Variation in worldwide incidence of amyotrophic lateral sclerosis: a meta-analysis

All Roads Lead to Rome: Different Molecular Players Converge to Common Toxic Pathways in Neurodegeneration

Multiple neurodegenerative diseases (NDDs) such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and Huntington’s disease (HD) are being suggested to have common cellular and molecular pathological mechanisms, characterized mainly by protein misfolding and aggregation. These large inclusions, most likely, represent an end stage of a molecular cascade; however, the soluble misfolded proteins, which take part in earlier steps of this cascade, are the more toxic players. These pathological proteins, which characterize each specific disease, lead to the selective vulnerability of different neurons, likely resulting from a combination of different intracellular mechanisms, including mitochondrial dysfunction, ER stress, proteasome inhibition, excitotoxicity, oxidative damage, defects in nucleocytoplasmic transport, defective axonal transport and neuroinflammation. Damage within these neurons is enhanced by damage from the nonneuronal cells, via inflammatory processes that accelerate the progression of these diseases. In this review, while acknowledging the hallmark proteins which characterize the most common NDDs; we place specific focus on the common overlapping mechanisms leading to disease pathology despite these different molecular players and discuss how this convergence may occur, with the ultimate hope that therapies effective in one disease may successfully translate to another.

Neurofilament light and heterogeneity of disease progression in amyotrophic lateral sclerosis: development and validation of a prediction model to improve interventional trials

Background

Interventional trials in amyotrophic lateral sclerosis (ALS) suffer from the heterogeneity of the disease as it considerably reduces statistical power. We asked if blood neurofilament light chains (NfL) could be used to anticipate disease progression and increase trial power.

Methods

In 125 patients with ALS from three independent prospective studies—one observational study and two interventional trials—we developed and externally validated a multivariate linear model for predicting disease progression, measured by the monthly decrease of the ALS Functional Rating Scale Revised (ALSFRS-R) score. We trained the prediction model in the observational study and tested the predictive value of the following parameters assessed at diagnosis: NfL levels, sex, age, site of onset, body mass index, disease duration, ALSFRS-R score, and monthly ALSFRS-R score decrease since disease onset. We then applied the resulting model in the other two study cohorts to assess the actual utility for interventional trials. We analyzed the impact on trial power in mixed-effects models and compared the performance of the NfL model with two currently used predictive approaches, which anticipate disease progression using the ALSFRS-R decrease during a three-month observational period (lead-in) or since disease onset (ΔFRS).

Results

Among the parameters provided, the NfL levels (P < 0.001) and the interaction with site of onset (P < 0.01) contributed significantly to the prediction, forming a robust NfL prediction model (R = 0.67). Model application in the trial cohorts confirmed its applicability and revealed superiority over lead-in and ΔFRS-based approaches. The NfL model improved statistical power by 61% and 22% (95% confidence intervals: 54%–66%, 7%–29%).

Conclusion

The use of the NfL-based prediction model to compensate for clinical heterogeneity in ALS could significantly increase the trial power.

NCT00868166, registered March 23, 2009; NCT02306590, registered December 2, 2014.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40035-021-00257-y.

Amyotrophic lateral sclerosis (ALS) among immigrant groups and Swedish-born individuals: a cohort study of all adults 18 years of age and older in Sweden

Background

There is a lack of studies of amyotrophic lateral sclerosis (ALS) in immigrants.

Objective

The objective is to study the association between country of birth and incident ALS in first-generation immigrants versus Swedish-born individuals, and in second-generation immigrants versus native Swedes.

Methods

Study populations included all adults aged 18 years and older in Sweden, in the first-generation study 6,128,698 individuals (2,975,141 men, 3,153,557 women) with 5,344 ALS cases (3017 men, 2327 women), and in the second-generation study 4,588,845 individuals (2,346,855 men and 2,241,990 women) with 3,420 cases (2027 men and 1393 women). ALS was defined as having at least one registered diagnosis of ALS in the National Patient Register 1998–2017. The incidence of ALS in different first-generation immigrant groups versus Swedish-born individuals was assessed by Cox regression, expressed as hazard ratios (HRs) with 95% confidence intervals (CI). The models were stratified by sex and adjusted for age, geographical residence in Sweden, educational level, marital status, and neighbourhood socioeconomic status.

