Age-specific ALS incidence: a dose-response meta-analysis

Deformability of Heterogeneous Red Blood Cells in Aging and Related Pathologies

Aging is interrelated with changes in red blood cell parameters and functionality. In this article, we focus on red blood cells (RBCs) and provide a review of the known changes associated with the characterization of RBC deformability in aging and related pathologies. The biophysical parameters complement the commonly used biochemical parameters and may contribute to a better understanding of the aging process. The power of the deformability measurement approach is well established in clinical settings. Measuring RBCs' deformability has the advantage of relative simplicity, and it reflects the complex effects developing in erythrocytes during aging. However, aging and related pathological conditions also promote heterogeneity of RBC features and have a certain impact on the variance in erythrocyte cell properties. The possible applications of deformability as an early biophysical biomarker of pathological states are discussed, and modulating PIEZO1 as a therapeutic target is suggested. The changes in RBCs' shape can serve as a proxy for deformability evaluation, leveraging single-cell analysis with imaging flow cytometry and artificial intelligence algorithms. The characterization of biophysical parameters of RBCs is in progress in humans and will provide a better understanding of the complex dynamics of aging.

Identification of potential drug targets for amyotrophic lateral sclerosis by Mendelian randomization analysis based on brain and plasma proteomics

Amyotrophic lateral sclerosis as a fatal neurodegenerative disease currently lacks effective therapeutic agents. Thus, finding new therapeutic targets to drive disease treatment is necessary. In this study, we utilized brain and plasma proteins as genetic instruments obtained from genome-wide association studies to conduct a Mendelian randomization analysis to identify potential drug targets for amyotrophic lateral sclerosis. Additionally, we validated our results externally using other datasets. We also used Bayesian co-localization analysis and phenotype scanning. Furthermore, we constructed a protein-protein interaction network to elucidate potential correlations between the identified proteins and existing targets. Mendelian randomization analysis indicated that elevated levels of ANO5 (OR = 1.30; 95 % CI, 1.14-1.49; P = 1.52E-04), SCFD1 (OR = 3.82; 95 % CI, 2.39-6.10; P = 2.19E-08), and SIGLEC9 (OR = 1.05; 95% CI, 1.03-1.07; P = 4.71E-05) are associated with an increased risk of amyotrophic lateral sclerosis, with external validation supporting these findings. Co-localization analysis confirmed that ANO5, SCFD1, and SIGLEC9 (coloc.abf-PPH4 = 0.848, 0.984, and 0.945, respectively) shared the same variant with amyotrophic lateral sclerosis, further substantiating potential role of these proteins as a therapeutic target. There are interactive relationships between the potential proteins and existing targets of amyotrophic lateral sclerosis. Our findings suggested that elevated levels of ANO5, SCFD1, and SIGLEC9 are connected with an increased risk of amyotrophic lateral sclerosis and might be promising therapeutic targets. However, further exploration is necessary to fully understand the underlying mechanisms involved.

Induced pluripotent stem cell production (CSSi019-A)(14432) from an asymptomatic subject carrying a expansion of C9orf72 gene

One of the genetic mutations most associated with the onset of amyotrophic lateral sclerosis, both in sporadic and familial cases, is the expansion of the C9orf72 gene. The presence of more than 30 repeats (GGGGCC) correlates with uncertain ALS symptomatology. Here we collected a dermal biopsy from a subject carrying 36 hexanucleotide repeats and reprogrammed it into an induced pluripotent stem cell line. Despite the number of repeat elements, the subject had no symptoms at the age of the biopsy (76 years), thus resulting in a healthy carrier of the mutation.

CD4+ T-Cell Senescence in Neurodegenerative Disease: Pathogenesis and Potential Therapeutic Targets

With the increasing proportion of the aging population, neurodegenerative diseases have become one of the major health issues in society. Neurodegenerative diseases (NDs), including multiple sclerosis (MS), Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS), are characterized by progressive neurodegeneration associated with aging, leading to a gradual decline in cognitive, emotional, and motor functions in patients. The process of aging is a normal physiological process in human life and is accompanied by the aging of the immune system, which is known as immunosenescence. T-cells are an important part of the immune system, and their senescence is the main feature of immunosenescence. The appearance of senescent T-cells has been shown to potentially lead to chronic inflammation and tissue damage, with some studies indicating a direct link between T-cell senescence, inflammation, and neuronal damage. The role of these subsets with different functions in NDs is still under debate. A growing body of evidence suggests that in people with a ND, there is a prevalence of CD4+ T-cell subsets exhibiting characteristics that are linked to senescence. This underscores the significance of CD4+ T-cells in NDs. In this review, we summarize the classification and function of CD4+ T-cell subpopulations, the characteristics of CD4+ T-cell senescence, the potential roles of these cells in animal models and human studies of NDs, and therapeutic strategies targeting CD4+ T-cell senescence.

Brain-Gut-Microbiota Axis in Amyotrophic Lateral Sclerosis: A Historical Overview and Future Directions

Amyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disease which is strongly associated with age. The incidence of ALS increases from the age of 40 and peaks between the ages of 65 and 70. Most patients die of respiratory muscle paralysis or lung infections within three to five years of the appearance of symptoms, dealing a huge blow to patients and their families. With aging populations, improved diagnostic methods and changes in reporting criteria, the incidence of ALS is likely to show an upward trend in the coming decades. Despite extensive researches have been done, the cause and pathogenesis of ALS remains unclear. In recent decades, large quantities of studies focusing on gut microbiota have shown that gut microbiota and its metabolites seem to change the evolvement of ALS through the brain-gut-microbiota axis, and in turn, the progression of ALS will exacerbate the imbalance of gut microbiota, thereby forming a vicious cycle. This suggests that further exploration and identification of the function of gut microbiota in ALS may be crucial to break the bottleneck in the diagnosis and treatment of this disease. Hence, the current review summarizes and discusses the latest research advancement and future directions of ALS and brain-gut-microbiota axis, so as to help relevant researchers gain correlative information instantly.

