Comparison of the ability of the King's and MiToS staging systems to predict disease progression and survival in amyotrophic lateral sclerosis

Update on recent advances in amyotrophic lateral sclerosis

In the last few years, our understanding of disease molecular mechanisms underpinning ALS has advanced greatly, allowing the first steps in translating into clinical practice novel research findings, including gene therapy approaches. Similarly, the recent advent of assistive technologies has greatly improved the possibility of a more personalized approach to supportive and symptomatic care, in the context of an increasingly complex multidisciplinary line of actions, which remains the cornerstone of ALS management. Against this rapidly growing background, here we provide an comprehensive update on the most recent studies that have contributed towards our understanding of ALS pathogenesis, the latest results from clinical trials as well as the future directions for improving the clinical management of ALS patients.

Amyotrophic Lateral Sclerosis and Other Motor Neuron Diseases

OBJECTIVE

This article reviews the clinical spectrum of amyotrophic lateral sclerosis (ALS), its variant presentations, and the approach to diagnosis and management. This review includes a detailed discussion of current and emerging disease-modifying therapies and the management of respiratory and bulbar manifestations of disease. An updated review of ALS genetics and pathophysiology is also provided. This article also touches on several other important motor neuron diseases.

LATEST DEVELOPMENTS

A new set of simplified diagnostic criteria may help identify patients at earlier stages of the disease. A coformulation of sodium phenylbutyrate and tauroursodeoxycholic acid has been shown to have a significant benefit on disease progression and survival, leading to approval by regulatory authorities in the United States and Canada. An oral formulation of edaravone and an antisense oligonucleotide to a SOD1 gene variation (tofersen) have also recently been approved by the US Food and Drug Administration (FDA). Phase 3 trials of intrathecal mesenchymal stem cells failed to meet primary end points for efficacy. Updated American Academy of Neurology quality measures for the care of patients with ALS were published in 2023.

ESSENTIAL POINTS

There has been continued progress in ALS genetics, diagnosis, and disease-modifying therapies. However, we still lack a definitive biomarker or a treatment that can halt the progression or reverse the course of disease. The evolving understanding of the genetic and pathophysiologic underpinnings of disease offers promise for more effective and clinically meaningful treatments in the future.

Healthcare resource utilization at different stages of amyotrophic lateral sclerosis: Results from a real-world survey

People with amyotrophic lateral sclerosis (pALS) require complex, multi-disciplinary care, resulting in extensive healthcare resource utilization (HCRU). To investigate the relationship between HCRU and ALS progression, the study objectives were (i) to characterize HCRU in pALS and (ii) to establish whether this varied according to disease stage, as defined using three different methodologies: neurologist-defined early/mid/late stage, the King's clinical staging system for ALS, and the Milan Torino Staging system for ALS (MiToS). Real-world data were drawn from the Adelphi ALS Disease-Specific Programme™, a point-in-time survey of neurologists in France, Germany, Italy, Spain, the UK, and the USA conducted July 2020-March 2021. The analysis included survey responses from 142 physicians with respect to 880 pALS. With advancing ALS stage, significant differences were observed in the number of healthcare professional consultations and X-rays per person (both p < 0.05 for all staging systems), and the proportion of pALS with emergency room admissions, intensive care unit admissions, and assisted ventilation (all p < 0.05 for all staging systems). Across stages, >55% of pALS received care from a general neurologist and a general/primary care practitioner. With increasing stage, there was a significant difference in the proportion receiving care from a physical therapist, pulmonologist/respiratory care practitioner, respiratory therapist, speech/language therapist, and palliative care team, and in the proportion receiving care only from professional caregivers (all p < 0.05 for all staging systems). This study confirmed the substantial HCRU required to support pALS through all stages of ALS and highlighted an increasing need for healthcare resources as the disease progresses.

Comparison Of King's Clinical Staging In Multinational Amyotrophic Lateral Sclerosis Cohorts

