Clinical and demographic factors and outcome of amyotrophic lateral sclerosis in relation to population ancestral origin

Copper toxicity and deficiency: the vicious cycle at the core of protein aggregation in ALS

The pathophysiology of ALS involves many signs of a disruption in copper homeostasis, with both excess free levels and functional deficiency likely occurring simultaneously. This is crucial, as many important physiological functions are performed by cuproenzymes. While it is unsurprising that many ALS symptoms are related to signs of copper deficiency, resulting in vascular, antioxidant system and mitochondrial oxidative respiration deficiencies, there are also signs of copper toxicity such as ROS generation and enhanced protein aggregation. We discuss how copper also plays a key role in proteostasis and interacts either directly or indirectly with many of the key aggregate-prone proteins implicated in ALS, such as TDP-43, C9ORF72, SOD1 and FUS as well as the effect of their aggregation on copper homeostasis. We suggest that loss of cuproprotein function is at the core of ALS pathology, a condition that is driven by a combination of unbound copper and ROS that can either initiate and/or accelerate protein aggregation. This could trigger a positive feedback cycle whereby protein aggregates trigger the aggregation of other proteins in a chain reaction that eventually captures elements of the proteostatic mechanisms in place to counteract them. The end result is an abundance of aggregated non-functional cuproproteins and chaperones alongside depleted intracellular copper stores, resulting in a general lack of cuproenzyme function. We then discuss the possible aetiology of ALS and illustrate how strong risk factors including environmental toxins such as BMAA and heavy metals can functionally behave to promote protein aggregation and disturb copper metabolism that likely drives this vicious cycle in sporadic ALS. From this synthesis, we propose restoration of copper balance using copper delivery agents in combination with chaperones/chaperone mimetics, perhaps in conjunction with the neuroprotective amino acid serine, as a promising strategy in the treatment of this incurable disease.

Potential of neuroimaging as a biomarker in amyotrophic lateral sclerosis: from structure to metabolism

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by motor neuron degeneration. The development of ALS involves metabolite alterations leading to tissue lesions in the nervous system. Recent advances in neuroimaging have significantly improved our understanding of the underlying pathophysiology of ALS, with findings supporting the corticoefferent axonal disease progression theory. Current studies on neuroimaging in ALS have demonstrated inconsistencies, which may be due to small sample sizes, insufficient statistical power, overinterpretation of findings, and the inherent heterogeneity of ALS. Deriving meaningful conclusions solely from individual imaging metrics in ALS studies remains challenging, and integrating multimodal imaging techniques shows promise for detecting valuable ALS biomarkers. In addition to giving an overview of the principles and techniques of different neuroimaging modalities, this review describes the potential of neuroimaging biomarkers in the diagnosis and prognostication of ALS. We provide an insight into the underlying pathology, highlighting the need for standardized protocols and multicenter collaborations to advance ALS research.

PCDHA9 as a candidate gene for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease. To identify additional genetic factors, we analyzed exome sequences in a large cohort of Chinese ALS patients and found a homozygous variant (p.L700P) in PCDHA9 in three unrelated patients. We generated Pcdhα9 mutant mice harboring either orthologous point mutation or deletion mutation. These mice develop progressive spinal motor loss, muscle atrophy, and structural/functional abnormalities of the neuromuscular junction, leading to paralysis and early lethality. TDP-43 pathology is detected in the spinal motor neurons of aged mutant mice. Mechanistically, we demonstrate that Pcdha9 mutation causes aberrant activation of FAK and PYK2 in aging spinal cord, and dramatically reduced NKA-α1 expression in motor neurons. Our single nucleus multi-omics analysis reveals disturbed signaling involved in cell adhesion, ion transport, synapse organization, and neuronal survival in aged mutant mice. Together, our results present PCDHA9 as a potential ALS gene and provide insights into its pathogenesis.

Management of amyotrophic lateral sclerosis in clinical practice: Results of the expert consensus using the Delphi methodology

Amyotrophic lateral sclerosis (ALS) is a rare disease characterized by a progressive and irreversible degeneration of upper and lower motor neurons leading to death. In France, limited data exist describing the criteria used in clinical practice for diagnosis and follow-up, and how novel therapies may fit in. The objective of this Delphi panel was to obtain an overview of current French practices in ALS diagnosis, management, and follow-up by determining the scales and criteria used in clinical practice outside of clinical trials, as well as the place of a future treatment like AMX0035, acting on endoplasmic reticulum (ER) stress and mitochondrial dysfunction, in the current therapeutic strategies. A questionnaire was administered to 24 ALS healthcare providers practicing in ALS centers in France. Two rounds of remote voting were organized, before proposition of final consensus statements. Consensus was considered reached when at least 66% of the voters agreed. Consensus were obtained to define the new Gold Coast criteria as the ones used in clinical practice to establish the diagnosis of ALS, thus replacing the revised El Escorial criteria, considered too complex and now mainly used to characterize the patient populations to be included in clinical trials. The clinical factors considered to establish ALS diagnosis are mainly the demonstration of progression of the motor deficit and elimination of differential diagnoses. The ALSFRS-R scale is used in daily clinical practice to assess patient's functional impairment in terms of number of points lost, with the bulbar, respiratory, and fine motor subscores being the most important to evaluate independently. A critical medical need was identified regarding the provision of new therapeutic alternatives in ALS. The panel members would support the earliest management of patients. In this landscape, based on data from a very encouraging phase II (Centaur trial), AMX0035 represents a new tool of choice in current treatment strategies for all patients for whom experts are confident in the diagnosis of ALS, in combination with riluzole. These results will need to be confirmed by the ongoing phase III trial (Phoenix trial).

Digital health solution for monitoring and surveillance of Amyotrophic Lateral Sclerosis in Brazil

Amyotrophic Lateral Sclerosis (ALS) is a complex and rare neurodegenerative disease given its heterogeneity. Despite being known for many years, few countries have accurate information about the characteristics of people diagnosed with ALS, such as data regarding diagnosis and clinical features of the disease. In Brazil, the lack of information about ALS limits data for the research progress and public policy development that benefits people affected by this health condition. In this context, this article aims to show a digital health solution development and application for research, intervention, and strengthening of the response to ALS in the Brazilian Health System. The proposed solution is composed of two platforms: the Brazilian National ALS Registry, responsible for the data collection in a structured way from ALS patients all over Brazil; and the Brazilian National ALS Observatory, responsible for processing the data collected in the National Registry and for providing a monitoring room with indicators on people diagnosed with ALS in Brazil. The development of this solution was supported by the Brazilian Ministry of Health (MoH) and was carried out by a multidisciplinary team with expertise in ALS. This solution represents a tool with great potential for strengthening public policies and stands out for being the only public database on the disease, besides containing innovations that allow data collection by health professionals and/or patients. By using both platforms, it is believed that it will be possible to understand the demographic and epidemiological data of ALS in Brazil, since the data will be able to be analyzed by care teams and also by public health managers, both in the individual and collective monitoring of people living with ALS in Brazil.

Motor neuron disease in black African patients at a tertiary care hospital in Soweto, South Africa

INTRODUCTION

In this brief report, we describe the nature of ALS in a South African cohort of patients of Black African ancestry - a population which has been historically understudied.

METHODS

We performed a chart review of all patients attending the ALS/MND clinic at the Chris Hani Baragwanath Academic Hospital in Soweto, Johannesburg, South Africa, during the period 1 January 2015 to 30 June 2020. Cross-sectional demographic and clinical data captured at the time of diagnosis was collected.

