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.

Differing patterns of cortical grey matter pathology identified by multifractal analysis in UMN-predominant ALS patients with and without corticospinal tract hyperintensity

The pathological hallmarks of amyotrophic lateral sclerosis (ALS) are degeneration of the primary motor cortex grey matter (GM) and corticospinal tract (CST) resulting in upper motor neuron (UMN) dysfunction. Conventional brain magnetic resonance imaging (MRI) shows abnormal CST hyperintensity in some UMN-predominant ALS patients (ALS-CST+) but not in others (ALS-CST-). In addition to the CST differences, we aimed to determine whether GM degeneration differs between ALS-CST+ and ALS-CST- patients by cortical thickness (CT), voxel-based morphometry (VBM) and fractal dimension analyses. We hypothesized that MRI multifractal (MF) measures could differentiate between neurologic controls (n = 14) and UMN-predominant ALS patients as well as between patient subgroups (ALS-CST+, n = 21 vs ALS-CST-, n = 27). No significant differences were observed in CT or GM VBM in any brain regions between patients and controls or between ALS subgroups. MF analyses were performed separately on GM of the whole brain, of frontal, parietal, occipital, and temporal lobes as well as of cerebellum. Estimating MF measures D (Q = 0), D (Q = 1), D (Q = 2), Δf, Δα of frontal lobe GM classified neurologic controls, ALS-CST+ and ALS-CST- groups with 98% accuracy and > 95% in F1, recall, precision and specificity scores. Classification accuracy was only 74% when using whole brain MF measures and < 70% for other brain lobes. We demonstrate that MF analysis can distinguish UMN-predominant ALS subgroups based on GM changes, which the more commonly used quantitative approaches of CT and VBM cannot.

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.

The effects of intervention with intravenous edaravone in Study 19 on hospitalization, tracheostomy, ventilation, and death in patients with amyotrophic lateral sclerosis

INTRODUCTION/AIMS

Intravenous (IV) edaravone is a US Food and Drug Administration-approved treatment for amyotrophic lateral sclerosis (ALS), shown in clinical trials to slow physical functional decline. In this study we compared the effect of IV edaravone (edaravone-first group) versus placebo followed by IV edaravone (placebo-first group) on survival and additional milestone events.

METHODS

This work is a post hoc analysis of Study 19/MCI186-19, which was a randomized, placebo-controlled, phase 3 study investigating IV edaravone versus placebo. Study 19 and its 24-week extension have been described previously (NCT01492686). Edaravone-first versus placebo-first group time to events for specific milestone(s) were analyzed post hoc. Time-to-event composite endpoints were time to death; time to death, tracheostomy, or permanent assisted ventilation (PAV); and time to death, tracheostomy, PAV, or hospitalization.

RESULTS

The risk for death, tracheostomy, PAV, or hospitalization was 53% lower among patients in the edaravone-first vs placebo-first groups (hazard ratio = 0.47 [95% confidence interval 0.25 to 0.88], P = .02). The overall effect of IV edaravone on ALS progression could be seen in the significant separation of time-to-event curves for time to death, tracheostomy, PAV, or hospitalization. ALS survival composite endpoint analyses (ALS/SURV) suggested a treatment benefit (least-squares mean difference) for the edaravone-first versus the placebo-first group at week 24 (0.15 ± 0.05 [95% confidence interval 0.06 to 0.25], P < .01) and week 48 (0.11 ± 0.05 [95% confidence interval 0.02 to 0.21], P = .02).

DISCUSSION

These analyses illustrate the value of timely and continued IV edaravone treatment, as earlier initiation was associated with a lower risk of death, tracheostomy, PAV, or hospitalization in patients with ALS.

Graph network measures reveal distinct white matter abnormalities in motor and extra-motor brain regions of two UMN-predominant ALS subtypes

BACKGROUND

Routine clinical magnetic resonance imaging (MRI) shows bilateral corticospinal tract (CST) hyperintensity in some patients with upper motor neuron (UMN)-predominant ALS (ALS-CST+) but not in others (ALS-CST-). Although, similar in their UMN features, the ALS-CST+ patient group is significantly younger in age, has faster disease progression and shorter survival than the ALS-CST- patient group. Reasons for the differences are unclear.

METHOD

In order to evaluate more objective MRI measures of these ALS subgroups, we used diffusion tensor images (DTI) obtained using single shot echo planar imaging sequence from 1.5 T Siemens MRI Scanner. We performed an exploratory whole brain white matter (WM) network analysis using graph theory approach on 45 ALS patients (ALS-CST+) (n = 21), and (ALS-CST-) (n = 24) and neurological controls (n = 14).

RESULTS

Significant (p < 0.05) differences in nodal degree measure between ALS patients and controls were observed in motor and extra motor regions, supplementary motor area, subcortical WM regions, cerebellum and vermis. Importantly, WM network abnormalities were significantly (p < 0.05) different between ALS-CST+ and ALS-CST- subgroups. Compared to neurologic controls, both ALS subgroups showed hubs in the right superior occipital gyrus and cuneus as well as significantly (p < 0.05) reduced small worldness supportive of WM network damage.

CONCLUSIONS

Significant differences between ALS-CST+ and ALS-CST- subgroups of WM network abnormalities, age of onset, symptom duration prior to MRI, and progression rate suggest these patients represent distinct clinical phenotypes and possibly pathophysiologic mechanisms of ALS.

Quantitative Brain MRI Metrics Distinguish Four Different ALS Phenotypes: A Machine Learning Based Study

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease whose diagnosis depends on the presence of combined lower motor neuron (LMN) and upper motor neuron (UMN) degeneration. LMN degeneration assessment is aided by electromyography, whereas no equivalent exists to assess UMN dysfunction. Magnetic resonance imaging (MRI) is primarily used to exclude conditions that mimic ALS. We have identified four different clinical/radiological phenotypes of ALS patients. We hypothesize that these ALS phenotypes arise from distinct pathologic processes that result in unique MRI signatures. To our knowledge, no machine learning (ML)-based data analyses have been performed to stratify different ALS phenotypes using MRI measures. During routine clinical evaluation, we obtained T1-, T2-, PD-weighted, diffusion tensor (DT) brain MRI of 15 neurological controls and 91 ALS patients (UMN-predominant ALS with corticospinal tract CST) hyperintensity, n = 21; UMN-predominant ALS without CST hyperintensity, n = 26; classic ALS, n = 23; and ALS patients with frontotemporal dementia, n = 21). From these images, we obtained 101 white matter (WM) attributes (including DT measures, graph theory measures from DT and fractal dimension (FD) measures using T1-weighted), 10 grey matter (GM) attributes (including FD based measures from T1-weighted), and 10 non-imaging attributes (2 demographic and 8 clinical measures of ALS). We employed classification and regression tree, Random Forest (RF) and also artificial neural network for the classifications. RF algorithm provided the best accuracy (70-94%) in classifying four different phenotypes of ALS patients. WM metrics played a dominant role in classifying different phenotypes when compared to GM or clinical measures. Although WM measures from both right and left hemispheres need to be considered to identify ALS phenotypes, they appear to be differentially affected by the degenerative process. Longitudinal studies can confirm and extend our findings.

