Prognosis for patients with amyotrophic lateral sclerosis: development and validation of a personalised prediction model

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.

Quantitative evaluation of factors influencing the 3 Hz repetitive nerve stimulation test in patients with amyotrophic lateral sclerosis

INTRODUCTION/AIMS

Previous studies have suggested that treatments targeting the neuromuscular junction (NMJ) may play a role in the treatment of amyotrophic lateral sclerosis (ALS). However, factors impacting repetitive nerve stimulation (RNS), a technique to evaluate NMJ function, have yet to be fully elucidated. We aimed to identify independent factors contributing to the decremental response of the accessory nerve and evaluated its value in ALS clinical practice.

METHODS

A total of 626 patients who were diagnosed with ALS and underwent 3 Hz RNS tests on the accessory nerve were enrolled. Data on their clinical and electrophysiological indicators were divided into a training set (collected from June 2016 to December 2022) and a test set (collected from January to August 2023). Stepwise regression was used in independent variable selection and model building.

RESULTS

Forty-two percent of patients had a decrement larger than 10% and 24% had a decrement larger than 15%. Onset age, sex, onset site, forced vital capacity (FVC) and motor unit potential (MUP) duration were independent factors contributing to the results of the RNS test. MUP duration had the greatest impact on decremental response, followed by FVC and onset age. The decremental response in females was larger than in males. Upper limb onset was found to contribute more to the decrement than lower limb or bulbar onset.

DISCUSSION

In patients with ALS, NMJ safety factor is reduced during re-innervation. Decremental response is affected by multiple factors, which needs to be considered in clinical trials targeting the NMJ in these patients.

Association Between Hypothalamic Volume and Metabolism, Cognition, and Behavior in Patients With Amyotrophic Lateral Sclerosis

BACKGROUND AND OBJECTIVES

Dysfunction of energy metabolism, cognition, and behavior are important nonmotor symptoms of amyotrophic lateral sclerosis (ALS), negatively affecting survival and quality of life, but poorly understood. Neuroimaging is ideally suited to studying nonmotor neurodegeneration in ALS, but few studies have focused on the hypothalamus, a key region for regulating energy homeostasis, cognition, and behavior. We evaluated, therefore, hypothalamic neurodegeneration in ALS and explored the relationship between hypothalamic volumes and dysregulation of energy metabolism, cognitive and behavioral changes, disease progression, and survival.

METHODS

Patients with ALS and population-based controls were included for this cross-sectional and longitudinal MRI study. The hypothalamus was segmented into 5 subregions and their volumes were calculated. Linear (mixed) models, adjusted for age, sex, and total intracranial volume, were used to compare hypothalamic volumes between groups and to analyze associations with metabolism, cognition, behavior, and disease progression. Cox proportional hazard models were used to investigate the relationship of hypothalamic volumes with survival. Permutation-based corrections for multiple hypothesis testing were applied to all analyses to control the family-wise error rate.

RESULTS

Data were available for 564 patients with ALS and 356 controls. The volume of the anterior superior subregion of the hypothalamus was smaller in patients with ALS than in controls (β = -0.70 [-1.15 to -0.25], p = 0.013). Weight loss, memory impairments, and behavioral disinhibition were associated with a smaller posterior hypothalamus (β = -4.79 [-8.39 to -2.49], p = 0.001, β = -10.14 [-15.88 to -4.39], p = 0.004, and β = -12.09 [-18.83 to -5.35], p = 0.003, respectively). Furthermore, the volume of this subregion decreased faster over time in patients than in controls (β = -0.25 [0.42 to -0.09], p = 0.013), and a smaller volume of this structure was correlated with shorter survival (hazard ratio = 0.36 [0.21-0.61], p = 0.029).

DISCUSSION

We obtained evidence for hypothalamic involvement in ALS, specifically marked by atrophy of the anterior superior subregion. Moreover, we found that atrophy of the posterior hypothalamus was associated with weight loss, memory dysfunction, behavioral disinhibition, and survival, and that this subregion deteriorated faster in patients with ALS than in controls. These findings improve our understanding of nonmotor involvement in ALS and could contribute to the identification of new treatment targets for this devastating disease.

Clinicopathological analysis of NEK1 variants in amyotrophic lateral sclerosis

Many genes have been linked to amyotrophic lateral sclerosis (ALS), including never in mitosis A (NIMA)-related kinase 1 (NEK1), a serine/threonine kinase that plays a key role in several cellular functions, such as DNA damage response and cell cycle regulation. Whole-exome sequencing studies have shown that NEK1 mutations are associated with an increased risk for ALS, where a significant enrichment of NEK1 loss-of-function (LOF) variants were found in individuals with ALS compared to controls. In particular, the p.Arg261His missense variant was associated with significantly increased disease susceptibility. This case series aims to understand the neuropathological phenotypes resulting from NEK1 mutations in ALS. We examined a cohort of three Scottish patients with a mutation in the NEK1 gene and evaluated the distribution and cellular expression of NEK1, as well as the abundance of phosphorylated TDP-43 (pTDP-43) aggregates, in the motor cortex compared to age- and sex-matched control tissue. We show pathological, cytoplasmic TDP-43 aggregates in all three NEK1-ALS cases. NEK1 protein staining revealed no immunoreactivity in two of the NEK1-ALS cases, indicating a LOF and corresponding to a reduction in NEK1 mRNA as detected by in situ hybridisation. However, the p.Arg261His missense mutation resulted in an increase in NEK1 mRNA molecules and abundant NEK1-positive cytoplasmic aggregates, with the same morphologic appearance, and within the same cells as co-occurring TDP-43 aggregates. Here we show the first neuropathological assessment of a series of ALS cases carrying mutations in the NEK1 gene. Specifically, we show that TDP-43 pathology is present in these cases and that potential NEK1 LOF can either be mediated through loss of NEK1 translation or through aggregation of NEK1 protein as in the case with p.Arg261His mutation, a potential novel pathological feature of NEK1-ALS.

Temporal stratification of amyotrophic lateral sclerosis patients using disease progression patterns

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

Pathological insights derived from neuroimaging in amyotrophic lateral sclerosis: emerging clinical applications

PURPOSE OF REVIEW

Neuroimaging has been instrumental in shaping current understanding of the pathoanatomical signature of amyotrophic lateral sclerosis (ALS) across clinically well defined patient cohorts. The potential utility of imaging as an objective disease marker, however, remains poorly defined.

RECENT FINDINGS

Increasingly advanced quantitative and computational imaging studies have highlighted emerging clinical applications for neuroimaging as a complementary clinical modality for diagnosis, monitoring, and modelling disease propagation. Multimodal neuroimaging has demonstrated novel approaches for capturing primary motor disease. Extra-motor subcortical dysfunction is increasingly recognized as key modulators of disease propagation.

SUMMARY

The neural signature of cortical and subcortical dysfunction in ALS has been well defined at the population level. Objective metrics of focal primary motor dysfunction are increasingly sensitive and translatable to the individual patient level. Integrity of extra-motor subcortical abnormalities are recognized to represent critical pathways of the ALS disease 'connectome', predicting pathological spread. Neuroimaging plays a pivotal role in capturing upper motor neuron pathology in ALS. Their potential clinical role as objective disease markers for disease classification, longitudinal monitoring, and prognosis in ALS have become increasingly well defined.

Sex Differences in Amyotrophic Lateral Sclerosis Survival and Progression: A Multidimensional Analysis

OBJECTIVE

To investigate sex-related differences in amyotrophic lateral sclerosis (ALS) prognosis and their contributing factors.

METHODS

Our primary cohort was the Piemonte and Aosta Register for ALS (PARALS); the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) and the Answer ALS databases were used for validation. Survival analyses were conducted accounting for age and onset site. The roles of forced vital capacity and weight decline were explored through a causal mediation analysis. Survival and disease progression rates were also evaluated after propensity score matching.

RESULTS

The PARALS cohort included 1,890 individuals (44.8% women). Men showed shorter survival when stratified by onset site (spinal onset HR 1.20, 95% CI 1.00-1.44, p = 0.0439; bulbar onset HR 1.36, 95% CI 1.09-1.70, p = 0.006917), although women had a steeper functional decline (+0.10 ALSFRS-R points/month, 95% CI 0.07-0.15, p < 0.00001) regardless of onset site. Instead, men showed worse respiratory decline (-4.2 forced vital capacity%/month, 95% CI -6.3 to -2.2, p < 0.0001) and faster weight loss (-0.15 kg/month, 95% CI -0.25 to -0.05, p = 0.0030). Causal mediation analysis showed that respiratory function and weight loss were pivotal in sex-related survival differences. Analysis of patients from PRO-ACT (n = 1,394, 40.9% women) and Answer ALS (n = 849, 37.2% women) confirmed these trends.

INTERPRETATION

The shorter survival in men is linked to worse respiratory function and weight loss rather than a faster disease progression. These findings emphasize the importance of considering sex-specific factors in understanding ALS pathophysiology and designing tailored therapeutic strategies. ANN NEUROL 2024;96:159-169.

