Heterogeneity in ALSFRS-R decline and survival: a population-based study in Italy

Treating amyotrophic lateral sclerosis with allogeneic Schwann cell-derived exosomal vesicles: a case report

Schwann cells are essential for the maintenance and function of motor neurons, axonal networks, and the neuromuscular junction. In amyotrophic lateral sclerosis, where motor neuron function is progressively lost, Schwann cell function may also be impaired. Recently, important signaling and potential trophic activities of Schwann cell-derived exosomal vesicles have been reported. This case report describes the treatment of a patient with advanced amyotrophic lateral sclerosis using serial intravenous infusions of allogeneic Schwann cell-derived exosomal vesicles, marking, to our knowledge, the first instance of such treatment. An 81-year-old male patient presented with a 1.5-year history of rapidly progressive amyotrophic lateral sclerosis. After initial diagnosis, the patient underwent a combination of generic riluzole, sodium phenylbutyrate for the treatment of amyotrophic lateral sclerosis, and taurursodiol. The patient volunteered to participate in an FDA-approved single-patient expanded access treatment and received weekly intravenous infusions of allogeneic Schwann cell-derived exosomal vesicles to potentially restore impaired Schwann cell and motor neuron function. We confirmed that cultured Schwann cells obtained from the amyotrophic lateral sclerosis patient via sural nerve biopsy appeared impaired (senescent) and that exposure of the patient's Schwann cells to allogeneic Schwann cell-derived exosomal vesicles, cultured expanded from a cadaver donor improved their growth capacity in vitro. After a period of observation lasting 10 weeks, during which amyotrophic lateral sclerosis Functional Rating Scale-Revised and pulmonary function were regularly monitored, the patient received weekly consecutive infusions of 1.54 × 10 12 (×2), and then consecutive infusions of 7.5 × 10 12 (×6) allogeneic Schwann cell-derived exosomal vesicles diluted in 40 mL of Dulbecco's phosphate-buffered saline. None of the infusions were associated with adverse events such as infusion reactions (allergic or otherwise) or changes in vital signs. Clinical lab serum neurofilament and cytokine levels measured prior to each infusion varied somewhat without a clear trend. A more sensitive in-house assay suggested possible inflammasome activation during the disease course. A trend for clinical stabilization was observed during the infusion period. Our study provides a novel approach to address impaired Schwann cells and possibly motor neuron function in patients with amyotrophic lateral sclerosis using allogeneic Schwann cell-derived exosomal vesicles. Initial findings suggest that this approach is safe.

Neurodegenerative and neuroinflammatory changes in SOD1-ALS patients receiving tofersen

The initiation of tofersen, a new specific antisense oligonucleotide (ASO) for SOD1 pathology, marked a significant turning point for SOD1-ALS patients. While clinical trials and early access program studies reported a significant reduction in plasma and cerebrospinal fluid (CSF) neurofilament levels, neuroinflammation following prolonged treatment was never assessed. In this multicenter study, we evaluated a cohort of 18 SOD1-ALS patients treated with tofersen, analyzing correlations between biomarkers of neurodegeneration/neuroinflammation and clinical variables indicative of disease progression. NfL, NfH, CHI3L1, and Serpina1 levels in serum and CSF were determined by semi-automated immunoassays (Ella™ technology). Generalized linear mixed models were employed to investigate longitudinal trends of these biomarkers. Our data highlighted a progressive decrease in CSF neurofilament levels during tofersen treatment (MR = 0.97, 95% CI 0.94-0.99, p = 0.006 and MR = 0.98, 95% CI 0.95-1.00, p = 0.076 for NfL and NfH in CSF, respectively). Conversely, CSF levels of SerpinA1 and CHI3L1 increased over time (MR = 1.12, 95% CI 1.08-1.16, p < 0.0001 and MR = 1.039, 95% CI 1.015-1.062, p = 0.001 for SerpinA1 and CHI3L1 in CSF, respectively), but these modifications were most apparent after six and twelve months of therapy, respectively. Disease progression rate did not correlate with these biomarker trends. We observed a significant decrease in neurofilament levels during Tofersen treatment, alongside an increase in neuroinflammatory markers, potentially linked to an immune response triggered by ASO treatment. Given the limited data on tofersen's long-term efficacy in ALS due to its recent introduction, identifying biomarkers that predict clinical outcomes such as diminished therapeutic response or adverse effects is crucial. These biomarkers may help to better understand the underlying pathomechanisms of ALS and tofersen's role in modulating disease progression.

Phenotypical Characterization of C9ALS Patients from the Emilia Romagna Registry of ALS: A Retrospective Case-Control Study

BACKGROUND/OBJECTIVES

C9ORF72 expansion is associated with significant phenotypic heterogeneity. This study aimed to characterize the clinical features of C9ALS patients from the Emilia Romagna ALS registry (ERRALS) and compare them with non-mutated ALS (nmALS) patients matched for sex, age at onset, and diagnostic delay, sourced from the same register.

METHODS

In total, 67 C9ALS patients were compared to 201 nmALS. Clinical data, phenotype, and prognostic factors were analyzed in the two groups and within the C9ALS group after stratification by sex.

RESULTS

C9ALS patients displayed a higher disease progression rate and shorter times to gastrostomy and invasive ventilation, despite no differences in overall survival. Female C9ALS had a more severe bulbar and upper motor neuron involvement compared to males. Cognitive and behavioral symptoms were more common in the C9ALS group, and the former was an independent prognostic factor. Prevalences of, autoimmune diseases, and dyslipidemia were significantly higher among C9ALS patients.

CONCLUSIONS

In our dataset, we show an overall increased disease progression rate in C9ALS patients and hint at sex-specific discrepancies in some phenotypical characteristics. We also suggest a possible clinically relevant involvement of C9ORF72 expansion in metabolism and autoimmunity.

Transcranial static magnetic stimulation for amyotrophic lateral sclerosis: a bicentric, randomised, double-blind placebo-controlled phase 2 trial

Background

Enhanced glutamatergic transmission leading to motor neuron death is considered the major pathophysiological mechanism of amyotrophic lateral sclerosis (ALS). Motor cortex excitability can be suppressed by transcranial static magnetic stimulation (tSMS), thus tSMS can be evaluated as a potential treatment for ALS. The aim of present study was to investigate the efficacy and safety of tSMS in ALS.