RESULTS

Seventy-one patients were included in the study. Males constituted 66% (n = 47), with a male to female sex ratio of 2:1. The median age at onset of symptoms was 46 years (IQR 40-57) with a median disease duration at diagnosis (diagnostic delay) of 2 years (IQR 1-3). The onset was spinal in 76% and bulbar in 23%. The median ALSFRS-R score at time of presentation was 29 (IQR 23-38.5). The median ALSFRS-R slope (unit/month) was 0.80 (IQR 0.43-1.39). Sixty five patients (92%) were diagnosed with the classic ALS phenotype. Fourteen patients were known to be HIV positive, and of those, 12 were on antiretroviral treatment (ART). None of the patients had familial ALS.

CONCLUSION

Our findings of an earlier age at symptom onset and seemingly advanced disease at presentation in patients with Black African ancestry support the existing literature on the African population.

Demographic changes in a large motor neuron disease cohort in Portugal: a 27 year experience

Objective: Motor Neuron Diseases (MND) have a large clinical spectrum, being the most common amyotrophic lateral sclerosis (ALS) but there is significant clinical heterogeneity. Our goal was to investigate this heterogeneity and any potential changes during a long period. Methods: We performed a retrospective cohort study among a large Portuguese cohort of MND patients (n = 1550) and investigated changing patterns in clinical and demographic characteristics over the 27-year period of our database. With that aim, patients were divided into three 9-year groups according to the date of their first visit to our unit: P1, 1994-2002; P2, 2003-2011; P3, 2012-2020. Results: The overall cohort's clinical and demographic characteristics are consistent with clinical experience, but our findings point to gradual changes over time. Time pattern analysis revealed statistically significant differences in the distribution of clinical phenotypes, the average age of onset, diagnostic delay, the proportin of patients using respiratory support with noninvasive ventilation (NIV), time to NIV, and survival. Across time, in the overall cohort, we found an increasing age at onset (p = 0.029), a decrease of two months in diagnostic delay (p < 0.001) and a higher relative frequency of progressive muscular atrophy patients. For ALS patients with spinal onset, from P1 to P2, there was a more widespread (54.8% vs 69.4%, p = 0.005) and earlier (36.9 vs 27.2 months, p = 0.05) use of NIV and a noteworthy 13-month increase in median survival (p = 0.041). Conclusions: Our results probably reflect better comprehensive care, and they are relevant for future studies exploring the impact of new treatments on ALS patients.

Iranian clinical practice guideline for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegeneration involving motor neurons. The 3-5 years that patients have to live is marked by day-to-day loss of motor and sometimes cognitive abilities. Enormous amounts of healthcare services and resources are necessary to support patients and their caregivers during this relatively short but burdensome journey. Organization and management of these resources need to best meet patients' expectations and health system efficiency mandates. This can only occur in the setting of multidisciplinary ALS clinics which are known as the gold standard of ALS care worldwide. To introduce this standard to the care of Iranian ALS patients, which is an inevitable quality milestone, a national ALS clinical practice guideline is the necessary first step. The National ALS guideline will serve as the knowledge base for the development of local clinical pathways to guide patient journeys in multidisciplinary ALS clinics. To this end, we gathered a team of national neuromuscular experts as well as experts in related specialties necessary for delivering multidisciplinary care to ALS patients to develop the Iranian ALS clinical practice guideline. Clinical questions were prepared in the Patient, Intervention, Comparison, and Outcome (PICO) format to serve as a guide for the literature search. Considering the lack of adequate national/local studies at this time, a consensus-based approach was taken to evaluate the quality of the retrieved evidence and summarize recommendations.

Amyotrophic Lateral Sclerosis and Serum Lipid Level Association: A Systematic Review and Meta-Analytic Study

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with unknown etiology. Many metabolic alterations occur during ALS progress and can be used as a method of pre-diagnostic and early diagnosis. Dyslipidemia is one of the physiological changes observed in numerous ALS patients. The aim of this study is to analyze the possible relationship between the rate of disease progression (functional rating scale (ALS-FRS)) and the plasma lipid levels at the early stage of ALS. A systematic review was carried out in July 2022. The search equation was "Triglycerides AND amyotrophic lateral sclerosis" and its variants. Four meta-analyses were performed. Four studies were included in the meta-analysis. No significant differences were observed between the lipid levels (total cholesterol, triglycerides, HDL cholesterol, and LDL cholesterol) and the ALS-FRS score at the onset of the disease. Although the number of studies included in this research was low, the results of this meta-analytic study suggest that there is no clear relationship between the symptoms observed in ALS patients and the plasma lipid levels. An increase in research, as well as an expansion of the geographical area, would be of interest.

A geographical study on amyotrophic lateral sclerosis in Rio Grande Do Norte, Brazil, from 2005 to 2018

OBJECTIVE

amyotrophic lateral sclerosis (ALS) is a rare and fatal neurodegenerative disorder with variable incidence and prevalence worldwide. However, clinical-epidemiological studies on ALS are scarce in Brazil. Thus, this study investigated whether ALS incidence had uniform spatial distribution in population-based cluster analysis in Rio Grande do Norte state (Brazil), from 2005 to 2018.

METHODS

new cases of ALS were identified in a database of the ALS multidisciplinary care center of the Onofre Lopes University Hospital in Natal (Rio Grande do Norte, Brazil). Approaches were based on incidence (empirical Bayes estimator and Moran's I analysis) and cluster analyses (Moran scatter plot and spatial correlogram).

RESULTS

a total of 177 patients (59% males) participated in the study; the mean age of ALS onset was 57 years. Mean annual incidence of ALS was 0.3769 per 100,000 inhabitants (95% confidence interval of 0.0889), higher in males than in females (0.4516 per 100,000 vs. 0.3044 per 100,000). According to spatial statistics, patients were homogeneously distributed throughout the studied area.

CONCLUSION

a low estimate was observed compared with other populations. Results did not indicate areas of increased risk or significant spatial geographic dependence, suggesting a random ALS incidence in Rio Grande do Norte.

Association of cerebral spinal fluid copper imbalance in amyotrophic lateral sclerosis

A plethora of environmental risk factors has been persistently implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS), including metal/metalloids. This study aimed to examine potential associations between cerebral spinal fluid (CSF) metal/metalloids and ALS risks. CSF concentrations of copper (Cu), nickel (Ni), mercury (Hg), arsenic (As), manganese (Mn), and iron (Fe) in ALS (spinal- and bulbar-onset) patients and controls were measured using inductively coupled plasma mass spectrometry (ICP-MS). Results from this study revealed marked differences between control, spinal-onset, and bulbar-onset groups. We report that Cu levels were lower in the ALS and spinal-onset groups compared to the control group. Ni level were higher in the spinal-onset group compared to the control and bulbar-onset groups. In addition, associations between CSF metal/metalloid levels with disease severity, sex, and serum triglycerides were also examined to broach the potential relevance of neurotoxic metal/metalloids in ALS disease heterogeneity.

The SOD1-mediated ALS phenotype shows a decoupling between age of symptom onset and disease duration

Superoxide dismutase (SOD1) gene variants may cause amyotrophic lateral sclerosis, some of which are associated with a distinct phenotype. Most studies assess limited variants or sample sizes. In this international, retrospective observational study, we compare phenotypic and demographic characteristics between people with SOD1-ALS and people with ALS and no recorded SOD1 variant. We investigate which variants are associated with age at symptom onset and time from onset to death or censoring using Cox proportional-hazards regression. The SOD1-ALS dataset reports age of onset for 1122 and disease duration for 883 people; the comparator population includes 10,214 and 9010 people respectively. Eight variants are associated with younger age of onset and distinct survival trajectories; a further eight associated with younger onset only and one with distinct survival only. Here we show that onset and survival are decoupled in SOD1-ALS. Future research should characterise rarer variants and molecular mechanisms causing the observed variability.

