis in patients with CO2 retention and reduced forced vital capacity can be considered for successful adherence. Adherence to noninvasive positive pressure ventilation may result in reduced tracheostomy conversion rates and prolonged tracheostomy-free survival.

Edaravone counteracts redox and metabolic disruptions in an emerging zebrafish model of sporadic ALS

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which the death of motor neurons leads to loss of muscle function. Additionally, cognitive and circadian disruptions are common in ALS patients, contributing to disease progression and burden. Most ALS cases are sporadic, and environmental exposures contribute to their aetiology. However, animal models of these sporadic ALS cases are scarce. The small vertebrate zebrafish is a leading organism to model neurodegenerative diseases; previous studies have proposed bisphenol A (BPA) or β-methylamino-l-alanine (BMAA) exposure to model sporadic ALS in zebrafish, damaging motor neurons and altering motor responses. Here we characterise the face and predictive validity of sporadic ALS models, showing their potential for the mechanistic study of ALS drugs. We phenotypically characterise the BPA and BMAA-induced models, going beyond motor activity and motor axon morphology, to include circadian, redox, proteostasis, and metabolomic phenotypes, and assessing their predictive validity for ALS modelling. BPA or BMAA exposure induced concentration-dependent activity impairments. Also, exposure to BPA but not BMAA induced motor axonopathy and circadian alterations in zebrafish larvae. Our further study of the BPA model revealed loss of habituation to repetitive startles, increased oxidative damage, endoplasmic reticulum (ER) stress, and metabolome abnormalities. The BPA-induced model shows predictive validity, since the approved ALS drug edaravone counteracted BPA-induced motor phenotypes, ER stress, and metabolic disruptions. Overall, BPA exposure is a promising model of ALS-related redox and ER imbalances, contributing to fulfil an unmet need for validated sporadic ALS models.

Erythrocytes' surface properties and stiffness predict survival and functional decline in ALS patients

Erythrocytes play a fundamental role in oxygen delivery to tissues and binding to inflammatory mediators. Evidences suggest that dysregulated erythrocyte function could contribute to the pathophysiology of several neurodegenerative diseases. We aimed to evaluate changes in morphological, biomechanical, and biophysical properties of erythrocytes from amyotrophic lateral sclerosis (ALS) patients, as new areas of study in this disease. Blood samples were collected from ALS patients, comparing with healthy volunteers. Erythrocytes were assessed using atomic force microscopy (AFM) and zeta potential analysis. The patients' motor and respiratory functions were evaluated using the revised ALS Functional Rating Scale (ALSFRS-R) and percentage of forced vital capacity (%FVC). Patient survival was also assessed. Erythrocyte surface roughness was significantly smoother in ALS patients, and this parameter was a predictor of faster decline in ALSFRS-R scores. ALS patients exhibited higher erythrocyte stiffness, as indicated by reduced AFM tip penetration depth, which predicted a faster ALSFRS-R score and respiratory subscore decay. A lower negative charge on the erythrocyte membrane was predictor of a faster ALSFRS-R and FVC decline. Additionally, a larger erythrocyte surface area was an independent predictor of lower survival. These changes in morphological and biophysical membrane properties of ALS patients' erythrocytes, lead to increased cell stiffness and morphological variations. We speculate that these changes might precipitate motoneurons dysfunction and accelerate disease progression. Further studies should explore the molecular alterations related to these observations. Our findings may contribute to dissect the complex interplay between respiratory function, tissue hypoxia, progression rate, and survival in ALS.

Dysphagia Assessments as Criteria in the 'Decision-Making Process' for Percutaneous Endoscopic Gastrostomy Placement in People with Amyotrophic Lateral Sclerosis: A Systematic Review

To review the assessment methods of dysphagia as a criterion for the decision-making process for Percutaneous Endoscopic Gastrostomy (PEG) placement in patients with Amyotrophic Lateral Sclerosis (ALS). Systematic review. A search was conducted in three databases (EMBASE, CINAHL, PUBMED) in December 2022 and updated in July 2023. Two reviewers independently screened, selected, and extracted data. Study quality was appraised using the Joanna Briggs Institute Critical Appraisal Tools. Systematic review registration number in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42022385461. The searches identified 240 records. The 10 eligible studies included 2 case reports, 4 retrospective studies, 3 prospective studies, and 1 cohort observational study. Study quality was low, with most studies having moderate to high risk of bias. Dysphagia is a common criterion for decision-making. Dysphagia assessment is usually in the form of either self-reports, objective instrumental assessments, or both. Dysphagia is a common criterion for the decision-making process, yet is missing in clinical guidelines. Establishing the optimal means of dysphagia assessment is important for timely decision-making procedures, so that life-threatening consequences of dysphagia are minimized.

Feasibility assessment of using the MiToS staging system for conducting economic evaluation in amyotrophic lateral sclerosis

OBJECTIVES

This study assessed the feasibility of using the Milano-Torino staging (MiToS) system for conducting economic evaluation to measure health outcomes in amyotrophic lateral sclerosis (ALS).

METHODS

A Markov model was developed using the MiToS system and evaluated with a hypothetical treatment versus standard of care. Health utilities and transition probabilities were derived from the literature. Four-time horizons (1, 5, 10, and 20 years) were examined. Treatment effects of 20-35% relative risk reduction (RRR) of progressing to the next MiToS stage were assessed. Three patient distribution scenarios were tested: (1) all patients began in stage 0; (2) patient distribution based on real-world TONiC study; (3) distribution based on the PRO-ACT database. Health outcomes (quality-adjusted life-years [QALYs], life-years [LYs]) were reported with a 3% discount rate.

RESULTS

A time horizon of 10 years fully captured treatment benefits: incremental QALYs were 0.28-0.60, 0.21-0.45, and 0.26-0.55 for scenarios 1-3, respectively; incremental LYs were 0.56-1.17, 0.46-0.97, and 0.53-1.11, respectively.

CONCLUSION

MiToS-based staging can be used for conducting economic analyses in ALS. Estimated incremental QALY and LY gains were meaningful within the context of ALS, for hypothetical treatments with RRR of 20-35%.