Methods

In this phase 2 trial, we randomly assigned ALS patients to receive daily tSMS or placebo stimulation over a period of 6 months. For each participant we calculated mean disease monthly progression rate (MPR) as the variation of the total ALS Functional Rating Scale-Revised (ALSRFS-R) score, before the beginning of the treatment (over a period of at least three months) and over the six-month treatment period. The primary efficacy outcome was the difference in MPR before and after the beginning of treatment. Secondary outcomes included safety and tolerability, compliance, and changes in corticospinal output. A long-term follow-up of 18 months was performed in all patients who completed the six-month treatment considering a composite endpoint event (tracheostomy or death). Trial registered at ClinicalTrials.gov, ID: NCT04393467, status: closed.

Findings

Forty participants were randomly assigned to real (n = 21) or placebo stimulation (n = 19). Thirty-two participants (18 real and 14 placebo) completed the 6-month treatment. The MPR did not show statistically significant differences between the two arms during the pre-treatment (mean ± Standard deviation; Real: 1.02 ± 0.62, Sham: 1.02 ± 0.57, p-value = 1.00) and treatment period (Real: 0.90 ± 0.55, Sham: 0.94 ± 0.55, p-value = 0.83). Results for secondary clinical endpoints showed that the treatment is feasible and safe, being compliance with tSMS high. The change in corticospinal output did not differ significantly between the two groups. At the end of the long-term follow-up of 18 months, patients of real group had a statistically significant higher tracheostomy-free survival compared with patients of placebo group (Hazard Ratio = 0.27 95% Confidence interval 0.09-0.80, p-value = 0.019).

Interpretation

tSMS did not modify disease progression during the 6 months of treatment. However, long-term follow-up revealed a substantial increase in tracheostomy free survival in patients treated with real stimulation supporting the evaluation of tSMS in larger and more prolonged studies.

Funding

The "Fondazione 'Nicola Irti' per le opere di carità e di cultura", Rome, Italy, supported present study.

Trends in Hospital Admissions for Patients with Amyotrophic Lateral Sclerosis: Insights from a Retrospective Cohort Study in a Province in Northern Italy

ALS is characterized by a highly heterogeneous course, ranging from slow and uncomplicated to rapid progression with severe extra-motor manifestations. This study investigated ALS-related hospitalizations and their connection to clinical aspects, comorbidities, and prognosis. We performed a retrospective cohort study including patients residing in Modena, Italy, newly diagnosed between 2007 and 2017 and followed up until 31 December 2022. Data were obtained from the Emilia Romagna ALS registry, regional hospitals, and medical records. Among the 249 patients, there were 492 hospital admissions, excluding those for diagnostic purposes; 63% of the patients had at least one hospitalization post-diagnosis, with an average stay of 19.90 ± 23.68 days. Younger patients were more likely to be hospitalized multiple times and experienced longer stays (44.23 ± 51.71 days if <65 years; 26.46 ± 36.02 days if older, p < 0.001). Patients who were hospitalized at least once more frequently underwent gastrostomy (64.97%) or non-invasive (66.24%) and invasive (46.50%) ventilation compared to those never hospitalized (21.74%, 31.52%, 13.04%, respectively, p < 0.001 for all). Emergency procedures led to longer hospitalizations (62.84 ± 48.91 days for non-invasive ventilation in emergencies vs. 39.88 ± 46.46 days electively, p = 0.012). Tracheostomy-free survival was not affected by hospitalizations. In conclusion, younger ALS patients undergo frequent and prolonged hospitalizations, especially after emergency interventions, although these do not correlate with reduced survival.

Amyotrophic lateral sclerosis stratification: unveiling patterns with virome, inflammation, and metabolism molecules

Amyotrophic lateral sclerosis (ALS) is an untreatable and clinically heterogeneous condition primarily affecting motor neurons. The ongoing quest for reliable biomarkers that mirror the disease status and progression has led to investigations that extend beyond motor neurons' pathology, encompassing broader systemic factors such as metabolism, immunity, and the microbiome. Our study contributes to this effort by examining the potential role of microbiome-related components, including viral elements, such as torque tenovirus (TTV), and various inflammatory factors, in ALS. In our analysis of serum samples from 100 ALS patients and 34 healthy controls (HC), we evaluated 14 cytokines, TTV DNA load, and 18 free fatty acids (FFA). We found that the evaluated variables are effective in differentiating ALS patients from healthy controls. In addition, our research identifies four unique patient clusters, each characterized by distinct biological profiles. Intriguingly, no correlations were found with site of onset, sex, progression rate, phenotype, or C9ORF72 expansion. A remarkable aspect of our findings is the discovery of a gender-specific relationship between levels of 2-ethylhexanoic acid and patient survival. In addition to contributing to the growing body of evidence suggesting altered peripheral immune responses in ALS, our exploratory research underscores metabolic diversity challenging conventional clinical classifications. If our exploratory findings are validated by further research, they could significantly impact disease understanding and patient care customization. Identifying groups based on biological profiles might aid in clustering patients with varying responses to treatments.

Improving the measurement properties of the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R): deriving a valid measurement total for the calculation of change

BACKGROUND

The Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) total score is a widely used measure of functional status in Amyotrophic Lateral Sclerosis/Motor Neuron Disease (ALS), but recent evidence has raised doubts about its validity. The objective was to examine the measurement properties of the ALSFRS-R, aiming to produce valid measurement from all 12 scale items.

METHOD

Longitudinal ALSFRS-R data were collected between 2013-2020 from 1120 people with ALS recruited from 35 centers, together with other scales in the Trajectories of Outcomes in Neurological Conditions-ALS (TONiC-ALS) study. The ALSFRS-R was analyzed by confirmatory factor analysis (CFA), Rasch Analysis (RA) and Mokken scaling.

RESULTS

No definite factor structure of the ALSFRS-R was confirmed by CFA. RA revealed the raw score total to be invalid even at the ordinal level because of multidimensionality; valid interval level subscale measures could be found for the Bulbar, Fine-Motor and Gross-Motor domains but the Respiratory domain was only valid at an ordinal level. All four domains resolved into a single valid, interval level measure by using a bifactor RA. The smallest detectable difference was 10.4% of the range of the interval scale.

CONCLUSION

A total ALSFRS-R ordinal raw score can lead to inferential bias in clinical trial results due to its non-linear nature. On the interval level transformation, more than 5 points difference is required before a statistically significant detectable difference can be observed. Transformation to interval level data should be mandatory in clinical trials.

SerpinA1 levels in amyotrophic lateral sclerosis patients: An exploratory study

BACKGROUND

SerpinA1, a serine protease inhibitor, is involved in the modulation of microglial-mediated inflammation in neurodegenerative diseases. We explored SerpinA1 levels in cerebrospinal fluid (CSF) and serum of amyotrophic lateral sclerosis (ALS) patients to understand its potential role in the pathogenesis of the disease.