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.

Categorization of the amyotrophic lateral sclerosis population via the clinical determinant of post-onset ΔFS for study design and medical practice

The amyotrophic lateral sclerosis (ALS) functional rating scale-revised (ALSFRS-R) has become the most widely utilized measure of disease severity in patients with ALS, with change in ALSFRS-R from baseline being a trusted primary outcome measure in ALS clinical trials. This is despite the scale having several established limitations, and although alternative scales have been proposed, it is unlikely that these will displace ALSFRS-R in the foreseeable future. Here, we discuss the merits of delta FS (ΔFS), the slope or rate of ALSFRS-R decline over time, as a relevant tool for innovative ALS study design, with an as yet untapped potential for optimization of drug effectiveness and patient management. In our view, categorization of the ALS population via the clinical determinant of post-onset ΔFS is an important study design consideration. It serves not only as a critical stratification factor and basis for patient enrichment but also as a tool to explore differences in treatment response across the overall population; thereby, facilitating identification of responder subgroups. Moreover, because post-onset ΔFS is derived from information routinely collected as part of standard patient care and monitoring, it provides a suitable patient selection tool for treating physicians. Overall, post-onset ΔFS is a very attractive enrichment tool that is, can and should be regularly incorporated into ALS trial design.

Serum neurofilament light chain in distinct phenotypes of amyotrophic lateral sclerosis: A longitudinal, multicenter study

OBJECTIVE

To assess the performance of serum neurofilament light chain (sNfL) in clinical phenotypes of amyotrophic lateral sclerosis (ALS).

METHODS

In 2949 ALS patients at 16 ALS centers in Germany and Austria, clinical characteristics and sNfL were assessed. Phenotypes were differentiated for two anatomical determinants: (1) upper and/or lower motor involvement (typical, typMN; upper/lower motor neuron predominant, UMNp/LMNp; primary lateral sclerosis, PLS) and (2) region of onset and propagation of motor neuron dysfunction (bulbar, limb, flail-arm, flail-leg, thoracic onset). Phenotypes were correlated to sNfL, progression, and survival.

RESULTS

Mean sNfL was - compared to typMN (75.7 pg/mL, n = 1791) - significantly lower in LMNp (45.1 pg/mL, n = 413), UMNp (58.7 pg/mL n = 206), and PLS (37.6 pg/mL, n = 84). Also, sNfL significantly differed in the bulbar (92.7 pg/mL, n = 669), limb (64.1 pg/mL, n = 1305), flail-arm (46.4 pg/mL, n = 283), flail-leg (53.6 pg/mL, n = 141), and thoracic (74.5 pg/mL, n = 96) phenotypes. Binary logistic regression analysis showed highest contribution to sNfL elevation for faster progression (odds ratio [OR] 3.24) and for the bulbar onset phenotype (OR 1.94). In contrast, PLS (OR 0.20), LMNp (OR 0.45), and thoracic onset (OR 0.43) showed reduced contributions to sNfL. Longitudinal sNfL (median 12 months, n = 2862) showed minor monthly changes (<0.2%) across all phenotypes. Correlation of sNfL with survival was confirmed (p < 0.001).

CONCLUSIONS

This study underscored the correlation of ALS phenotypes - differentiated for motor neuron involvement and region of onset/propagation - with sNfL, progression, and survival. These phenotypes demonstrated a significant effect on sNfL and should be recognized as independent confounders of sNfL analyses in ALS trials and clinical practice.

Adherence to practice parameters in Medicare beneficiaries with amyotrophic lateral sclerosis

OBJECTIVE

Physician adherence to evidence-based clinical practice parameters impacts outcomes of amyotrophic lateral sclerosis (ALS) patients. We sought to investigate compliance with the 2009 practice parameters for treatment of ALS patients in the United States, and sociodemographic and provider characteristics associated with adherence.

METHODS

In this population-based, retrospective cohort study of incident ALS patients in 2009-2014, we included all Medicare beneficiaries age ≥20 with ≥1 International Classification of Diseases, Ninth Revision, Clinical Modification ALS code (335.20) in 2009 and no prior years (N = 8,575). Variables of interest included race/ethnicity, sex, age, urban residence, Area Deprivation Index (ADI), and provider specialty (neurologist vs. non-neurologist). Outcomes were use of practice parameters, which included feeding tubes, non-invasive ventilation (NIV), riluzole, and receiving care from a neurologist.

RESULTS

Overall, 42.9% of patients with ALS received neurologist care. Black beneficiaries (odds ratio [OR] 0.56, 95% confidence interval [CI] 0.47-0.67), older beneficiaries (OR 0.964, 95% CI 0.961-0.968 per year), and those living in disadvantaged areas (OR 0.70, 95% CI 0.61-0.80) received less care from neurologists. Overall, only 26.7% of beneficiaries received a feeding tube, 19.2% NIV, and 15.3% riluzole. Neurologist-treated patients were more likely to receive interventions than other ALS patients: feeding tube (OR 2.80, 95% CI 2.52-3.11); NIV (OR 10.8, 95% CI 9.28-12.6); and riluzole (OR 7.67, 95% CI 6.13-9.58), after adjusting for sociodemographics. These associations remained marked and significant when we excluded ALS patients who subsequently received a code for other diseases that mimic ALS.

CONCLUSIONS

ALS patients treated by neurologists received care consistent with practice parameters more often than those not treated by a neurologist. Black, older, and disadvantaged beneficiaries received less care consistent with the practice parameters.

Evaluating emerging drugs in phase II & III for the treatment of amyotrophic lateral sclerosis

INTRODUCTION

Amyotrophic Lateral Sclerosis is a rapidly progressive motor neuron disorder causing severe disability and premature death. Owing to the advances in uncovering ALS pathophysiology, efficient clinical trial design and research advocacy program, several disease-modifying drugs have been approved for treating ALS. Despite this progress, ALS remains a rapidly disabling and life shortening condition. There is a critical need for more effective therapies.

AREAS COVERED

Here, we reviewed the emerging ALS therapeutics undergoing phase II & III clinical trials. To identify the investigational drugs, we searched ALS and phase II/III trials that are active and recruiting or not yet recruiting on clinicaltrials.gov and Pharmaprojects database.

EXPERT OPINION

The current pipeline is larger and more diverse than ever, with drugs targeting potential genetic and retroviral causes of ALS and drugs targeting a wide array of downstream pathways, including RNA metabolism, protein aggregation, integrated stress response and neuroinflammation.We remain most excited about those that target direct causes of ALS, e.g. antisense oligonucleotides targeting causative genes. Drugs that eliminate abnormal protein aggregates are also up-and-coming. Eventually, because of the heterogeneity of ALS pathophysiology, biomarkers that determine which biological events are most important for an individual ALS patient are needed.

Advances in symptom management and in monitoring disease progression in motor neuron disease

The aim of supportive management of motor neuron disease is to improve survival, promote good quality of life and patient independence and autonomy whilst preparing for future progression and the end of life. Multidisciplinary specialist care aims to address the multifaceted and interacting biopsychosocial problems associated with motor neuron disease that leads to proven benefits in both survival and quality of life. This chapter will explore principles, structure and details of treatment options, and make recommendations for practice and for future research.

Recent advances in the genetics of familial and sporadic ALS

ALS shows complex genetic inheritance patterns. In about 5% to 10% of cases, there is a family history of ALS or a related condition such as frontotemporal dementia in a first or second degree relative, and for about 80% of such people a pathogenic gene variant can be identified. Such variants are also seen in people with no family history because of factor influencing the expression of genes, such as age. Genetic susceptibility factors also contribute to risk, and the heritability of ALS is between 40% and 60%. The genetic variants influencing ALS risk include single base changes, repeat expansions, copy number variants, and others. Here we review what is known of the genetic landscape and architecture of ALS.

Current neuroprotective therapies and future prospects for motor neuron disease

Four medications with neuroprotective disease-modifying effects are now in use for motor neuron disease (MND). With FDA approvals for tofersen, relyvrio and edaravone in just the past year, 2022 ended a quarter of a century when riluzole was the sole such drug to offer to patients. The acceleration of approvals may mean we are witnessing the beginning of a step-change in how MND can be treated. Improvements in understanding underlying disease biology has led to more therapies being developed to target specific and multiple disease mechanisms. Consideration for how the pipeline of new therapeutic agents coming through in clinical and preclinical development can be more effectively evaluated with biomarkers, advances in patient stratification and clinical trial design pave the way for more successful translation for this archetypal complex neurodegenerative disease. While it must be cautioned that only slowed rates of progression have so far been demonstrated, pre-empting rapid neurodegeneration by using neurofilament biomarkers to signal when to treat, as is currently being trialled with tofersen, may be more effective for patients with known genetic predisposition to MND. Early intervention with personalized medicines could mean that for some patients at least, in future we may be able to substantially treat what is considered by many to be one of the most distressing diseases in medicine.