Epidemiological time-trend of amyotrophic lateral sclerosis (ALS) over two decades: The French population-based register of ALS in Limousin (FRALim register)

INTRODUCTION

Population-based registers are key to understanding disease patterns. Taking advantage of the long-standing operation of the French register of amyotrophic lateral sclerosis (ALS) in Limousin (FRALim register), we sought to determine the time trends in incidence, clinical features and survival of ALS patients from 2000 to 2020.

METHODS

FRALim register included incident cases through multiple sources of ascertainment. A capture-recapture method was used to assess the exhaustiveness of case ascertainment. Crude and standardized incidences were calculated per 100,000 person-years of follow-up (PYFU). Time-period was divided (period 2000 to 2010 and period 2011 to 2020) to compare incidence rates and clinical features. Survival was analyzed using Kaplan-Meier method. Cox proportional hazards model was performed to calculate hazards for the time periods.

RESULTS

Overall, 501 incident cases were identified during 21 years. The overall crude incidence was 3.26 (95% CI 2.97 to 3.55) per 100 000 PYFU. The exhaustiveness of the register was estimated at 98.8% (95% CI 97.4-99.6%) by capture-recapture analysis. Several fluctuations were observed without a consistent trend over the last two decades. The crude and standardized incidences were higher in males than females. The peak of incidence was observed in the 75-79 years age band. Almost one-third of the cases exhibited a bulbar onset. There were significant differences in clinical features between time periods. Four hundred and ninety-one cases were included in the survival analysis. The median survival time from diagnosis was 16.0 months (95% CI 14.3 to 17.7 months). Patients in the last decade experienced a lower risk of dying but the difference did not reach statistical significance (adjusted HR: 0.89 (95% CI 0.73 to 1.08, P=0.229).

CONCLUSION

We provided reliable epidemiological data over two decades. We showed that incidence has been relatively stable, while clinical variability was observed. A slight improvement in survival time was found in the last decade but it was not statistically significant. Further quality register data are needed to improve our understanding of ALS epidemiological trends.

Spatio-temporal clustering of amyotrophic lateral sclerosis in France: A population-based study

OBJECTIVE

To assess spatial aggregates of amyotrophic lateral sclerosis (ALS) incident cases, using a solid geo-epidemiological statistical method, in France.

METHODS

This population-based study (2003-2011) investigated 47.1 million person-years of follow-up (PYFU). Case ascertainment of incident ALS cases was based on multiple sources (ALS referral centers, hospital centres and health insurance data). Neurologists confirmed all ALS diagnoses. Exhaustiveness was estimated through capture-recapture. Aggregates were investigated in four steps: (a) geographical modelling (standardized incidence ratio (SIR) calculation), (b) analysis of the spatial distribution of incidence (Phothoff-Winttinghill's test, Global Moran's Index, Kulldorf's spatial scan statistic, Local Moran's Index), (c) classification of the level of certainty of spatial aggregates (i.e. definite cluster; probable over-incidence area; possible over-incidence area) and (d) evaluation of the robustness of the results.

RESULTS

The standardized incidence of ALS was 2.46/100,000 PYFU (95% CI 2.31-2.63, European population as reference) based on 1199 incident cases. We identified 13 areas of spatial aggregates: one cluster (stable in robustness analysis), five probable over-incidence areas (2 stable in robustness analysis) and seven possible over-incidence areas (including 4 stable areas in robustness analysis). A cluster was identified in the Rhône-Alpes region: 100 observed vs 54.07 expected cases for 2,411,514 PYFU, SIR: 1.85 (95% CI 1.50-2.25).

CONCLUSION

We report here one of the largest investigations of incidence and spatial aggregation of ALS ever performed in a western country. Using a solid methodology framework for case ascertainment and cluster analysis, we identified 13 areas that warrant further investigation.

The Global Burden of Motor Neuron Disease: An Analysis of the 2019 Global Burden of Disease Study

Up-to-date, accurate information on the disease burden of motor neuron disease (MND) is the cornerstone for evidence-based resource allocation and healthcare planning. We aimed to estimate the burden of MND globally from 1990 to 2019, as part of the Global Burden of Disease, Injuries and Risk Factor (GBD) study. Amyotrophic lateral sclerosis, progressive muscular atrophy, primary lateral sclerosis, pseudobulbar palsy, spinal muscular atrophy and hereditary spastic paraplegia- were included for analysis as MNDs. We measured age-standardized incidence, prevalence, death, and disability-adjusted life-years (DALYs) in 204 countries and territories worldwide from 1990 to 2019 using spatial Bayesian analyses. The effects of age, sex, and the sociodemographic index (measures of income per capita, education, and fertility) on incidence, prevalence, death, and disability-adjusted life-years due to MNDs were explored. According to 2019 GBD estimates, there were ~268,673 [95% uncertainty interval (UI), 213,893-310,663] prevalent cases and 63,700 (95% UI, 57,295-71,343) incident cases of MND worldwide. In 2019, MND caused 1,034,606 (95% UI, 979,910-1,085,401) DALYs and 39,081 (95% UI, 36,566-41,129) deaths worldwide. The age-standardized rates of prevalence, incidence, death, and DALYs for MNDs in 2019 were 3.37 (95% UI, 2.9-3.87) per 100,000 people, 0.79 (95% UI, 0.72-0.88) per 100,000 people, 0.48 (95% UI, 0.45-0.51) per 100,000 people, and 12.66 (95% UI, 11.98-13.29) per 100,000 people, respectively. The global prevalence and deaths due to MND in 2019 were increased (1.91% [95% UI, 0.61-3.42] and 12.39% [95% UI, 5.81-19.27], respectively) compared to 1990, without significant change in incidence. More than half of the prevalence and deaths due to MND occurred in three high-income regions (North America, Western Europe, and Australasia). In most cases, the prevalence, incidence, and DALYs of MNDs were high in regions with high sociodemographic index; however, in high-income East Asia, these were relatively low compared to similar sociodemographic index groups elsewhere. The burden of MND increased between 1990 and 2019. Its expected increase in the future highlights the importance of global and national healthcare planning using more objective evidence. Geographical heterogeneity in the MND burden might suggest the influences of sociodemographic status and genetic background in various regions.

Amyotrophic lateral sclerosis mortality rates in Latin America and the Caribbean: a meta-analysis

Background: Recent studies have described a low occurrence of Amyotrophic Lateral Sclerosis (ALS) in Latin America. Significant differences in ALS risk have been reported among ethnic populations in the region. We conducted a meta-analysis using population-based data to describe ALS mortality rates in Latin America. We explored sources of heterogeneity among key covariates.Methods: National mortality registries from Latin American countries were searched to identify ALS deaths according to the International Classification of Diseases (ICD-9: code 335.2 and ICD-10: code G12.2). Crude and standardized mortality rates were calculated. A random-effect meta-analysis was conducted to estimate pooled mortality rates. Subgroup analysis was performed as a means of investigating heterogeneity.Results: Overall, 28,548 ALS deaths and 819 million person-years of follow-up (PYFU) from ten Latin American countries were considered. Standardized mortality varied among countries. The highest mortality rates were observed in Uruguay and Costa Rica at 1.3 and 1.2 per 100,000 PYFU, respectively. The pooled crude mortality rate was 0.38 (95%CI: 0.28-0.53) and the pooled standardized mortality was 0.62 (95%CI: 0.49-0.77) per 100,000 PYFU. Heterogeneity was high (I2: 99.9%, Cochran's Q p < 0.001). Subgroup analysis showed a higher mortality rate among countries with a higher proportion of Caucasian populations and higher income levels.Conclusion: There is a lower ALS occurrence in Latin America compared to Europe and North America. This meta-analysis supports the hypothesis of a higher ALS risk among the Caucasian population. Further studies are needed to investigate the role of ancestral origins in ALS, taking socioeconomic status into consideration.