METHODS

SerpinA1, neurofilament light (NfL) and heavy (NfH) chain, and chitinase-3-like protein-1 (CHI3L1) were determined in CSF and serum of ALS patients (n = 110) and healthy controls (n = 10) (automated next-generation ELISA), and correlated with clinical parameters, after identifying three classes of progressors (fast, intermediate, slow). Biomarker levels were analyzed for diagnostic power and association with progression and survival.

RESULTS

SerpinA1serum was significantly decreased in ALS (median: 1032 μg/mL) compared with controls (1343 μg/mL) (p = 0.02). SerpinA1CSF was elevated only in fast progressors (8.6 μg/mL) compared with slow (4.43 μg/mL, p = 0.01) and intermediate (4.42 μg/mL, p = 0.03) progressors. Moreover, SerpinA1CSF correlated with neurofilament and CHI3L1 levels in CSF. Contrarily to SerpinA1CSF , neurofilament and CHI3L1 concentrations in CSF correlated with measures of disease progression in ALS, while SerpinA1serum mildly related with time to generalization (rho = 0.20, p = 0.04). In multivariate analysis, the ratio between serum and CSF SerpinA1 (SerpinA1 ratio) and NfHCSF were independently associated with survival.

CONCLUSIONS

Higher SerpinA1CSF levels are found in fast progressors, suggesting SerpinA1 is a component of the neuroinflammatory mechanisms acting upon fast-progressing forms of ALS. Both neurofilaments or CHI3L1CSF levels outperformed SerpinA1 at predicting disease progression rate in our cohort, and so the prognostic value of SerpinA1 alone as a measure remains inconclusive.

Effect of tauroursodeoxycholic acid on survival and safety in amyotrophic lateral sclerosis: a retrospective population-based cohort study

Background

Oral tauroursodeoxycholic acid (TUDCA) is a commercial drug currently tested in patients with amyotrophic lateral sclerosis (ALS) both singly and combined with sodium phenylbutyrate. This retrospective study aimed to investigate, in a real-world setting, whether TUDCA had an impact on the overall survival of patients with ALS who were treated with this drug compared to those patients who received standard care only.

Methods

This propensity score-matched study was conducted in the Emilia Romagna Region (Italy), which has had an ALS regional registry since 2009. Out of 627 patients with ALS diagnosed from January 1st, 2015 to June 30th, 2021 and recorded in the registry with available information on death/tracheostomy, 86 patients took TUDCA and were matched in a 1:2 ratio with patients who received only usual care according to age at onset, sex, phenotype, diagnostic latency, ALS Functional Rating Scale-Revised (ALSFRS-R) at first visit, disease progression rate at first visit, and BMI at diagnosis. The primary outcome was survival difference (time from onset of symptoms to tracheostomy/death) between TUDCA exposed and unexposed patients.

Findings

A total of 86 patients treated with TUDCA were matched to 172 patients who did not receive treatment. TUDCA-exposed patients were stratified based on dosage (less than or equal to 1000 mg/day or greater) and duration (less than or equal to 12 months or longer) of treatment. The median overall survival was 49.6 months (95% CI 41.7-93.5) among those treated with TUDCA and 36.2 months (95% CI 32.7-41.6) in the control group, with a reduced risk of death observed in patients exposed to a higher dosage (defined as ≥ 1000 mg/day) of TUDCA (HR 0.56; 95% CI 0.38-0.83; p = 0.0042) compared to both the control group and those with lower TUDCA dosages (defined as < 1000 mg/day). TUDCA was generally well-tolerated, except for a minority of patients (n = 7, 8.1%) who discontinued treatment due to side effects, primarily gastrointestinal and mild in severity; only 2 adverse events required hospital access but resolved without sequelae.

Interpretation

In this population-based exploratory study, patients with ALS who were treated with TUDCA may have prolonged survival compared to patients receiving standard care only. Additional prospective randomized studies are needed to confirm the efficacy and safety of this drug.

Funding

Emilia-Romagna Region.

Factors predicting disease progression in C9ORF72 ALS patients

OBJECTIVE

To unveil clinical features, comorbidities, disease progression and prognostic factors in a population-based cohort of ALS patients carrying C9ORF72 expansion (C9 + ALS).

METHODS

This is a retrospective observational study on ALS patients residing in Emilia Romagna and Piedmont-Valle D'Aosta regions whose data are available through population based registers. We analysed patients who underwent genetic testing, focusing on C9 + ALS subgroup.

RESULTS

Among 2204 genotyped patients of the two registers, 150 were C9 + ALS. In comparison with patients without mutation, a higher proportion of family history (12.85 vs 68%, p < 0.001) and frontotemporal dementia (3.93% vs 10.67%, p < 0.001) was detected in C9 + ALS. C9 + ALS presented a faster disease progression as measured by monthly decline in ALS Functional Rating Scale-Revised (1.86 ± 3.30 vs 1.45 ± 2.35, p < 0.01) and in forced vital capacity (5.90 ± 5.24 vs 2.97 ± 3.47, p < 0.01), a shorter diagnostic delay (8.93 ± 6.74 vs 12.68 ± 12.86 months, p < 0.01) and earlier onset (58.91 ± 9.02 vs 65.04 ± 11.55 years, p < 0.01). Consistently, they reached death or tracheostomy earlier than other patients (31 vs 37 months, HR = 1.52, 95% C.I. 1.27-1.82, p < 0.001). With respect to other genotyped patients, C9 + ALS patients did not present a significantly higher prevalence of concomitant diseases. Independent prognostic factors of survival of C9 + ALS included sex, age, progression rate, presence of frontotemporal dementia and thyroid disorders, with the latter being associated with prolonged ALS survival (43 vs 29 months, HR = 0.42, 95% C.I. 0.24-0.74, p = 0.003).

CONCLUSION

Even in the context of a more aggressive disease, C9 + ALS had a longer survival in presence of thyroid disorders. This finding may suggest protective pathogenic pathways in C9 + ALS to be explored, looking for therapeutic strategies to slow disease course.

Identifying patterns in amyotrophic lateral sclerosis progression from sparse longitudinal data

The clinical presentation of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, varies widely across patients, making it challenging to determine if potential therapeutics slow progression. We sought to determine whether there were common patterns of disease progression that could aid in the design and analysis of clinical trials. We developed an approach based on a mixture of Gaussian processes to identify clusters of patients sharing similar disease progression patterns, modeling their average trajectories and the variability in each cluster. We show that ALS progression is frequently nonlinear, with periods of stable disease preceded or followed by rapid decline. We also show that our approach can be extended to Alzheimer's and Parkinson's diseases. Our results advance the characterization of disease progression of ALS and provide a flexible modeling approach that can be applied to other progressive diseases.