Neutrophil-to-lymphocyte ratio at diagnosis as a biomarker for survival of amyotrophic lateral sclerosis

Introduction: The neutrophil-to-lymphocyte ratio (NLR) has previously been reported to be associated with survival in ALS. To provide further information about the role of NLR as a biomarker in ALS, we performed a systematic review, analyzed data from our local cohort of ALS subjects and performed a meta-analysis. Methods: (1) The systematic review used established methods. (2) Using data from our cohort of subjects, we analyzed the association of NLR with survival. (3) Meta-analysis was performed using previous studies and our local data. Results: (1) In the systematic review, higher NLR was associated with shorter survival in all studies. (2) In our subjects, survival was significantly shorter in patients in the highest NLR groups. (3) Meta-analysis showed subjects with highest NLR tertile or with NLR >3 had significantly shorter survival than other subjects. Discussion: This study supports NLR as a biomarker in ALS; high NLR is associated with poor survival.

Evaluation of the therapeutic effects of rehabilitation therapy on patients with amyotrophic lateral sclerosis-a meta-analysis

Objective

To investigate the effect of rehabilitation therapy on the global function, respiratory function, and quality of life in patients with amyotrophic lateral sclerosis (ALS).

Methods

PubMed, Web of Science, and The National Library of Medicine (NLM) were systematically searched and the search period was between the date of database establishment and December 31, 2023. The outcome measures finally analyzed included the ALS functional rating scale/revised (ALSFRS/ALSFRS-R), forced vital capacity percentage predicted (FVC%), fatigue severity scale (FSS), and maximal expiratory pressure (MEP).

Results

A total of 13 randomized controlled trials (RCTs) were included, and 5 outcome measures were pooled and analyzed. A total of 657 patients with ALS were enrolled, with 299 in the experimental group (rehabilitation therapy, such as resistance training, endurance training, aerobic training, respiratory muscle training, and standard rehabilitation therapy) and 358 in the control group (conventional interventions, such as simple joint movements or daily stretching). The ALSFRS scores were better in the experimental group than in the control group at 0-4 months (MD = 3.36, 95% CI: 0.82, 5.91, Z = 2.59, p = 0.009) and at 5-8 months (MD = 5.00, 95% CI: -2.42, 7.58, Z = 3.80, p < 0.001). Moreover, the ALSFRS-R scores of the experimental group was better than that of the control group at 5-8 months (MD = 2.83, 95% CI: 1.21, 4.45, Z = 3.42, p < 0.001) and 9-12 months (MD = 1.87, 95% CI: -0.37, 4.11, Z = 1.63, p = 0.10). It was also found that the MEP value of the experimental group was significantly better than that of the control group after intervention (MD = 18.49, 95% CI: 1.47, 35.50, Z = 2.13, p = 0.03). However, there were no significant differences in FVC% value and FSS scores at 0-5 months and 6-12 months between the two groups.

Conclusion

Rehabilitation therapy is helpful in improving the short-, medium-, and long-term global function score of patients with ALS, with positive effects on respiratory function.

Role of the repeat expansion size in predicting age of onset and severity in RFC1 disease

RFC1 disease, caused by biallelic repeat expansion in RFC1, is clinically heterogeneous in terms of age of onset, disease progression and phenotype. We investigated the role of the repeat size in influencing clinical variables in RFC1 disease. We also assessed the presence and role of meiotic and somatic instability of the repeat. In this study, we identified 553 patients carrying biallelic RFC1 expansions and measured the repeat expansion size in 392 cases. Pearson's coefficient was calculated to assess the correlation between the repeat size and age at disease onset. A Cox model with robust cluster standard errors was adopted to describe the effect of repeat size on age at disease onset, on age at onset of each individual symptoms, and on disease progression. A quasi-Poisson regression model was used to analyse the relationship between phenotype and repeat size. We performed multivariate linear regression to assess the association of the repeat size with the degree of cerebellar atrophy. Meiotic stability was assessed by Southern blotting on first-degree relatives of 27 probands. Finally, somatic instability was investigated by optical genome mapping on cerebellar and frontal cortex and unaffected peripheral tissue from four post-mortem cases. A larger repeat size of both smaller and larger allele was associated with an earlier age at neurological onset [smaller allele hazard ratio (HR) = 2.06, P < 0.001; larger allele HR = 1.53, P < 0.001] and with a higher hazard of developing disabling symptoms, such as dysarthria or dysphagia (smaller allele HR = 3.40, P < 0.001; larger allele HR = 1.71, P = 0.002) or loss of independent walking (smaller allele HR = 2.78, P < 0.001; larger allele HR = 1.60; P < 0.001) earlier in disease course. Patients with more complex phenotypes carried larger expansions [smaller allele: complex neuropathy rate ratio (RR) = 1.30, P = 0.003; cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) RR = 1.34, P < 0.001; larger allele: complex neuropathy RR = 1.33, P = 0.008; CANVAS RR = 1.31, P = 0.009]. Furthermore, larger repeat expansions in the smaller allele were associated with more pronounced cerebellar vermis atrophy (lobules I-V β = -1.06, P < 0.001; lobules VI-VII β = -0.34, P = 0.005). The repeat did not show significant instability during vertical transmission and across different tissues and brain regions. RFC1 repeat size, particularly of the smaller allele, is one of the determinants of variability in RFC1 disease and represents a key prognostic factor to predict disease onset, phenotype and severity. Assessing the repeat size is warranted as part of the diagnostic test for RFC1 expansion.

Whole-body fasciculation detection in amyotrophic lateral sclerosis using motor unit MRI

OBJECTIVE

Compare fasciculation rates between amyotrophic lateral sclerosis (ALS) patients and healthy controls in body regions relevant for diagnosing ALS using motor unit MRI (MUMRI) at baseline and 6 months follow-up, and relate this to single-channel surface EMG (SEMG).

METHODS

Tongue, biceps brachii, paraspinals and lower legs were assessed with MUMRI and biceps brachii and soleus with SEMG in 10 healthy controls and 10 patients (9 typical ALS, 1 primary lateral sclerosis [PLS]).

RESULTS

MUMRI-detected fasciculation rates in typical ALS patients were higher compared to healthy controls for biceps brachii (2.40 ± 1.90 cm-3min-1vs. 0.04 ± 0.10 cm-3min-1, p = 0.004), paraspinals (1.14 ± 1.61 cm-3min-1vs. 0.02 ± 0.02 cm-3min-1, p = 0.016) and lower legs (1.42 ± 1.27 cm-3min-1vs. 0.13 ± 0.10 cm-3min-1, p = 0.004), but not tongue (1.41 ± 1.94 cm-3min-1vs. 0.18 ± 0.18 cm-3min-1, p = 0.556). The PLS patient showed no fasciculation. At baseline, 6/9 ALS patients had increased fasciculation rates compared to healthy controls in at least 2 body regions. At follow-up every patient had increased fasciculation rates in at least 2 body regions. The MUMRI-detected fasciculation rate correlated with SEMG-detected fasciculation rates (τ = 0.475, p = 0.006).

CONCLUSION

MUMRI can non-invasively image fasciculation in multiple body regions and appears sensitive to disease progression in individual patients.

SIGNIFICANCE

MUMRI has potential as diagnostic tool for ALS.

Predicting amyotrophic lateral sclerosis (ALS) progression with machine learning

OBJECTIVE

To predict ALS progression with varying observation and prediction window lengths, using machine learning (ML).

METHODS

We used demographic, clinical, and laboratory parameters from 5030 patients in the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) database to model ALS disease progression as fast (at least 1.5 points decline in ALS Functional Rating Scale-Revised (ALSFRS-R) per month) or non-fast, using Extreme Gradient Boosting (XGBoost) and Bayesian Long Short Term Memory (BLSTM). XGBoost identified predictors of progression while BLSTM provided a confidence level for each prediction.

RESULTS

ML models achieved area under receiver-operating-characteristics curve (AUROC) of 0.570-0.748 and were non-inferior to clinician assessments. Performance was similar with observation lengths of a single visit, 3, 6, or 12 months and on a holdout validation dataset, but was better for longer prediction lengths. 21 important predictors were identified, with the top 3 being days since disease onset, past ALSFRS-R and forced vital capacity. Nonstandard predictors included phosphorus, chloride and albumin. BLSTM demonstrated higher performance for the samples about which it was most confident. Patient screening by models may reduce hypothetical Phase II/III clinical trial sizes by 18.3%.

CONCLUSION

Similar accuracies across ML models using different observation lengths suggest that a clinical trial observation period could be shortened to a single visit and clinical trial sizes reduced. Confidence levels provided by BLSTM gave additional information on the trustworthiness of predictions, which could aid decision-making. The identified predictors of ALS progression are potential biomarkers and therapeutic targets for further research.