LAENALS: epidemiological and clinical features of amyotrophic lateral sclerosis in Latin America

OBJECTIVE

The Latin American Epidemiologic study of ALS (LAENALS) aims to gather data on ALS epidemiology, phenotype, and risk factors in Cuba, Chile, and Uruguay, to understand the impact of genetic and environmental factors on ALS.

METHODS

A harmonized data collection protocol was generated, and a Latin-American Spanish language Register was constructed. Patient data were collected in Uruguay in 2018, in Chile from 2017 to 2019, and in Cuba between 2017 and 2018. Statistical analysis was performed using SPSS 25.0.0 software. Crude cumulative incidence, standardized incidence, and prevalence were calculated in the population aged 15 years and older.

RESULTS

During 2017-2019, 90 people with ALS from Uruguay (55.6% men), 219 from Chile (54.6% men), and 49 from Cuba (55.1% men) were included. The cumulative crude incidence in 2018 was 1.73/100,000 persons in Uruguay, 1.08 in Chile and 0.195 in Cuba. Crude prevalence in 2018 was 2.19 per 100,000 persons in Uruguay, 1.39 in Chile and 0.55 in Cuba. Mean age at onset was 61.8 ± 11.96 SD years in Uruguay, 61.9 ± 10.4 SD years in Chile, and 60.21 ± 12.45 SD years in Cuba (p = 0.75). Median survival from onset was 32.43 months (21.93 - 42.36) in Uruguay, 24 months (13.5 - 33.5) in Chile, and 29 months (15 - 42.5) in Cuba (p = 0.006).

CONCLUSIONS

These preliminary data from LAENALS confirm the lower incidence and prevalence of ALS in counties with admixed populations. The LAENALS database is now open to other Latin American countries for harmonized prospective data collection.

Elevation of inositol pyrophosphate IP7 in the mammalian spinal cord of amyotrophic lateral sclerosis

Background

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder associated with progressive impairment of spinal motor neurons. Continuous research endeavor is underway to fully understand the molecular mechanisms associating with this disorder. Although several studies have implied the involvement of inositol pyrophosphate IP7 in ALS, there is no direct experimental evidence proving this notion. In this study, we analyzed inositol pyrophosphate IP7 and its precursor IP6 in the mouse and human ALS biological samples to directly assess whether IP7 level and/or its metabolism are altered in ALS disease state.

Methods

We used a liquid chromatography-mass spectrometry (LC-MS) protocol originally-designed for mammalian IP6 and IP7 analysis. We measured the abundance of these molecules in the central nervous system (CNS) of ALS mouse model SOD1(G93A) transgenic (TG) mice as well as postmortem spinal cord of ALS patients. Cerebrospinal fluid (CSF) and peripheral blood mononuclear cells (PBMCs) from ALS patients were also analyzed to assess if IP7 status in these biofluids is associated with ALS disease state.

Results

SOD1(G93A) TG mice showed significant increase of IP7 level in the spinal cord compared with control mice at the late stage of disease progression, while its level in cerebrum and cerebellum remains constant. We also observed significantly elevated IP7 level and its product-to-precursor ratio (IP7/IP6) in the postmortem spinal cord of ALS patients, suggesting enhanced enzymatic activity of IP7-synthesizing kinases in the human ALS spinal cord. In contrast, human CSF did not contain detectable level of IP6 and IP7, and neither the IP7 level nor the IP7/IP6 ratio in human PBMCs differentiated ALS patients from age-matched healthy individuals.

Conclusion

By directly analyzing IP7 in the CNS of ALS mice and humans, the findings of this study provide direct evidence that IP7 level and/or the enzymatic activity of IP7-generating kinases IP6Ks are elevated in ALS spinal cord. On the other hand, this study also showed that IP7 is not suitable for biofluid-based ALS diagnosis. Further investigation is required to elucidate a role of IP7 in ALS pathology and utilize IP7 metabolism on the diagnostic application of ALS.

A history of home mechanical ventilation: The past, present and future

This state-of-the-art review provides an overview of the history of home mechanical ventilation (HMV), including early descriptions of mechanical ventilation from ancient and Renaissance perspectives and the mass development of ventilators designed for long-term use during the poliomyelitis epidemic. Seminal data from key clinical trials supports the application of HMV in certain patients with chronic obstructive pulmonary disease, neuromuscular disease and obesity-related respiratory failure. Innovative engineering coupled with refined physiological understanding now permits widespread delivery of home mechanical ventilation to a global population, using portable devices with advanced ventilatory modes and telemonitoring capabilities. Exponential growth in digital technology continues, and ongoing research is needed to understand how to harness clinical and physiological data to benefit patients and healthcare services in a clinically- and cost-effective manner.

Neutrophils Are Associated with Higher Risk of Incident Amyotrophic Lateral Sclerosis in a BMI- and Age-Dependent Manner

OBJECTIVE

Peripheral immune markers have been associated with the progression and prognosis of amyotrophic lateral sclerosis (ALS). However, whether dysregulation of peripheral immunity is a risk factor for ALS or a consequence of motor neuron degeneration has not yet been clarified. We aimed to identify longitudinal associations between prediagnostic peripheral immunity and the risk of incident ALS.