Characterising ALS disease progression according to El Escorial and Gold Coast criteria

BACKGROUND

The Gold Coast criteria (GCC) have been proposed as a means of selecting patients for amyotrophic lateral sclerosis (ALS) clinical trials. We aimed to characterise disease progression according to the GCC.

METHODS

Data from population-based ALS registries from the Netherlands and Belgium were analysed. The GCC additionally define ALS as lower motor neuron (LMN) dysfunction in ≥2 body regions without upper motor neuron dysfunction. Therefore, the revised El Escorial criteria (rEEC) were supplemented with a 'Gold Coast ALS' category for patients with only LMN dysfunction in ≥2 body regions. We assessed survival time, ALS Functional Rating Scale (ALSFRS-R) progression rates and between-patient variability per diagnostic category.

RESULTS

We included 5957 ALS patients, of whom 600 (10.1%) fulfilled the GCC but not the rEEC, and 95 (1.6%) fulfilled only the rEEC. ALSFRS-R progression rates were similar for the rEEC (0.84 points/month) and GCC (0.81 points/month) with similar variability (standard deviation of 0.59 vs. 0.60) and median survival time (17.8 vs.18.7 months). Survival time and average progression rates varied (p<0.001) between categories. Per category, however, there was considerable between-patient variability with progression rates ranging from: -2.10 to -0.14 (definite), -1.94 to -0.06 (probable), -2.10 to -0.02 (probable laboratory supported), -1.79 to -0.02 (possible) and -1.31 to 0.08 (Gold Coast).

CONCLUSIONS

The GCC broaden the definition of ALS, allowing more patients to participate in trials, while minimally impacting population heterogeneity. Given the large variability per diagnostic category, selecting only specific categories for trials may not result in a more homogeneous study population.

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.

Measurement of upper limb function in ALS: a structure review of current methods and future directions

Measurement of upper limb function is critical for tracking clinical severity in amyotrophic lateral sclerosis (ALS). The Amyotrophic Lateral Sclerosis Rating Scale-revised (ALSFRS-r) is the primary outcome measure utilised in clinical trials and research in ALS. This scale is limited by floor and ceiling effects within subscales, such that clinically meaningful changes for subjects are often missed, impacting upon the evaluation of new drugs and treatments. Technology has the potential to provide sensitive, objective outcome measurement. This paper is a structured review of current methods and future trends in the measurement of upper limb function with a particular focus on ALS. Technologies that have the potential to radically change the upper limb measurement field and explore the limitations of current technological sensors and solutions in terms of costs and user suitability are discussed. The field is expanding but there remains an unmet need for simple, sensitive and clinically meaningful tests of upper limb function in ALS along with identifying consensus on the direction technology must take to meet this need.

Epidemiological, Clinical and Genetic Features of ALS in the Last Decade: A Prospective Population-Based Study in the Emilia Romagna Region of Italy

Increased incidence rates of amyotrophic lateral sclerosis (ALS) have been recently reported across various Western countries, although geographic and temporal variations in terms of incidence, clinical features and genetics are not fully elucidated. This study aimed to describe demographic, clinical feature and genotype-phenotype correlations of ALS cases over the last decade in the Emilia Romagna Region (ERR). From 2009 to 2019, our prospective population-based registry of ALS in the ERR of Northern Italy recorded 1613 patients receiving a diagnosis of ALS. The age- and sex-adjusted incidence rate was 3.13/100,000 population (M/F ratio: 1.21). The mean age at onset was 67.01 years; women, bulbar and respiratory phenotypes were associated with an older age, while C9orf72-mutated patients were generally younger. After peaking at 70-75 years, incidence rates, among women only, showed a bimodal distribution with a second slight increase after reaching 90 years of age. Familial cases comprised 12%, of which one quarter could be attributed to an ALS-related mutation. More than 70% of C9orf72-expanded patients had a family history of ALS/fronto-temporal dementia (FTD); 22.58% of patients with FTD at diagnosis had C9orf72 expansion (OR 6.34, p = 0.004). In addition to a high ALS incidence suggesting exhaustiveness of case ascertainment, this study highlights interesting phenotype-genotype correlations in the ALS population of ERR.

Qualitative measures that assess functional disability and quality of life in ALS

BACKGROUND

Selection of appropriate trial endpoints and outcome measures is particularly important in rare disease and rapidly progressing disease such as amyotrophic lateral sclerosis (ALS) where the challenges to conducting clinical trials, are substantial: patient and disease heterogeneity, limited understanding of exact disease pathophysiology, and lack of robust and available biomarkers. To address these challenges in ALS, the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised version (ALSFRS-R) was developed and has become a key primary endpoint in ALS clinical trials to assess functional disability and disease progression, often replacing survival as a primary outcome. However, increased understanding of the ALS disease journey and improvements in assistive technology for ALS patients have exposed issues with the ALSFRS-R, including non-linearity, multidimensionality and floor and ceiling effects that could challenge its continued utility as a primary outcome measure in ALS clinical trials. Recently, other qualitative scale measures of functioning disability have been developed to help address these issues. With this in mind, we conducted a literature search aimed at identifying both established and promising new measures for potential use in clinical trials.

METHODS

We searched PubMed, Google, Google Scholar, and the reference sections of key studies to identify papers that discussed qualitative measures of functional status for potential use in ALS studies. We also searched clinicaltrials.gov to identify functional status and health-related quality of life (HRQoL) measures that have been used in ALS interventional studies.

RESULTS

In addition to the ALSFRS-R, we identified several newer qualitative scales including ALSFRS-EX, ALS-MITOS, CNS-BFS, DALS-15, MND-DS, and ROADS. Strengths and limitations of each measure were identified and discussed, along with their potential to act as a primary or secondary outcome to assess patient functional status in ALS clinical trials.

CONCLUSION

This paper serves as a reference guide for researchers deciding which qualitative measures to use as endpoints in their ALS clinical trials to assess functional status. This paper also discusses the importance of including ALS HRQoL and ALS cognitive screens in future clinical trials to assess the value of a new ALS therapy more comprehensively.