Differential cortical gray matter changes in early- and late-onset patients with amyotrophic lateral sclerosis

Age at onset may be an important feature associated with distinct subtypes of amyotrophic lateral sclerosis (ALS). Little is known about the neuropathological mechanism of early-onset ALS (EO-ALS) and late-onset ALS (LO-ALS). Ninety ALS patients were divided into EO-ALS and LO-ALS group, and 128 healthy controls were matched into young controls(YCs) and old controls (OCs). A voxel-based morphometry approach was employed to investigate differences in gray matter volume (GMV). Significant age at onset-by-diagnosis interactions were found in the left parietal operculum, left precentral gyrus, bilateral postcentral gyrus, right occipital gyrus, and right orbitofrontal cortex. Post hoc analysis revealed a significant decrease in GMV in all affected regions of EO-ALS patients compared with YCs, with increased GMV in 5 of the 6 brain regions, except for the right orbitofrontal cortex, in LO-ALS patients compared with OCs. LO-ALS patients had a significantly increased GMV than EO-ALS patients after removing the aging effect. Correspondingly, GMV of the left postcentral gyrus correlated with disease severity in the 2 ALS groups. Our findings suggested that the pathological mechanisms in ALS patients with different ages at onset might differ. These findings provide unique insight into the clinical and biological heterogeneity of the 2 ALS subtypes.

Advances in molecular pathology, diagnosis, and treatment of amyotrophic lateral sclerosis

Although the past two decades have produced exciting discoveries in the genetics and pathology of amyotrophic lateral sclerosis (ALS), progress in developing an effective therapy remains slow. This review summarizes the critical discoveries and outlines the advances in disease characterization, diagnosis, imaging, and biomarkers, along with the current status of approaches to ALS care and treatment. Additional knowledge of the factors driving disease progression and heterogeneity will hopefully soon transform the care for patients with ALS into an individualized, multi-prong approach able to prevent disease progression sufficiently to allow for a dignified life with limited disability.

Addressing Outcome Measure Variability in Myasthenia Gravis Clinical Trials

An increasing number of clinical trials are enrolling patients with myasthenia gravis (MG). A lack of standardization in the performance of outcome measures leads to confusion among site research teams and is a source of variability in clinical trial data. MGNet, the NIH-supported Rare Disease Clinical Research Network for MG, views standardization of MG outcome measures as a critical need. To address this issue, a group of experts summarized key outcome measures used in MG clinical trials and a symposium was convened to address issues contributing to outcome measure variability. Consensus recommendations resulted in changes to outcome measure instructions and, in some cases, modifications to specific instruments. Recommended changes were posted for public commentary before finalization. Changes to the MG-Activities of Daily Living, MG-Quality of Life-15r, and MG-Impairment Index were limited to adding details to the administration instructions. Recommendations for proper positioning of participants and how to score items that could not be performed because of non-MG reasons were provided for the MG Composite. The Quantitative MG (QMG) score required the most attention, and changes were made both to the instructions and the performance of certain items resulting in the QMG-Revised. The Postintervention Status was believed to have a limited role in clinical trials, except for the concept of minimal manifestation status. As a next step, training materials and revised source documents, which will be freely available to study teams, will be created and posted on the MGNet website. Further studies are needed to validate changes made to the QMG-Revised.

Pulmonary care for ALS: Progress, gaps, and paths forward

INTRODUCTION

Adults with amyotrophic lateral sclerosis (ALS) have been using home mechanical ventilation for over 50 years. More recently, home respiratory care has evolved to include portable home ventilators, airway clearance devices, and physiological assessments with telemonitoring capability.

CURRENT STATE OF RESPIRATORY CARE

National organizations currently offer incentives for providing a pulmonary care specialist within a multidisciplinary ALS clinic; however, several critical gaps exist between the available technology and employing a clinician with the necessary expertise.

GAPS IN CARE

Lack of formal training and poor financial incentives have led to a paucity of both clinicians and active clinical research engaging in the home respiratory care of ALS. Criteria for noninvasive ventilation (NIV) initiation are controversial, and few guidelines exist on the ideal subsequent adjustments of NIV with evolving disease. Consequently, many patients with ALS tolerate NIV poorly and must face the harrowing decision of hospice vs tracheostomy. Advancement of respiratory care in ALS has been hindered by critical gaps in pulmonologist availability, training in chronic respiratory failure, financial support, clinical research, and clarity on ventilation management beyond initiation.

BRINGING RESPIRATORY CARE UP TO SPEED

Only a multifaceted approach will suffice for addressing the voids in ALS respiratory care, including various education initiatives, financial incentives, clinical research programs, and elevating the standard of respiratory care.

Predictors of Peak Expiratory Cough Flow in Individuals with Amyotrophic Lateral Sclerosis

Dystussia is prevalent in individuals with amyotrophic lateral sclerosis (ALS), leading to a diminished physiologic capacity to effectively defend the airway. We aimed to identify predictors of peak expiratory cough flow rate in individuals with ALS. One hundred and thirty-four individuals with a confirmed diagnosis of ALS (El-Escorial criteria revised) completed the ALS Functional Rating Scale-Revised (ALSFRS-R) and underwent pulmonary function and cough spirometry testing. Pearson's correlation coefficients and hierarchical multiple regression modeling were conducted to determine predictors of voluntary cough peak expiratory flow rate (p < 0.05). The full model including age, bulbar disease, cough spirometry metrics, and respiratory parameters had a marginal R² = 0.635, F (7, 126) = 30.241, p < 0.0005, adjusted R² = 0.61. Maximum expiratory pressure, compression phase, and vital capacity did not contribute and were therefore removed (p < 0.05). The most parsimonious predictive model included age, bulbar disease, peak inspiratory flow rate and duration, peak expiratory rise time, and inspiratory pressure generation with a marginal R² = 0.543. Although expiratory pressure generation has historically served as the therapeutic target to improve dystussia in ALS, the current dataset highlighted that the inability to quickly and forcefully inspire during the inspiratory phase of voluntary cough places patients at a mechanical disadvantage to generate subsequent high-velocity expiratory airflow to clear the airway. Thus, therapeutic training programs that include both inspiratory and expiratory strength targets may optimize airway clearance capacity in this challenging patient population.