Graph theory network analysis provides brain MRI evidence of a partial continuum of neurodegeneration in patients with UMN-predominant ALS and ALS-FTD

OBJECTIVE

Our routine clinical neuroimaging showed hyperintense signal along the corticospinal tract only in some but not all patients with upper motor neuron (UMN)-predominant ALS. ALS patients with CST hyperintensity (ALS-CST+) and those without CST hyperintensity (ALS-CST-) present with nearly identical clinical UMN-predominant symptoms. Some previous studies have suggested that ALS patients with frontotemporal dementia (FTD) are on a continuum with ALS patients without FTD, while others have not. We aimed to determine whether: (a) ALS-CST+, ALS-CST-, and ALS-FTD patients show differential sites of predominant neurodegeneration occurring primarily cortically in the perikaryon or subcortically in the white matter (WM), or (b) UMN-predominant ALS is on a continuum with ALS-FTD.

METHODS

Exploratory whole brain grey matter (GM) voxel-based morphometry and WM network analysis using graph theory approach were performed. In this exploratory study, MRI data from 58 ALS patients (ALS-FTD, n = 15; ALS-CST+, n = 19; ALS-CST-, n = 24) and 14 neurological controls were obtained.

RESULTS

Significant differences in degree measures (evaluating WM networks) were observed between ALS patients and controls in frontal, motor, extra-motor, subcortical, and cerebellar regions. GM atrophy was observed only in the ALS-FTD subgroup and not in the other ALS subgroups.

CONCLUSION

Although WM network disruption by the ALS disease process showed different patterns between ALS-CST+, ALS-CST-, and ALS-FTD subgroups, there were some overlaps, particularly in prefrontal regions and between ALS-CST+ and ALS-FTD patients. Our preliminary findings suggest a partial continuum of, at least, WM degeneration between these subgroups with predominance of cortical pathology ("neuronopathy") in ALS-FTD patients and subcortical WM pathology ("axonopathy") in ALS-CST+ and ALS-CST- patients.

ALS risk factors: Industrial airborne chemical releases

Most amyotrophic lateral sclerosis (ALS) cases are sporadic (∼90%) and environmental exposures are implicated in their etiology. Large industrial facilities are permitted the airborne release of certain chemicals with hazardous properties and report the amounts to the US Environmental Protection Agency (EPA) as part of its Toxics Release Inventory (TRI) monitoring program. The objective of this project was to identify industrial chemicals released into the air that may be associated with ALS etiology. We geospatially estimated residential exposure to contaminants using a de-identified medical claims database, the SYMPHONY Integrated Dataverse®, with ∼26,000 nationally distributed ALS patients, and non-ALS controls matched for age and gender. We mapped TRI data on industrial releases of 523 airborne contaminants to estimate local residential exposure and used a dynamic categorization algorithm to solve the problem of zero-inflation in the dataset. In an independent validation study, we used residential histories to estimate exposure in each year prior to diagnosis. Air releases with positive associations in both the SYMPHONY analysis and the spatio-temporal validation study included styrene (false discovery rate (FDR) 5.4e-5), chromium (FDR 2.4e-4), nickel (FDR 1.6e-3), and dichloromethane (FDR 4.8e-4). Using a large de-identified healthcare claims dataset, we identified geospatial environmental contaminants associated with ALS. The analytic pipeline used may be applied to other diseases and identify novel targets for exposure mitigation. Our results support the future evaluation of these environmental chemicals as potential etiologic contributors to sporadic ALS risk.

Pesticides applied to crops and amyotrophic lateral sclerosis risk in the U.S

BACKGROUND

Environmental exposures are implicated in the etiology of amyotrophic lateral sclerosis (ALS). Application of insecticides, herbicides, and fungicides with neurotoxic properties to crops is permitted in the U.S., however reporting of the quantities is government mandated.

OBJECTIVE

To identify pesticides that may be associated with ALS etiology for future study.

METHODS

We geospatially estimated exposure to crop-applied pesticides as risk factors for ALS in a large de-identified medical claims database, the SYMPHONY Integrated Dataverse®. We extracted residence at diagnosis of ∼26,000 nationally distributed ALS patients, and matched non-ALS controls. We mapped county-level U.S. Geological Survey data on applications of 423 pesticides to estimate local residential exposure. We randomly broke the SYMPHONY dataset into two groups to form independent discovery and validation cohorts, then confirmed top hits using residential history information from a study of NH, VT, and OH.

RESULTS

Pesticides with the largest positive statistically significant associations in both the discovery and the validation studies and evidence of neurotoxicity in the literature were the herbicides 2,4-D (OR 1.25 95 % CI 1.17-1.34) and glyphosate (OR 1.29 95 %CI 1.19-1.39), and the insecticides carbaryl (OR 1.32 95 %CI 1.23-1.42) and chlorpyrifos (OR 1.25 95 %CI 1.17-1.33).

SIGNIFICANCE

Our geospatial analysis results support potential neurotoxic pesticide exposures as risk factors for sporadic ALS. Focused studies to assess these identified potential relationships are warranted.

Slowing the loss of physical function in amyotrophic lateral sclerosis with edaravone: Post hoc analysis of ALSFRS-R item scores in pivotal study MCI186-19

Introduction

Phase 3 study MCI186‐19 demonstrated less loss of physical function with edaravone versus placebo, as measured by the revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS‐R) total score. A 1‐point drop in an individual ALSFRS‐R item may be clinically meaningful. We assessed ALSFRS‐R item score changes to identify clinical features protected by edaravone treatment.

Methods

Time‐to‐event analysis was used to assess the cumulative probabilities of reductions in ALSFRS‐R item scores and Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ‐40) subdomain scores.

Results

Edaravone use was accompanied by: (1) delayed drop of ≥1 point in ALSFRS‐R item score for four items: salivation, walking, climbing stairs, orthopnea (unadjusted), or for two items: walking, climbing stairs (after Bonferroni correction for multiple comparisons); (2) delayed score transition from 4 or 3 at baseline to ≤2 for five items: swallowing, eating motion, walking, climbing stairs, orthopnea (unadjusted), or for one item: climbing stairs (after Bonferroni correction for multiple comparisons); and (3) delayed worsening of ALSAQ‐40 domain scores representing daily living/independence, eating and drinking (unadjusted).

Discussion

These post‐hoc analyses identified the ALSFRS‐R item scores and ALSAQ‐40 domain scores that were associated with preserved gross motor function and health‐related quality of life, respectively, after edaravone treatment. Limitations of post‐hoc analyses should be considered when interpreting these results. We recommend that clinical trials employing the ALSFRS‐R include this type of analysis as a pre‐specified secondary outcome measure.