Genotype-phenotype association of TARDBP mutations in Chinese patients with amyotrophic lateral sclerosis: a single-center study and systematic review of published literature

BACKGROUND

This study aims to determine the genetic and clinical features of TARDBP-mutated patients in our cohort of Chinese patients with amyotrophic lateral sclerosis (ALS) combined with data in the literature.

METHODS

We performed TARDBP mutation screening in 1258 Chinese ALS patients, including 1204 sporadic ALS (sALS) and 54 familial ALS (fALS) patients. A systematic literature review was conducted by searching TARDBP-mutated patients from China in the online databases.

RESULTS

In our cohort, the mutant frequency of TARDBP variants was 0.3% (4/1258), with two recurrent variants (p.G294V, p.G298V) and one novel variant (p.S332G) identified. Combining with data in the literature review, the TARDBP-mutant frequency in the Chinese population was 1.4% (83/5998), with 0.8% (46/5470) in sALS and 7.0% (37/528) in fALS. Most patients had limb onset (63.0%), with an average life expectancy of 4.3 years (range 0.5-13). Disease durations significantly differed (p = 0.002), with p.M337V showing the longest duration (80 months) and p.N378D showing the shortest duration (16.7 months).

CONCLUSION

Our study found that TARDBP mutation was not rare in Chinese fALS patients. Different TARDBP mutations were associated with specific features in phenotypes.

Survival analysis of clinical and genetic factors in an amyotrophic lateral sclerosis cohort from China

OBJECTIVES

To investigate the clinical and genetic factors influencing the survival of amyotrophic lateral sclerosis (ALS) patients in China.

METHODS

Patients were enrolled in the study between December 2013 and December 2018. Clinical variables were recorded upon patient diagnosis. Causative genes related to ALS were screened by whole-exome sequencing and validated by Sanger sequencing. Each patient was followed up every 3-6 months until the endpoint (death or tracheotomy) or the last connection time on 31 December 2020. Propensity score matching analysis was performed to match the genetic and non-genetic ALS patients. The Kaplan-Meier method and multivariable Cox regression were performed for survival analysis.

RESULTS

A total of 337 patients, including 32 with genetic ALS and 305 with non-genetic ALS, were enrolled in the study. Before matching, in univariate analysis, age of onset (P < 0.001), site of onset (P = 0.036), diagnostic delay (P < 0.001), ALSFRS-R score at diagnosis (P < 0.001), ΔALSFRS-R (P < 0.001), and causative mutations (P  = 0.020) were significant prognostic factors. These factors remained statistically significant after multivariate analysis. After matching, in the multivariate analysis, age of onset (P = 0.003), site of onset (P = 0.014), diagnostic delay (P = 0.007), ALSFRS-R score at diagnosis (P = 0.010), ΔALSFRS-R (P = 0.007), and causative mutations (P = 0.003) were found to be significant prognostic factors.

CONCLUSION

Both clinical factors and genetic factors influenced survival in our ALS cohort. Clarifying of the underlying mechanisms is crucial for the development of future therapies.

Investigating the Genetic Profile of the Amyotrophic Lateral Sclerosis/Frontotemporal Dementia (ALS-FTD) Continuum in Patients of Diverse Race, Ethnicity and Ancestry

Preliminary evidence suggests that commonly used genetic tests may be less likely to identify a genetic etiology for ALS-FTD in patients of underrepresented race, ethnicity, and ancestry (REA), as compared to European REA. Patients of underrepresented REA may therefore be less likely to receive accurate and specific genetic counseling information and less likely to have access to gene-targeted therapies currently in clinical trials. We compiled outcome data from 1911 ALS-FTD patients tested at a commercial laboratory over a seven-year period for C9orf72 hexanucleotide repeat expansion (HRE) alone or C9orf72 and multigene sequencing panel testing. We compared the incidence of pathogenic (P), likely pathogenic (LP), and uncertain variants in C9orf72 and other ALS-FTD genes, as well as age at testing, in patients of different REA. The diagnostic rate in patients of European REA (377/1595, 23.64%) was significantly higher than in patients of underrepresented REA (44/316, 13.92%) (p < 0.001). Patients of European REA were more likely to have the C9orf72 HRE (21.3%) than patients of underrepresented REA (10.4%) (p < 0.001). The overall distribution of positive test outcomes in all tested genes was significantly different between the two groups, with relatively more P and LP variants in genes other than C9orf72 identified in patients of underrepresented REA. The incidence of uncertain test outcomes was not significantly different between patients of European and underrepresented REA. Patients with positive test outcomes were more likely to be younger than those with negative or uncertain outcomes. Although C9orf72 HRE assay has been advocated as the first, and in some cases, only genetic test offered to patients with ALS-FTD in the clinical setting, this practice may result in the reduced ascertainment of genetic ALS-FTD in patients of diverse REA.

A Brazilian multicentre study on the clinical and epidemiological profiles of 1116 patients with amyotrophic lateral sclerosis and its phenotypic variants

Objective: We conducted a multicentre, cross-sectional analysis of Brazilian patients with amyotrophic lateral sclerosis (ALS) and its phenotypic variants. We describe and compare their clinical and epidemiological data. Methods: We collected data from 1,116 patients who visited seven rehabilitation hospitals in the SARAH network from 1 January 2009 to 20 March 2020. This representative sample of patients was from 308 cities in 25 states from the country's five regions. Results: The median age at onset was 55 years, and we found a significant linear correlation between the age at onset and the Municipal Human Development Index (MHDI) but not survival time. We found a four-year difference using a cutoff value of 0.750 (p < 0.001). There was a male predominance, with a 1.2:1 sex ratio. The median time from onset to diagnosis was 17.6 months, and the most common phenotypic presentations were spinal-onset and bulbar-onset ALS (62.7% and 14.7%, respectively). In total, 12.9% of the patients had familial ALS, likely due to the overrepresentation of ALS type 8 patients in our population. Conclusions: In general, our numbers are consistent with most international series and with those of other Brazilian cohorts. When patients were analyzed according to their MHDI a considerable delay in symptom onset was found, suggesting the possibility of an environmental effect on these patients. Brazil has a longer diagnostic delay which is similar to other less-developed countries. This is a substantial concern and should be a priority for health authorities and neurology societies.