Health utilities and quality-adjusted life years for patients with amyotrophic lateral sclerosis receiving reldesemtiv or placebo in FORTITUDE-ALS

AIMS

To estimate the health utilities and quality-adjusted life years (QALYs) in patients with amyotrophic lateral sclerosis (ALS) receiving reldesemtiv versus placebo in FORTITUDE-ALS.

MATERIALS AND METHODS

We performed a post hoc analysis of clinical trial data from FORTITUDE-ALS (NCT03160898). This Phase IIb, double-blind, randomized, dose-ranging, placebo-controlled, parallel-group, 12-week trial evaluated reldesemtiv in patients with ALS. Health utilities from the five-level version of the EuroQol five-dimensional questionnaire (EQ-5D-5L) were estimated using ALS Functional Rating Scale-Revised (ALSFRS-R) scores collected during the trial. QALYs were estimated using the area under the curve method.

RESULTS

The full analysis set consisted of 456 patients (reldesemtiv n = 342, placebo n = 114), who received at least one dose of the double-blind study drug, and had ALSFRS-R assessed at baseline and at least one post-baseline assessment. The difference in EQ-5D-5L utility least-squares (LS) mean change from baseline to week 12 for reldesemtiv versus placebo, adjusted for baseline values, was statistically significant (0.03, 95% confidence interval [CI]: 0.01, 0.05; p = .0008). The incremental QALY of reldesemtiv versus placebo adjusted for baseline utility values showed a modest, but statistically significant difference (0.004, 95% CI: 0.001, 0.007; p = .0058).

CONCLUSIONS

This post hoc analysis of FORTITUDE-ALS suggests that reldesemtiv showed a modest but significant benefit in health utilities and QALYs compared with placebo. Future long-term studies that include direct collection of EQ-5D-5L data will be needed to confirm our findings.ClinicalTrials.gov identifier: NCT03160898.

Targeting the Nrf2 signaling pathway using phytochemical ingredients: A novel therapeutic road map to combat neurodegenerative diseases

BACKGROUND

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a classical nuclear transcription factor that regulates the system's anti-oxidative stress response. The activation of Nrf2 induces the expression of antioxidant proteins and improves the system's anti-oxidative stress ability. Accumulating evidence suggests that Nrf2-centered signaling pathways may be a key pharmacological target for the treatment of neurodegenerative diseases (NDDs). However, phytochemicals as new therapeutic agents against NDDs have not been clearly delineated.

PURPOSE

To review the therapeutic effects of phytochemical ingredients on NDDs by activating Nrf2 and reducing oxidative stress injury.

METHODS

A comprehensive search of published articles was performed using various literature databases including PubMed, Google Scholar, and China National Knowledge Infrastructure. The search terms included "Nrf2", "phytochemical ingredients", "natural bioactive agents", "neurodegenerative diseases", "Antioxidant", "Alzheimer's disease", "Parkinson's disease", "Huntington's disease", "amyotrophic lateral sclerosis" "multiple sclerosis", "toxicity", and combinations of these keywords. A total of 769 preclinical studies were retrieved until August 2022, and we included 39 of these articless on phytochemistry, pharmacology, toxicology and other fields.

RESULTS

Numerous in vivo and in vitro studies showed that phytochemical ingredients could act as an Nrf2 activator in the treatment of NDDs through the antioxidant defense mechanism. These phytochemical ingredients, such as salidroside, naringenin, resveratrol, sesaminol, ellagic acid, ginsenoside Re, tanshinone I, sulforaphane, curcumin, naringin, tetramethylpyrazine, withametelin, magnolol, piperine, and myricetin, had the potential to improve Nrf2 signaling, thereby combatting NDDs.

CONCLUSION

As Nrf2 activators, phytochemical ingredients may provide a novel potential strategy for the treatment of NDDs. Here, we reviewed the interaction between phytochemical ingredients, Nrf2, and its antioxidant damaging pathway in NDDs and explored the advantages of phytochemical ingredients in anti-oxidative stress, which provides a reliable basis for improving the treatment of NDDs. However, further clinical trials are needed to determine the safety and efficacy of Nrf2 activators for NDDs.

Predictive parameters of early respiratory decline in Amyotrophic Lateral Sclerosis

BACKGROUND

Respiratory insufficiency is a common symptom during the course of Amyotrophic Lateral Sclerosis (ALS). The diagnostic workup may be challenging and includes a wide array of diagnostic measures. In this study, we aimed at analyzing the relationship between hypercapnia-associated symptoms, blood gas parameters, and pulmonary function tests.

METHODS

We included 109 patients (56 women, 53 men, 62.4 ± 11.9 years) with definite, possible or probable ALS according to El Escorial criteria. All patients received either arterial blood gas analysis, nocturnal capnometry, or both. Pulmonary function was assessed by spirometry and peak-cough flow. Clinical symptoms potentially indicating hypercapnia were assessed using 17 dichotomous (yes/no) items.

RESULTS

Of 109 ALS-patients, 40 had hypercapnia. The highest accuracy and specificity for predicting hypercapnia was observed for dyspnea at rest (Youden's index 17%; 95% CI 2%-34%; sensitivity 23%, 95% CI 9%-38%; specificity 95%; 95% CI 88%-100%). Daytime fatigue yielded the highest sensitivity of 58% (95% CI 40% - 76%). Logistic regression for all assessed symptoms combined yielded an area under the ROC of 0.8 (95% CI 0.7-0.9). Compared to the clinical symptoms, FVC and peak-cough flow showed higher sensitivity (70% and 87%, respectively) but lacked specificity (33% and 20%).

CONCLUSION

Evaluation of the presence of hypercapnic symptoms can be utilized to predict incipient respiratory insufficiency and should complement pulmonary function tests. Further studies are needed to validate specific questionnaires in this regard. No single hypercapnia-associated symptom or pulmonary function test on its own seems sufficient to safely predict hypercapnia.