Progressive arm muscle weakness in ALS follows the same sequence regardless of onset site: use of TOMS, a novel analytic method to track limb strength

Objective: Examine sequence of weakness in arm muscles from longitudinal hand-held dynamometry (HHD) data in ALS for congruence with contiguous spread of neurodegeneration along spinal cord segments. Methods: Longitudinal HHD data from the Ceftriaxone clinical trial were examined using nonlinear mixed models, assuming a logistic trajectory from normal to zero strength. Unobserved baseline normal strength of weak muscles was assumed using strength of the best-preserved muscle. A novel metric called "time from onset to midway strength" (TOMS) was estimated for each muscle group, and TOMS ratios were examined to identify sequence of weakness, overall and by onset site. Results: Shoulder flexion (SF), elbow flexion (EF), elbow extension (EE), wrist extension (WE), and first dorsal interosseous (FDI) were measured on each side. Over a median of 36 weeks, 513 subjects provided 2589 sets of HHD measures. TOMS increased sequentially in the following order: FDI, WE, SF, EF, and EE. TOMS ratios estimates with 95% CIs (adjusted for multiple comparisons) were: WE/FDI 1.32 (1.24-1.41), SF/WE 1.06 (1.01-1.10), EF/SF 1.06 (1.02-1.10), and EE/EF 1.18 (1.12-1.23). Elbow and shoulder flexors weakened sooner than did elbow extensors. The sequence of arm muscle weakness progression was similar regardless of onset site. Conclusion: Nonsegmental progression of arm muscle weakness that is similar for different onset sites favors cortical influence/network spread over contiguous spread of neurodegeneration in the spinal cord. Furthermore, this study confirms the "split elbow" pattern. TOMS and other proposed methods may have value as outcome measures in clinical research.

Evidence for generalizability of edaravone efficacy using a novel machine learning risk-based subgroup analysis tool

Introduction: The edaravone development program for amyotrophic lateral sclerosis (ALS) included trials MCI186-16 (Study 16) and MCI186-19 (Study 19). A cohort enrichment strategy was based on a Study 16 post hoc analysis and applied to Study 19 to elucidate a treatment effect in that study. To determine whether the Study 19 results could be generalized to a broader ALS population, we used a machine learning (ML) model to create a novel risk-based subgroup analysis tool. Methods: A validated ML model was used to rank order all Study 16 participants by predicted time to 50% expected vital capacity. Subjects were stratified into nearest-neighbor risk-based subgroups that were systematically expanded to include the entire Study 16 population. For each subgroup, a statistical analysis generated heat maps that revealed statistically significant effect sizes. Results: A broad region of the Study 16 heat map with significant effect sizes was identified, including up to 70% of the trial population. Incorporating participants identified in the cohort enrichment strategy yielded a broad group comprising 76% of the original participants with a statistically significant treatment effect. This broad group spanned the full range of the functional score progression observed in Study 16. Conclusions: This analysis, applying predictions derived using an ML model to a novel methodology for subgroup identification, ascertained a statistically significant edaravone treatment effect in a cohort of participants with broader disease characteristics than the Study 19 inclusion criteria. This novel methodology may assist clinical interpretation of study results and potentially inform efficient future clinical trial design strategies.

Reproductive History and Age of Onset for Women Diagnosed with Amyotrophic Lateral Sclerosis: Data from the National ALS Registry: 2010-2018

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurological disease of largely unknown etiology with no cure. The National ALS Registry is a voluntary online system that collects demographic and reproductive history (females only) data from patients with ALS. We will examine the association between demographic and reproductive history among female patients aged >18 years and various ages of onset for ALS.

METHODS

Data from a cross-sectional study were collected and examined for 1,018 female ALS patients. Patient characteristics examined were demographics including race, BMI, and familial history of ALS. Among patients, information on reproductive history, including age at menopause, ever pregnant, and age at first pregnancy was collected. Unadjusted and adjusted logistic regression models were used to estimate OR and 95% CI in this study.

RESULTS

Women were more likely to be diagnosed with ALS before age 60 if they were nonwhite (p = 0.015), had attended college (p = 0.0012), had a normal BMI at age 40 (p < 0.0001), completed menopause before age 50 (p < 0.0001), and had never been pregnant (p = 0.046) in the univariate analysis. Women diagnosed with ALS before age 60 were also more likely to have limb site of onset (p < 0.0001). In the multivariate analysis, those who completed menopause before age 50 were more likely to be diagnosed with ALS before age 60 (OR = 1.8, 95% CI: 1.4-2.3) compared with women who completed menopause at or after age 50, after controlling for race, ever pregnant, age at first pregnancy, family history of ALS, education status, smoking history, and BMI at age 40. For women who were diagnosed with ALS before age 50, the odds of them entering menopause before age 50 climb to 48.7 (95% CI: 11.8, 200.9). The mean age of ALS diagnosis for women who completed menopause before age 50 was 58 years and 64 years for women who entered menopause after age 50 (p < 0.0001).

CONCLUSION

Women who reported completing menopause before age 50 were significantly more likely to be diagnosed with ALS before age 60 compared with those who reported entering menopause after age 50. More research is needed to determine the relationship between female reproductive history, especially regarding endogenous estrogen exposure and early-onset ALS.

The Incidence of Amyotrophic Lateral Sclerosis in Ohio 2016-2018: The Ohio Population-Based ALS Registry

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a fatal, neuromuscular disease with no cure. ALS incidence rates have not been assessed specifically in Ohio, yet the state contains both metropolitan and rural areas with a variety of environmental factors that could contribute to disease etiology. We report the incidence of ALS in Ohio residents diagnosed from October 2016 through September 2018.

METHODS

We engaged practitioners from 9 Ohio sites to identify newly diagnosed ALS patients and to complete case report forms with demographic and clinical information. ALS was diagnosed according to the Awaji criteria and classified as either definite, probable, or possible. We developed a method to estimate missing cases using a Poisson regression model to impute cases in counties with evidence of undercounting.

RESULTS

We identified 333 newly diagnosed ALS patients residing in Ohio during the 2-year index period and found incidence rates varied in the 88 state counties. After incorporating the estimated 27% of missing cases, the corrected crude annual incidence was 1.96/100,000 person-years, and the age- and gender-standardized incidence was 1.71/100,000 person-years (standardized to the 2010 US census).

DISCUSSION/CONCLUSION

The estimated Ohio incidence of ALS is overall similar to that reported in other states in the USA. This study reveals a geospatial variation in incidence within the state, and areas with higher rates warrant future investigation.

Amyotrophic Lateral Sclerosis Risk, Family Income, and Fish Consumption Estimates of Mercury and Omega-3 PUFAs in the United States

Most amyotrophic lateral sclerosis (ALS) cases are considered sporadic, without a known genetic basis, and lifestyle factors are suspected to play an etiologic role. We previously observed increased risk of ALS associated with high nail mercury levels as an exposure biomarker and thus hypothesized that mercury exposure via fish consumption patterns increases ALS risk. Lifestyle surveys were obtained from ALS patients (n = 165) and n = 330 age- and sex-matched controls without ALS enrolled in New Hampshire, Vermont, or Ohio, USA. We estimated their annual intake of mercury and omega-3 polyunsaturated fatty acid (PUFA) via self-reported seafood consumption habits, including species and frequency. In our multivariable model, family income showed a significant positive association with ALS risk (p = 0.0003, adjusted for age, sex, family history, education, and race). Neither the estimated annual mercury nor omega-3 PUFA intakes via seafood were associated with ALS risk. ALS incidence is associated with socioeconomic status; however, consistent with a prior international study, this relationship is not linked to mercury intake estimated via fish or seafood consumption patterns.