Specialized multidisciplinary care improves ALS survival in Belgium: a population-based retrospective study

ALS is a neurodegenerative disease characterized by loss of motor neurons, resulting in progressive weakness and wasting of muscles. The average survival time is 2-5 years, mostly due to respiratory failure. Since current therapies can prolong survival time by only a few months, multidisciplinary care remains the cornerstone of the management of ALS. At the ALS Expert Centre of University Hospitals Leuven, a large proportion of Belgian ALS patients are seen for diagnosis and a significant number is also in follow-up with the multidisciplinary team. In this retrospective study, we compared the outcome of incident patients who were in follow-up at our site with patients who were not in follow-up. We included 659 patients of which 557 (84.5%) received specialized care at the ALS Expert Centre. After adjusting for clinically relevant prognostic parameters, multidisciplinary follow-up significantly prolonged survival (p = 0.004; HR = 0.683; CI 95% [0.528 - 0.884]). This increase in survival is mainly driven by patients with spinal onset (p = 0.035; HR = 0.746; CI 95% [0.568 - 0.980]), since no significant increased survival time was observed in patients with bulbar onset (p = 0.28; HR = 0.778; CI 95% [0.495 - 1.223]). These data confirm that multidisciplinary follow-up contributes to a better outcome of patients, emphasizing the importance of multidisciplinary specialized care in ALS.

Time from amyotrophic lateral sclerosis symptom onset to key disease milestones: analysis of data from a multinational cross-sectional survey

OBJECTIVE

To determine the average time from Amyotrophic Lateral Sclerosis (ALS) symptom onset to 11 pre-defined milestones, overall and according to ALS progression rate and geographic location.

METHODS

Data were drawn from the Adelphi Real World ALS Disease-Specific ProgrammeTM, a point-in-time survey of neurologists caring for people living with ALS (pALS) conducted in France, Germany, Italy, Spain, the United Kingdom and the United States from 2020-2021. ALS progression rate was calculated using time since symptom onset and ALS Functional Rating Scale Revised score.

RESULTS

Survey results were available for N = 1003 pALS (progression rate for N = 867). Mean time from symptom onset was 3.8 months to first consultation, 8.0 months to diagnosis, 16.2 months to employment change (part-time/sick leave/retirement/unemployment), 17.5 months to use of a walking aid, 18.5 months to first occurrence of caregiver support, 22.8 months to use of a wheelchair, 24.6 months to use of a communication aid, 27.3 months to use of a respiratory aid, 28.6 months to use of gastrostomy feeding, 29.7 months to use of eye gaze technology and 30.3 months to entering a care facility. Multivariate analysis indicated significant effects of fast (versus slow) progression rate on time to reach all 11 milestones, as well as US (versus European) location, age, body mass index and bulbar onset (versus other) on time to reach milestones.

CONCLUSIONS

pALS rapidly reached clinical and disease-related milestones within 30 months from symptom onset. Milestones were reached significantly faster by pALS with fast versus slow progression. Geographic differences were observed.

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.

Remote pulmonary function testing allows for early identification of need for non-invasive ventilation in a subset of persons with ALS

The traditional ALS multidisciplinary clinical practice of quarterly respiratory assessment may leave some individuals in danger of developing untreated respiratory insufficiency between visits or beginning non-invasive ventilation (NIV) later than would be optimal. Remote, or home-based, pulmonary function testing (rPFT) allows patients with ALS to perform regular respiratory testing at more frequent intervals in the home. The aim of this study was to determine the clinical benefit of weekly rPFT compared to standard, quarterly in-clinic respiratory assessments: the number of individuals with earlier identification of NIV need, the magnitude of this advance notice, and the individual factors predicting benefit. Participants with ALS (n = 39) completed rPFT training via telemedicine and then completed one year of weekly self-guided assessments in the home. Over this period, 17 individuals exhibited remotely-measured FVC dropping below 50% of predicted, the value often used for recommendation of NIV initiation. In 13 individuals with clinical detection of this event, the median and range of advance notice of need for NIV was 53 (-61-294) days. Prescription of NIV occurred for 21 individuals on the study, six of whom began NIV as a result of remote testing, prior to indication of need as determined by in-person assessments. Weekly home assessments appeared to be of greatest clinical value in a subset of patients with low baseline respiratory test values and rapid respiratory decline. This has potential implications for clinical management of ALS as well as the conduct of clinical trials that rely on respiratory endpoints.

Remote monitoring of amyotrophic lateral sclerosis using wearable sensors detects differences in disease progression and survival: a prospective cohort study

BACKGROUND

There is an urgent need for objective and sensitive measures to quantify clinical disease progression and gauge the response to treatment in clinical trials for amyotrophic lateral sclerosis (ALS). Here, we evaluate the ability of an accelerometer-derived outcome to detect differential clinical disease progression and assess its longitudinal associations with overall survival in patients with ALS.

METHODS

Patients with ALS wore an accelerometer on the hip for 3-7 days, every 2-3 months during a multi-year observation period. An accelerometer-derived outcome, the Vertical Movement Index (VMI), was calculated, together with predicted disease progression rates, and jointly analysed with overall survival. The clinical utility of VMI was evaluated using comparisons to patient-reported functionality, while the impact of various monitoring schemes on empirical power was explored through simulations.

FINDINGS

In total, 97 patients (70.1% male) wore the accelerometer for 1995 days, for a total of 27,701 h. The VMI was highly discriminatory for predicted disease progression rates, revealing faster rates of decline in patients with a worse predicted prognosis compared to those with a better predicted prognosis (p < 0.0001). The VMI was strongly associated with the hazard for death (HR 0.20, 95% CI: 0.09-0.44, p < 0.0001), where a decrease of 0.19-0.41 unit was associated with reduced ambulatory status. Recommendations for future studies using accelerometery are provided.

INTERPRETATION

The results serve as motivation to incorporate accelerometer-derived outcomes in clinical trials, which is essential for further validation of these markers to meaningful endpoints.

FUNDING

Stichting ALS Nederland (TRICALS-Reactive-II).

Unraveling the Heterogeneity of ALS-A Call to Redefine Patient Stratification for Better Outcomes in Clinical Trials

Despite tremendous efforts in basic research and a growing number of clinical trials aiming to find effective treatments, amyotrophic lateral sclerosis (ALS) remains an incurable disease. One possible reason for the lack of effective causative treatment options is that ALS may not be a single disease entity but rather may represent a clinical syndrome, with diverse genetic and molecular causes, histopathological alterations, and subsequent clinical presentations contributing to its complexity and variability among individuals. Defining a way to subcluster ALS patients is becoming a central endeavor in the field. Identifying specific clusters and applying them in clinical trials could enable the development of more effective treatments. This review aims to summarize the available data on heterogeneity in ALS with regard to various aspects, e.g., clinical, genetic, and molecular.

The prognostic value of systematic genetic screening in amyotrophic lateral sclerosis patients

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with complex genetic architecture. Emerging evidence has indicated comorbidity between ALS and autoimmune conditions, suggesting a potential shared genetic basis. The objective of this study is to assess the prognostic value of systematic screening for rare deleterious mutations in genes associated with ALS and aberrant inflammatory responses.

METHODS

A discovery cohort of 494 patients and a validation cohort of 69 patients were analyzed in this study, with population-matched healthy subjects (n = 4961) served as controls. Whole exome sequencing (WES) was performed to identify rare deleterious variants in 50 ALS genes and 1177 genes associated with abnormal inflammatory responses. Genotype-phenotype correlation was assessed, and an integrative prognostic model incorporating genetic and clinical factors was constructed.

RESULTS

In the discovery cohort, 8.1% of patients carried confirmed ALS variants, and an additional 15.2% of patients carried novel ALS variants. Gene burden analysis revealed 303 immune-implicated genes with enriched rare variants, and 13.4% of patients harbored rare deleterious variants in these genes. Patients with ALS variants exhibited a more rapid disease progression (HR 2.87 [95% CI 2.03-4.07], p < 0.0001), while no significant effect was observed for immune-implicated variants. The nomogram model incorporating genetic and clinical information demonstrated improved accuracy in predicting disease outcomes (C-index, 0.749).

CONCLUSION

Our findings enhance the comprehension of the genetic basis of ALS within the Chinese population. It also appears that rare deleterious mutations occurring in immune-implicated genes exert minimal influence on the clinical trajectories of ALS patients.

Unveiling the SOD1-mediated ALS phenotype: insights from a comprehensive meta-analysis

BACKGROUND AND OBJECTIVES

Amyotrophic lateral sclerosis associated with mutations in SOD1 (SOD1-ALS) might be susceptible to specific treatment. The aim of the study is to outline the clinical features of SOD1-ALS patients by comparing them to patients without ALS major gene variants and patients with variants in other major ALS genes. Defining SOD1-ALS phenotype may assist clinicians in identifying patients who should be prioritized for genetic testing.