METHODS

A total of 345,000 individuals from the UK Biobank between 2006 and 2010 were included at the baseline. The counts of peripheral immune markers (neutrophils, lymphocytes, monocytes, platelets, and CRP) and its derived metrics (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], lymphocyte-to-monocyte ratio [LMR], and systemic immune-inflammation index [SII]) were analyzed in relation to the following incident ALS by Cox proportional hazard models. Subgroup and interaction analyses were performed to explore the covariates of these relationships further.

RESULTS

After adjusting for all covariates, the multivariate analysis showed that high neutrophil counts and their derived metrics (NLR and SII) were associated with an increased risk of ALS incidence (per SD increment hazard ratio [HR] = 1.15, 95% confidence interval [CI] = 1.02-1.29 for neutrophils; HR = 1.15, 95% CI = 1.03-1.28 for NLR; and HR = 1.17, 95% CI = 1.05-1.30 for SII). Subgroup and interaction analyses revealed that body mass index (BMI) and age had specific effects on this association. In participants with BMI ≥ 25 or age < 65 years, higher neutrophil counts, and their metrics increased the risk of incident ALS; however, in participants with BMI < 25 or age ≥ 65 years, neutrophils had no effect on incident ALS.

INTERPRETATION

Our study provides evidence that increased neutrophil levels and neutrophil-derived metrics (NLR and SII) are associated with an increased risk of developing ALS. ANN NEUROL 2023;94:942-954.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Targeting Mitochondrial Sirtuins in Age-Related Neurodegenerative Diseases and Fibrosis

Aging is a natural and complex biological process that is associated with widespread functional declines in numerous physiological processes, terminally affecting multiple organs and tissues. Fibrosis and neurodegenerative diseases (NDs) often occur with aging, imposing large burdens on public health worldwide, and there are currently no effective treatment strategies for these diseases. Mitochondrial sirtuins (SIRT3-5), which are members of the sirtuin family of NAD+-dependent deacylases and ADP-ribosyltransferases, are capable of regulating mitochondrial function by modifying mitochondrial proteins that participate in the regulation of cell survival under various physiological and pathological conditions. A growing body of evidence has revealed that SIRT3-5 exert protective effects against fibrosis in multiple organs and tissues, including the heart, liver, and kidney. SIRT3-5 are also involved in multiple age-related NDs, including Alzheimer's disease, Parkinson's disease, and Huntington's disease. Furthermore, SIRT3-5 have been noted as promising targets for antifibrotic therapies and the treatment of NDs. This review systematically highlights recent advances in knowledge regarding the role of SIRT3-5 in fibrosis and NDs and discusses SIRT3-5 as therapeutic targets for NDs and fibrosis.

Quality of life in patients with chronic respiratory failure on home mechanical ventilation

Home mechanical ventilation (HMV) is a treatment for chronic respiratory failure that has shown clinical and cost effectiveness in patients with underlying COPD, obesity-related respiratory failure and neuromuscular disease (NMD). By treating chronic respiratory failure with adequate adherence to HMV, improvement in patient-reported outcomes including health-related quality of life (HRQoL) have been evaluated using general and disease-specific quantitative, semi-qualitative and qualitative methods. However, the treatment response in terms of trajectory of change in HRQoL is not uniform across the restrictive and obstructive disease groups. In this review, the effect of HMV on HRQoL across the domains of symptom perception, physical wellbeing, mental wellbeing, anxiety, depression, self-efficacy and sleep quality in stable and post-acute COPD, rapidly progressive NMD (such as amyotrophic lateral sclerosis), inherited NMD (including Duchenne muscular dystrophy) and obesity-related respiratory failure will be discussed.

Insight into Elderly ALS Patients in the Emilia Romagna Region: Epidemiological and Clinical Features of Late-Onset ALS in a Prospective, Population-Based Study

Few studies have focused on elderly (>80 years) amyotrophic lateral sclerosis (ALS) patients, who represent a fragile subgroup generally not included in clinical trials and often neglected because they are more difficult to diagnose and manage. We analyzed the clinical and genetic features of very late-onset ALS patients through a prospective, population-based study in the Emilia Romagna Region of Italy. From 2009 to 2019, 222 (13.76%) out of 1613 patients in incident cases were over 80 years old at diagnosis, with a female predominance (F:M = 1.18). Elderly ALS patients represented 12.02% of patients before 2015 and 15.91% from 2015 onwards (p = 0.024). This group presented with bulbar onset in 38.29% of cases and had worse clinical conditions at diagnosis compared to younger patients, with a lower average BMI (23.12 vs. 24.57 Kg/m²), a higher progression rate (1.43 vs. 0.95 points/month), and a shorter length of survival (a median of 20.77 vs. 36 months). For this subgroup, genetic analyses have seldom been carried out (25% vs. 39.11%) and are generally negative. Finally, elderly patients underwent less frequent nutritional- and respiratory-supporting procedures, and multidisciplinary teams were less involved at follow-up, except for specialist palliative care. The genotypic and phenotypic features of elderly ALS patients could help identify the different environmental and genetic risk factors that determine the age at which disease onset occurs. Since multidisciplinary management can improve a patient's prognosis, it should be more extensively applied to this fragile group of patients.

Retinal fingerprints of ALS in patients: Ganglion cell apoptosis and TDP-43/p62 misplacement

Introduction

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neuron function. Although ophthalmic deficits are not considered a classic symptom of ALS, recent studies suggest that changes in retinal cells, similar to those in the spinal cord motor neurons, have been observed in postmortem human tissues and animal models.