Degeneration of gray and white matter differs between hypometabolic and hypermetabolic brain regions in a patient with ALS-FTD: a longitudinal MRI - PET multimodal study

OBJECTIVE

[18F]-fluoro-2-deoxy-d-glucose positron emission tomography (18F-FDG PET) imaging and magnetic resonance imaging (MRI) of brain in ALS patients with frontotemporal lobe dementia (ALS-FTD) reveal hypometabolism and hypermetabolism, as well as gray matter (GM) and white matter (WM) abnormalities in different brain regions, respectively. Hypometabolism arising from neuronal dysfunction or loss is the most recognized pathophysiologic change in neurodegeneration, whereas mechanisms underlying hypermetabolism remain unclear. We hypothesize that hypometabolic and hypermetabolic brain regions in ALS-FTD represent differential degeneration of GM and WM structures, as revealed by co-registered MRI in a two time-point longitudinal multimodal study. Methods: A 69-year-old female with ALS-FTD underwent 18F-FDG PET, diffusion tensor imaging (DTI), and T1-weighted MRI at baseline (15 months after symptom onset), and 20.4 months later. Cerebral glucose metabolism rate, cortical thickness, cortical area, and WM network changes were measured longitudinally. Results and conclusion: The patient had symptoms and signs of bulbar-onset upper motor neuron (UMN)-predominant ALS with language and behavioral dysfunction. Evaluation at baseline showed bulbar dysfunction, and impaired language and executive function. At follow-up, worsened bulbar and other motor functions, and prominent FTD both reflected significant progression. Cortical thickness and surface area showed differential involvement in the hypometabolic and hypermetabolic regions. WM connections from frontal regions to other brain regions were completely absent by graph theory-based network analysis when compared to temporal regions indicating prominent frontal lobe degeneration. Structural neuroimaging reveals different patterns of GM and WM involvement in the hypometabolic and hypermetabolic brain regions in a patient with ALS-FTD.

Machine learning suggests polygenic risk for cognitive dysfunction in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a multi-system disease characterized primarily by progressive muscle weakness. Cognitive dysfunction is commonly observed in patients; however, factors influencing risk for cognitive dysfunction remain elusive. Using sparse canonical correlation analysis (sCCA), an unsupervised machine-learning technique, we observed that single nucleotide polymorphisms collectively associate with baseline cognitive performance in a large ALS patient cohort (N = 327) from the multicenter Clinical Research in ALS and Related Disorders for Therapeutic Development (CReATe) Consortium. We demonstrate that a polygenic risk score derived using sCCA relates to longitudinal cognitive decline in the same cohort and also to in vivo cortical thinning in the orbital frontal cortex, anterior cingulate cortex, lateral temporal cortex, premotor cortex, and hippocampus (N = 90) as well as post-mortem motor cortical neuronal loss (N = 87) in independent ALS cohorts from the University of Pennsylvania Integrated Neurodegenerative Disease Biobank. Our findings suggest that common genetic polymorphisms may exert a polygenic contribution to the risk of cortical disease vulnerability and cognitive dysfunction in ALS.

Machine learning suggests polygenic risk for cognitive dysfunction in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a multi-system disease characterized primarily by progressive muscle weakness. Cognitive dysfunction is commonly observed in patients; however, factors influencing risk for cognitive dysfunction remain elusive. Using sparse canonical correlation analysis (sCCA), an unsupervised machine-learning technique, we observed that single nucleotide polymorphisms collectively associate with baseline cognitive performance in a large ALS patient cohort (N = 327) from the multicenter Clinical Research in ALS and Related Disorders for Therapeutic Development (CReATe) Consortium. We demonstrate that a polygenic risk score derived using sCCA relates to longitudinal cognitive decline in the same cohort and also to in vivo cortical thinning in the orbital frontal cortex, anterior cingulate cortex, lateral temporal cortex, premotor cortex, and hippocampus (N = 90) as well as post-mortem motor cortical neuronal loss (N = 87) in independent ALS cohorts from the University of Pennsylvania Integrated Neurodegenerative Disease Biobank. Our findings suggest that common genetic polymorphisms may exert a polygenic contribution to the risk of cortical disease vulnerability and cognitive dysfunction in ALS.

Generation of two induced pluripotent stem cell (iPSC) lines from an ALS patient with simultaneous mutations in KIF5A and MATR3 genes

Fibroblasts from an amyotrophic lateral sclerosis patient with simultaneous mutations in the MATR3 gene and KIF5A gene were isolated and reprogrammed into induced pluripotent stem cells via a non-integrating Sendai viral vector. The generated iPSC clones demonstrated normal karyotype, expression of pluripotency markers, and the capacity to differentiate into three germ layers. The unique presence of two simultaneous mutations in ALS-associated genes represent a novel tool for the study of ALS disease mechanisms.

A Cost-Effectiveness Framework for Amyotrophic Lateral Sclerosis, Applied to Riluzole

OBJECTIVES

Reexamine cost-effectiveness of riluzole in the treatment of amyotrophic lateral sclerosis (ALS) in light of recent advances in disease staging and understanding of stage-specific drug effect.

METHODS

ALS was staged according to the "fine'til 9" (FT9) staging method. Stage-specific health utilities (EQ-5D, US valuation) were estimated from an institutional cohort, whereas literature informed costs and transition probabilities. Costs at 2018 prices were disaggregated into recurring costs (RCs) and "one-off" transition/"tollgate" costs (TCs). Five- and 10-year horizons starting in stage 1 disease were examined from healthcare sector and societal perspectives using Markov models to evaluate riluzole use, at a threshold of $100 000/quality-adjusted life year (QALY). Probabilistic and deterministic sensitivity analyses were conducted.

RESULTS

Mean EQ-5D utilities for stages 0 to 4 were 0.79, 0.74, 0.63, 0.54, and 0.46, respectively. From the healthcare sector perspective at the 5-year horizon, riluzole use contributed to 0.182 QALY gained at the cost difference of $12 348 ($5403 riluzole cost, $8870 RC and -$1925 TC differences), translating to an incremental cost-effectiveness ratio (ICER) of $67 658/QALY. Transition probability variation contributed considerably to ICER uncertainty (-30.2% to +90.0%). ICER was sensitive to drug price and RCs, whereas higher TCs modestly reduced ICER due to delayed tollgates.

CONCLUSION

This study provides a framework for health economic studies of ALS treatments using FT9 staging. Prospective stage-specific and disaggregated cost measurement is warranted for accurate future cost-effectiveness analyses. Appropriate separation of TCs from RCs substantially mitigates the high burden of background cost of care on the ICER.