Hypoxia signaling in human health and diseases: implications and prospects for therapeutics

Molecular oxygen (O₂) is essential for most biological reactions in mammalian cells. When the intracellular oxygen content decreases, it is called hypoxia. The process of hypoxia is linked to several biological processes, including pathogenic microbe infection, metabolic adaptation, cancer, acute and chronic diseases, and other stress responses. The mechanism underlying cells respond to oxygen changes to mediate subsequent signal response is the central question during hypoxia. Hypoxia-inducible factors (HIFs) sense hypoxia to regulate the expressions of a series of downstream genes expression, which participate in multiple processes including cell metabolism, cell growth/death, cell proliferation, glycolysis, immune response, microbe infection, tumorigenesis, and metastasis. Importantly, hypoxia signaling also interacts with other cellular pathways, such as phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) signaling, nuclear factor kappa-B (NF-κB) pathway, extracellular signal-regulated kinases (ERK) signaling, and endoplasmic reticulum (ER) stress. This paper systematically reviews the mechanisms of hypoxia signaling activation, the control of HIF signaling, and the function of HIF signaling in human health and diseases. In addition, the therapeutic targets involved in HIF signaling to balance health and diseases are summarized and highlighted, which would provide novel strategies for the design and development of therapeutic drugs.

Considerations for Amyotrophic Lateral Sclerosis (ALS) Clinical Trial Design

Thoughtful clinical trial design is critical for efficient therapeutic development, particularly in the field of amyotrophic lateral sclerosis (ALS), where trials often aim to detect modest treatment effects among a population with heterogeneous disease progression. Appropriate outcome measure selection is necessary for trials to provide decisive and informative results. Investigators must consider the outcome measure's reliability, responsiveness to detect change when change has actually occurred, clinical relevance, and psychometric performance. ALS clinical trials can also be performed more efficiently by utilizing statistical enrichment techniques. Innovations in ALS prediction models allow for selection of participants with less heterogeneity in disease progression rates without requiring a lead-in period, or participants can be stratified according to predicted progression. Statistical enrichment can reduce the needed sample size and improve study power, but investigators must find a balance between optimizing statistical efficiency and retaining generalizability of study findings to the broader ALS population. Additional progress is still needed for biomarker development and validation to confirm target engagement in ALS treatment trials. Selection of an appropriate biofluid biomarker depends on the treatment mechanism of interest, and biomarker studies should be incorporated into early phase trials. Inclusion of patients with ALS as advisors and advocates can strengthen clinical trial design and study retention, but more engagement efforts are needed to improve diversity and equity in ALS research studies. Another challenge for ALS therapeutic development is identifying ways to respect patient autonomy and improve access to experimental treatment, something that is strongly desired by many patients with ALS and ALS advocacy organizations. Expanded access programs that run concurrently to well-designed and adequately powered randomized controlled trials may provide an opportunity to broaden access to promising therapeutics without compromising scientific integrity or rushing regulatory approval of therapies without adequate proof of efficacy.

Edaravone efficacy in amyotrophic lateral sclerosis with reduced forced vital capacity: Post-hoc analysis of Study 19 (MCI186-19) [clinical trial NCT01492686]

Background

Edaravone slowed the rate of functional decline in subjects with amyotrophic lateral sclerosis (ALS) in phase 3 study MCI186-19 (Study 19). One of the Study 19 inclusion criteria was forced vital capacity (FVC) ≥80% of predicted (≥80%p). Therefore, the study provided no information on edaravone efficacy in subjects with FVC <80%p. In Study 19, 24-week, double-blind treatment was followed by open-label treatment where all subjects received edaravone. At 24 weeks, some subjects had FVC <80%p (FVC₂₄ <80%p). This allowed for post-hoc assessment of the effects of edaravone in subgroups of subjects with FVC₂₄ ≥80%p vs <80%p.

Objective

To address the question of the efficacy of edaravone in ALS patients with FVC <80%p.

Methods

Post-hoc analysis of Study 19 comparing edaravone efficacy at week 48 in subjects with FVC₂₄ ≥80%p vs <80%p.

Results

With edaravone treatment, subjects in both the FVC₂₄ ≥80%p and the FVC₂₄ <80%p subgroups experienced a reduction in ALS Functional Rating Scale-Revised (ALSFRS-R) score loss vs placebo subjects through week 48. For the FVC₂₄ ≥80%p subgroup, the changes in ALSFRS-R scores from baseline to week 48 were −7.63 for edaravone-edaravone vs −9.69 for placebo-edaravone, a difference of 2.05 (P = .034; 95% CI: 0.16, 3.94). For the FVC₂₄ <80%p subgroup, the changes in ALSFRS-R scores from baseline to week 48 were −10.26 for edaravone-edaravone vs −15.20 for placebo-edaravone, a difference of 4.94 (P = .0038; 95% CI: 1.64, 8.25). Linear regression analysis indicated that, in the FVC₂₄ <80%p subgroup, there was a notable change in the slope of the ALSFRS-R score-vs-time graph after the start of edaravone treatment.

Conclusion

ALS subjects in the Study 19 placebo arm had a slowing in disease progression, even when edaravone was added with an FVC of <80%p prior to starting edaravone. A randomized, placebo-controlled study is needed to validate these post-hoc findings.

Comparative Performance of Different Respiratory Test Parameters for Detection of Early Respiratory Insufficiency in Patients With ALS

OBJECTIVE

To compare the performance of different respiratory function testing in a multidisciplinary ALS clinic.

METHODS

Demographics, clinical data, and respiratory testing parameters were abstracted from the medical records of patients who attended a multidisciplinary ALS clinic from 2008-2016. We compared the performance of the three primary respiratory test parameters used by Medicare for the initiation of non-invasive ventilation (NIV), (forced vital capacity (FVC) < 50% predicted, maximum inspiratory pressure (MIP) < 60 cm H20, and abnormal overnight pulse oximetry (OvOx)) on how they related to several clinically relevant attributes.

RESULTS

476 subjects were identified who underwent at least one respiratory test. Abnormalities of OvOx, MIP, and FVC occurred at a median of 1.6, 1.5, and 3.8 years from disease onset, respectively (p < 0.00001). Subjects with bulbar-onset ALS exhibited earlier abnormalities in MIP and FVC than in spinal-onset ALS (p <0.005). The median survival after an abnormal OvOx, MIP, or FVC test was 1.4, 1.4, and 0.9 years, respectively (p < 0.0001). Utilizing the ALS Functional Rating Score respiratory subscales, at the time of reported respiratory symptoms there were abnormalities in OvOx (60%), MIP (69%), and FVC (19%). Conversely, when respiratory parameter abnormalities preceded reported respiratory symptoms, this occurred with frequencies in OvOx (79%), MIP (42%) or FVC (24%). Four hundred forty-three subjects (93.1%) developed at least one abnormal respiratory measure meeting Medicare criteria for NIV consideration, but fewer than 50% in our cohort demonstrated NIV use. Improved survival in subjects using NIV was statistically significant in patients with bulbar-onset ALS.