Low plasma hyaluronan is associated with faster functional decline in patients with amyotrophic lateral sclerosis

Objective: Hyaluronan, a glycosaminoglycan that forms a major constituent of the extracellular matrix, has been shown to be increased in the serum of patients with amyotrophic lateral sclerosis (ALS) with longer disease duration. We sought to determine whether measures of venous hyaluronan may serve as a predictive marker for disease progression in patients with ALS. Methods: Sixty-two patients with ALS, and 59 healthy control participants provided a plasma sample for the assessment of hyaluronan. Hyaluronan was compared against functional measures of disability, disease progression, and survival. Results: Hyaluronan was lower in patients with ALS when compared to healthy controls. Plasma hyaluronan was positively correlated with the change in the revised ALS functional rating scale, ΔFRS. Hyaluronan was also found to improve the prognostic power of the ΔFRS. Conclusion: Hyaluronan may serve as a predictive marker for functional decline in patients with ALS. Longitudinal studies are needed to fully explore the prognostic value of hyaluronan as a biomarker for disease progression, and to improve our understanding of components of the extracellular matrix specific to the pathophysiology of ALS.

Can amyotrophic lateral sclerosis progression really pause? A cohort study using the medical research council scale

Objective: To assess the frequency and predictors of plateaus in ALS progression as assessed by the Medical Research Council (MRC) Scale. Methods: All patients attending the ALS Center of Turin, with a diagnosis between 2007 and 2014 were considered. At each visit, muscle strength was evaluated in several muscles and assessed using the MRC scale. Concomitant ALSFRSr scores were retrieved. Plateaus were calculated as a stable overall MRC or ALSFRSr score lasting at least 6, 12 or 18 months. Results: According to MRC scale scores, 122 (22.8%), 71 (13.2%) and 59 (11.0%) patients experienced a plateau lasting at least 6, 12 and 18 months. ALSFRSr scores revealed similar estimates [134, (25.0%), 89 (16.6%) and 67 (12.5%), respectively]. Plateaus were more frequent at high scores and appeared a median of 24.6 months (IQR 6.7-47.7) after the diagnosis. Only the predominant upper motor neuron phenotype (OR 4.06, 95% CI 2-06-8.10, p-value <0.001) and diagnostic delay OR 1.03, 95% CI 1.01-10.5, p-value = 0.005) were significantly correlated with their appearance. Discussion: Plateaus in ALS progression as assessed using either ALSFRSr or MRC scale are not infrequent and should be expected especially in less aggressive phenotypes. Similar results were found both using the MRC scale and the ALSFRSr scores, suggesting a comparable reliability of these scales in grasping the disease progression.

The Gut Microbiota-Immunity Axis in ALS: A Role in Deciphering Disease Heterogeneity?

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disorder with an unknown etiology and no effective treatment, and is characterized by large phenotypic heterogeneity, including variable sites, ages of symptom onset and rates of disease progression. Increasing data support the role of the microbiota-immunity axis in the pathogenesis of neurodegenerative diseases. In the present study, we compared the inflammatory and microbiota profile of ALS patients with different clinical characteristics, with healthy family caregivers. Measuring a panel of 30 inflammatory cytokines in serum and fecal samples, we observed a distinct cytokine profile both at the systemic and intestinal level in patients compared to controls and even in patients with different clinical phenotypes and progression rates. The 16S targeted metagenome analysis revealed slight differences in patients compared to controls as well as in patients with slow progression, marked by the reduction of butyrate-producing bacteria and a decrease of the Firmicutes/Bacteroidetes ratio in ALS. Finally, the short chain fatty acid analysis did not show a different distribution among the groups. If confirmed in a larger number of patients, the inflammatory cytokine profile and the microbial composition could be appropriate biomarker candidates for deciphering ALS heterogeneity.

Milano-Torino Staging and Long-Term Survival in Chinese Patients with Amyotrophic Lateral Sclerosis

(1) Background: The aim of this longitudinal study was to evaluate the association between disease progression according to the Milano–Torino staging (MITOS) system and long-term survival in Chinese patients with amyotrophic lateral sclerosis (ALS). We also examined factors affecting MITOS progression. (2) Methods: Patients were enrolled and underwent follow-up at 6, 12, 18, and 24 months, and their demographic and clinical data, including the Milano–Torino stage, Amyotrophic Lateral Sclerosis Functional Rating Scale—Revised (ALSFRS-R) score and neuropsychiatric data, were evaluated. The sensitivity and specificity of predicting survival outcomes based on MITOS progression and ALSFRS-R score decline from baseline to 6 months were compared. The associations between MITOS progression from baseline to 6 months and survival outcome at 12, 18 and 24 months were examined, and factors associated with disease progression were evaluated with subgroup analyses. (3) Results: Among the 100 patients included, 74% were in stage 0 at baseline, and approximately 95% progressed to a higher stage of the MITOS system at 24 months. MITOS progression from baseline to 6 months and ALSFRS-R decline showed comparable value for predicting survival at 12, 18, and 24 months. MITOS progression from baseline to 6 months is strongly associated with death outcomes. Older age at onset and increased depression and anxiety scores may be related to disease progression. (4) Conclusions: MITOS progression during the early disease course could serve as a prognostic marker of long-term survival and may have utility in clinical trials. Age at onset and diagnosis and neuropsychiatric factors might be associated with disease progression.

Emotional Lability at Disease Onset Is an Independent Prognostic Factor of Faster Disease Progression in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fast progressing neurodegenerative disease leading to quadriplegia, anarthria and respiratory insufficiency. A large variety of phenotypes and disability progression requires individually tailored management. Identification of predictors of poor prognosis may not only improve management, but also allow for more precise patients’ stratification for clinical trials or research studies. The aim of the study was to investigate the influence of emotional lability present at disease onset on ALS progression by exploring its direct impact on the decay of the ALS Functional Rating Scale-Revised (ALSFRS-R). The study was performed in a group of 1145 patients from Germany, Poland, Portugal and Turkey between 2014 and 2018. The analysis showed that the presence of emotional lability at ALS onset was linked to a faster decline of ALSFRS-R (0.70 vs 0.50, p<0.0001), in case of either bulbar (0.80 vs 0.65, p<0.05) or limb disease onset (0.59 vs 0.46, p <0.01). It was most prominent in the bulbar subscore of ALSFRS-R. A multiple regression analysis showed a direct influence of emotional lability at ALS onset on disease progression, regardless of age, gender, site of onset, weight loss, cognitive impairment and diagnosis delay (β=0.071; p=0.019). It can therefore be concluded that the presence of emotional lability at the disease onset is an independent factor of faster disease progression in ALS.

Biochemical parameters in determination of nutritional status in amyotrophic lateral sclerosis

OBJECTIVES

Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disorder without effective treatment. Progressive dysphagia, depression, and hypermetabolism may lead to malnutrition. The aim of the present study was to analyze the potential utility of readily available, relatively inexpensive, and rapid strategy for using laboratory parameters to assess nutritional status of ALS patients.