Results

After adjusting for potential confounders, the HRs were lower in foreign-born men, 0.71 (95% CI 0.63–0.81), and women, 0.80 (95% CI 0.70–0.92). The ALS risk was lower among men and women from most Western countries (Europe outside Nordic countries, and North America), and from other regions of the world (Africa, Asia, and Latin America). Among men and women with foreign-born parents, the risk of ALS did not differ significantly from native Swedes.

Significance

In general, the risk of ALS was lower in first-generation men and women but did not differ in second-generation individuals.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10765-6.

Therapeutic Potential of Polyphenols in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are severe neurodegenerative disorders that belong to a common disease spectrum. The molecular and cellular aetiology of the spectrum is a highly complex encompassing dysfunction in many processes, including mitochondrial dysfunction and oxidative stress. There is a paucity of treatment options aside from therapies with subtle effects on the post diagnostic lifespan and symptom management. This presents great interest and necessity for the discovery and development of new compounds and therapies with beneficial effects on the disease. Polyphenols are secondary metabolites found in plant-based foods and are well known for their antioxidant activity. Recent research suggests that they also have a diverse array of neuroprotective functions that could lead to better treatments for neurodegenerative diseases. We present an overview of the effects of various polyphenols in cell line and animal models of ALS/FTD. Furthermore, possible mechanisms behind actions of the most researched compounds (resveratrol, curcumin and green tea catechins) are discussed.

Estimated Prevalence and Incidence of Amyotrophic Lateral Sclerosis and SOD1 and C9orf72 Genetic Variants

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a rare neurological disorder characterized by progressive deterioration of motor neurons. Assessment of the size/geographic distribution of the ALS population, including ALS with genetic origin, is needed to understand the burden of the disease and the need for clinical intervention and therapy.

OBJECTIVES

The main objective of this study was to estimate the number of prevalent and incident ALS cases overall and superoxide dismutase 1 (SOD1) and chromosome 9 open reading frame 72 (C9orf72) ALS in 22 countries across Europe (Belgium, France, Germany, Ireland, Italy, Netherlands, Norway, Russia, Spain, Sweden, and UK), North America (USA and Canada), Latin America (Argentina, Brazil, Colombia, Mexico, and Uruguay), and Asia (China, Japan, South Korea, and Taiwan).

METHODS

A comprehensive literature search was conducted to identify population-based studies reporting ALS prevalence and/or incidence rates. Pooled prevalence and incidence rates were obtained using a meta-analysis approach at the country and regional geographic level. A country-level pooled estimate was used when ≥2 studies were available per country and geographic regional pooled estimates were used otherwise. The proportion of cases with a SOD1 or C9orf72 mutation among sporadic (sALS) and familial (fALS) cases were obtained from a previous systematic review and meta-analysis.

RESULTS

Pooled prevalence rates (per 100,000 persons) and incidence rates (per 100,000 person-years) were 6.22 and 2.31 for Europe, 5.20 and 2.35 for North America, 3.41 and 1.25 for Latin America, 3.01 and 0.93 for Asian countries excluding Japan, and 7.96 and 1.76 for Japan, respectively. Significant heterogeneity in reported incidence and prevalence was observed within and between countries/geographic regions. The estimated number of 2020 ALS cases across the 22 countries is 121,028 prevalent and 41,128 incident cases. The total estimated number of prevalent SOD1 cases is 2,876 cases, of which, 1,342 (47%) were fALS and 1,534 (53%) were sALS, and the number of incident SOD1 cases is 946 (434 [46%] fALS and 512 [54%] sALS). The total estimated number of prevalent C9orf72 cases is 4,545 (1,198 [26%] fALS, 3,347 [74%] sALS), and the number of incident C9orf72 cases is 1,706 (450 [26%] fALS and 1,256 [74%] sALS).