Methods

In this study, we examined by immunofluorescence analysis the retinal cell layers of sporadic ALS patients in post-mortem retinal slices. We evaluated the presence of cytoplasmic TDP-43 and SQSTM1/p62 aggregates, activation of the apoptotic pathway, and microglia and astrocytes reactivity.

Results

We found in the retinal ganglion cell layer of ALS patients the increase of mislocalized TDP-43, SQSTM1/p62 aggregates, activation of cleaved caspase-3, and microglia density, suggesting that retinal changes can be used as an additional diagnostic tool for ALS.

Discussion

The retina is considered part of the central nervous system, and neurodegenerative changes in the brain may be accompanied by structural and possibly functional changes in the neuroretina and ocular vasculature. Therefore, using in vivo retinal biomarkers as an additional diagnostic tool for ALS may provide an opportunity to longitudinally monitor individuals and therapies over time in a noninvasive and cost-effective manner.

Protective Effects of Lovastatin in a Population-Based ALS Study and Mouse Model

OBJECTIVE

The objective of this study was to use a novel combined pharmacoepidemiologic and amyotrophic lateral sclerosis (ALS) mouse model approach to identify potential motor neuron protective medications.

METHODS

We constructed a large, population-based case-control study to investigate motor neuron disease (MND) among US Medicare beneficiaries aged 66 to 90 in 2009. We included 1,128 incident MND cases and 56,400 age, sex, race, and ethnicity matched controls. We calculated MND relative risk for >1,000 active ingredients represented in Part D (pharmacy) claims in 2006 to 2007 (>1 year before diagnosis/reference). We then applied a comprehensive screening approach to select medications for testing in SOD1^G93A mice: sulfasalazine, telmisartan, and lovastatin. We treated mice with the human dose equivalent of the medication or vehicle via subcutaneous osmotic pump before onset of weakness. We then assessed weight, gait, and survival. In additional mice, we conducted histological studies.

RESULTS

We observed previously established medical associations for MND and an inverse dose-response association between lovastatin and MND, with 28% reduced risk at 40 mg/day. In SOD1^G93A mouse studies, sulfasalazine and telmisartan conferred no benefit, whereas lovastatin treatment delayed onset and prolonged survival. Lovastatin treated mice also had less microgliosis, misfolded SOD1, and spinal motor neuron loss in the ventral horn.

INTERPRETATION

Lovastatin reduced the risk of ALS in humans, which was confirmed in an ALS mouse model by delayed symptom onset, prolonged survival, and preservation of motor neurons. Although further studies to understand the mechanism are required, lovastatin may represent a potential neuroprotective therapy for patients with ALS. These data demonstrate the utility of a combined pharmacoepidemiologic and mouse model approach. ANN NEUROL 2023.

Amyotrophic lateral sclerosis

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

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.

Incidence of amyotrophic lateral sclerosis in older adults

INTRODUCTION/AIMS

We investigated the age- and sex-specific incidence and survival of Medicare beneficiaries with amyotrophic lateral sclerosis (ALS) in patients 66 to 90 years of age.

METHODS

We identified all incident ALS cases within a population-based sample of Medicare beneficiaries in 2009 (total: 22 000 177 person-years at risk for ALS). We calculated age- and sex-specific incidence in 2009 according to multiple, progressively more stringent case definitions. Our most inclusive definition required one ALS code, whereas the most restrictive definition required at least one additional ALS code more than 6 months after the first code, including one from a neurologist. We identified associated imaging studies and electrodiagnostic testing and followed all cases through the end of 2014 to determine survival.

RESULTS

The overall incidence for our most inclusive definition was 22.84 per 100 000 person-years for men and 16.05 per 100 000 person-years for women. The overall incidence was 5.72 per 100 000 person-years for men and 3.99 per 100 000 person-years for women for our most restrictive definition. For our most inclusive definition, fewer than 39.7% of cases ever had an ALS diagnosis from a neurologist, more than 50% had an electrodiagnostic test or imaging study, and 40.1% survived less than 1 year after diagnosis, with 25.5% of these cases surviving no more than 6 months. Cases not meeting the most restrictive definition were more likely than those who did meet the restrictive definition to be older, black, or Asian.

DISCUSSION

The oldest and marginalized Medicare beneficiaries diagnosed with ALS are less likely to be included in epidemiological studies with restrictive definitions, but future studies will need to assess the accuracy of diagnosis.

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

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

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.

Analysis of incidence of motor neuron disease in England 1998-2019: use of three linked datasets

Objective: This study uses three linked datasets to provide an estimate of incidence of motor neuron disease (MND) in England from 1998 to 2019. Comparison is made to previous British studies. It examines age at diagnosis and ethnicity of those affected.

Methods: The literature was searched for studies of MND incidence in Great Britain from 1995 to date. The QResearch and linked Hospital Episode Statistics and Death register databases were searched from 1998 to 2019 for cases of MND, and incidence calculated from 16.8 million adults and 112 million adult years of data.

Results: We found 6437 adults with a diagnosis of MND giving an incidence of MND of 5.69/100,000 person years (95% CI 5.51–5.88); 6.57 (6.41–6.99) in men and 4.72 (4.49–4.97) in women when age-standardized to the 2011 UK population. The median age of diagnosis was 72 years. Peak incidence occurred in the 80–84 year age group in men and 75–79 in women. Age-standardized incidence was as high in Bangladeshi, Black Caribbean, Indian, other Asian and Pakistani people as in White people. Black African and Chinese people had a lower incidence.