CONCLUSIONS

Abnormalities in OvOx and MIP perform better than FVC at early detection of neuromuscular respiratory weakness in ALS. Initiation of NIV in patients with respiratory insufficiency may improve overall survival in ALS. In the setting of the COVID-19 pandemic, FVC and MIP have not been routinely performed due to infectious aerosol generation. OvOx, which we now routinely mail to patients' homes, has been utilized exclusively during the COVID-19 pandemic, and allows for continued remote monitoring of respiratory status of patients with ALS.

Peak expiratory flow is a reliably household pulmonary function parameter correlates with disease severity and survival of patients with amyotrophic lateral sclerosis

Background

Amyotrophic lateral sclerosis (ALS) is an incurable and fatal neurodegenerative disease; most ALS patients die within 3 to 5 years after symptom onset, usually as a consequence of respiratory failure. In the present study, we aim to screen the survival-related pulmonary function parameters, and to explore the predictive value of peak expiratory flow (PEF) in disease severity and prognosis in patients with ALS.

Methods

The discovery cohort included 202 ALS patients, and the demographic and clinical characteristics of eligible patients were collected and pulmonary function tests were performed using MS-PFT spirometer. In the validation cohort, 62 newly diagnosed ALS patients performed the pulmonary function test by MS-PFT spirometer and household peak flow meter (KOKA) simultaneously.

Results

Among 12 pulmonary function parameters, FVC, FEV1, PEF, MEF75%, and MVV were identified to be independent predictive factors for survival. PEF was highly correlated with FVC (r = 0.797), MVV (r = 0.877), FEV1 (r = 0.847), and MEF75% (r = 0.963). Besides, the values of PEF were positively associated with disease severity (ALSFRS-R score, r_s = 0.539, P < 0.0001), and negatively associated with progression rate (ΔALSFRS-R, r_s = -0.316, P < 0.0001). Finally, we also confirmed that the values of KOKA-measured PEF were highly correlated with the ones measured using MS-PFT spirometer (r = 0.9644, p < 0.0001).

Conclusions

Our work emphasizes the critical role of PFTs in predicting prognosis of ALS patients. PEF is an easily available pulmonary function index, which is also a promising indicator in predicting disease severity and survival for ALS patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02635-z.

Respiratory function tests in amyotrophic lateral sclerosis: The role of maximal voluntary ventilation

BACKGROUND

Pulmonary function tests are routinely used to measure progression in ALS. This study aimed to assess the change of various respiratory tests, in particular maximal voluntary ventilation (MVV), which evaluates respiratory endurance.

METHODS

A group of 51 patients were assessed 3 times (T1, T2, T3, separated by 5.4 months), including slow (SVC) and forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), peak expiratory flow (PEF), maximal inspiratory (MIP) and expiratory (MEP) pressures, MVV, and sniff nasal inspiratory pressure (SNIP). In addition, body mass index (BMI), ALSFRS-R and phrenic nerve responses were obtained 4 times. Patients with dementia and marked bulbar involvement were excluded.

RESULTS

Mean ALSFRS-R was high at entry (42.9) and its decline was moderately slow at 0.4/month. FVC and FEV1 declined significantly in the three time frames analysed. MVV reduced significantly only between T1-T3 and SVC between T2-T3, and MIP, MEP, PEF and SNIP did not change significantly. The amplitude and the latency of the motor response of the phrenic nerve changed significantly, and BMI declined significantly in most time periods, and ALSFRS-R changed significantly in the 4 time periods. We found a strong correlation between MVV, and FVC, SVC, FEV1, SNIP, phrenic nerve amplitude/area (p < 0.001), and markedly with PEF (rho = 0.821) and ALSFRS-R (rho = 0.713).

CONCLUSIONS

Our study of early affected patients supports the use of a set of volitional and non-volitional respiratory tests to assess disease progression, rather than any single test. We found MVV a potentially useful marker of pulmonary function in ALS.

Correlations between measures of ALS respiratory function: is there an alternative to FVC?

Background: An ongoing longitudinal study in six European sites includes a 3-monthly assessment of forced vital capacity (FVC), slow vital capacity (SVC), peak cough flow (PCF), and Sniff nasal inspiratory pressure (SNIP). The aim of this interim analysis was to assess the potential for SNIP to be a surrogate for aerosol generating procedures given COVID-19 related restrictions. Methods: This was a prospective observational study. Patients attending six study sites with King's Stage 2 or 3 ALS completed baseline FVC/SVC/SNIP/PCF and repeated assessments 3 monthly. Data were collected from March 2018 to March 2020, after which a COVID-19 related study suspension was imposed. Correlations between the measures were calculated. A Bayesian multiple outcomes random-effects model was constructed to investigate rates of decline across measures. Results: In total, 270 cases and 828 assessments were included (Mean age 65.2 ± 15.4 years; 32.6% Female; 60% Kings stage 2; 81.1% spinal onset). FVC and SVC were the most closely correlated outcomes (0.95). SNIP showed the least correlation with other metrics 0.53 (FVC), 0.54 (SVC), 0.60 (PCF). All four measures significantly declined over time. SNIP in the bulbar onset group showed the fastest rate of decline. Discussion: SNIP was not well correlated with FVC and SVC, probably because it examines a different aspect of respiratory function. Respiratory measures declined over time, but differentially according to the site of onset. SNIP is not a surrogate for FVC and SVC, but is a complementary measure, declining linearly and differentiating spinal and bulbar onset patients.