METHODS

This study included 203 patients with ALS. The analysis of inflammatory parameters: C Reactive Protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell count (WBC), lymphocytes number (LN), and fibrinogen concentration (FC) was followed by nutritional markers: serum concentration of albumin (ALB), prealbumin (PALB), transferrin (TRNF), and creatinine (CREA), which were correlated with demographic and clinical parameters: body mass index (BMI), ALS phenotype, disease duration, diagnosis delay, and functional and respiratory assessment.

RESULTS

Nearly 20% of patients had biochemical features of inflammation. Among patients without inflammation (n = 163), a decreased serum TRNF concentration was found in 84% of cases, PALB in 39%, ALB in 25%, and CREA in 53%. The median of PALB was the highest in patients with PMA (23.5 mg/dL) and the lowest in PBP (16.6 mg/dL) (p < 0.05). The CREA concentration correlated with the BMI (r = 0.25; p < 0.01), while PALB and TRNF significantly varied depending on the severity of dysphagia. Patients with dysphagia qualified to enteral nutrition showed significantly decreased concentration of PALB, triglycerides, as well as reduced forced vital capacity, BMI, and functional status.

CONCLUSIONS

CREA, PALB, ALB, and TNFR are easily accessible, accurate, and low-cost parameters useful in assessment of the nutritional status in ALS.

Insights into Amyotrophic Lateral Sclerosis from a Machine Learning Perspective

Objective: Amyotrophic lateral sclerosis (ALS) disease state prediction usually assumes linear progression and uses a classifier evaluated by its accuracy. Since disease progression is not linear, and the accuracy measurement cannot tell large from small prediction errors, we dispense with the linearity assumption and apply ordinal classification that accounts for error severity. In addition, we identify the most influential variables in predicting and explaining the disease. Furthermore, in contrast to conventional modeling of the patient’s total functionality, we also model separate patient functionalities (e.g., in walking or speaking). Methods: Using data from 3772 patients from the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) database, we introduce and train ordinal classifiers to predict patients’ disease state in their last clinic visit, while accounting differently for different error severities. We use feature-selection methods and the classifiers themselves to determine the most influential variables in predicting the disease from demographic, clinical, and laboratory data collected in either the first, last, or both clinic visits, and the Bayesian network classifier to identify interrelations among these variables and their relations with the disease state. We apply these methods to model each of the patient functionalities. Results: We show the error distribution in ALS state prediction and demonstrate that ordinal classifiers outperform classifiers that do not account for error severity. We identify clinical and lab test variables influential to prediction of different ALS functionalities and their interrelations, and specific value combinations of these variables that occur more frequently in patients with severe deterioration than in patients with mild deterioration and vice versa. Conclusions: Ordinal classification of ALS state is superior to conventional classification. Identification of influential ALS variables and their interrelations help explain disease mechanism. Modeling of patient functionalities separately allows relation of variables and their connections to different aspects of the disease as may be expressed in different body segments.

Using automated electronic medical record data extraction to model ALS survival and progression

BACKGROUND

To assess the feasibility of using automated capture of Electronic Medical Record (EMR) data to build predictive models for amyotrophic lateral sclerosis (ALS) outcomes.

METHODS

We used an Informatics for Integrating Biology and the Bedside search discovery tool to identify and extract data from 354 ALS patients from the University of Kansas Medical Center EMR. The completeness and integrity of the data extraction were verified by manual chart review. A linear mixed model was used to model disease progression. Cox proportional hazards models were used to investigate the effects of BMI, gender, and age on survival.

RESULTS

Data extracted from the EMR was sufficient to create simple models of disease progression and survival. Several key variables of interest were unavailable without including a manual chart review. The average ALS Functional Rating Scale - Revised (ALSFRS-R) baseline score at first clinical visit was 34.08, and average decline was - 0.64 per month. Median survival was 27 months after first visit. Higher baseline ALSFRS-R score and BMI were associated with improved survival, higher baseline age was associated with decreased survival.

CONCLUSIONS

This study serves to show that EMR-captured data can be extracted and used to track outcomes in an ALS clinic setting, potentially important for post-marketing research of new drugs, or as historical controls for future studies. However, as automated EMR-based data extraction becomes more widely used there will be a need to standardize ALS data elements and clinical forms for data capture so data can be pooled across academic centers.

Unraveling the Complexity of Amyotrophic Lateral Sclerosis Survival Prediction

Objective: The heterogeneity of amyotrophic lateral sclerosis (ALS) survival duration, which varies from <1 year to >10 years, challenges clinical decisions and trials. Utilizing data from 801 deceased ALS patients, we: (1) assess the underlying complex relationships among common clinical ALS metrics; (2) identify which clinical ALS metrics are the "best" survival predictors and how their predictive ability changes as a function of disease progression. Methods: Analyses included examination of relationships within the raw data as well as the construction of interactive survival regression and classification models (generalized linear model and random forests model). Dimensionality reduction and feature clustering enabled decomposition of clinical variable contributions. Thirty-eight metrics were utilized, including Medical Research Council (MRC) muscle scores; respiratory function, including forced vital capacity (FVC) and FVC % predicted, oxygen saturation, negative inspiratory force (NIF); the Revised ALS Functional Rating Scale (ALSFRS-R) and its activities of daily living (ADL) and respiratory sub-scores; body weight; onset type, onset age, gender, and height. Prognostic random forest models confirm the dominance of patient age-related parameters decline in classifying survival at thresholds of 30, 60, 90, and 180 days and 1, 2, 3, 4, and 5 years. Results: Collective prognostic insight derived from the overall investigation includes: multi-dimensionality of ALSFRS-R scores suggests cautious usage for survival forecasting; upper and lower extremities independently degenerate and are autonomous from respiratory decline, with the latter associating with nearer-to-death classifications; height and weight-based metrics are auxiliary predictors for farther-from-death classifications; sex and onset site (limb, bulbar) are not independent survival predictors due to age co-correlation. Conclusion: The dimensionality and fluctuating predictors of ALS survival must be considered when developing predictive models for clinical trial development or in-clinic usage. Additional independent metrics and possible revisions to current metrics, like the ALSFRS-R, are needed to capture the underlying complexity needed for population and personalized forecasting of survival.