Conclusion: The use of three linked national datasets captured 33% more people than a primary care dataset alone. Patients were older than in previous studies and rates were high in all ethnic groups studied except Black African and Chinese people. We present the highest incidence of MND reported globally in the past 50 years. Methodological differences may in part explain differences with previous reports. The use of national datasets may have captured additional MND patients with serious comorbidities who have not seen a neurologist before death. A limitation of this approach is that unlike population registers, which minimize false positive diagnosis by neurologist review of each patient, we cannot review diagnosis for individuals as data are anonymized.

Use of Pharyngeal High-Resolution Manometry to Evaluate Dysphagia in Adults with Motor Neurone Disease: A Scoping Review

There has been a recent shift towards proactive dysphagia intervention in motor neurone disease (MND) to maintain physiological reserve. Pharyngeal high-resolution manometry (PHRM) can quantify swallowing pathophysiology to inform and evaluate proactive dysphagia intervention. This study aims to explore the current use of PHRM as a dysphagia evaluation in adults with MND. A scoping review based on the Joanna Briggs Framework was completed. Four electronic databases (PubMed, EMBASE, CINAHL and Web of Science core) were searched (inception to March 2021) by two independent researchers. Data were analysed according to (i) PHRM protocol and analysis methods and the feasibility of same, (ii) swallow biomechanics data and (iii) dysphagia intervention effects as measured by PHRM. Six studies with 78 people with MND (PwMND) were included. There was considerable variation in PHRM protocol and analysis methods. Five studies reported a 100% completion rate and three studies reported no adverse events. Swallow biomechanics data were reported across all studies. The effects of sensory stimulation, increased bolus consistency, effortful swallow and cricopharyngeal myotomy were evaluated using PHRM with 20 PwMND across four studies with varying effects. Literature on the use of PHRM in PwMND is limited. Variability in PHRM methods restricts comparison of metrics. PHRM appears to be a feasible tool for PwMND. PHRM can provide novel swallow physiology data in PwMND and quantify discrete effects of compensatory and surgical dysphagia interventions not detectable by videofluoroscopy or FEES. Further research on the effects of proactive dysphagia intervention as measured by PHRM is required.

Prevalence of amyotrophic lateral sclerosis in Latium region, Italy

OBJECTIVE

Prevalence estimate of amyotrophic lateral sclerosis (ALS) ranged between 1.1/100,000 and 11.2/100,000 inhabitants with different design of the study (prospective or retrospective) and sample size. The aim of this study is to conduct for the first time an estimate of the ALS prevalence in the Latium region.

MATERIALS AND METHODS

The study was performed in Latium, a region located in the center of Italy, with a population, as of January 1, 2016, of 5888.472 inhabitants. In this region, a network of 15 clinical centers (of which 4 referral ALS centers are located in Rome) and 10 local health authorities involved in the diagnosis and treatment of ALS patients has been identified. Each patient was classified according to the El Escorial revised criteria.

RESULTS

The prevalence study in 2016 identified 353 ALS cases (200 males). By considering population aged >=20 years, the total crude prevalence rate resulted 7.33 (CI95% 6.59-8.14) × 100,000 and 8.75 and 6.05 in males and females, respectively. Age-specific prevalence rates did not differ among males and females in the population aged less than 49 years. The difference emerged in population aged > 50 years. This type of diagnosis was recorded for 343 patients (11 missing). 68% of these patients have a definite diagnosis, 14% likely, 11% possible, and 12% defined as suspect.

CONCLUSIONS

The estimate of prevalence rates observed in this study is probably in line with the values reported in the literature for prospective prevalence studies.

Cognitive reserve in amyotrophic lateral sclerosis (ALS): a population-based longitudinal study

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is often associated with cognitive and/or behavioural impairment. Cognitive reserve (CR) may play a protective role in offsetting cognitive impairment. This study examined the relationship between CR and longitudinal change in cognition in an Irish ALS cohort.

METHODS

Longitudinal neuropsychological assessment was carried out on 189 patients over 16 months using the Edinburgh cognitive and behavioural ALS screen (ECAS) and an additional battery of neuropsychological tests. CR was measured by combining education, occupation and physical activity data. Joint longitudinal and time-to-event models were fitted to investigate the associations between CR, performance at baseline and decline over time while controlling for non-random drop-out.

RESULTS

CR was a significant predictor of baseline neuropsychological performance, with high CR patients performing better than those with medium or low CR. Better cognitive performance in high CR individuals was maintained longitudinally for ECAS, social cognition, executive functioning and confrontational naming. Patients displayed little cognitive decline over the course of the study, despite controlling for non-random drop-out.

CONCLUSIONS

These findings suggest that CR plays a role in the presentation of cognitive impairment at diagnosis but is not protective against cognitive decline. However, further research is needed to examine the interaction between CR and other objective correlates of cognitive impairment in ALS.

Clinical features and incidence trends of amyotrophic lateral sclerosis in Navarre, Spain, 2007-2018: a population-based study

Objective: Amyotrophic Lateral Sclerosis (ALS) is a heterogeneous neurodegenerative disorder with a median survival of 3 years. The aim of our study is to analyze the incidence, age-related phenotype and clinical onset, geographical distribution, survival and diagnostic delay of ALS in Navarre. Methods: This is a population-based observational retrospective study, including all residents of Navarre (a northern Spanish region) from 2007 to 2018, who were followed until 30th September 2020. Results: We observed a global incidence 2.47/100,000 person-years, with an upward trend throughout the study, with the highest being in the age group of 70-74 years old. Point prevalence in December 2018 was 6.64/100,000 inhabitants (95%CI: 4.52-8.45). Upper limbs weakness onset was the most frequent in young people (<60 years), and bulbar, lower limbs weakness, generalized and respiratory associated with older age. Bulbar phenotype is the most frequent in women and in 80+ group. The median survival from clinical onset was 27.7 months (95%CI: 24.0-31.4), higher in spinal phenotype and younger onset age, and the diagnosis delay was 10.0 months (95%CI: 8.9-11.2) from clinical onset. Conclusions: We have observed a trend of increasing incidence in older people where the bulbar phenotype and female predominance.