Trends in survival of ALS from a population-based registry

Objective: To assess survival of ALS patients in general and in selected demographic and clinical subgroups comparing two periods (1998-2000 vs. 2008-2010). Methods: Newly diagnosed adults resident of Lombardy, Northern Italy from a population-based registry were included. Data were collected on age at diagnosis, sex, site of onset, diagnostic delay, and El-Escorial diagnostic category. Patients were followed until death or last observation. Survival was evaluated using Kaplan-Meier curves and Cox's proportional hazards models. Results: In 2008-2010 (267 patients), median survival was 2.4 years and 1-year, 2-year, 3-year and 5-year survival rates were 79%, 56%, 41% and 24%. Longer survival was associated with male sex, younger age, spinal onset, and longer diagnostic delay. Multivariable analysis confirmed higher death in 65-69yr (HR 2.8; 95% CI 1.4-5.6), 70-74yr (HR 3.2; 95% CI 1.6-6.3) and 75 + yr (HR 6.9; 95% CI 3.5-13.8) categories, compared to ≤49yr, in females (HR 1.4; 95% CI 1.02-1.8), compared to males, and in patients diagnosed after 6-12 months (HR 1.9; 95% CI 1.4-2.7), compared with longer diagnostic delay. In 1998-2000 (235 patients), median survival was 2.2 years. The 1-year, 2-year, 3-year and 5-year survival rates were 77%, 53%, 38% and 20%. When adjusting for demographic and clinical variables, the HR for death in 2008-2010 versus 1998-2000 was 0.80 (95% CI 0.66-0.98). A significant increase of survival in 2008-2010 was found only in patients aged 50-59yr and 70-74yr at diagnosis. Conclusions: Survival of ALS has increased over time in the last decades, especially in middle aged and elderly patients. The benefits of comprehensive care in selected age groups might explain our findings.

Non-Motor Symptoms of Amyotrophic Lateral Sclerosis: A Multi-Faceted Disorder

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive degeneration of motor pathways. A growing body of evidence from recent years suggests that ALS results in a wide range of non-motor symptoms as well, which can have a significant impact on patients' quality of life. These symptoms could also, in turn, provide useful information as biomarkers for disease progression, and can shed insight on ALS mechanisms. Here we aim to review a wide range of non-motor symptoms of ALS, with emphasis on their importance to research and clinical treatment of patients.

Epidemiological and genetic features of amyotrophic lateral sclerosis in Latin America and the Caribbean: a systematic review

Introduction: Heterogeneity of amyotrophic lateral sclerosis (ALS) has been suggested in terms of epidemiology, phenotypes and genetics between geographic areas and populations. However, there is limited information in Latin America. We conducted a systematic review that aimed to describe the epidemiology, frequency of genetic mutations, clinical characteristics and survival of ALS patients in this region. Methods: We reviewed Medline, Scopus, Scielo and LILACS databases up to April 2020. The search terms "Amyotrophic Lateral Sclerosis" or "Motor Neuron Disease" were used in combination with the list of Latin American countries from the United Nations. All observational studies were included. A methodological overview was performed using the principles of descriptive epidemiology. Results: Overall, 1364 publications were identified and 36 studies were selected, covering 13 Latin American countries. According to the original reports, ALS occurrence varied among countries with a standardized incidence ranging from 0.3 per 100,000 person-years follow up (PYFU) in Ecuador to 3.6 per 100,000 PYFU in Uruguay. A low proportion of the C9orf72 repeat expansion was reported in Cuba and Brazil. We identified age at onset between 50 and 60 years. Survival time was higher than 40 months in half of the studies. Data from multiethnic populations reported a higher risk of developing ALS in Caucasians compared to admixed and Black populations. Conclusion: This review provides a perspective of ALS variability across Latin America and highlights specific differences when comparing to Europe and North America. However, we cannot draw firm conclusions because of different methodological concerns within the studies.

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

Background: Assessing clinical progression in amyotrophic lateral sclerosis (ALS) remains a challenge. We evaluated the validity and predictive capabilities of the King's and Milano-Torino Staging (MiToS) systems in a cohort of patients with ALS to demonstrate their benefit in clinical practice.Methodology: A cohort study was performed by including ALS incident cases in a referral center from 2007 to 2016. The staging systems were determined at time of diagnosis and follow-up. The standardized median times to reach each stage were computed. A multi-state model in the framework of the Cox model evaluated the predictive value of measurements. The survival C-statistic was reported as a measure of prediction ability.Results: Overall, 298 incident cases were included. The King's and MiToS systems described a progressive increase in the risk of dying with each elapsed stage. However, a lower resolution for late disease description for the King's system was observed, and late stages overlapped for the MiToS system. Slight variations in the staging systems appeared to improve performance based on validity and prediction abilities: (i) in the King's (C-statistic = 0.783), by adding a new stage involving the need for both gastrostomy and NIV: (ii) in the MiToS (C-statistic = 0.792), by merging stage 3 and stage 4 into a single stage 3.Conclusion: Both King's and MiToS are valid systems but have certain limitations. Variations in the staging systems may provide a more suitable framework for describing progression and survival. Further research is needed to evaluate the variations in the staging systems.

Time-trend evolution and determinants of sex ratio in Amyotrophic Lateral Sclerosis: a dose-response meta-analysis

BACKGROUND

A noticeable change of the male-to-female sex ratio (SR) has been observed in Amyotrophic Lateral Sclerosis (ALS) leading to an apparent regression of SR with time (SR close to 1:1).

OBJECTIVE

To provide a global SR estimate and investigate its relation with respect to population age.

METHODS

A systematic review and meta-analysis was conducted including only population-based studies with a high-quality methodology in European ancestral origin population. Male-to-female SR was estimated by three different measures: SR number, SR crude incidence and SR standardized incidence. Standard and dose-response meta-analyses were performed to assess the pooled SR measures (irrespective of population age) and the evolution of the SR measures with respect to population age, respectively. Potential sources of heterogeneity were investigated via meta-regression.

RESULTS

Overall, 3254 articles were retrieved in the literature search. Thirty-nine studies stratified by time periods were included. The overall pooled male-to-female ratio was 1.28 (95% CI 1.23-1.32) for SR number, 1.33 (95% CI 1.29-1.38) for SR crude incidence and 1.35 (95% CI 1.31-1.40) for SR standardized incidence. The SR number with respect to population age reveals a progressive reduction of SR at increasing age, while the SR crude incidence in relation to age displays a U-shaped curve.

CONCLUSIONS

The number and the incidence of ALS cases were consistently higher in males than females. Dose-response meta-analysis showed that SR measures change with respect to population age. Further original research is needed to clarify if our findings are reproducible in other populations.

Sensitivity of Awaji Criteria and Revised El Escorial Criteria in the Diagnosis of Amyotrophic Lateral Sclerosis (ALS) at First Visit in a Tunisian Cohort

Background

Amyotrophic lateral sclerosis (ALS) is a fatal disease whose diagnosis and early management can improve survival. The most used diagnostic criteria are the revised El Escorial criteria (rEEC) and Awaji criteria (AC). The comparison of their sensitivities showed contradictory results. Our study aimed to compare the sensitivities of these two criteria in the diagnosis of definite ALS, at first visit, in a Tunisian hospital cohort.

Materials and Methods

This was a retrospective study including 173 patients diagnosed with ALS at the Department of Neurology of the Razi Hospital between January 2003 and April 2018.After studying the clinical features of the disease in our study population,each patient was categorized according to the rEEC and AC based on data collected in his medical record during his first visit to our department. Then, we compared the sensitivities of these two criteria in the diagnosis of definite ALS.

Results

Our Tunisian cohort was characterized by a slower disease progression. The sensitivity of the AC (69.4%) was significantly higher than that of the rEEC (40.5%) (p < 0.001). When the clinical signs evolved for less than 6 months, the sensitivities were 61% for AC and 12% for rEEC (p < 0.001). After 24 months of disease progression, the sensitivities were 78.2% for AC and 69.1% for rEEC (p = 0.063). It was impossible to categorize seventeen patients by the two criteria.