Factors associated with Noninvasive ventilation compliance in patients with ALS/MND

Background: Although noninvasive ventilation (NIV) improves survival and quality of life (QOL) in ALS, use of NIV is suboptimal. Objective: To determine compliance with "early" NIV initiation, requisite for the feasibility of a large study of early NIV initiation, and examine factors impacting compliance. Methods: Seventy-three ALS participants with forced vital capacities (FVC) >50% were enrolled. Participants with FVC over 80% (Group 1) were initiated on NIV early (FVC between 80 and 85%). Participants with FVC between 50 and 80% (Group 2) started NIV at FVC between 50 and 55%. Symptom surveys, QOL scores, and NIV compliance (machine download documenting use ≥4 hours/night >60% of time) were collected following NIV initiation. Results: 53.6% of Group 1 and 50% of Group 2 were compliant 28 days following NIV initiation, with increased compliance over time. Participants who were unmarried, had lower income, lower educational attainment, or limited caregiver availability were less likely to be compliant. Bothersome symptoms in non-compliant participants included facial air pressure, frequent arousals with difficulty returning to sleep, and claustrophobia. Both compliant and noncompliant participants felt improved QOL with NIV; improvement was significantly greater in compliant participants. Conclusions: These data suggest ALS patients can comply with NIV early in their disease, and potentially benefit as evidenced by improved QOL scores, supporting both feasibility and need for a study comparing early versus late NIV initiation. Moreover, modifiable symptoms were identified that could be optimized to improve compliance. Further studies are needed to determine the impact of "early" intervention on survival and QOL.

Pulmonary function decline in amyotrophic lateral sclerosis

Background: There has been no comprehensive longitudinal study of pulmonary functions (PFTS) in ALS determining which measure is most sensitive to declines in respiratory muscle strength. Objective: To determine the longitudinal decline of PFTS in ALS and which measure supports Medicare criteria for NIV initiation first. Methods: Serial PFTs (maximum voluntary ventilation (MVV), maximum inspiratory pressure measured by mouth (MIP) or nasal sniff pressure (SNIP), maximum expiratory pressure (MEP), and Forced Vital Capacity (FVC)) were performed over 12 months on 73 ALS subjects to determine which measure showed the sentinel decline in pulmonary function. The rate of decline for each measure was determined as the median slope of the decrease over time. Medicare-based NIV initiation criteria were met if %FVC was ≤ 50% predicted or MIP was ≤ 60 cMH₂O. Results: 65 subjects with at least 3 visits were included for analyses. All median slopes were significantly different than zero. MEP and sitting FVC demonstrated the largest rate of decline. Seventy subjects were analyzed for NIV initiation criteria, 69 met MIP criteria first; 11 FVC and MIP criteria simultaneously and none FVC criteria first. Conclusions: MEP demonstrated a steeper decline compared to other measures suggesting expiratory muscle strength declines earliest and faster and the use of airway clearance interventions should be initiated early. When Medicare criteria for NIV initiation are considered, MIP criteria are met earliest. These results suggest that pressure-based measurements are important in assessing the timing of NIV and the use of pulmonary clearance interventions.

Hypoxia-Inducible Factor (HIF) in Ischemic Stroke and Neurodegenerative Disease

Hypoxia is one of the most common pathological conditions, which can be induced by multiple events, including ischemic injury, trauma, inflammation, tumors, etc. The body's adaptation to hypoxia is a highly important phenomenon in both health and disease. Most cellular responses to hypoxia are associated with a family of transcription factors called hypoxia-inducible factors (HIFs), which induce the expression of a wide range of genes that help cells adapt to a hypoxic environment. Basic mechanisms of adaptation to hypoxia, and particularly HIF functions, have being extensively studied over recent decades, leading to the 2019 Nobel Prize in Physiology or Medicine. Based on their pivotal physiological importance, HIFs are attracting increasing attention as a new potential target for treating a large number of hypoxia-associated diseases. Most of the experimental work related to HIFs has focused on roles in the liver and kidney. However, increasing evidence clearly demonstrates that HIF-based responses represent an universal adaptation mechanism in all tissue types, including the central nervous system (CNS). In the CNS, HIFs are critically involved in the regulation of neurogenesis, nerve cell differentiation, and neuronal apoptosis. In this mini-review, we provide an overview of the complex role of HIF-1 in the adaptation of neurons and glia cells to hypoxia, with a focus on its potential involvement into various neuronal pathologies and on its possible role as a novel therapeutic target.

Hypermetabolism associated with worse prognosis of amyotrophic lateral sclerosis

BACKGROUND AND OBJECTIVE

Exploration of hypermetabolism in amyotrophic lateral sclerosis (ALS) with different ethnicities is needed to understand its metabolic implications for clinical management. We aimed to evaluate the features of hypermetabolism and investigate its association with clinical characteristics and prognosis of ALS in a prospective Chinese cohort.

METHODS

This prospective study was conducted at Peking University Third Hospital, China from 2017 to 2020. 343 participants were enrolled initially. After strict screening, 147 matched health controls and 93 patients with ALS were eligible and underwent detailed clinical assessments. Disease severity and progression were evaluated using recognized scales. Metabolic assessments included body composition and metabolic index (MI) [hypermetabolism if MI ≥ 120.0%]. Patients were followed up every 6 months for survival analysis.

RESULTS

Compared with controls, hypermetabolism was significantly more prevalent in ALS (p = 0.009). MI was consistently higher in ALS than controls (p = 0.009). Further correlation analysis showed that MI significantly decreased with disease progression, as graded by King's College staging system (p < 0.001). MI was significantly correlated with fat-free mass and fat mass (p = 0.005 and 0.007). Survival analysis showed that hypermetabolism independently indicated a worse prognosis for ALS (HR = 1.020, CI = 1.004-1.036, p = 0.013).

CONCLUSION

A significant increase in the prevalence and degree of hypermetabolism was identified in ALS compared with strictly matched controls. Metabolic index, which is significantly associated with disease progression and body composition, is an independent prognostic indicator for a worse survival of ALS.