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.

Key Molecules and Pathways Underlying Sporadic Amyotrophic Lateral Sclerosis: Integrated Analysis on Gene Expression Profiles of Motor Neurons

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by progressive loss of motor neurons. The complex mechanisms underlying ALS are yet to be elucidated, while the lack of disease biomarkers and therapeutic options are associated with the poor prognosis of ALS patients. In this study, we performed bioinformatics analysis to clarify potential mechanisms in sporadic ALS (sALS). We compared three gene expression profiles (GSE18920, GSE56500, and GSE68605) of motor neurons obtained from sALS patients and healthy controls to discover differentially expressed genes (DEGs), and then performed integrated bioinformatics analyses to identify key molecules and pathways underlying sALS. We found that these DEGs were mainly enriched in the structure and functions of extracellular matrix (ECM), while functional enrichment in blood vessel morphogenesis was less correlated with motor neurons. The clustered subnetworks of the constructed protein-protein interaction network for DEGs and the group of selected hub genes were more significantly involved in the organization of collagen-containing ECM. The transcriptional factors database proposed RelA and NF-κB1 from NF-κB family as the key regulators of these hub genes. These results mainly demonstrated the alternations in ECM-related gene expression in motor neurons and suggested the role of NF-κB regulatory pathway in the pathogenesis of sALS.

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.

The epidemiology of amyotrophic lateral sclerosis in Moscow (Russia)

Objectives: To estimate the incidence of amyotrophic lateral sclerosis (ALS) in Moscow by investigating multiple sources of cases. Incidence rates from previous Russian studies ranged from 0.3 to 0.7 per 100,000/year. Methods: A retrospective study of the incidence of ALS was performed in the South district of Moscow (population, 1,760,000, 2015). Several data sources were investigated. The medical records of the calendar year 2015 were examined by an ALS expert who accepted only patients with definite or probable ALS according to the revised El Escorial criteria. Crude and standardized incidence rates were calculated, the latter adjusted to the Russian and the European population. Results: Twenty-two patients were found, accounting for a crude incidence of 1.25/100,000/year (95% CI 0.78-1.89) and a standardized incidence of 1.22 (Russia) and 1.28 (Europe). The sample included 11 men and 11 women aged 36-73 years (mean 56). Five patients (23%) had bulbar onset ALS. The mean diagnostic delay was 12.8 ± 9.2 months (8.5 ± 4.8 in men and 17.2 ± 10.6 in women) (p = 0.02). Family history of ALS was present in two cases. Conclusion: The incidence of ALS in the Russian Federation is higher than previously reported but lower than in other countries. Poor diagnostic ascertainment, particularly in women, and the shorter life expectancy of the Russian population are possible explanations.

Potential Preventive Strategies for Amyotrophic Lateral Sclerosis

It may seem useless to propose preventive measures for a disease without established pathogenesis and successful therapy, such as amyotrophic lateral sclerosis (ALS). However, we will show that ALS shares essential molecular mechanisms with aging and that established anti-aging strategies, such as healthy diet or individually adjusted exercise, may be successfully applied to ameliorate the condition of ALS patients. These strategies might be applied for prevention if persons at ALS risk could be identified early enough. Recent research advances indicate that this may happen soon.

Objectives, design and main findings until 2020 from the Rotterdam Study

The Rotterdam Study is an ongoing prospective cohort study that started in 1990 in the city of Rotterdam, The Netherlands. The study aims to unravel etiology, preclinical course, natural history and potential targets for intervention for chronic diseases in mid-life and late-life. The study focuses on cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1700 research articles and reports. This article provides an update on the rationale and design of the study. It also presents a summary of the major findings from the preceding 3 years and outlines developments for the coming period.

Validity of death certificates in the identification of cases of amyotrophic lateral sclerosis (ALS) in the Limousin region, France. A population-based study

Objectives: Mortality data have been used as a proxy for amyotrophic lateral sclerosis (ALS) incidence. However, the accuracy of death certificates (DCs) needs to be validated. This study aims to assess the accuracy of DCs in the identification of ALS cases. Methods: This is a retrospective population-based validation study. DC information, provided by the "Centre d'épidémiologie sur les causes médicales de décès", including ICD10 codes for specific cause of death for patients recorded in the French register of ALS cases in the Limousin region (FRALim) and deceased between 2000 and 2011, was assessed. The FRALim register was used as gold standard. Results: In the study period, DCs were available for 197 patients diagnosed with ALS, of whom 185 (93.9%) were correctly identified with an ICD10 code (G12.2) corresponding to ALS. The overall sensitivity was 93.9% (95% CI 89.6-96.8) and the positive predictive value (PPV) was 64.9 (59.1-70.4), with higher values in the period 2004-2011 (75.0-78.9). Stratification for sex, age, and year at death did not show difference in accuracy, except a lower PPV during the first years of observation. Conclusions: DCs identifying subjects with a diagnosis of ALS in the Limousin region, France showed an overall good sensitivity and moderate PPV. The absence of ALS diagnosis as the main and underlying cause of death on DCs highlights the need to use DC in combination with other administrative data to create algorithms with higher accuracy performances.