DISCUSSION

The estimated number of patients with SOD1 and C9orf72 ALS suggests that although the proportions of SOD1 and C9orf72 are higher among those with fALS, the majority of SOD1 and C9orf72 ALS cases may be found among those with sALS (about 53 and 74%, respectively). These results suggest that classification of fALS based on reported family history does not capture the full picture of ALS of genetic origin.

Genetic testing in motor neuron disease and frontotemporal dementia: a 5-year multicentre evaluation

INTRODUCTION

Motor neuron disease (MND) and frontotemporal dementia (FTD) comprise a neurodegenerative disease spectrum. Genetic testing and counselling is complex in MND/FTD owing to incomplete penetrance, variable phenotype and variants of uncertain significance. Affected patients and unaffected relatives are commonly referred to clinical genetics to consider genetic testing. However, no consensus exists regarding how such genetic testing should best be undertaken and on which patients.

OBJECTIVE

We sought to ascertain UK clinical genetics testing practice in MND/FTD referrals, with the aim of helping inform guideline development.

METHODS

MND/FTD clinical genetics referrals comprising both affected patients and unaffected relatives between 2012 and 2016 were identified and a standardised proforma used to collate data from clinical records.

RESULTS

301 referrals (70 affected, 231 unaffected) were reviewed across 10 genetics centres. Previously identified familial variants were known in 107 cases and 58% subsequently underwent testing (8 of 8 diagnostic and 54 of 99 predictive). The median number of genetic counselling appointments was 2 for diagnostic and 4 for predictive testing. Importantly, application of current UK Genomic Test Directory eligibility criteria would not have resulted in detection of all pathogenic variants observed in this cohort.

CONCLUSION

We propose pragmatic MND/FTD genetic testing guidelines based on appropriate genetic counselling.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION/CONCLUSION

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

Muscle Function Differences between Patients with Bulbar and Spinal Onset Amyotrophic Lateral Sclerosis. Does It Depend on Peripheral Glucose?

BACKGROUND

One of the pathogenic mechanisms of ALS disease is perturbed energy metabolism particularly glucose metabolism. Given the substantial difference in the severity and the prognosis of the disease, depending on whether it has a bulbar or spinal onset, the aim of the study was to determine metabolic differences between both types of ALS, as well as the possible relationship with muscle function.

MATERIALS AND METHODS

A descriptive, analytical, quantitative, and transversal study was carried out in hospitals and Primary Care centers in the region of Valencia, Spain. Fasting glucose and alkaline phosphatase (AP) levels in venous blood, muscle percentage, fat percentage, muscle strength (MRC scale), and functional capacity (Barthel Index) were measured in 31 patients diagnosed with ALS (20 with spinal onset ALS and 11 with bulbar onset ALS). A healthy control of 29 people was included.

RESULTS

No significant differences were observed in blood AP and glucose levels between spinal onset and bulbar onset ALS patients. However, a significant positive correlation was observed between the mean values of both substances in patients with spinal onset ALS. Moreover, a lower percentage of muscle mass and a higher percentage of fat mass were also seen in spinal ALS patients, who also presented lower muscle strength and lower functional capacity.

CONCLUSION

The results of this study seem to point to a possible difference in the peripheral use of glucose between patients with bulbar onset ALS and spinal onset ALS, who appear to have possible insulin resistance. These metabolic differences could explain the lower muscle percentage and lower muscular function in spinal onset ALS patients, although further studies are required.

Defective Oligodendroglial Lineage and Demyelination in Amyotrophic Lateral Sclerosis

Motor neurons and their axons reaching the skeletal muscle have long been considered as the best characterized targets of the degenerative process observed in amyotrophic lateral sclerosis (ALS). However, the involvement of glial cells was also more recently reported. Although oligodendrocytes have been underestimated for a longer time than other cells, they are presently considered as critically involved in axonal injury and also conversely constitute a target for the toxic effects of the degenerative neurons. In the present review, we highlight the recent advances regarding oligodendroglial cell involvement in the pathogenesis of ALS. First, we present the oligodendroglial cells, the process of myelination, and the tight relationship between axons and myelin. The histological abnormalities observed in ALS and animal models of the disease are described, including myelin defects and oligodendroglial accumulation of pathological protein aggregates. Then, we present data that establish the existence of dysfunctional and degenerating oligodendroglial cells, the chain of events resulting in oligodendrocyte degeneration, and the most recent molecular mechanisms supporting oligodendrocyte death and dysfunction. Finally, we review the arguments in support of the primary versus secondary involvement of oligodendrocytes in the disease and discuss the therapeutic perspectives related to oligodendrocyte implication in ALS pathogenesis.