METHODS

We performed an extensive literature research including original studies which reported the clinical features of SOD1-ALS and at least one of the following patient groups: C9ORF72 hexanucleotide repeat expansion (C9-ALS), TARDBP (TARDBP-ALS), FUS (FUS-ALS) or patients without a positive test for a major-ALS gene (N-ALS). A random effects meta-analytic model was applied to clinical data extracted encompassing sex, site and age of onset. To reconstruct individual patient survival data, the published Kaplan-Meier curves were digitized. Data were measured as odds ratio (OR) or standardized mean difference (SMD) as appropriate. Median survival was compared between groups.

RESULTS

Twenty studies met the inclusion criteria. We identified 721 SOD1-ALS, 470 C9-ALS, 183 TARDBP-ALS, 113 FUS-ALS and 2824 N-ALS. SOD1-ALS showed a higher rate of spinal onset compared with N-ALS and C9-ALS (OR = 4.85, 95% CI = 3.04-7.76; OR = 10.47, 95% CI = 4.32-27.87) and an earlier onset compared with N-ALS (SMD = - 0.45, 95% CI = - 0.72 to - 0.18). SOD1-ALS had a similar survival compared with N-ALS (p = 0.14), a longer survival compared with C9-ALS (p < 0.01) and FUS-ALS (p = 0.019) and a shorter survival compared with TARDBP-ALS (p < 0.01).

DISCUSSION

This study indicates the presence of a specific SOD1-ALS phenotype. Insights in SOD1-ALS clinical features are important in genetic counseling, disease prognosis and support patients' stratification in clinical trials.

Clinical and Genetic Aspects of Juvenile Amyotrophic Lateral Sclerosis: A Promising Era Emerges

Juvenile Amyotrophic Lateral Sclerosis is a genetically heterogeneous neurodegenerative disorder, which is frequently misdiagnosed due to low clinical suspicion and little knowledge about disease characteristics. More than 20 different genetic loci have been associated with both sporadic and familial juvenile Amyotrophic Lateral Sclerosis. Currently, almost 40% of cases have an identifiable monogenic basis; type 6, associated with FUS gene variants, is the most prevalent globally. Despite several upper motor neuron-dominant forms being generally associated with long-standing motor symptoms and slowly progressive course, certain subtypes with lower motor neuron-dominant features and early bulbar compromise lead to rapidly progressive motor handicap. For some monogenic forms, there is a well-established genotypic-phenotypic correlation. There are no specific biochemical and neuroimaging biomarkers for the diagnosis of juvenile Amyotrophic Lateral Sclerosis. There are several inherited neurodegenerative and neurometabolic disorders which can lead to the signs of motor neuron impairment. This review emphasizes the importance of high clinical suspicion, assessment, and proper diagnostic work-up for juvenile Amyotrophic Lateral Sclerosis.

Data-independent acquisition proteomics of cerebrospinal fluid implicates endoplasmic reticulum and inflammatory mechanisms in amyotrophic lateral sclerosis

While unbiased proteomics of human cerebrospinal fluid (CSF) has been used successfully to identify biomarkers of amyotrophic lateral sclerosis (ALS), high-abundance proteins mask the presence of lower abundance proteins that may have diagnostic and prognostic value. However, developments in mass spectrometry (MS) proteomic data acquisition methods offer improved protein depth. In this study, MS with library-free data-independent acquisition (DIA) was used to compare the CSF proteome of people with ALS (n = 40), healthy (n = 15) and disease (n = 8) controls. Quantified protein groups were subsequently correlated with clinical variables. Univariate analysis identified 7 proteins, all significantly upregulated in ALS versus healthy controls, and 9 with altered abundance in ALS versus disease controls (FDR < 0.1). Elevated chitotriosidase-1 (CHIT1) was common to both comparisons and was proportional to ALS disability progression rate (Pearson r = 0.41, FDR-adjusted p = 0.035) but not overall survival. Ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1; upregulated in ALS versus healthy controls) was proportional to disability progression rate (Pearson r = 0.53, FDR-adjusted p = 0.003) and survival (Kaplan Meier log-rank p = 0.013) but not independently in multivariate proportional hazards models. Weighted correlation network analysis was used to identify functionally relevant modules of proteins. One module, enriched for inflammatory functions, was associated with age at symptom onset (Pearson r = 0.58, FDR-adjusted p = 0.005) and survival (Hazard Ratio = 1.78, FDR = 0.065), and a second module, enriched for endoplasmic reticulum proteins, was negatively correlated with disability progression rate (r = -0.42, FDR-adjusted p = 0.109). DIA acquisition methodology therefore strengthened the biomarker candidacy of CHIT1 and UCHL1 in ALS, while additionally highlighted inflammatory and endoplasmic reticulum proteins as novel sources of prognostic biomarkers.

Forced Expiratory Volume in One Second Quotient (FEV1Q) as a Prognostic Factor in Amyotrophic Lateral Sclerosis Patients: Comparing Its Predictive Value to Other Lung Function Measurements

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the first and second motor neurons. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) have conventionally served as indicators of respiratory muscle strength. Recently, FEV1Q (FEV1 divided by the sex-specific first percentile values of absolute FEV1 in adults with lung disease) has been suggested as a predictor of mortality. While FVC has been utilized as a prognostic factor, FEV1Q has not yet been examined.

METHODS

This retrospective unicenter study evaluated FEV1Q as a predictor of mortality in ALS patients, comparing its predictive efficacy with other measurements, including FEV1, FVC, sniff nasal inspiratory pressure, and maximal inspiratory pressure. The study utilized univariate analysis for each variable employing the Cox proportional hazards model to determine the statistical significance and predictive power of each measurement.

RESULTS

Forty-five patients were included, female predominant (60%) and an average age at diagnosis of 69.2 ± 11 years. Almost all (95%) met the criteria for non-invasive ventilation (NIV) and initiated (93%) during the study period, a mean of 137 days after diagnosis. The mortality rate observed was 57%, occurring at a median of 398 days post-diagnosis. On average, patients underwent 1.7 pulmonary function tests, revealing a decline in various parameters, including FEV1, FEV1Q, and FVC. However, only FEV1Q was a statistically significant predictor of mortality (p < 0.0083) in a Cox regression analysis. A negative coefficient for FEV1Q indicated that higher values were associated with a reduced mortality risk, with an average FEV1Q of 2.68 observed at the time of death.

CONCLUSION

FEV1Q emerged as the only statistically significant predictor of mortality among the evaluated respiratory measurements in ALS patients. This study is the first to focus on applying FEV1Q in the clinical evaluation of ALS, marking an initial step in understanding its potential role in patient follow-up. However, further studies are needed before these findings can be incorporated into clinical practice.

Disease survival and progression in TARDBP ALS patients from Sardinia, Italy

BACKGROUND

Common genes implicated in amyotrophic lateral sclerosis (ALS) development may also influence its progression rate. The C9orf72 mutations featured a faster progression rate while the European SOD1 mutations were associated with a slower progression. In this study, we assessed the relationship between TARDBP and ALS progression/survival.

METHODS

ALS incident patients (2010-2019) were diagnosed by El Escorial revised criteria and staged over the disease course by the King's staging system. Disease progression was analysed by Kaplan-Meier survival curves and Cox regression models, with survival measured from symptom onset to death/tracheostomy or censor date.

RESULTS

The study population included 76 patients carrying TARDBP mutations (A382T/G295S), 28 patients carrying the C9orf72 GGGGCC expansion, and 158 patients who had no evidence of causative genetic mutations (nmALS group). TARDBP patients reached death/tracheostomy later than C9orf72 and nmALS patients, independently of possible prognostic indicators (sex, age at ALS onset, diagnostic delay, phenotype at onset, and family history of ALS). On King's staging, the time elapsed between disease onset (King's stage 1) and involvement of the second body region (King's stage 2B) was similar in TARDBP and nmALS patients but longer in TARDBP than in C9orf72 patients. TARDBP patients reached King's stages 3 and 4 later than C9orf72 and nmALS patients.

CONCLUSIONS

TARDBP patients have a better survival/prognosis than C9orf72-positive and nmALS patients. King's staging also suggested that the higher survival rate and the slower progression associated with the TARDBP mutation could mainly be attributed to the longer time elapsed between King's stages 2B to 3.

Prognostic value of motor and extramotor involvement in ALS

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder resulting in upper and lower motor neuron loss. ALS often has a focal onset of weakness, which subsequently spreads to other body regions. Survival is limited to two to five years after disease onset, often due to respiratory failure. Cognitive impairment is present in approximately 30% to 50% of patients and in 10%-15% of patients, the clinical criteria of frontotemporal dementia (FTD) are met.

METHODS

In this retrospective single-center ALS cohort study, we examined the occurrence of cognitive and behavioral impairment in relation to motor impairment at disease presentation and studied its impact on survival.

RESULTS

The degree of lower motor neuron involvement was associated with a worse survival, but there was no effect for upper motor neuron involvement. Patients who were cognitively normal had a significantly better survival compared to patients with cognitive or behavioral impairment and to patients with comorbid FTD. There was no significant difference regarding survival between patients with FTD and patients with cognitive or behavioral impairment.