Neuroimaging in primary lateral sclerosis

Increased interest in the underlying pathogenesis of primary lateral sclerosis (PLS) and its relationship to amyotrophic lateral sclerosis (ALS) has corresponded to a growing number of CNS imaging studies, especially in the past decade. Both its rarity and uncertainty of definite diagnosis prior to 4 years from symptom onset have resulted in PLS being less studied than ALS. In this review, we highlight most relevant papers applying magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET) to analyzing CNS changes in PLS, often in relation to ALS. In patients with PLS, mostly brain, but also spinal cord has been evaluated since significant neurodegeneration is essentially restricted to upper motor neuron (UMN) structures and related pathways. Abnormalities of cortex and subcortical white matter tracts have been identified by structural and functional MRI and MRS studies, while metabolic and cell-specific changes in PLS brain have been revealed using various PET radiotracers. Future neuroimaging studies will continue to explore the interface between the PLS-ALS continuum, identify more changes unique to PLS, apply novel MRI and MRS sequences showing greater structural and neurochemical detail, as well as expand the repertoire of PET radiotracers that reveal various cellular pathologies. Neuroimaging has the potential to play an important role in the evaluation of novel therapies for patients with PLS.

Risk factors for amyotrophic lateral sclerosis: A regional United States case-control study

Most amyotrophic lateral sclerosis (ALS) cases are considered sporadic, without a known genetic basis, and environmental exposures are thought to play a causal role. To learn more about sporadic ALS etiology, we recruited n = 188 ALS patients from northern New England and Ohio and matched controls 2:1 from the general population of the same regions. Questionnaires evaluated the association between a variety of lifestyle, behavioral (ie, hobbies and activities), and occupational factors and the risk of ALS, including the duration of time between exposure and ALS onset, and exposure frequency. Head trauma was associated with increased ALS risk (adjusted odds ratio [OR] 1.60 95% confidence interval [CI] 1.04‐2.45), with significantly greater effects for injuries occurring 10 or more years prior to symptom onset (P = .037). ALS risk was increased for those reporting severe electrical burns (adjusted OR 2.86, 95% CI 1.37‐6.03), with odds ratios highest for burns after age 30 (OR 3.14), and for burns 10 or more years prior to symptom onset (OR 3.09). Hobbies involving lead were the most strongly associated with ALS risk (adjusted OR 2.92, 95% CI 1.45‐5.91). Exposures to lead 20 or more years prior to diagnosis had larger effect sizes compared to those occurring more recently. Holding a job in mechanics, painting, or construction was associated with ALS. The identification of these specific environmental factors associated with ALS highlight the need for future prospective and laboratory studies to assess causality, biological mechanisms, and find prevention or treatment opportunities.

A Phase 2, Double-Blind, Randomized, Dose-Ranging Trial Of Reldesemtiv In Patients With ALS

Objective:

To evaluate safety, dose response, and preliminary efficacy of reldesemtiv over 12 weeks in patients with amyotrophic lateral sclerosis (ALS).

Methods:

Patients (≤2 years since diagnosis) with slow upright vital capacity (SVC) of ≥60% were randomized 1:1:1:1 to reldesemtiv 150, 300, or 450 mg twice daily (bid) or placebo; active treatment was 12 weeks with 4-week follow-up. Primary endpoint was change in percent predicted SVC at 12 weeks; secondary measures included ALS Functional Rating Scale-Revised (ALSFRS-R) and muscle strength mega-score.

Results:

Patients (N = 458) were enrolled; 85% completed 12-week treatment. The primary analysis failed to reach statistical significance (p = 0.11); secondary endpoints showed no statistically significant effects (ALSFRS-R, p = 0.09; muscle strength megascore, p = 0.31). Post hoc analyses pooling all active reldesemtiv-treated patients compared against placebo showed trends toward benefit in all endpoints (progression rate for SVC, ALSFRS-R, and muscle strength mega-score (nominal p values of 0.10, 0.01 and 0.20 respectively)). Reldesemtiv was well tolerated, with nausea and fatigue being the most common side effects. A dose-dependent decrease in estimated glomerular filtration rate was noted, and transaminase elevations were seen in approximately 5% of patients. Both hepatic and renal abnormalities trended toward resolution after study drug discontinuation.

Conclusions:

Although the primary efficacy analysis did not demonstrate statistical significance, there were trends favoring reldesemtiv for all three endpoints, with effect sizes generally regarded as clinically important. Tolerability was good; modest hepatic and renal abnormalities were reversible. The impact of reldesemtiv on patients with ALS should be assessed in a pivotal Phase 3 trial. (ClinicalTrials.gov Identifier: NCT03160898)

The NEALS primary lateral sclerosis registry

BACKGROUND AND OBJECTIVE

Primary lateral sclerosis (PLS) is a neurodegenerative disease characterized by progressive upper motor neuron dysfunction. Because PLS patients represent only 1 to 4% of patients with adult motor neuron diseases, there is limited information about the disease's natural history. The objective of this study was to establish a large multicenter retrospective longitudinal registry of PLS patients seen at Northeast ALS Consortium (NEALS) sites to better characterize the natural progression of PLS. Methods: Clinical characteristics, electrophysiological findings, laboratory values, disease-related symptoms, and medications for symptom management were collected from PLS patients seen between 2000 and 2015. Results: The NEALS registry included data from 250 PLS patients. Median follow-up time was 3 years. The mean rate of functional decline measured by ALSFRS-R total score was -1.6 points/year (SE:0.24, n = 124); the mean annual decline in vital capacity was -3%/year (SE:0.55, n = 126). During the observational period, 18 patients died, 17 patients had a feeding tube placed and 7 required permanent assistive ventilation. Conclusions: The NEALS PLS Registry represents the largest available aggregation of longitudinal clinical data from PLS patients and provides a description of expected natural disease progression. Data from the registry will be available to the PLS community and can be leveraged to plan future clinical trials in this rare disease.

Time to diagnosis and factors affecting diagnostic delay in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive, degenerative neuromuscular disease with limited treatment options. The diagnosis of ALS can be challenging for numerous reasons, resulting in delays that may compromise optimal management and enrollment into clinical trials. Several studies have examined the process and challenges regarding the clinical diagnosis of ALS. Twenty-one studies that were almost exclusively from the English literature published between 1990 and 2020 were identified via PubMed using relevant search terms and included patient populations from the United States, Canada, Japan, Egypt, and several countries in South America and Europe. Probable or definitive ALS patients were identified using El Escorial or revised El Escorial/Airlie House Criteria. Time to diagnosis or diagnostic delay was defined as mean or median time from patient-reported first symptom onset to formal diagnosis by a physician, as recorded in medical records. The typical time to diagnosis was 10-16 months from symptom onset. Several points of delay in the diagnosis course were identified, including specialist referrals and misdiagnoses, often resulting in unnecessary procedures and surgeries. Bulbar onset was noted to significantly reduce time to ALS diagnosis. Future interventions and potential research opportunities were reviewed.