Phrenic nerve study as outcome in clinical trials for amyotrophic lateral sclerosis

Introduction: Respiratory tests are fundamental for monitoring respiratory function in ALS, and essential in clinical trials. Slow vital capacity (SVC) was canceled in some countries to prevent COVID-19 transmission. We aimed to test phrenic nerve motor responses as an option to SVC in clinical trials. Methodology: Patients followed-up in our unit were selected respecting inclusion criteria used elsewhere: possible/probable/definite disease; onset-age 18-80years; disease duration from disease duration ≤24months; body mass index (BMI)>20kg/m²; respiratory subscore of the revised ALS functional rating scale (ALSFRS-R)≥11; upright SVC ≥ 70%. We added normal phrenic responses (meanPhrenAmpl, ≥0.4mV). All patients were on riluzole. SVC and meanPhrenAmpl were recorded at study entry (T0) and 24 weeks later (T1). Decays were determined. Sample size was calculated for a treatment effect of 30% on the decay rate. Results: We included 317 ALS patients (191 males, 225 spinal-onset), mean onset-age 59.9 ± 10.7 (31-80)years, mean onset BMI 25.48 ± 3.2 (20.1-35)kg/m², mean disease duration 10.5 ± 5.6 (1-24)months, mean ALSFRS-R 41.54 ± 4.3 (22-47) and respiratory subscore 11.83 ± 0.38 (11-12). MeanPhrenAmpl and SVC were weakly but significantly correlated at T0 and T1. At T1, MeanPhrenAmpl decayed 16.94 ± 16.45% and SVC 13.5 ± 16.86%. For the proposed drug effect, 174 and 272 patients would be needed to recruit using respectively meanPhrenAmpl and SVC decline as the primary outcome measurement (accepting no dropouts). Discussion: Contrary to SVC, meanPhrenAmpl is non-volitional and not associated with aerosolization risk. Lower recruitment number (98 patients less) would be needed, translating shorter inclusion period, trial length and costs, and probable lower missed data rate. MeanPhrenAmp is an alternative test in ALS clinical trials.

Diaphragmatic dysfunction at the first visit to a chest diseases outpatient clinic in 500 patients with amyotrophic lateral sclerosis

INTRODUCTION

In this study, we aimed to evaluate diaphragmatic dysfunction (DD) by using a practical approach in patients with amyotrophic lateral sclerosis (ALS) at the first visit to a chest diseases outpatient clinic.

METHODS

Patients with ALS seen in our outpatient clinic for the past 5 y and followed up for at least 1 y, were retrospectively evaluated. Having at least one of the following three criteria was accepted as DD: (a) paradoxical abdominal movement (PAM), (b) sitting-supine forced vital capacity (FVC) difference ≥ 20%, (c) sitting-supine arterial oxygen saturation measured by pulse oximetry (SpO₂ ) difference ≥ 4%. Respiratory symptoms, arterial blood gas analysis, sleep studies, noninvasive mechanical ventilation use, and mortality were recorded.

RESULTS

Five-hundred patients with ALS were included (female/male: 220/280, age: 58.9 ± 11.3 y). Of the patients, 22.8% had daytime hypercapnia. DD was observed in 55% of the patients (PAM in 112, sitting-supine FVC difference ≥ 20% in 50, and sitting-supine SpO₂ difference ≥ 4% in 113 patients). Of the patients with DD, 31.6% (n = 87) had no respiratory symptoms, 46.4% had FVC > 70% and 33.5% had FVC <50%. Nocturnal hypoxemia (sleep time spent with SpO₂  < 90% ≥30%) was present in 59.7%, and all patients with nocturnal hypoxemia had DD. Obstructive sleep apnea (8 severe, 14 moderate, 39 mild) was detected in 55% of the patients with polysomnography (n = 61) or polygraphy (n = 50). During follow-up, 52.2% of the patients died. Mean survival time was shorter in patients with DD (P < .001).

CONCLUSION

Paradoxical abdomimal movement (PAM), sitting-supine SpO₂ difference ≥ 4% and sitting-supine FVC difference ≥ 20% are indicators of DD, which should be routinely evaluated at every outpatient visit.

Effects of a 12-week combined aerobic and strength training program in ambulatory patients with amyotrophic lateral sclerosis: a randomized controlled trial

OBJECTIVE

To compare the effectiveness of a combined aerobic, strength, and flexibility training program with flexibility alone on disease-specific and health-related symptoms in ambulatory amyotrophic lateral sclerosis (ALS) patients.

METHODS

Thirty-two ambulatory patients with ALS were equally randomized into a combined aerobic-strength intervention group or a stretching control group. The intervention period for both groups was identical, 12 consecutive weeks, two sessions per week. The combined intervention program consisted of aerobic training by recumbent cycling, flexibility achieved by stretching and passive exercises, and strength training via functional exercises. Patients in the control group performed basic stretching exercises of the upper and lower limb at home. Outcome measures included the ALS Functional Rating Scale-Revised (ALSFRS-R), respiratory function, mobility, fatigue, and quality of life and were collected 1-week prior to the intervention, after 6-weeks of training, and at the completion of the intervention.

RESULTS

Twenty-eight participants (17 males, 11 females); mean age (S.D.) = 58.5 (13.2) years; mean disease duration (S.D.) = 7.3 (12.0) years, completed the study. According to the group X time analysis, significant differences were found in respiratory function, mobility, and the ALSFRS-R in favor of the aerobic-strength group. These patients maintained their abilities, whereas, a significant decrease was observed in the flexibility training group. Scores of the SF-36 categories "physical functioning", "energy fatigue" and "wellbeing" were higher following the intervention in the aerobic-strength group compared with the stretching control group.

CONCLUSIONS

A 12-week combined aerobic and strength training program is far superior to flexibility alone in improving respiratory function, mobility, and wellbeing in ambulatory ALS patients.

Amyotrophic lateral sclerosis: update on clinical management

PURPOSE OF REVIEW

The current review will provide recent updates in the clinical management of amyotrophic lateral sclerosis (ALS).

RECENT FINDINGS

Although there is no cure for ALS, there are new treatments, growing knowledge of genetics, development of clinical staging systems, and the recent coronavirus disease 2019 pandemic that have recently impacted the clinical management of ALS. Increased understanding of genetics has helped provide insights into pathophysiology, the staging systems and clinical measures help to provide tools for monitoring disease clinically, and the recent coronavirus disease 2019 pandemic has provided opportunities to develop telemedicine and remote monitoring of disease thereby increasing accessibility to care and reducing burden of travel to centers for people living with the disease and their caregivers.

SUMMARY

ALS is a progressive neurodegenerative disease that causes degeneration of the motor neurons which leads to paralysis and respiratory failure. Despite the lack of a cure, multidisciplinary care, proactive respiratory management, nutritional care and management of symptoms as well as pharmacological interventions that can improve quality of life and survival.