Background: Amyotrophic lateral sclerosis (ALS) shows considerable clinical heterogeneity, which affects clinical trials. A clinical staging system has been proposed for ALS with potential applications in patient care, research, trial design and health economic analyses. The King's system consists of five stages. We have previously shown that progressive clinical stages were reached at predictable proportions through the disease course, but this needs to be validated in other independent samples. Objectives: We aimed to compare King's clinical staging in ALS in four patient groups, located in different regions and countries and using different health care systems from the original study population in South London. Methods: Clinical data were extracted from two European phase 3 randomized controlled trials (MitoTarget and LiCALS) and from two databases predominately from the United States: the PRO-ACT Consortium Database and a database of patients from the PatientsLikeMe website. Clinical stage was estimated using an algorithm, and standardized time to each clinical stage was calculated in deceased patients. Results: 8,796 patients were included, of whom 1,959 had died by the end of follow-up. Stages occurred in the same order as in the original study for all cohorts. Median standardized times to stages (interquartile range) were Stage 2: 0.61 (0.47-0.75), Stage 3: 0.68 (0.56-0.81), Stage 4A: 0.82 (0.71-0.91), Stage 4B: 0.82 (0.69-0.92) and Stage 4 0.80 (0.67-0.91). Discussion: Timings for all stages were similar to those reported in the original study, except Stage 2 which occurred later in the clinical trial databases due to recruitment occurring after diagnosis.

Amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a fatal CNS neurodegenerative disease. Despite intensive research, current management of amyotrophic lateral sclerosis remains suboptimal from diagnosis to prognosis. Recognition of the phenotypic heterogeneity of amyotrophic lateral sclerosis, global CNS dysfunction, genetic architecture, and development of novel diagnostic criteria is clarifying the spectrum of clinical presentation and facilitating diagnosis. Insights into the pathophysiology of amyotrophic lateral sclerosis, identification of disease biomarkers and modifiable risks, along with new predictive models, scales, and scoring systems, and a clinical trial pipeline of mechanism-based therapies, are changing the prognostic landscape. Although most recent advances have yet to translate into patient benefit, the idea of amyotrophic lateral sclerosis as a complex syndrome is already having tangible effects in the clinic. This Seminar will outline these insights and discuss the status of the management of amyotrophic lateral sclerosis for the general neurologist, along with future prospects that could improve care and outcomes for patients with amyotrophic lateral sclerosis.

Comparison of Slow and Forced Vital Capacity on Ability to Evaluate Respiratory Function in Bulbar-Involved Amyotrophic Lateral Sclerosis

Background and Objective

The percent-predicted forced vital capacity (FVC%) in the pulmonary function test (PFT) is generally used to evaluate the respiratory function in amyotrophic lateral sclerosis (ALS). The slow vital capacity (SVC) is another method to evaluate the respiratory function. Some neurologists found that the FVC% was not reflective of respiratory symptoms and the percent-predicted SVC (SVC%) was found to be higher in some patients with bulbar-onset ALS. We aimed to compare the percent predicted SVC (SVC%) with FVC% in evaluating the respiratory function and investigate the associations between the associations between clinical characteristics and the difference between the SVC% and the FVC% (SVC%-FVC%) in bulbar-involved ALS patients.

Method

This prospective study included patients with bulbar-involved ALS who visited the Peking University Third Hospital between October 2020 and November 2021. They underwent comprehensive clinical assessments, including bulbar symptom assessments, revised ALS functional rating scale (ALSFRS-R), Rasch-Built Overall Amyotrophic Lateral Sclerosis Disability Scale (Roads), and PFTs. The group differences were analyzed using parametric and non-parametric tests.

Results

A total of 59 participants were initially enrolled, and 51 of them were included in the final analysis. In patients with bulbar-involved ALS, the SVC% (73.82 ± 21.95%) was significantly higher (p = 0.013) than the FVC% (71.42 ± 23.15%). After controlling for other relevant variables, a partial correlation analysis showed a significant correlation (r = −0.352, p = 0.041) between ALSFRS-R1 score and SVC%-FVC%.

Conclusion

Our prospective study found that the SVC% was significantly higher and more reflective of actual respiratory function than the FVC% in patients with bulbar-involved ALS. Furthermore, the severity of dysarthria was found to be positively correlated with SVC%-FVC%, providing a clinical marker for predicting SVC%-FVC%.

Recent advances in the diagnosis and prognosis of amyotrophic lateral sclerosis

The diagnosis of amyotrophic lateral sclerosis can be challenging due to its heterogeneity in clinical presentation and overlap with other neurological disorders. Diagnosis early in the disease course can improve outcomes as timely interventions can slow disease progression. An evolving awareness of disease genotypes and phenotypes and new diagnostic criteria, such as the recent Gold Coast criteria, could expedite diagnosis. Improved prognosis, such as that achieved with the survival model from the European Network for the Cure of ALS, could inform the patient and their family about disease course and improve end-of-life planning. Novel staging and scoring systems can help monitor disease progression and might potentially serve as clinical trial outcomes. Lastly, new tools, such as fluid biomarkers, imaging modalities, and neuromuscular electrophysiological measurements, might increase diagnostic and prognostic accuracy.