2-Deoxy-2-[18 F]fluoro-d-glucose positron emission tomography, cortical thickness and white matter graph network abnormalities in brains of patients with amyotrophic lateral sclerosis and frontotemporal dementia suggest early neuronopathy rather than axonopathy

BACKGROUND AND PURPOSE

Amyotrophic lateral sclerosis (ALS) is a motor neuron disorder, although extra-motor degeneration is well recognized, especially in frontotemporal regions manifested as ALS with frontotemporal dementia (ALS-FTD). Previous neuroimaging studies of the brains of ALS-FTD patients have measured abnormalities of either grey matter (GM) or white matter (WM) structures but not of both together. Therefore, the aim was to evaluate both GM and WM in the same ALS-FTD patient using functional and structural neuroimaging. By doing so, insights could be gained into whether neurodegeneration in ALS-FTD is primarily a neuronopathy or axonopathy.

METHODS

After high-resolution brain 2-deoxy-2-[¹⁸ F]fluoro-D-glucose (¹⁸ F-FDG) positron emission tomography (PET) and magnetic resonance imaging (MRI) scans were obtained in ALS-FTD patients and in age- and sex-matched neurological controls, changes in metabolic rate, cortical thickness (CT) and WM network analysis using graph theory were analyzed.

RESULTS

Significant reductions in ¹⁸ F-FDG PET metabolism, CT and WM connections were observed in motor and extra-motor brain regions of ALS-FTD patients compared to controls. Both CT and underlying WM networks were abnormal in frontal, temporal, parietal and occipital lobes of ALS-FTD patients with 86 of 90 brain regions showing reductions of CT.

CONCLUSION

Abnormalities in significantly fewer WM networks underlying the affected cortical regions suggest that neurodegeneration in brains of ALS-FTD patients is primarily a 'neuronopathy' rather than an 'axonopathy.'

Real-world evidence of riluzole effectiveness in treating amyotrophic lateral sclerosis

OBJECTIVE

To compare the effect of riluzole on median survival in population studies of patients with amyotrophic lateral sclerosis (ALS) with that observed in clinical trials. Methods: Two independent PubMed searches were conducted, to identify population studies that reported median survival for ALS patients who were either treated with riluzole or remained riluzole-free. Results: We identified 14 studies that met the inclusion criteria of reporting median survival and an additional study that reported mean survival of both riluzole and riluzole-free patients. Analysis of the 15 studies found that a majority reported increased survival of riluzole vs. riluzole-free patients. In 8 studies, the median survival for patients treated with riluzole was 6-19 months longer compared with patients not treated with riluzole (p < 0.05). Three additional studies reported a clinically meaningful treatment effect (range 3-5.9 months) but did not meet statistical significance. The remaining 4 studies did not show a meaningful treatment effect between riluzole and riluzole-free groups (<3 months), and differences among the groups were not significant. Also, 5 of the studies used multivariate regression analysis to investigate the level of association between treatment with riluzole and survival; these analyses supported the positive effect of riluzole on survival. Conclusions: A majority of population studies that compared riluzole vs. riluzole-free ALS patients found significant differences in median survival between the two groups, ranging from 6 to 19 months. This is substantially longer than the 2- to 3-month survival benefit observed in the pivotal clinical trials of riluzole.

Validation of serum neurofilaments as prognostic and potential pharmacodynamic biomarkers for ALS

OBJECTIVE

To identify preferred neurofilament assays and clinically validate serum neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH) as prognostic and potential pharmacodynamic biomarkers relevant to amyotrophic lateral sclerosis (ALS) therapy development.

METHODS

In this prospective, multicenter, longitudinal observational study of patients with ALS (n = 229), primary lateral sclerosis (n = 20), and progressive muscular atrophy (n = 11), biological specimens were collected, processed, and stored according to strict standard operating procedures (SOPs). Neurofilament assays were performed in a blinded manner by independent contract research organizations.

RESULTS

For serum NfL and pNfH measured using the Simoa assay, there were no missing data (i.e., technical replicates below the lower limit of detection were not encountered). For the Iron Horse and Euroimmun pNfH assays, such missingness was encountered in ∼4% and ∼10% of serum samples, respectively. Mean coefficients of variation for NfL in serum and CSF were both ∼3%. Mean coefficients of variation for pNfH in serum and CSF were ∼4%-5% and ∼2%-3%, respectively, in all assays. Baseline serum NfL concentration, but not pNfH, predicted the future Revised ALS Functional Rating Scale (ALSFRS-R) slope and survival. Incorporation of baseline serum NfL into mixed effects models of ALSFRS-R slopes yields an estimated sample size saving of ∼8%. Depending on the method used to estimate effect size, use of serum NfL (and perhaps pNfH) as pharmacodynamic biomarkers, instead of the ALSFRS-R slope, yields significantly larger sample size savings.

CONCLUSIONS

Serum NfL may be considered a clinically validated prognostic biomarker for ALS. Serum NfL (and perhaps pNfH), quantified using the Simoa assay, has potential utility as a pharmacodynamic biomarker of treatment effect.

Long-term edaravone efficacy in amyotrophic lateral sclerosis: Post-hoc analyses of Study 19 (MCI186-19)

Background

In a Phase 3 study, amyotrophic lateral sclerosis (ALS) patients experienced significantly less physical functional decline with 24‐week edaravone vs placebo, followed by open‐label treatment for an additional 24 weeks.

Methods

Outcome (the change in ALS Functional Rating Scale–Revised, ALSFRS‐R, from baseline) was projected for placebo patients through 48 weeks and compared with 48‐week edaravone or 24‐week edaravone after switching from placebo.

Results

A total of 123 patients received open‐label treatment (65 edaravone‐edaravone; 58 placebo‐edaravone). The projected ALSFRS‐R decline for placebo from baseline through week 48 was greater than for 48‐week edaravone (P < .0001). For patients switching from placebo to edaravone, ALSFRS‐R slope approached that of continued edaravone for 48 weeks. ALSFRS‐R decline did not differ between actual and projected edaravone through week 48.

Conclusions

Compared with placebo, these analyses suggest that edaravone is beneficial in ALS patients even after 6 mo of receiving placebo, and efficacy is maintained for up to 1 year.

https://doi.org/10.1002/mus.26770.

Pattern of lung function decline in patients with amyotrophic lateral sclerosis: implications for timing of noninvasive ventilation

Background

The course of lung function decline in amyotrophic lateral sclerosis (ALS) and the effect of noninvasive positive-pressure ventilation (NIPPV) on that decline are uncertain. We sought to model lung function decline, determine when NIPPV is initiated along that course, and assess its impact on the course of decline.

Methods

An observed sigmoid pattern of forced vital capacity decline was reproduced with a four-parameter nonlinear mixed-effects logistic model.

Results

Analyses were performed on 507 patients overall and in 353 patients for whom a determination of adherence to NIPPV was ascertained. A sigmoid bi-asymptotic model provided a statistical fit of the data and showed a period of stable vital capacity, followed by an accelerated decline, an inflection point, then a slowing in decline to a plateau. By the time NIPPV was initiated in accordance with reimbursement guidelines, vital capacity had declined by ≥85% of the total range. Nearly half of the total loss of vital capacity occurred over 6.2 months centred at an inflection point occurring 17 months after disease onset and 5.2 months before initiation of NIPPV at a vital capacity of about 60%. Fewer bulbar symptoms and a faster rate of decline of lung function predicted adherence to NIPPV, but the intervention had no impact on final vital capacity.