What Is in the Literature

This installment of what is in the literature is on amyotrophic lateral sclerosis (ALS). The pathophysiology of ALS remains open and the role of genes, a foothold into pathophysiology, but there are >22 genes identified, and the mechanisms are not known for any. Despite the lack of a firm understanding of pathophysiology, drug trials continue based on possible mechanisms, but no new drugs beyond riluzole and edaravone have been positive in phase 3 trials. There are a number of formal stem cell trials underway, and the results of a phase 2 trial are described. Major efforts to make trials more sensitive are being considered. There are a number of articles with helpful and practical findings for the diagnosis and management of ALS.

Cerebrospinal fluid MFG-E8 as a promising biomarker of amyotrophic lateral sclerosis

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a fatal progressive neurodegenerative disease resulting in the dysfunction of upper and lower motor neurons. Biomarkers in fluid have been used to monitor the disease and its progression. Milk fat globule-EGF factor 8 (MFG-E8) is an inflammation modulator, which is involved in the pathogenesis of neurodegenerative diseases. We here took this study to evaluate the predictive value of MFG-E8 in ALS.

METHODS

This study consisted of 19 patients with ALS and 15 healthy controls. Cerebrospinal fluid (CSF) were collected from all participants and tested for the levels of MFG-E8, neurofilament light (NFL), and heavy chain (NFH). The correlations between MFG-E8 and NFL, NFH, ALS severity, cognitive status, and forced vital capacity (FVC) were analyzed.

RESULTS

We found that MFG-E8 performs well in distinguishing ALS from controls, with relatively higher level of MFG-E8 in ALS subjects, than controls. Moreover, MFG-E8 negatively correlated with the revised ALS function rating scale (ALS-FRS), but not with the levels of NFL and NFH, disease duration, progression rate, mini-mental state examination (MMSE), and FVC.

CONCLUSIONS

The study proved that CSF MFG-E8 helps distinguish ALS from controls. However, the protein in CSF negatively predicted disease severity.

Non-invasive ventilation in amyotrophic lateral sclerosis

Non-invasive ventilation (NIV) has become an important cornerstone of symptomatic treatment in amyotrophic lateral sclerosis (ALS), improving survival and quality of life. In this review, we summarize the most important recent developments and insights, including evidence of efficacy, indication criteria and time of initiation, ventilation parameters and adaptation strategies, treatment of complicating factors, transition from NIV to invasive ventilation, termination of NIV and end-of-life management. Recent publications have questioned former conventions and guideline recommendations, especially with regard to timing and prognostic factors; therefore, a fresh look and re-evaluation of current evidence is needed.

Variation in noninvasive ventilation use in amyotrophic lateral sclerosis

Objective

We sought to examine prevalence and predictors of noninvasive ventilation (NIV) in a composite cohort of patients with amyotrophic lateral sclerosis (ALS) followed in a clinical trials setting (Pooled Resource Open-Access ALS Clinical Trials database).

Methods

NIV initiation and status were ascertained from response to question 12 of the revised ALS Functional Rating Scale (ALSFRS-R). Factors affecting NIV use in patients with forced vital capacity (FVC) ≤50% of predicted were examined. Predictors of NIV were evaluated by Cox proportional hazard models and generalized linear mixed models.

Results

Among 1,784 patients with 8,417 simultaneous ALSFRS-R and FVC% measures, NIV was used by 604 (33.9%). Of 918 encounters when FVC% ≤50%, NIV was reported in 482 (52.5%). Independent predictors of NIV initiation were lower FVC% (hazard ratio [HR] 1.27, 95% confidence interval [CI] 1.17–1.37 for 10% drop), dyspnea (HR 2.62, 95% CI 1.87–3.69), orthopnea (HR 4.09, 95% CI 3.02–5.55), lower bulbar and gross motor subscores of ALSFRS-R (HRs 1.09 [95% CI 1.03–1.14] and 1.13 [95% CI 1.07–1.20], respectively, per point), and male sex (HR 1.73, 95% CI 1.31–2.28). Adjusted for other variables, bulbar onset did not significantly influence time to NIV (HR 0.72, 95% CI 0.47–1.08). Considerable unexplained variability in NIV use was found.

Conclusion

NIV use was lower than expected in this ALS cohort that was likely to be optimally managed. Absence of respiratory symptoms and female sex may be barriers to NIV use. Prospective exploration of factors affecting adoption of NIV may help bridge this gap and improve care in ALS.

Respiratory Assessment of ALS Patients: A Nationwide Survey of Current Dutch Practice

BACKGROUND AND OBJECTIVE

Non-invasive ventilation (NIV) is an established treatment for respiratory failure in patients with amyotrophic lateral sclerosis (ALS). Several studies have shown room for improvement with regard to respiratory care for ALS patients, including latency of referral. These studies focused on the time period starting at the moment of referral to a home ventilation service (HVS) onwards. In the current study we performed a nationwide survey to gain insight in the trajectory before referral. We questioned the assessment of respiratory impairment by ALS physicians/care teams, including criteria for referral to an HVS.

METHODS

We requested 40 ALS care teams in the Netherlands to fill in an online questionnaire on respiratory management in ALS patients.

RESULTS

Thirty-two ALS care teams (80%) responded. Forced vital capacity was the most frequently used test at each outpatient visit (72%) and often served as a criterion (78%) for referral to an HVS. Other respiratory function measurements that were performed less often included peak cough flow (50%), maximum inspiratory/expiratory pressure (31% /28%) and sniff nasal inspiratory pressure (13%). Morning headache was the most frequently questioned complaint (94%), followed by daytime sleepiness (91%). Dyspnoea and orthopnoea were reported by 38% and 59% as important complaints. Out of all patients under the care of the ALS care teams, the mean estimated proportion of patients that was referred to an HVS was 69% (range 20-100%). When physicians refrained from referral, the most often cited reasons were patient's decision to withhold NIV (94%) and cognitive impairment (50%). Sixteen percent of the respondents stated bulbar impairment as a reason to refrain from referral.

CONCLUSION

Despite findings in previous studies on the superiority of SNIP and PCF as compared to FVC, our study shows that a majority of ALS care teams still prefers to use FVC for the assessment of respiratory dysfunction and for the timing of referral to an HVS. Another finding is that bulbar impairment is not an obstacle for referral for NIV.