Conclusion

Our study demonstrated that patients in AC are more sensitive than rEEC in the early diagnosis of ALS in our Tunisian cohort. However, this superiority is gradually reduced during the evolution of the disease.

Multicentre, prospective registry study of amyotrophic lateral sclerosis in mainland China (CHALSR): study protocol

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a representative rare disease characterised by progressive, fatal motor neuron degeneration. Due to the unknown aetiology and variability of the phenotypes, there are no accurate reports concerning the epidemiology or clinical characteristics of the disease. The low prevalence, as previously reported, makes it difficult to carry out studies with large samples. The aim of this study was to explore the natural history and clinical features of ALS in mainland China through a multicentre, prospective cohort study. The findings will both offer a better understanding of ALS and also support the development of a model to study other rare diseases.

METHODS AND ANALYSIS

Patients from 88 representative hospitals in different parts of mainland China will be recruited through a specially designed online data system (http://www.chalsr.net/). We aim to recruit 4752 ALS patients over a 3-year period. Baseline data will be recorded, and follow-up data will be collected every 3 months. The primary outcome is effective survival. Overall survival and indices of disease progression will be measured as the secondary outcomes.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the ethics committee of Peking University Third Hospital (M2019388). Informed written consent will be obtained from each participant. Dissemination of the study protocol and data will take place primarily through a specially designed online data system (http://www.chalsr.net/). The collective results of the study will be published in peer-reviewed journals and shared in scientific presentations.

TRIAL REGISTRATION NUMBER

NCT04328675.

Hypermetabolism is a reality in amyotrophic lateral sclerosis compared to healthy subjects

RATIONALE

Hypermetabolism (HM) in Amyotrophic lateral sclerosis (ALS) is the reflection of a high energy metabolic level, but this alteration seems controversial. The main objective of the study was to confirm the existence of HM during ALS compared to healthy subjects.

METHODS

A cohort of ALS patients was compared to a control group without metabolic disorder. The assessment included anthropometric criteria measurements, body composition by bioelectric impedance analysis and resting energy expenditure (REE) by indirect calorimetry. HM was defined as a variation > +10% between measured and calculated REE. Statistical analysis used Mann-Withney and Chi2 tests. Multivariate analysis included logistic regression.

RESULTS

287 patients and 75 controls were included. The metabolic level was higher in ALS patients (1500 kcal/24 h [1290-1693] vs. 1230 kcal/24 h [1000-1455], p < 0.0001) as well as the REE/fat free mass ratio (33.5 kcal/kg/24 h [30.4-37.8] vs. 28.3 kcal/kg/24 h [26.1-33.6], p < 0.0001). 55.0% of ALS patients had HM vs. 13.3% of controls (p < 0.0001). HM was strongly and positively associated with ALS (OR = 9.50 [4.49-20.10], p < 0.0001).

CONCLUSIONS

HM in ALS is a reality, which affects more than half of the patients and is associated with ALS. This work confirms a very frequent metabolic deterioration during ALS. The identification of HM can allow a better adaptation of the patients' nutritional intake.

Motor Neuron Disease Register for England, Wales and Northern Ireland-an analysis of incidence in England

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) has a reported incidence of 1-2/100,000 person-years. It is estimated that there are 5000 people with ALS in the UK at any one time; however, the true figure and geographical distribution, are unknown. In this study, we describe the establishment of a population register for England, Wales, and Northern Ireland and report-estimated incidence. Methods: People with a diagnosis of ALS given by a consultant neurologist and whose postcode of residence is within England, Wales, or Northern Ireland were eligible. The catchment area was based on six data contributors that had been participating since 2016. All centres included in this analysis were in England, and therefore Wales and Northern Ireland are not included in this report. Crude age- and sex-specific incidence rates were estimated using population census records for the relevant postcodes from Office of National Statistics census data. These rates were standardized to the UK population structure using direct standardization. Results: There were 232 people in the database with a date of diagnosis between 2017 and 2018, when missing data were imputed there were an estimated 287-301 people. The denominator population of the catchment area is 7,251,845 according to 2011 UK census data. Age- and sex-adjusted incidence for complete cases was 1.61/100,000 person-years (95% confidence interval 1.58, 1.63), and for imputed datasets was 2.072/100,000 person-years (95% CI 2.072, 2.073). Discussion: We found incidence in this previously unreported area of the UK to be similar to other published estimates. As the MND Register for England, Wales, and Northern Ireland grows we will update incidence estimates and report on further analyses.

Amyotrophic lateral sclerosis in Antalya, Turkey. A prospective study, 2016-2018

OBJECTIVE

The aim of the study is to find the prevalence and incidence of amyotrophic lateral sclerosis in Antalya and to define patient characteristics.

METHODS

The study represents five major districts in the Antalya metropolitan region, with a population of 1,286,943, which is defined as the provincial center. In cooperation with the neurology departments of all hospitals and private practices, existing cases were identified and new cases were recorded with continuous monitoring. Detailed demographic and clinical features of each patient were recorded, Revised El-Escorial Criteria were used for diagnosis. Incidence and prevalence rates are standardized by age based on USA 2016 population.

RESULTS

Point prevalence rates of 2016, 2017 and 2018 are 3.7, 4.7 and 5.4 per hundred thousand, respectively. Standardized prevalence rates for the US population are 5.5, 7.1 and 8.6 per hundred thousand in the same order. The incidence rate in 2017 is 1.4 per hundred thousand, and 2018 is 1.2. Standardized incidence rates for the US population are 2.1 and 1.8 per hundred thousand, respectively. About 75.6% of the cases were classified as definite, 11.0% probable, 11.0% possible, 2.4% probable laboratory-supported. The male/female ratio is 2.0 for total cases and 2.8 for new cases. The site of onset is spinal in 81.7% of patients and bulbar in 18.3%.

CONCLUSIONS

ALS rates detected in Antalya and the general features of the disease show similarities with European countries rather than Asian countries and comply with the literature.

The roles of iron and HFE genotype in neurological diseases

Iron accumulation is a recurring pathological phenomenon in many neurological diseases including Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, and others. Iron is essential for normal development and functions of the brain; however, excess redox-active iron can also lead to oxidative damage and cell death. Especially for terminally differentiated cells like neurons, regulation of reactive oxygen species is critical for cell viability. As a result, cellular iron level is tightly regulated. Although iron accumulation related to neurological diseases has been well documented, the pathoetiological contributions of the homeostatic iron regulator (HFE), which controls cellular iron uptake, is less understood. Furthermore, a common HFE variant, H63D HFE, has been identified as a modifier of multiple neurological diseases. This review will discuss the roles of iron and HFE in the brain as well as their impact on various disease processes.

Characteristics of amyotrophic lateral sclerosis in Lebanon-a chart review

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder primarily manifesting as motor deficits. It is caused by motor neuron death and leads to progressive disability and demise. It can present at any age, manifest as several phenotypes, and may have a variable progression pattern. Methods: This retrospective study is based on chart review of subjects presenting to the American University of Beirut Medical Center from June 2015 till March 2020. It aims to describe the characteristics of ALS in Lebanon. Results: Out of 140 subjects identified, 113 had classical ALS. The mean age in classical and atypical ALS were 55.5 and 55.6 years, male gender was predominant in both groups, and the mean duration from disease onset to diagnosis was 10 months in classic ALS compared to 22 months in atypical ALS. The median survival in subjects with classical ALS was 31 months which was significantly lower than atypical ALS phenotypes of 41.5 months. Additionally, more than half of patients (57%) were found to have a moderate ALSFRS-R progression rate. Conclusions: The study is the first to report the characteristics of amyotrophic lateral sclerosis in Lebanon. Moreover, we were able to categorize patients with classical phenotype according to disease progression using the ALSFRS-R score which can be a useful tool in determining disease prognosis at an early stage.