Conclusions

In patients with ALS, vital capacity decline is rapid but slows after an inflection point regardless of NIPPV. Initiating NIPPV along reimbursement guidelines occurs after ≥85% of vital capacity loss has already occurred.

In patients with amyotrophic lateral sclerosis, vital capacity decline is rapid but slows after an inflection point regardless of NIPPV. Initiation of NIPPV according to guidelines occurs when >85% of vital capacity loss has already occurred.http://bit.ly/2JOiEZG

Unbiased MRI Analyses Identify Micropathologic Differences Between Upper Motor Neuron-Predominant ALS Phenotypes

Amyotrophic lateral sclerosis (ALS) is an incurable and progressively fatal neurodegenerative disease that manifests with distinct clinical phenotypes, which are seen in neuroimaging, and clinical studies. T2- and proton density (PD)-weighted magnetic resonance imaging (MRI) displays hyperintense signal along the corticospinal tract (CST) in some ALS patients with upper motor neuron (UMN)-predominant signs. These patients tend to be younger and have significantly faster disease progression. We hypothesize that such ALS patients with CST hyperintensity (ALS-CST+) comprise a clinical subtype distinct from other ALS subtypes, namely patients with UMN-predominant ALS without CST hyperintensity, classic ALS, and ALS with frontotemporal dementia (FTD). Novel approaches such as fractal dimension analysis on conventional MRI (cMRI) and advanced MR techniques such as diffusion tensor imaging (DTI) reveal significant differences between ALS-CST+ and the aforementioned ALS subtypes. Our unbiased neuroimaging studies demonstrate that the ALS-CST+ group, which can be initially identified by T2-, PD-, and FLAIR-weighted cMRI, is distinctive and distinguishable from other ALS subtypes with possible differences in disease pathogenesis.

Variation in noninvasive ventilation use in amyotrophic lateral sclerosis

Objective

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

Methods

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

Results

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

Conclusion

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

Longitudinal 18F-FDG PET and MRI Reveal Evolving Imaging Pathology That Corresponds to Disease Progression in a Patient With ALS-FTD

Single time point positron emission tomography (PET) studies of patients with amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD), have demonstrated hypometabolism or hypermetabolism in certain brain regions. To determine whether longitudinal (at baseline and 20.4 months later) PET and magnetic resonance imaging (MRI) reveal evolving brain imaging pathology corresponding to clinical progression in a patient with ALS-FTD, cerebral glucose metabolic rate, cortical thickness (CT) and cortical area (CA) were obtained and symmetric percent change (SPC) for each calculated. The patient had worsening symptoms and signs of bulbar-onset upper motor neuron-predominant ALS as well as language and behavioral dysfunction. At baseline, minimally decreased ALSFRS-R (42/48) reflecting bulbar dysfunction was observed, along with language and executive function difficulties. At follow-up, bulbar and limb function rapidly declined as revealed by lower ALSFRS-R (27/48) and worsening language and cognitive function. PET revealed either hyper- and hypo-metabolic changes in several brain regions, especially in the left hemisphere. Marked clinical decline was accompanied by worsening cerebral and subcortical hyper and hypo-metabolism along with CT changes in regions known to degenerate in the primary progressive aphasia (PPA) form of ALS-FTD. Our case report demonstrates the progressive functional and structural neuroimaging abnormalities underlying clinical motor and neurocognitive deficits evolving in a patient with bulbar-onset ALS-FTD. Correlating neurological and neurocognitive decline with PET and MRI neuroimaging measures can provide better insights into pathophysiological mechanisms of ALS and ALS-FTD.

Revised Airlie House consensus guidelines for design and implementation of ALS clinical trials

OBJECTIVE

To revise the 1999 Airlie House consensus guidelines for the design and implementation of preclinical therapeutic studies and clinical trials in amyotrophic lateral sclerosis (ALS).

METHODS

A consensus committee comprising 140 key members of the international ALS community (ALS researchers, clinicians, patient representatives, research funding representatives, industry, and regulatory agencies) addressed 9 areas of need within ALS research: (1) preclinical studies; (2) biological and phenotypic heterogeneity; (3) outcome measures; (4) disease-modifying and symptomatic interventions; (5) recruitment and retention; (6) biomarkers; (7) clinical trial phases; (8) beyond traditional trial designs; and (9) statistical considerations. Assigned to 1 of 8 sections, committee members generated a draft set of guidelines based on a "background" of developing a (pre)clinical question and a "rationale" outlining the evidence and expert opinion. Following a 2-day, face-to-face workshop at the Airlie House Conference Center, a modified Delphi process was used to develop draft consensus research guidelines, which were subsequently reviewed and modified based on comments from the public. Statistical experts drafted a separate document of statistical considerations (section 9).

RESULTS

In this report, we summarize 112 guidelines and their associated backgrounds and rationales. The full list of guidelines, the statistical considerations, and a glossary of terms can be found in data available from Dryad (appendices e-3-e-5, doi.org/10.5061/dryad.32q9q5d). The authors prioritized 15 guidelines with the greatest potential to improve ALS clinical research.

CONCLUSION

The revised Airlie House ALS Clinical Trials Consensus Guidelines should serve to improve clinical trial design and accelerate the development of effective treatments for patients with ALS.

Additional evidence for a therapeutic effect of dextromethorphan/quinidine on bulbar motor function in patients with amyotrophic lateral sclerosis: A quantitative speech analysis

Aims

A recent double‐blind placebo‐controlled crossover 70‐day trial demonstrated that a fixed combination of dextromethorphan and quinidine (DM/Q) improves speech and swallowing function in most patients with amyotrophic lateral sclerosis. In this study, a subset of participants, many of whom did not substantially improve while on DM/Q, were re‐evaluated using computer‐based speech analyses and expert clinician ratings of the overall severity of speech impairment.

Methods

Speech samples were recorded from the subset of 10 patients at four visits made at approximately 30‐day intervals. The recordings were analysed by automated computer‐based analysis of speech pausing patterns. Severity of speech impairment was rated by three experienced speech‐language pathologists using direct magnitude estimation. Scores on patient‐reported and clinician‐administered scales of bulbar motor involvement were obtained at each visit.

Results

The effects of DM/Q were detected on several of the objective speech measures, including total pause duration (s) (Cohen's d = 0.73, 95% confidence interval (CI) –1.70, 0.24), pause time (%) (d = 0.77, 95% CI –1.75, 0.21), and mean speech event duration (s) (d = 0.52, 95% CI –0.44, 1.47), but not on clinician ratings of speech or the speech components of the self‐report or clinician‐administered scales.

Conclusions

These findings suggest that even patients with modest improvement while on DM/Q may experience quantifiable improvements in speech when assessed using sensitive and objective measures. This study provides additional evidence of the positive impact of DM/Q on one or more of the neural systems that control bulbar motor function and production of speech.