CONCLUSIONS

The extent of motor and extramotor involvement in patients with ALS at disease presentation holds complementary prognostic information.

Neurodegenerative biomarkers outperform neuroinflammatory biomarkers in amyotrophic lateral sclerosis

OBJECTIVE

To describe the diagnostic and prognostic performance, and longitudinal trajectories, of potential biomarkers of neuroaxonal degeneration and neuroinflammation in amyotrophic lateral sclerosis (ALS).

METHODS

This case-control study included 192 incident ALS patients, 42 ALS mimics, 114 neurological controls, and 117 healthy controls from Stockholm, Sweden. Forty-four ALS patients provided repeated measurements. We assessed biomarkers of (1)neuroaxonal degeneration: neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH) in cerebrospinal fluid (CSF) and NfL in serum, and (2)neuroinflammation: chitotriosidase-1 (CHIT1) and monocyte chemoattractant protein 1 (MCP-1) in CSF. To evaluate diagnostic performance, we calculated the area under the curve (AUC). To estimate prognostic performance, we applied quantile regression and Cox regression. We used linear regression models with robust standard errors to assess temporal changes over time.

RESULTS

Neurofilaments performed better at differentiating ALS patients from mimics (AUC: pNfH 0.92, CSF NfL 0.86, serum NfL 0.91) than neuroinflammatory biomarkers (AUC: CHIT1 0.71, MCP-1 0.56). Combining biomarkers did not improve diagnostic performance. Similarly, neurofilaments performed better than neuroinflammatory biomarkers at predicting functional decline and survival. The stratified analysis revealed differences according to the site of onset: in bulbar patients, neurofilaments and CHIT1 performed worse at predicting survival and correlations were lower between biomarkers. Finally, in bulbar patients, neurofilaments and CHIT1 increased longitudinally but were stable in spinal patients.

CONCLUSIONS

Biomarkers of neuroaxonal degeneration displayed better diagnostic and prognostic value compared with neuroinflammatory biomarkers. However, in contrast to spinal patients, in bulbar patients neurofilaments and CHIT1 performed worse at predicting survival and seemed to increase over time.

Describing and characterising variability in ALS disease progression

BACKGROUND, OBJECTIVES

Decrease in the revised ALS Functional Rating Scale (ALSFRS-R) score is currently the most widely used measure of disease progression. However, it does not sufficiently encompass the heterogeneity of ALS. We describe a measure of variability in ALSFRS-R scores and demonstrate its utility in disease characterization.

METHODS

We used 5030 ALS clinical trial patients from the Pooled Resource Open-Access ALS Clinical Trials database to calculate variability in disease progression employing a novel measure and correlated variability with disease span. We characterized the more and less variable populations and designed a machine learning model that used clinical, laboratory and demographic data to predict class of variability. The model was validated with a holdout clinical trial dataset of 84 ALS patients (NCT00818389).

RESULTS

Greater variability in disease progression was indicative of longer disease span on the patient-level. The machine learning model was able to predict class of variability with accuracy of 60.1-72.7% across different time periods and yielded a set of predictors based on clinical, laboratory and demographic data. A reduced set of 16 predictors and the holdout dataset yielded similar accuracy.

DISCUSSION

This measure of variability is a significant determinant of disease span for fast-progressing patients. The predictors identified may shed light on pathophysiology of variability, with greater variability in fast-progressing patients possibly indicative of greater compensatory reinnervation and longer disease span. Increasing variability alongside decreasing rate of disease progression could be a future aim of trials for faster-progressing patients.

Biomarker Qualification for Neurofilament Light Chain in Amyotrophic Lateral Sclerosis: Theory and Practice

OBJECTIVE

To explore whether the utility of neurofilament light chain (NfL), as a biomarker to aid amyotrophic lateral sclerosis (ALS) therapy development, would be enhanced by obtaining formal qualification from the US Food and Drug Administration for a defined context-of-use.

METHODS

Consensus discussion among academic, industry, and patient advocacy group representatives.

RESULTS

A wealth of scientific evidence supports the use of NfL as a prognostic, response, and potential safety biomarker in the broad ALS population, and as a risk/susceptibility biomarker among the subset of SOD1 pathogenic variant carriers. Although NfL has not yet been formally qualified for any of these contexts-of-use, the US Food and Drug Administration has provided accelerated approval for an SOD1-lowering antisense oligonucleotide, based partially on the recognition that a reduction in NfL is reasonably likely to predict a clinical benefit.

INTERPRETATION

The increasing incorporation of NfL into ALS therapy development plans provides evidence that its utility-as a prognostic, response, risk/susceptibility, and/or safety biomarker-is already widely accepted by the community. The willingness of the US Food and Drug Administration to base regulatory decisions on rigorous peer-reviewed data-absent formal qualification, leads us to conclude that formal qualification, despite some benefits, is not essential for ongoing and future use of NfL as a tool to aid ALS therapy development. Although the balance of considerations for and against seeking NfL biomarker qualification will undoubtedly vary across different diseases and contexts-of-use, the robustness of the published data and careful deliberations of the ALS community may offer valuable insights for other disease communities grappling with the same issues. ANN NEUROL 2024;95:211-216.

Clinical factors and vascular endothelial growth factor as determinants of disease progression in Indian patients with amyotrophic lateral sclerosis

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder. Prognostication remains sub-optimally defined. We aimed to assess clinical determinants of disease progression rates in Indian patients with ALS and to assess the role of vascular endothelial growth factor (VEGF) in disease progression.

METHODS

In this cross-sectional study, consecutive patients with clinically definite/probable ALS according to the revised El Escorial criteria and controls were included. Patients were classified into fast or slow progressors based on disease progression rate (DPR). Serum and CSF VEGF level was assessed for patients and controls.

RESULTS

Of 142 patients recruited, 93 (65.5%) were male. Mean age at enrollment was 49.37 ± 12.65 years. Mean duration of symptoms was 20.53 ± 20.88 months. Mean DPR was 1.14 ± 0.94. Based on DPR, 81 (57%) patients were slow progressors and 61 (43%) were fast progressors. Univariate analysis demonstrated a statistically significant association of DPR with age at onset, symptom duration, time to spread, wasting of small muscles of the hand, frontal release signs, and neurophysiologic bulbar abnormalities. On multivariate analysis, age at onset and symptom duration had a significant association with disease progression. The CSF VEGF levels of ALS patients (46.18 ± 27.8) were significantly elevated compared to controls (25.95 ± 25.64 pg/ml) (p = 0.001), but not serum VEGF.

CONCLUSION

Age at symptom onset and duration of disease had a significant impact on disease progression in Indian patients with ALS. CSF VEGF levels were significantly elevated in ALS compared to controls, indicating the role of CSF VEGF as a potential biomarker.

Higher Glycemic Index and Glycemic Load Diet Is Associated with Slower Disease Progression in Amyotrophic Lateral Sclerosis

OBJECTIVE

High-caloric diets may slow the progression of amyotrophic lateral sclerosis; however, key macronutrients have not been identified. We examined whether dietary macronutrients are associated with the rate of progression and length of survival among the prospective cohort study participants.

METHODS

Participants with a confirmed diagnosis of sporadic amyotrophic lateral sclerosis enrolled in the Multicenter Cohort Study of Oxidative Stress were included (n = 304). We evaluated baseline macronutrient intake assessed by food frequency questionnaire in relation to change in revised amyotrophic lateral sclerosis functional rating scale total-score, and tracheostomy-free survival using linear regression and Cox proportional hazard models. Baseline age, sex, disease duration, diagnostic certainty, body mass index, bulbar onset, revised amyotrophic lateral sclerosis functional rating scale total-score, and forced vital capacity were included as covariates.

RESULTS

Baseline higher glycemic index and load were associated with less decline of revised amyotrophic lateral sclerosis functional rating scale total score at 3-month follow-up (β = -0.13, 95% CI -0.2, -0.01, p = 0.03) and (β = -0.01, 95% CI -0.03, -0.0007, p = 0.04), respectively. Glycemic index second-quartile, third-quartile, and fourth-quartile groups were associated with less decline at 3 months by 1.9 (95% CI -3.3, -0.5, p = 0.008), 2.0 (95% CI -3.3, -0.6, p = 0.006), and 1.6 (95% CI -3.0, -0.2, p = 0.03) points compared with the first-quartile group; the glycemic load fourth-quartile group had 1.4 points less decline compared with the first-quartile group (95% CI -2.8, 0.1, p = 0.07). Higher glycemic index was associated with a trend toward longer tracheostomy-free survival (HR 0.97, 95% CI 0.93, 1.00, p = 0.07).

INTERPRETATION

Higher dietary glycemic index and load are associated with slower disease progression in amyotrophic lateral sclerosis. ANN NEUROL 2024;95:217-229.