Laryngeal electromyography in amyotrophic lateral sclerosis

BACKGROUND

Bulbar involvement is a hallmark of amyotrophic lateral sclerosis (ALS), but surprisingly very few studies have addressed the frequency, pattern and clinical relevance of laryngeal involvement in the disease.

METHODS

Twenty-six patients with spinal-onset ALS underwent nasofibroscopy (NF), followed by laryngeal electromyography (LEMG). We also studied resting activity and motor unit potentials of the genioglossus and masseter muscles.

RESULTS

Twenty-four patients presented neurogenic changes in at least one laryngeal muscle. There were fibrillation and/or fasciculation potentials associated with chronic neurogenic changes in the same muscle in 16 patients; of these, 9 had no alteration in the genioglossus. We found no patient with tongue neurogenic changes and normal LEMG. NF was abnormal in 14 patients; in the remaining 12, LEMG identified neurogenic changes in 11 of them.

CONCLUSION

LEMG is able to identify laryngeal denervation in patients with ALS, sometimes before clinical manifestations are noticed. This technique may be a useful diagnostic tool for selected patients with suspicion of ALS.

What do we know about the variability in survival of patients with amyotrophic lateral sclerosis?

INTRODUCTION

ALS is a fatal neurodegenerative disease. However, patients show variability in the length of survival after symptom onset. Understanding the mechanisms of long survival could lead to possible avenues for therapy.

AREAS COVERED

This review surveys the reported length of survival in ALS, the clinical features that predict survival in individual patients, and possible factors, particularly genetic factors, that could cause short or long survival. The authors also speculate on possible mechanisms.

EXPERT OPINION

a small number of known factors can explain some variability in ALS survival. However, other disease-modifying factors likely exist. Factors that alter motor neurone vulnerability and immune, metabolic, and muscle function could affect survival by modulating the disease process. Knowing these factors could lead to interventions to change the course of the disease. The authors suggest a broad approach is needed to quantify the proportion of variation survival attributable to genetic and non-genetic factors and to identify and estimate the effect size of specific factors. Studies of this nature could not only identify novel avenues for therapeutic research but also play an important role in clinical trial design and personalized medicine.

Incidence and prevalence of amyotrophic lateral sclerosis in urban China: a national population-based study

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease and information on disease burden of ALS in mainland China was limited. We aimed to estimate the prevalence and incidence of ALS in China.

METHODS

We used 2012-2016 data from China's Urban Employee Basic Medical Insurance and Urban Residence Basic Medical Insurance, covering approximately 0.43 billion individuals. ALS cases were identified by the primary diagnosis (International Classification of Diseases code or text of diagnosis) in the insurance database.

RESULTS

The crude prevalence and incidence in 2016 were 2.91 per 100 000 person-years (95% CI 2.31 to 3.58) and 1.65 (95% CI 1.33 to 2.01), respectively. The standardised prevalence and incidence based on 2010 Chinese census data were 2.97 (95% CI 2.91 to 3.03) and 1.62 (95% CI 1.58 to 1.67), respectively. The annual prevalence between 2013 and 2016 remained relatively constant, ranging from 2.91 (95% CI 2.31 to 3.58) in 2016 to 3.29 (95% CI 2.51 to 4.17) in 2014 (linear regression: β=-0.129, p=0.104). Both rates peaked in the group aged 75-79 years.

CONCLUSIONS

The prevalence and incidence of ALS in mainland China were lower than those in developed countries, and maintained a relatively stable trend. The age at onset and age at diagnosis for ALS patients were younger than those in developed countries. Further research is expected to clarify the potential pathophysiological mechanism of ALS.

Atlanta metropolitan area amyotrophic lateral sclerosis (ALS) surveillance: incidence and prevalence 2009-2011 and survival characteristics through 2015

Amyotrophic lateral sclerosis (ALS) is a fatal, rare, and hard to diagnose neurological disease with unknown etiology. Objective: To understand the incidence, prevalence, and survival characteristics of ALS cases in the Atlanta metropolitan area. Methods: Neurologists in Clayton, Cobb, DeKalb, Fulton, and Gwinnett counties provided case reports for ALS patients under their care from 1 January 2009 to 31 December 2011. Incidence and prevalence rates were calculated for 2009, 2010, and 2011 by sex, race, and ethnicity. Using data from the National Death Index, survival time was calculated for age, sex, race, ethnicity, and El Escorial criteria. Results: There were 281 unique ALS cases reported, which is approximately 104% of the expected cases. The majority of the 281 cases were white, non-Hispanic, male, and in the 50-59 age category. The overall average incidence rate for 2009 to 2011 was 1.54 per 100,000 person-years, with higher annual incidence rates for whites, males, and non-Hispanics. The prevalence rates for 2009, 2010, and 2011 were 5.05, 5.44, and 5.56 per 100,000, respectively. Median survival time was highest for the 18-39 age group, Asians, non-Hispanics, and males. Additionally, the log-rank tests for homogeneity across strata indicate a statistical significance between strata for the age category for survival time. Conclusion: The findings for Atlanta are similar to other population-based studies in the United States. Although the Atlanta metropolitan area was selected to over-represent the minority population, the strongest predictor of survival time was age at diagnosis.

Applying the D50 disease progression model to gray and white matter pathology in amyotrophic lateral sclerosis

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The D50 disease progression model well characterized a cross-sectional ALS cohort.

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VBM reveled ALS-related widespread gray and white matter density decreases.

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A spread of structural alterations occurs along with D50 model derived disease phases.

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White-matter alterations were associated with higher disease aggressiveness.

Therapeutic management and research in Amyotrophic Laterals Sclerosis (ALS) have been limited by the substantial heterogeneity in progression and anatomical spread that are endemic of the disease. Neuroimaging biomarkers represent powerful additions to the current monitoring repertoire but have yielded inconsistent associations with clinical scores like the ALS functional rating scale. The D50 disease progression model was developed to address limitations with clinical indices and the difficulty obtaining longitudinal data in ALS. It yields overall disease aggressiveness as time taken to reach halved functionality (D50); individual disease covered in distinct phases; and calculated functional state and calculated functional loss as acute descriptors of local disease activity. It greatly reduces the noise of the ALS functional rating scale and allows the comparison of highly heterogeneous disease and progression subtypes. In this study, we performed Voxel-Based Morphometry for 85 patients with ALS (60.1 ± 11.5 years, 36 female) and 62 healthy controls. Group-wise comparisons were performed separately for gray matter and white matter using ANCOVA testing with threshold-free cluster enhancement. ALS-related widespread gray and white matter density decreases were observed in the bilateral frontal and temporal lobes (p < 0.001, family-wise error corrected). We observed a progressive spread of structural alterations along the D50-derived phases, that were primarily located in frontal, temporal and occipital gray matter areas, as well as in supratentorial neuronal projections (p < 0.001 family-wise error corrected). ALS patients with higher overall disease aggressiveness (D50 < 30 months) showed a distinct pattern of supratentorial white matter density decreases relative to patients with lower aggressiveness; no significant differences were observed for gray matter density (p < 0.001 family-wise error corrected).