Association between macronutrient intake and amyotrophic lateral sclerosis prognosis

Objectives: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease, and the nutritional state of ALS patients is associated with survival. The purpose of the present study was to investigate whether macronutrient intake at early stage of the disease was positively associated with survival and duration from symptom onset to death, tracheostomy, or non-invasive ventilation (NIV) in ALS.Methods: ALS patients diagnosed according to EI Escorial criteria were recruited from 2011 to 2016 and followed up until 2017, when they reached the endpoint of death, tracheostomy, or NIV use. Dietary intake was estimated based on a 24-hour recall conducted less than 2 years from symptom onset, and the survival time was defined as the duration from symptom onset to the endpoint.Results: ALS patients were categorized as short-term group (n=79) and long-term group (n=69) according to the mean survival time (33.03±14.01 months). Short-term survival was negatively associated with fat, protein, and meat intake, and positively associated with carbohydrate intake after adjustment for confounders. In addition, the survival time was positively associated with fat, protein, and meat intake but was not associated with carbohydrate intake.Discussion: The present study suggested that higher intake of fat and protein, particularly from meat at early stage of the disease, could prolong the survival of ALS patients. However, further clinical trials are necessary to confirm the beneficial effects of higher fat and protein intake on mortality in ALS patients.

Imaging muscle as a potential biomarker of denervation in motor neuron disease

OBJECTIVE

To assess clinical, electrophysiological and whole-body muscle MRI measurements of progression in patients with motor neuron disease (MND), as tools for future clinical trials, and to probe pathophysiological mechanisms in vivo.

METHODS

A prospective, longitudinal, observational, clinicoelectrophysiological and radiological cohort study was performed. Twenty-nine patients with MND and 22 age-matched and gender-matched healthy controls were assessed with clinical measures, electrophysiological motor unit number index (MUNIX) and T2-weighted whole-body muscle MRI, at first clinical presentation and 4 months later. Between-group differences and associations were assessed using age-adjusted and gender-adjusted multivariable regression models. Within-subject longitudinal changes were assessed using paired t-tests. Patterns of disease spread were modelled using mixed-effects multivariable regression, assessing associations between muscle relative T2 signal and anatomical adjacency to site of clinical onset.

RESULTS

Patients with MND had 30% higher relative T2 muscle signal than controls at baseline (all regions mean, 95% CI 15% to 45%, p<0.001). Higher T2 signal was associated with greater overall disability (coefficient -0.009, 95% CI -0.017 to -0.001, p=0.023) and with clinical weakness and lower MUNIX in multiple individual muscles. Relative T2 signal in bilateral tibialis anterior increased over 4 months in patients with MND (right: 10.2%, 95% CI 2.0% to 18.4%, p=0.017; left: 14.1%, 95% CI 3.4% to 24.9%, p=0.013). Anatomically, contiguous disease spread on MRI was not apparent in this model.

CONCLUSIONS

Whole-body muscle MRI offers a new approach to objective assessment of denervation over short timescales in MND and enables investigation of patterns of disease spread in vivo. Muscles inaccessible to conventional clinical and electrophysiological assessment may be investigated using this methodology.

Increasing the efficiency of clinical trials in neurodegenerative disorders using group sequential trial designs

OBJECTIVES

Clinical trials in neurodegenerative disorders are facing high futility rates and rising development costs. We aim to review and exemplify the value of group sequential trial designs (i.e., designs with one or more prospectively planned interim analyses) within the field of amyotrophic lateral sclerosis.

STUDY DESIGN AND SETTING

We reviewed the literature to identify sequentially conducted trials. Subsequently, we reanalyzed the dexpramipexole trial (EMPOWER), a classically designed and conducted trial involving 942 participants, by sequentially monitoring the functional questionnaire and survival endpoint. Finally, we simulated the performance of the sequential methodology under different treatment effects.

RESULTS

Only six (12%) randomized, placebo-controlled trials incorporated stopping rules for both futility and superiority. Despite its high enrollment rate, sequential reanalysis of the EMPOWER study reduced the total trial duration with 140 days (23.4%, 95% confidence interval [CI] 13.2-34.4%), the number of follow-ups with 2,688 visits (23.6%, 95% CI 11.3-38.6%), and the total drug exposure time with 73,377 days (20.6%, 95% CI 9.8-35.9%). The functional questionnaire considerably increased the heterogeneity in the test statistics, which may negatively affect sequential monitoring.

CONCLUSION

Group sequential trials can result in important reductions in the trial duration, which could make clinical trials more ethical by reducing the patients' exposure to noneffective treatments or by limiting their time on placebo.

Using an onset-anchored Bayesian hierarchical model to improve predictions for amyotrophic lateral sclerosis disease progression

BACKGROUND

Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's disease, is a rare disease with extreme between-subject variability, especially with respect to rate of disease progression. This makes modelling a subject's disease progression, which is measured by the ALS Functional Rating Scale (ALSFRS), very difficult. Consider the problem of predicting a subject's ALSFRS score at 9 or 12 months after a given time-point.

METHODS

We obtained ALS subject data from the Pooled Resource Open-Access ALS Clinical Trials Database, a collection of data from various ALS clinical trials. Due to the typical linearity of the ALSFRS, we consider several Bayesian hierarchical linear models. These include a mixture model (to account for the two potential classes of "fast" and "slow" ALS progressors) as well as an onset-anchored model, in which an additional artificial data-point, using time of disease onset, is utilized to improve predictive performance.

RESULTS

The onset-anchored model had a drastically reduced posterior predictive mean-square-error distributions, when compared to the Bayesian hierarchical linear model or the mixture model under a cross-validation approach. No covariates, other than time of disease onset, consistently improved predictive performance in either the Bayesian hierarchical linear model or the onset-anchored model.

CONCLUSIONS

Augmenting patient data with an additional artificial data-point, or onset anchor, can drastically improve predictive modelling in ALS by reducing the variability of estimated parameters at the cost of a slight increase in bias. This onset-anchored model is extremely useful if predictions are desired directly after a single baseline measure (such as at the first day of a clinical trial), a feat that would be very difficult without the onset-anchor. This approach could be useful in modelling other diseases that have bounded progression scales (e.g. Parkinson's disease, Huntington's disease, or inclusion-body myositis). It is our hope that this model can be used by clinicians and statisticians to improve the efficacy of clinical trials and aid in finding treatments for ALS.

Assessment of the factorial validity and reliability of the ALSFRS-R: a revision of its measurement model

The amyotrophic lateral sclerosis functional rating scale-revised (ALSFRS-R) is a widely used primary outcome measure in amyotrophic lateral sclerosis (ALS) clinical practice and clinical trials. ALSFRS-R items cannot, however, validly be summed to obtain a total score, but constitute domain scores reflecting a profile of disease severity. Currently, there are different measurement models for estimating domain scores. The objective of the present study is, therefore, to derive the measurement model that best fits the data for a valid and uniform estimation of ALSFRS-R domain scores. Data from 1556 patients with ALS were obtained from a population-based register in The Netherlands. A random split of the sample provided a calibration and validation set. Measurement models of the ALSFRS-R were investigated using both exploratory factor analyses and confirmatory factor analyses. The measurement model with a four-factor structure (i.e., bulbar, fine motor, gross motor, and respiratory function), with correlated factors and cross-loading items on dressing and hygiene and turning in bed and adjusting bed clothes on both motor function scales, provided the best fit to the data in both sets. Correlation between factors ranged from weak to modest, confirming that the ALSFRS-R constitutes a profile of four clinically relevant domain scores rather than a total score that expresses disease severity. The internal consistency of the four domain scores was satisfactory. Our revision of the measurement model may allow for a more adequate estimation of disease severity and disease progression in epidemiological studies and clinical trials.