Novel approaches to motoneuron disease/ALS treatment using non-invasive brain and spinal stimulation: IFCN handbook chapter

Non-invasive brain stimulation techniques have been exploited in motor neuron disease (MND) with multifold objectives: to support the diagnosis, to get insights in the pathophysiology of these disorders and, more recently, to slow down disease progression. In this review, we consider how neuromodulation can now be employed to treat MND, with specific attention to amyotrophic lateral sclerosis (ALS), the most common form with upper motoneuron (UMN) involvement, taking into account electrophysiological abnormalities revealed by human and animal studies that can be targeted by neuromodulation techniques. This review article encompasses repetitive transcranial magnetic stimulation methods (including low-frequency, high-frequency, and pattern stimulation paradigms), transcranial direct current stimulation as well as experimental findings with the newer approach of trans-spinal direct current stimulation. We also survey and discuss the trials that have been performed, and future perspectives.

Language deficits in primary lateral sclerosis: cortical atrophy, white matter degeneration and functional disconnection between cerebral regions

BACKGROUND

Primary lateral sclerosis (PLS) is traditionally regarded as a pure upper motor neuron disorder, but recent cases series have highlighted cognitive deficits in executive and language domains.

METHODS

A single-centre, prospective neuroimaging study was conducted with comprehensive clinical and genetic profiling. The structural and functional integrity of language-associated brain regions and networks were systematically evaluated in 40 patients with PLS in comparison to 111 healthy controls. The structural integrity of the arcuate fascicle, frontal aslant tract, inferior occipito-frontal fascicle, inferior longitudinal fascicle, superior longitudinal fascicle and uncinate fascicle was evaluated. Functional connectivity between the supplementary motor region and the inferior frontal gyrus and connectivity between Wernicke's and Broca's areas was also assessed.

RESULTS

Cortical thickness reductions were observed in both Wernicke's and Broca's areas. Fractional anisotropy reduction was noted in the aslant tract and increased radical diffusivity (RD) identified in the aslant tract, arcuate fascicle and superior longitudinal fascicle in the left hemisphere. Functional connectivity was reduced along the aslant track, i.e. between the supplementary motor region and the inferior frontal gyrus, but unaffected between Wernicke's and Broca's areas. Cortical thickness alterations, structural and functional connectivity changes were also noted in the right hemisphere.

CONCLUSIONS

Disease-burden in PLS is not confined to motor regions, but there is also a marked involvement of language-associated tracts, networks and cortical regions. Given the considerably longer survival in PLS compared to ALS, the impact of language impairment on the management of PLS needs to be carefully considered.

Trajectories and contributing factors of neural compensation in healthy and pathological aging

Neural degeneration is a hallmark of healthy aging and can be associated with specific cognitive impairments. However, neural degeneration per se is not matched by unremitting declines in cognitive abilities. Instead, middle-aged and older adults typically maintain surprisingly high levels of cognitive functioning, suggesting that the human brain can adapt to structural degeneration by neural compensation. Here, we summarize prevailing theories and recent empirical studies on neural compensation with a focus on often neglected contributing factors, such as lifestyle, metabolism and neural plasticity. We suggest that these factors moderate the relationship between structural integrity and neural compensation, maintaining psychological well-being and behavioral functioning. Finally, we discuss that a breakdown in neural compensation may pose a tipping point that distinguishes the trajectories of healthy vs pathological aging, but conjoint support from psychology and cognitive neuroscience for this alluring view is still scarce. Therefore, future experiments that target the concomitant processes of neural compensation and associated behavior will foster a comprehensive understanding of both healthy and pathological aging.

Individualized predictions for clinical milestone in amyotrophic lateral sclerosis: A multialgorithmic approach

Objective

The phenotypic heterogeneity and complex disease trajectory complicate the ability to predict specific clinical milestone for individual patients with amyotrophic lateral sclerosis (ALS). Here we developed individualized prediction models to estimate the time to the loss of autonomy in swallowing function.

Methods

Utilizing the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) database, we built three models of distinct time-to-event prediction algorithms: accelerated failure time (AFT), cox proportional hazard (COX) and random survival forest (RSF) for an individualized risk assessment of the swallowing milestone. The target variable was defined as the time to a decline in the ALSFRS-R swallowing item score to 1 or below, indicating a need for supplementary tube feeding.

Results

Internal cross-validation revealed the median concordance index (C-index) of 0.851 (IQR, 0.842-0.859) for AFT, 0.850 (0.841-0.859) for COX and 0.846 (0.839-0.854) for RSF, and all models demonstrated good distributional calibration with predicted and observed event probabilities closely matched across different time intervals. For external validation with a registry dataset with characteristics different from PRO-ACT, the discriminative power was replicated with comparable C-indices for all models, whereas the calibration revealed a left-skewed distribution suggesting a bias towards overestimation of event probabilities in real-world data. While all models were effective at stratifying patients, the results of RSF model, unlike AFT and COX, did not match well with the KM curves of the corresponding risk groups, supporting the importance of nuanced understanding of data structure and algorithmic properties.

Conclusion

Our models are implemented into a web application which could be applied to individualized counselling, management and clinical trial design for gastrostomy intervention. Further studies for model optimization will advance personalized care in patients with ALS.

A Palliative Care Approach to Amyotrophic Lateral Sclerosis

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a degenerative disease characterized by motor dysfunction. Currently, treatment options are limited and management is based mostly on symptom control and quality of life optimization, so palliative care plays a fundamental role. Our objective was to characterize the ALS population in Madeira Island that was referenced and/or followed by a palliative care unit over a five-year period.

METHODS

Longitudinal, retrospective, descriptive, and observational study to analyze patients with ALS who were referred and/or followed by a palliative care unit during a five-year period, between 2017 and 2021. Patient's medical electronic and physical records were analyzed to gather data. Descriptive and inferential statistical analysis was done using Microsoft Excel and Statistical Package for the Social Sciences (version 28.0.1).

RESULTS

During this five-year period, a total of 38 patients were diagnosed with ALS in Madeira Island and 23 (60.53%) were referred to palliative care. Three patients died before assessment, so 20 (50.63%) were followed by the palliative care team. They had a median life expectancy of 425 days and the median time spent in palliative care was 137 days. Of this population, 56.52% (n=13) was male with an average age of 64 years. The median period from diagnosis to referral was 167 days, with most referrals being made by family medicine (39.13%; n=9) motivated by uncontrolled symptoms (95.65%; n=22). The median period from referral to first assessment by a palliative care physician was 19 days. The Palliative Performance Scale (PPS) and Confusion Assessment Method (CAM) applied on the first visit had a median score of 40% in the former and was negative in 95.00% (n=19) of patients in the latter. Advanced care directives were present in 55.00% (n=11) of patients and all provided care was in accordance with the patient's wishes. The most common symptoms were dysphagia, dyspnea, pain, anxiety, and sialorrhea. The most used drugs were morphine, riluzole, butylscopolamine, bisacodyl, and midazolam. As for other interventions, 55.00% (n=11) of patients underwent noninvasive ventilation (NIV), 15.00% (n=3) were submitted to percutaneous endoscopic gastrostomy (PEG), and one patient (5.00%) was nasogastrically intubated. The death rate was 95.00% (n=19) with 73.68% (n=14) of deaths occurring in the palliative care unit.

CONCLUSION

Literature has shown that there are many advantages to the early inclusion of palliative care in ALS management, achieving effective symptom control and greater quality of life, but also reducing caregiver burden. However, in this study, we found that referrals to palliative care were late and included mostly cases of advanced disease with uncontrolled symptoms.

A randomized, double-blind, placebo-controlled phase 2 study to assess safety, tolerability, and efficacy of RT001 in patients with amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

RT001 is a deuterated synthetic homologue of linoleic acid, which makes membrane polyunsaturated fatty acids resistant to lipid peroxidation, a process involved in motor neuron degeneration in amyotrophic lateral sclerosis (ALS).

METHODS

We conducted a randomized, multicenter, placebo-controlled clinical trial. Patients with ALS were randomly allocated to receive either RT001 or placebo for 24 weeks. After the double-blind period, all patients received RT001 during an open-label phase for 24 weeks. The primary outcome measures were safety and tolerability. Key efficacy outcomes included the ALS Functional Rating Scale (ALSFRS-R), percent predicted slow vital capacity, and plasma neurofilament light chain concentration.

RESULTS

In total, 43 patients (RT001 = 21; placebo = 22) were randomized. RT001 was well tolerated; one patient required dose reduction due to adverse events (AEs). Numerically, there were more AEs in the RT001 group compared to the placebo group (71% versus 55%, p = 0.35), with gastrointestinal symptoms being the most common (43% in RT001, 27% in placebo, p = 0.35). Two patients in the RT001 group experienced a serious AE, though unrelated to treatment. The least-squares mean difference in ALSFRS-R total score at week 24 of treatment was 1.90 (95% confidence interval = -1.39 to 5.19) in favor of RT001 (p = 0.25). The directions of other efficacy outcomes favored RT001 compared to placebo, although no inferential statistics were performed.