A rare CACNA1H variant associated with amyotrophic lateral sclerosis causes complete loss of Cav3.2 T-type channel activity

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progressive loss of cortical, brain stem and spinal motor neurons that leads to muscle weakness and death. A previous study implicated CACNA1H encoding for Cav3.2 calcium channels as a susceptibility gene in ALS. In the present study, two heterozygous CACNA1H variants were identified by whole genome sequencing in a small cohort of ALS patients. These variants were functionally characterized using patch clamp electrophysiology, biochemistry assays, and molecular modeling. A previously unreported c.454GTAC > G variant produced an inframe deletion of a highly conserved isoleucine residue in Cav3.2 (p.ΔI153) and caused a complete loss-of-function of the channel, with an additional dominant-negative effect on the wild-type channel when expressed in trans. In contrast, the c.3629C > T variant caused a missense substitution of a proline with a leucine (p.P1210L) and produced a comparatively mild alteration of Cav3.2 channel activity. The newly identified ΔI153 variant is the first to be reported to cause a complete loss of Cav3.2 channel function. These findings add to the notion that loss-of-function of Cav3.2 channels associated with rare CACNA1H variants may be risk factors in the complex etiology of ALS.

Newer Immunotherapies for the Treatment of Acute Neuromuscular Disease in the Critical Care Unit

OPINION STATEMENT

PURPOSE OF REVIEW: In this review, we discuss current treatment options for commonly encountered neuromuscular disorders in intensive care units. We will discuss epidemiology, pathophysiology, and acute and chronic treatment options for myasthenia gravis, Guillain-Barré syndrome, West Nile virus, Botulism, and amyotrophic lateral sclerosis.

RECENT FINDINGS

Eculizumab is the newest immunomodulator therapy approved by the Food and Drug Administration in treatment of myasthenia gravis, shown to improve long-term functional outcomes. Edaravone is the newest therapy in management of amyotrophic lateral sclerosis, shown to slow functional deterioration. Efgartigimod showed great promise in a phase 2 safety and efficacy trial in the treatment of stable generalized myasthenia gravis. Eculizumab was found to be safe in a small phase 2 trial for use in Guillain-Barré syndrome. Currently, therapies such as plasma exchange, intravenous immunoglobulins, and steroids remain the mainstay of treatment in the ICU for many neuromuscular disorders. While there are some newer immunotherapies available, few have been studied in the acute setting. However, with the advent of new immunotherapies and biologics, changes in these approaches may be on the horizon.

Global variation in prevalence and incidence of amyotrophic lateral sclerosis: a systematic review and meta-analysis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a global disease, which adversely affects the life quality of patients and significantly increases the burden of families and society. We aimed to assess the changing incidence, prevalence of ALS around the world.

METHODS

We searched Medline, Embase, Web of Science, and Cochrane library to identify articles published until September 9, 2018. Each included study was independently reviewed for methodological quality by two reviewers. We used a random-effects model to summarize individual studies and assessed heterogeneity (I²) with the χ² test on Cochrane's Q statistic.

RESULTS

We identified 124 studies that were eligible for final inclusion, including 110 studies of incidence and 58 studies of prevalence. The overall crude worldwide ALS prevalence and incidence were 4.42 (95% CI 3.92-4.96) per 1,00,000 population and 1.59 (95% CI 1.39-1.81) per 1,00,000 person-years, respectively. ALS prevalence and incidence increased by age until the age of 70-79. Since 1957, incidence has been significantly rising year by year, and this upward trend was weakened after standardization. The longest survival time were in Asia (ranging from 3.74 years in South Asia to 9.23 years in West Asia).

CONCLUSIONS

With the aggravation of population aging and the rapid growth of economy, developing regions following the development pattern of the developed regions may suffer rising ALS prevalence and incidence which may increase their disease burden as well. These data highlight the need for research into underlying mechanism and innovations in health-care systems.

Histamine beyond its effects on allergy: Potential therapeutic benefits for the treatment of Amyotrophic Lateral Sclerosis (ALS)

ALS currently remains a challenge despite many efforts in performing successful clinical trials and formulating therapeutic solutions. By learning from current failures and striving for success, scientists and clinicians are checking every possibility to search for missing hints and efficacious treatments. Because the disease is very complex and heterogeneous and, moreover, targeting not only motor neurons but also several different cell types including muscle, glial, and immune cells, the right answer to ALS is conceivably a multidrug strategy or the use of broad-spectrum molecules. The aim of the present work is to gather evidence about novel perspectives on ALS pathogenesis and to present recent and innovative paradigms for therapy. In particular, we describe how an old molecule possessing immunomodulatory and neuroprotective functions beyond its recognized effects on allergy, histamine, might have a renewed and far-reaching momentum in ALS.

Association Between Premorbid Body Mass Index and Amyotrophic Lateral Sclerosis: Causal Inference Through Genetic Approaches

Purpose: Inverse association between premorbid body mass index (BMI) and amyotrophic lateral sclerosis (ALS) was implied in observational studies; however, whether this association is causal remains largely unknown. Materials and Methods: We first conducted a meta-analysis to investigate whether there exits an association between premorbid BMI and ALS. We then employed a two-sample Mendelian randomization approach to evaluate the causal relationship of genetically increased BMI with the risk of ALS. The Mendelian randomization analysis was implemented using summary statistics for independent instruments obtained from large-scale genome-wide association studies of BMI (up to ~770,000 individuals) and ALS (up to ~81,000 individuals). The causal effect of BMI on ALS was estimated using inverse-variance weighted methods and was further validated through extensive complementary and sensitivity analyses. Results: The meta-analysis showed that a unit increase of premorbid BMI can result in about 3.0% (95% CI 2.1-4.5%) risk reduction of ALS. Using 1,031 instruments that were strongly related to BMI, the causal effect of per one standard deviation increase of BMI was estimated to be 1.04 (95% CI 0.97-1.11, p = 0.275) in the European population. This null association between BMI and ALS also held in the East Asian population and was robust against various modeling assumptions and outlier biases. Additionally, the Egger-regression and MR-PRESSO ruled out the possibility of horizontal pleiotropic effects of instruments. Conclusion: Our results do not support the causal role of genetically increased or decreased BMI on the risk of ALS.