Patients with ALS show highly correlated progression rates in left and right limb muscles

Objective:

Amyotrophic lateral sclerosis (ALS) progresses at different rates between patients, making clinical trial design difficult and dependent on large cohorts of patients. Currently, there are few data showing whether the left and right limbs progress at the same or different rates. This study addresses rates of decline in specific muscle groups of patients with ALS and assesses whether there is a relationship between left and right muscles in the same patient, regardless of overall progression.

Methods:

A large cohort of patients was used to assess decline in muscle strength in right and left limbs over time using 2 different methods: The Tufts Quantitative Neuromuscular Exam and Accurate Test of Limb Isometric Strength protocol. Then advanced linear regression statistical methods were applied to assess progression rates in each limb.

Results:

This report shows that linearized progression models can predict general slopes of decline with good accuracy. Critically, the data demonstrate that while overall decline is variable, there is a high degree of correlation between left and right muscle decline in ALS. This implies that irrespective of which muscle starts declining soonest or latest, their rates of decline following onset are more consistent.

Conclusions:

First, this study demonstrates a high degree of power when using unilateral treatment approaches to detect a slowing in disease progression in smaller groups of patients, thus allowing for paired statistical tests. These findings will be useful in transplantation trials that use muscle decline to track disease progression in ALS. Second, these findings discuss methods, such as tactical selection of muscle groups, which can improve the power efficiency of all ALS clinical trials.

What does the ALSFRS-R really measure? A longitudinal and survival analysis of functional dimension subscores in amyotrophic lateral sclerosis

INTRODUCTION

ALS functional rating scale (revised) (ALSFRS-R) is the most widely used functional rating system in patients with amyotrophic lateral sclerosis (ALS). However, heterogeneity in ALSFRS-R progression renders analysis challenging. We have explored the characteristics of total ALSFRS-R, and ALSFRS-R subscores in longitudinal and survival models, to determine whether subscore analysis enhances the precision of the instrument.

METHODS

All cases with ALSFRS-R scores on the Irish ALS register were included. ALSFRS-R subscores were defined for bulbar, motor and respiratory domains. Longitudinal models were used to visualise fitted total ALSFRS-R and ALSFRS-R subscore progression. In addition, the prognostic value of convenience and computed ALSFRS-R slope and subscore slopes were compared.

RESULTS

407 incident cases were identified with a complete ALSFRS-R measure. 233 (57%) patients were male, and 125 (31%) had bulbar-onset disease. ALSFRS-R bulbar and motor subscore slopes provided a better fit in prognostic models when combined over the total ALSFRS-R slope. Longitudinal analysis revealed that the ALSFRS-R motor subscore deteriorated earlier in spinal-onset disease over bulbar-onset disease, while in bulbar-onset disease the ALSFRS-R bulbar subscore deteriorated earlier and faster than in spinal-onset disease.

DISCUSSION

Our analysis builds on previous knowledge of ALSFRS-R subscores. Decline in ALSFRS-R motor subscores in patients with spinal-onset disease, and decline in ALSFRS-R bulbar subscores in patients with bulbar-onset disease, may predate reported disease onset dates. Respiratory subscores were not prognostically informative after adjustment for bulbar and motor subscores. These results provide robust evidence that the ALSFRS-R should not be reported as a single combined score, but rather as domain specific subscores.

The ALSFRS as an outcome measure in therapeutic trials and its relationship to symptom onset

The reduction in ALS Functional Rating Score (ALSFRS) from reported symptom onset to diagnosis is used to estimate rate of disease progression. ALSFRS decline may be non-linear or distorted by drop-outs in therapeutic trials, reducing the reliability of change in slope as an outcome measure. The PRO-ACT database uniquely allows such measures to be explored using historical data from negative therapeutic trials. The decline of functional scores was analysed in 18 pooled trials, comparing rates of decline based on symptom onset with rates calculated between interval assessments. Strategies to mitigate the effects of trial drop-out were considered. Results showed that progression rate calculated by symptom onset underestimated the subsequent rate of disability accumulation, although it predicted survival more accurately than four-month interval estimates of δALSFRS or δFVC. Individual ALSFRS and FVC progression within a typical trial duration were linear. No simple solution to correct for trial drop-out was identified, but imputation using δALSFRS appeared least disruptive. In conclusion, there is a trade-off between the drive to recruit trial participants soon after symptom onset, and reduced reliability of the ALSFRS-derived progression rate at enrolment. The need for objective markers of disease activity as an alternative to survival-based end-points is clear and pressing.

Stratification of ALS patients' survival: a population-based study

The natural history of amyotrophic lateral sclerosis (ALS) and patient risk stratification are areas of considerable research interest. We aimed (1) to describe the survival of a representative cohort of French ALS patients, and (2) to identify covariates associated with various patterns of survival using a risk classification analysis. ALS patients recruited in the FRALim register (2000-2013) were included. Time-to-death analyses were performed using Kaplan-Meier method and Cox model. A recursive partitioning and amalgamation (RECPAM) algorithm analysis identified subgroups of patients with different patterns of survival. Among 322 patients, median survival times were 26.2 and 15.6 months from time of onset and of diagnosis, respectively. Four groups of patients were identified, depending on their baseline characteristics and survival (1) ALSFRS-R slope >0.46/month and definite or probable ALS (median survival time (MST) 10.6 months); (2) ALSFRS-R slope >0.46/month and possible or probable laboratory-supported ALS (MST: 18.1 months); (3) ALSFRS-R slope ≤0.46/month and definite or probable ALS (MST: 22.5 months), and (4) ALSFRS-R slope ≤0.46/month and possible or probable laboratory-supported ALS (MST: 37.6 months). Median survival time is among the shortest ever reported by a worldwide population-based study. This is probably related to the age structure of the patients (the oldest identified to date), driven by the underlying population (30 % of subjects older than 60 years). Further research in the field of risk stratification could help physicians better anticipate prognosis of ALS patients, and help improve the design of randomized controlled trials.