CONCLUSIONS

Initial data indicate that RT001 is safe and well tolerated. Given the exploratory nature of the study, a larger clinical trial is required to evaluate its efficacy.

Distinct neuroinflammatory signatures exist across genetic and sporadic amyotrophic lateral sclerosis cohorts

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive loss of upper and lower motor neurons. ALS is on a pathogenetic disease spectrum with frontotemporal dementia, referred to as ALS-frontotemporal spectrum disorder (ALS-FTSD). For mutations associated with ALS-FTSD, such as the C9orf72 hexanucleotide repeat expansion, the molecular factors associated with heterogeneity along this spectrum require further characterization. Here, using a targeted NanoString molecular barcoding approach, we interrogate neuroinflammatory dysregulation and heterogeneity at the level of gene expression in post-mortem motor cortex tissue from a cohort of clinically heterogeneous C9-ALS-FTSD cases. We identified 20 dysregulated genes in C9-ALS-FTSD, with enrichment of microglial and inflammatory response gene sets. Two genes with significant correlations to available clinical metrics were selected for validation: FKBP5, a correlate of cognitive function, and brain-derived neurotrophic factor (BDNF), a correlate of disease duration. FKBP5 and its signalling partner, NF-κB, appeared to have a cell type-specific staining distribution, with activated (i.e. nuclear) NF-κB immunoreactivity in C9-ALS-FTSD. Expression of BDNF, a correlate of disease duration, was confirmed to be higher in individuals with long compared to short disease duration using BaseScope™ in situ hybridization. Our analyses also revealed two distinct neuroinflammatory panel signatures (NPS), NPS1 and NPS2, delineated by the direction of expression of proinflammatory, axonal transport and synaptic signalling pathways. We compared NPS between C9-ALS-FTSD cases and those from sporadic ALS and SOD1-ALS cohorts and identified NPS1 and NPS2 across all cohorts. Moreover, a subset of NPS was also able to separate publicly available RNA sequencing data from independent C9-ALS and sporadic ALS cohorts into two inflammatory subgroups. Importantly, NPS subgroups did not clearly segregate with available demographic, genetic, clinical or pathological features, highlighting the value of molecular stratification in clinical trials for inflammatory subgroup identification. Our findings thus underscore the importance of tailoring therapeutic approaches based on distinct molecular signatures that exist between and within ALS-FTSD cohorts.

Accurate personalized survival prediction for amyotrophic lateral sclerosis patients

Amyotrophic Lateral Sclerosis (ALS) is a rapidly progressive neurodegenerative disease. Accurately predicting the survival time for ALS patients can help patients and clinicians to plan for future treatment and care. We describe the application of a machine-learned tool that incorporates clinical features and cortical thickness from brain magnetic resonance (MR) images to estimate the time until a composite respiratory failure event for ALS patients, and presents the prediction as individual survival distributions (ISDs). These ISDs provide the probability of survival (none of the respiratory failures) at multiple future time points, for each individual patient. Our learner considers several survival prediction models, and selects the best model to provide predictions. We evaluate our learned model using the mean absolute error margin (MAE-margin), a modified version of mean absolute error that handles data with censored outcomes. We show that our tool can provide helpful information for patients and clinicians in planning future treatment.

Rab Geranylgeranyltransferase Subunit Beta as a Potential Indicator to Assess the Progression of Amyotrophic Lateral Sclerosis

BACKGROUND

Currently, there is no effective treatment for amyotrophic lateral sclerosis (ALS), a devastating neurodegenerative disorder. Many biomarkers have been proposed, but because ALS is a clinically heterogeneous disease with an unclear etiology, biomarker discovery for ALS has been challenging due to the lack of specificity of these biomarkers. In recent years, the role of autophagy in the development and treatment of ALS has become a research hotspot. In our previous studies, we found that the expression of RabGGTase (low RABGGTB expression and no change in RABGGTA) is lower in the lumbar and thoracic regions of spinal cord motoneurons in SOD1G93A mice compared with WT (wild-type) mice groups, and upregulation of RABGGTB promoted prenylation modification of Rab7, which promoted autophagy to protect neurons by degrading SOD1. Given that RabGGTase is associated with autophagy and autophagy is associated with inflammation, and based on the above findings, since peripheral blood mononuclear cells are readily available from patients with ALS, we proposed to investigate the expression of RabGGTase in peripheral inflammatory cells.

METHODS

Information and venous blood were collected from 86 patients diagnosed with ALS between January 2021 and August 2023. Flow cytometry was used to detect the expression of RABGGTB in monocytes from peripheral blood samples collected from patients with ALS and healthy controls. Extracted peripheral blood mononuclear cells (PBMCs) were differentiated in vitro into macrophages, and then the expression of RABGGTB was detected by immunofluorescence. RABGGTB levels in patients with ALS were analyzed to determine their impact on disease progression.

RESULTS

Using flow cytometry in monocytes and immunofluorescence in macrophages, we found that RABGGTB expression in the ALS group was significantly higher than in the control group. Age, sex, original location, disease course, C-reactive protein (CRP), and interleukin-6 (IL-6) did not correlate with the ALS functional rating scale-revised (ALSFRS-R), whereas the RABGGTB level was significantly correlated with the ALSFRS-R. In addition, multivariate analysis revealed a significant correlation between RABGGTB and ALSFRS-R score. Further analysis revealed a significant correlation between RABGGTB expression levels and disease progression levels (ΔFS).

CONCLUSIONS

The RABGGTB level was significantly increased in patients with ALS compared with healthy controls. An elevated RABGGTB level in patients with ALS is associated with the rate of progression in ALS, suggesting that elevated RABGGTB levels in patients with ALS may serve as an indicator for tracking ALS progression.

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.

Regional spreading pattern is associated with clinical phenotype in amyotrophic lateral sclerosis

Increasing evidence shows that disease spreading in amyotrophic lateral sclerosis (ALS) follows a preferential pattern with more frequent involvement of contiguous regions from the site of symptom onset. The aim of our study was to assess if: (i) the burden of upper (UMN) and lower motor neuron (LMN) involvement influences directionality of disease spreading; (ii) specific patterns of disease progression are associated with motor and neuropsychological features of different ALS subtypes (classic, bulbar, primary lateral sclerosis, UMN-predominant, progressive muscular atrophy, flail arm, flail leg); and (iii) specific clinical features may help identify ALS subtypes, which remain localized to the site of onset for a prolonged time (regionally entrenching ALS). A single-centre, retrospective cohort of 913 Italian ALS patients was evaluated to assess correlations between directionality of the disease process after symptom onset and motor/neuropsychological phenotype. All patients underwent an extensive evaluation including the following clinical scales: Penn Upper Motor Neuron Score (PUMNS), MRC Scale for Muscle Strength and the Edinburgh Cognitive and Behavioural ALS Screen (ECAS). The most frequent initial spreading pattern was that towards adjacent horizontal regions (77.3%), which occurred preferentially in patients with lower MRC scores (P = 0.038), while vertical diffusion (21.1%) was associated with higher PUMNS (P < 0.001) and with reduced survival (P < 0.001). Non-contiguous disease spreading was associated with more severe UMN impairment (P = 0.003), while contiguous disease pattern with lower MRC scores. Furthermore, non-contiguous disease spreading was associated with more severe cognitive impairment in both executive and visuospatial ECAS domains. Individuals with regionally entrenching ALS were more frequently female (45.6% versus 36.9%; P = 0.028) and had higher frequencies of symmetric disease onset (40.3% versus 19.7%; P < 0.001) and bulbar phenotype (38.5% versus 16.4%; P < 0.001). Our study suggests that motor phenotypes characterized by a predominant UMN involvement are associated with a vertical pattern of disease progression reflecting ipsilateral spreading within the motor cortex, while those with predominant LMN involvement display more frequently a horizontal spreading from one side of the spinal cord to the other. These observations raise the hypothesis that one of the mechanisms underlying disease spreading in ALS pathology is represented by diffusion of toxic factors in the neuron microenvironment. Finally, it is possible that in our cohort, regionally entrenching ALS forms are mainly observed in patients with atypical bulbar phenotypes, characterized by a slowly progressive course and relatively benign prognosis.

Neuroprognostication for Patients with Amyotrophic Lateral Sclerosis: An Updated, Evidence-Based Review

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder that presents and progresses in various ways, making prognostication difficult. Several paradigms exist for providers to elucidate prognosis in a way that addresses not only the amount of time a patient has to live, but also a patient's quality of their life moving forward. Prognostication, with regard to both survivability and quality of life, is impacted by several features that include, but are not limited to, patient demographics, clinical features on presentation, and over time, access to therapy, and access to multidisciplinary clinics. An understanding of the impact that these features have on the life of a patient with ALS can help providers to develop a better and more personalized approach for patients related to their clinical prognosis after a diagnosis is made. The ultimate goal of prognostication is to empower patients with ALS to take control and make decisions with their care teams to ensure that their goals are addressed and met.