Changing epidemiology of motor neurone disease in Scotland

OBJECTIVES

Scotland benefits from an integrated national healthcare team for motor neurone disease (MND) and a tradition of rich clinical data capture using the Scottish MND Register (launched in 1989; one of the first national registers). The Scottish register was re-launched in 2015 as Clinical Audit Research and Evaluation of MND (CARE-MND), an electronic platform for prospective, population-based research. We aimed to determine if incidence of MND is changing over time.

METHODS

Capture-recapture methods determined the incidence of MND in 2015-2016. Incidence rates for 2015-2016 and 1989-1998 were direct age and sex standardised to allow time-period comparison. Phenotypic characteristics and socioeconomic status of the cohort are described.

RESULTS

Coverage of the CARE-MND platform was 99%. Crude incidence in the 2015-2017 period was 3.83/100,000 person-years (95% CI 3.53-4.14). Direct age-standardised incidence in 2015 was 3.42/100,000 (95% CI 2.99-3.91); in 2016, it was 2.89/100,000 (95% CI 2.50-3.34). The 1989-1998 direct standardised annual incidence estimate was 2.32/100,000 (95% CI 2.26-2.37). 2015-2016 standardised incidence was 66.9% higher than Northern European estimates. Socioeconomic status was not associated with MND.

CONCLUSIONS

Our data show a changing landscape of MND in Scotland, with a rise in incidence by 36.0% over a 25-year period. This is likely attributable to ascertainment in the context of improved neurological services in Scotland. Our data suggest that CARE-MND is a reliable national resource and findings can be extrapolated to the other Northern European populations.

Amyotrophic Lateral Sclerosis, a Possible Sequela of Chronic Myeloid Leukemia

Amyotrophic lateral sclerosis is a fatal neurodegenerative disorder with progressive deterioration of both upper and lower motor neuron functions. It is a rare disease with one study demonstrating a prevalence of 3.9 cases per 100,000 in the USA in the year 2010-2011. It is a fatal disease with most of the deaths resulting from respiratory failure. There is no cure of this illness with some evidence supporting an improved median survival by two to three months with Riluzole (one of the agents used for treatment). Not much is known about the possible etiologies of ALS, a few studies have shown a possible likely association of ALS with various malignancies. Here we present an interesting case of a 35-year-old female with a diagnosis of chronic myeloid leukemia for seven years presented with a sub-acute decline in her motor function.

Global, regional, and national burden of motor neuron diseases 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Understanding how prevalence, incidence, and mortality of motor neuron diseases change over time and by location is crucial for understanding the causes of these disorders and for health-care planning. Our aim was to produce estimates of incidence, prevalence, and disability-adjusted life-years (DALYs) for motor neuron diseases for 195 countries and territories from 1990 to 2016 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016.

METHODS

The motor neuron diseases included in this study were amyotrophic lateral sclerosis, spinal muscular atrophy, hereditary spastic paraplegia, primary lateral sclerosis, progressive muscular atrophy, and pseudobulbar palsy. Incidence, prevalence, and DALYs were estimated using a Bayesian meta-regression model. We analysed 14 165 site-years of vital registration cause of death data using the GBD 2016 cause of death ensemble model. The 84 risk factors quantified in GBD 2016 were tested for an association with incidence or death from motor neuron diseases. We also explored the relationship between Socio-demographic Index (SDI; a compound measure of income per capita, education, and fertility) and age-standardised DALYs of motor neuron diseases.

FINDINGS

In 2016, globally, 330 918 (95% uncertainty interval [UI] 299 522-367 254) individuals had a motor neuron disease. Motor neuron diseases have caused 926 090 (881 566-961 758) DALYs and 34 325 (33 051-35 364) deaths in 2016. The worldwide all-age prevalence was 4·5 (4·1-5·0) per 100 000 people, with an increase in age-standardised prevalence of 4·5% (3·4-5·7) over the study period. The all-age incidence was 0·78 (95% UI 0·71-0·86) per 100 000 person-years. No risk factor analysed in GBD showed an association with motor neuron disease incidence. The largest age-standardised prevalence was in high SDI regions: high-income North America (16·8, 95% UI 15·8-16·9), Australasia (14·7, 13·5-16·1), and western Europe (12·9, 11·7-14·1). However, the prevalence and incidence were lower than expected based on SDI in high-income Asia Pacific.

INTERPRETATION

Motor neuron diseases have low prevalence and incidence, but cause severe disability with a high fatality rate. Incidence of motor neuron diseases has geographical heterogeneity, which is not explained by any risk factors quantified in GBD, suggesting other unmeasured risk factors might have a role. Between 1990 and 2016, the burden of motor neuron diseases has increased substantially. The estimates presented here, as well as future estimates based on data from a greater number of countries, will be important in the planning of services for people with motor neuron diseases worldwide.

FUNDING

Bill & Melinda Gates Foundation.