The application of the D50 disease progression model separates measures of disease aggressiveness from disease accumulation. It revealed a strong correlation between disease phases and in-vivo measures of cerebral structural integrity. This study underscores the proposed corticofugal spread of cerebral pathology in ALS. We recommend application of the D50 model in studies linking clinical data with neuroimaging correlates.

Metabolic Alteration and Amyotrophic Lateral Sclerosis Outcome: A Systematic Review

Background: The development of strategies that could not only efficiently detect the onset of Amyotrophic Lateral Sclerosis (ALS), a fatal neurodegenerative disorder with no cure but also predict its development and evaluate therapeutic intervention would be of great value. In this respect, the metabolic status of ALS patients has called attention. Hence, this study aimed to investigate the potential correlation between changes in ALS's metabolic parameters with the disease outcome in a systematic review. Methods: The manuscripts were manually searched within different databases (PubMed, Web of Science and Cochrane). The inclusion criteria were original articles and reviews about individuals with ALS and its survival, disease prognosis and metabolism (weight, cholesterol, hypertension, BMI, and glycaemia). The authors also established three different exclusion criteria: studies including ALS and other degenerative disorders, works including animal models and published before the year 2000. Results: In total, 29 papers were selected. From all manuscripts, only 82.8% ensured the participation of sALS patients. Also, 27.6% of selected studies described the presence of a genetic mutation. Regarding ALS prognosis, patient's age, the age of ALS onset, ALS duration and survival, <50% of the papers addressed these issues. Specifically, regarding metabolism, 65.5% of articles mentioned BMI, 20.7% mentioned any data concerning hypertension, 6.89% cardiovascular risk, 10.3% obesity, 13.78% diabetes and 10.3% glycaemia. Concerning lipid metabolism, more results were gathered, but still, they did not suffice to establish a correlation with ALS development. Conclusions: Altogether, the authors concluded that available information is not enough to establish a link between ALS and metabolism. In reality, less than half of the manuscripts evaluated show an association between both factors. Nonetheless, it is worth mentioning that metabolism does influence ALS, but not in a unique manner. There is a debate about patients' hypo- and hypermetabolism. Thus, to provide a reliable record, a public policy in which all research and clinical centers might assess the parameters discussed herein is suggested. Accordingly, this systematic review attempts to provide a comprehensible database to facilitate multicentered collaboration, validation, and clinical translation.

A retrospective study of the clinical phenotype and predictors of survival in non-Caucasian Hispanic patients with amyotrophic lateral sclerosis

BACKGROUND

Little is known about the clinical phenotype of amyotrophic lateral sclerosis (ALS) in non-Caucasian populations. Here, we aimed to describe the clinical characteristics, prognostic factors and survival of Mexican patients with ALS.

METHODS

We conducted a retrospective study by reviewing the medical records of patients with ALS that attended and were regularly followed at a third level hospital in Mexico City from 2000 to 2015. We calculated absolute and relative frequencies of the clinical characteristics from all the participants. We also estimated correlation coefficients between clinical features and overall survival. Additionally, survival rates were compared for all participants grouped according to different clinical features using the Kaplan-Meier method and the log-rank test.

RESULTS

We enrolled 45 ALS patients, 53.33% had spinal-onset ALS and 46.66% presented bulbar ALS. The male/female ratio was 0.8. The mean age at onset of symptoms was 58.11 years. Mean survival time from onset was 64.73 ± 34.83 months. Cumulative survival rate after 5 years of disease onset was 44.44%. Age at onset and age at diagnosis inversely correlated with overall survival time. Also, we found that bulbar-onset, short diagnostic delay, percutaneous endoscopic gastrostomy, mechanical ventilation, and lower total cholesterol serum levels were associated with short survival.

CONCLUSIONS

The clinical characteristics of Mexican ALS patients differ from the disease phenotype observed in Caucasians. Nonetheless, the predictive value of certain well-recognized prognostic factors remains consistent in our population. The current study provides relevant information for a better understanding of prognostic factors in ALS patients from Mexico and other Latin American countries.

Residential exposure to ultra high frequency electromagnetic fields emitted by Global System for Mobile (GSM) antennas and amyotrophic lateral sclerosis incidence: A geo-epidemiological population-based study

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of unknown etiology. Mobile communication antennas have increased over the last few decades. Consequently, there has been a steady increase in environmental exposure to ultra high frequency electromagnetic fields (UHF-EMFs) emitted by Global System for Mobile (GSM) communication antennas, which raises concerns about possible health risks in the general population. We aimed to evaluate the relationship between residential exposure to UHF-EMFs generated by GSM antennas and the risk of ALS in general population. A geo-epidemiological population-based study was performed in Limousin (France). ALS incident cases were identified through a register (FRALim, 2000-2012 period). A model to estimate UHF-EMF exposure was developed based on the distance and the power of GSM antennas. Exposure to multiple emissions from multiple directions was considered. A non-cumulative and a cumulative model were established. A geographic information system integrated the raster model of exposure, and the residential distribution of observed and expected cases. A generalized linear model was performed to test the association. Overall, 312 ALS cases were included. We estimated exposures below 1.72 V/m in urban areas and below 1.23 V/m in rural areas for 90% of the population. A gradient effect between UHF-EMF exposure and ALS incidence was apparent with a statistically significant trend. A significant increased risk of ALS was observed between the non-exposure category and the highest exposure category, with a relative risk of 1.78 (95% CI: 1.28-2.48) in the non-cumulative model and 1.83 (95% CI: 1.32-2.54) in the cumulative model. Our results suggest a possible association between residential UHF-EMF exposure and ALS. Ecological studies are a means of generating hypotheses. Further studies are needed to clarify the potential role of EMFs on neurodegeneration.

Comparison of the clinical and genetic features of amyotrophic lateral sclerosis across Cuban, Uruguayan and Irish clinic-based populations

OBJECTIVES

This study compares the clinical characteristics of patients with amyotrophic lateral sclerosis (ALS) within three clinic-based populations from Cuba, Uruguay and Ireland and determines the impact of known ALS-associated genetic variants on phenotypic manifestations within the Cuban population.

METHODS

Demographic and clinical information was collected on 115 Cuban, 220 Uruguayan and 1038 Irish patients with ALS attending national specialist clinics through 1996-2017. All Cuban patients and 676 Irish patients underwent next-generation DNA sequencing and were screened for the pathogenic C9orf72 repeat expansion.

RESULTS

The mean age of onset was younger in the Cuban (53.0 years, 95% CI 50.4 to 55.6) and Uruguayan (58.2 years, 95% CI 56.5 to 60.0) populations compared with the Irish population (61.6 years, 95% CI 60.9 to 62.4). No differences in survival between populations were observed. 1.7 % (95% CI 0.6 to 4.1) of Cubans with ALS carried the C9orf72 repeat expansion compared with 9.9% (95% CI 7.8 to 12.0) of Irish patients with ALS (p=0.004). Other known variants identified in the Cuban population included ANG (one patient), CHCHD10 (one patient) and DCTN1 (three patients).

CONCLUSIONS AND RELEVANCE

This study is the first to describe the clinical characteristics of ALS in Cuban and Uruguayan populations and report differences between the Cuban and Irish genetic signature in terms of known ALS-associated genetic variants. These novel clinical and genetic data add to our understanding of ALS across different and understudied populations.