Deconstructing progression of amyotrophic lateral sclerosis in stages: a Markov modeling approach

OBJECTIVES

Propose an empirical amyotrophic lateral sclerosis (ALS) staging approach called Fine'til 9 (FT9) based on how many of the patient's ALS functional rating scale (ALSFRS-R) subscores are 9 or less (of normal 12). Gain insights into progression of ALS by applying Markov models to ALS stages by multiple systems (King's, Milan-Torino system (MITOS) and FT9).

METHODS

Patients from the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) dataset were staged using ALSFRS-R responses. Risks of progression through stages and death were estimated, as were effects of prognostic variables on these risks.

RESULTS

A total of 29,947 time points in 3199 patients from the PRO-ACT dataset were assigned stages. Although the three systems were moderately correlated, MITOS stages were heavily skewed toward advanced disease, whereas King's and FT9 stages were more balanced. Non-sequential progression was observed with King's system. Markov models adequately described transitions from stage to stage in the first year of observation, but underestimated risks beyond that point. Regardless of staging method, initial rate of ALSFRS-R decline had a powerful effect on rate of progression through sequential stages, whereas age predominantly influenced stage-specific mortality.

CONCLUSION

King's and FT9 are more sensitive to observed progression of disease in clinical trials than MITOS. FT9 can partition the course similar to King's, and may have advantages of sequential progression and easy applicability to retrospective data. Markov transition intensity estimates may be of value for counseling, health economic studies, and research design. In particular, this framework permits estimation of multidimensional effects of variables (including treatment) on outcome.

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.

MR Imaging-based Estimation of Upper Motor Neuron Density in Patients with Amyotrophic Lateral Sclerosis: A Feasibility Study

Purpose To determine if magnetic resonance (MR) imaging metrics can estimate primary motor cortex (PMC) motor neuron (MN) density in patients with amyotrophic lateral sclerosis (ALS). Materials and Methods Between 2012 and 2014, in situ brain MR imaging was performed in 11 patients with ALS (age range, 35-81 years; seven women and four men) soon after death (mean, 5.5 hours after death; range, 3.2-9.6 hours). The brain was removed, right PMC (RPMC) was excised, and MN density was quantified. RPMC metrics (thickness, volume, and magnetization transfer ratio) were calculated from MR images. Regression modeling was used to estimate MN density by using RPMC and global MR imaging metrics (brain and tissue volumes); clinical variables were subsequently evaluated as additional estimators. Models were tested at in vivo MR imaging by using the same imaging protocol (six patients with ALS; age range, 54-66 years; three women and three men). Results RPMC mean MN density varied over a greater than threefold range across patients and was estimated by a linear function of normalized gray matter volume (adjusted R² = 0.51; P = .008; <10% error in most patients). When considering only sporadic ALS, a linear function of normalized RPMC and white matter volumes estimated MN density (adjusted R² = 0.98; P = .01; <10% error in all patients). In vivo data analyses detected decreases in MN density over time. Conclusion PMC mean MN density varies widely in end-stage ALS possibly because of disease heterogeneity. MN density can potentially be estimated by MR imaging metrics. ^© RSNA, 2018 Online supplemental material is available for this article.

Laughter, crying and sadness in ALS

BACKGROUND

Pseudobulbar affect (PBA) is prevalent in amyotrophic lateral sclerosis (ALS), but there is limited information on its associations and course.

OBJECTIVES

Explore prevalence, associations, course and manifestations of PBA in outpatient cohort of patients with ALS and examine its relationship to depression.

METHODS

Self-reported measures of PBA and depression (Center for Neurologic Study-Lability Scale (CNS-LS) and Patient Health Questionnaire (PHQ-9), respectively) were obtained from consecutive patients with ALS using tablet devices in waiting rooms (Knowledge Program).

RESULTS

PBA (CNS-LS ≥13) was seen in 209/735 patients (28.4%). PBA was associated with bulbar onset and dysfunction, upper motor neuron dysfunction, cognitive impairment, depression and lower quality of life. A multivariable model that included lower bulbar and gross motor subscores, female gender, younger age and shorter duration of disease predicted PBA with 74% accuracy. CNS-LS scores increased only slowly with time. Women with PBA reported more crying than men. Crying (but not laughter) correlated with depression, and crying was associated with poorer quality of life. Exploratory factor analysis of pooled questions of CNS-LS and PHQ-9 identified three underlying factors (laughter, crying and depression) loaded on appropriate questions of the respective instruments.

CONCLUSION

This study identifies associations of PBA and additionally finds PBA (especially crying-predominant PBA) more prevalent in women with ALS. Although the two self-report instruments (CNS-LS and PHQ-9) discriminate well between PBA and depression, there is significant overlap between depression and crying in PBA. Studies of PBA should stratify for gender, examine crying and laughter as separate outcomes and adjust for depression.

Finger extension weakness and downbeat nystagmus motor neuron disease syndrome: A novel motor neuron disorder?

Introduction: Disturbances of eye movements are infrequently encountered in motor neuron diseases (MNDs) or motor neuropathies, and there is no known syndrome that combines progressive muscle weakness with downbeat nystagmus. Methods: To describe the core clinical features of a syndrome of MND associated with downbeat nystagmus, clinical features were collected from 6 patients. Results: All patients had slowly progressive muscle weakness and wasting in combination with downbeat nystagmus, which was clinically most obvious in downward and lateral gaze. Onset was in the second to fourth decade with finger extension weakness, progressing to other distal and sometimes more proximal muscles. Visual complaints were not always present. Electrodiagnostic testing showed signs of regional motor axonal loss in all patients. Discussion: The etiology of this syndrome remains elusive. Because finger extension weakness and downbeat nystagmus are the discriminating clinical features of this MND, we propose the name FEWDON‐MND syndrome. Muscle Nerve56: 1164–1168, 2017

Positron emission tomography imaging in a case of E200K mutation-related spongiform encephalopathy with non-diagnostic magnetic resonance imaging and cerebrospinal fluid testing

Objective:

Creutzfeldt–Jakob disease is a rapidly progressive spongiform encephalopathy. The E200K mutation is found in a majority of genetically transmitted Creutzfeldt–Jakob disease cases.

Methods:

We describe the case and associated neuroimaging of an E200K-129M gene-mutation-related fatal spongiform encephalopathy with resultant clinical insomnia and thalamic changes.

Results:

A 46-year-old Caucasian male presented with, who was well until 2 months prior to admission, a rapidly progressive dementia followed by a change in personality with auditory and visual hallucinations. His wife noted progressively worsening jerking and other limb movements and that he kept his eyes open overnight and was “awake” at all hours. Magnetic resonance imaging, electroencephalogram and initial cerebrospinal fluid analysis were essentially non-diagnostic. Positron emission topography revealed severe bilateral thalamic hypometabolism. Posthumous cerebrospinal fluid analysis revealed abnormal PrP 27-30 protein. Autopsy confirmed prion disease and presence of the E200K-129M mutation.

Conclusion:

This report highlights that positron emission topography imaging may help diagnose E200K-129M mutation-related spongiform encephalopathy. In cases of non-diagnostic magnetic resonance imaging, electroencephalogram and cerebrospinal fluid studies, early positron emission topography may help in the workup of rapidly progressive dementia.