Estimation of the prevalence and incidence of motor neuron diseases in two Spanish regions: Catalonia and Valencia

According to the degree of upper and lower motor neuron degeneration, motor neuron diseases (MND) can be categorized into amyotrophic lateral sclerosis (ALS), primary lateral sclerosis (PLS) or progressive muscular atrophy (PMA). Although several studies have addressed the prevalence and incidence of ALS, there is a high heterogeneity in their results. Besides this, neither concept has been previously studied in PLS or PMA. Thus, the objective of this study was to estimate the prevalence and incidence of MND, (distinguishing ALS, PLS and PMA), in the Spanish regions of Catalonia and Valencia in the period 2011-2019. Two population-based Spanish cohorts were used, one from Catalonia and the other from Valencia. Given that the samples that comprised both cohorts were not random, i.e., leading to a selection bias, we used a two-part model in which both the individual and contextual observed and unobserved confounding variables are controlled for, along with the spatial and temporal dependence. The prevalence of MND was estimated to be between 3.990 and 6.334 per 100,000 inhabitants (ALS between 3.248 and 5.120; PMA between 0.065 and 0.634; and PLS between 0.046 and 1.896), and the incidence between 1.682 and 2.165 per 100,000 person-years for MND (ALS between 1.351 and 1.754; PMA between 0.225 and 0.628; and PLS between 0.409-0.544). Results were similar in the two regions and did not differ from those previously reported for ALS, suggesting that the proposed method is robust and that neither region presents differential risk or protective factors.

The Association Between Maladaptive Metacognitive Beliefs and Emotional Distress in People Living With Amyotrophic Lateral Sclerosis

OBJECTIVE

Approximately half of all people living with amyotrophic lateral sclerosis (ALS) experience persistent or recurrent emotional distress, yet little is known about the psychological processes that maintain emotional distress in this population. The self-regulatory executive functioning (S-REF) model specifies that maladaptive metacognitive beliefs and processes are central to the development and maintenance of emotional distress. This study explored whether maladaptive metacognitive beliefs are associated with emotional distress after controlling for demographic factors, time since diagnosis, and current level of physical functioning.

DESIGN

In a cross-sectional design, 75 adults with a diagnosis of ALS completed self-report questionnaires. Participants had a mean age of 60.40 years, mean duration of symptoms 63.92 months, and male:female gender ratio of 14:11.

MAIN OUTCOME MEASURES

Questionnaires assessed emotional distress (HADS, adapted for ALS), physical functioning (ALSFRS-R), repetitive negative thinking (RTQ-10), metacognitive beliefs (MCQ-30), and demographic factors.

RESULTS

Maladaptive metacognitive beliefs explained additional variance in emotional distress after controlling for age, gender, time since diagnosis, physical functioning, and repetitive negative thinking. Repetitive negative thinking partially mediated the relationships between positive and negative metacognitive beliefs and emotional distress.

CONCLUSIONS

These data support the utility of the metacognitive model in understanding emotional distress in people with ALS. Examination of the temporal relationship between maladaptive metacognitive beliefs and emotional distress in people living with ALS may help to guide the development of therapeutic approaches.

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.

Diagnostics of Amyotrophic Lateral Sclerosis: Up to Date

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by gradual loss of upper and lower motor neurons and their pathways, usually without affecting the extraocular and sphincter muscles. The cause of the disease is not yet known. It is a chain of subsequent events, ending in programmed cell death in selective neuronal subpopulations. The prognosis for survival is rather short with a median of 2 to 4 years. Survival may be prolonged based on prompt diagnosis, ALS subtype and proper management with supportive treatment (tracheostomy, gastrostomy, etc.). According to the clinical picture, the typical form of ALS with upper and lower motoneuron involvement and progressive bulbar paralysis with bulbar muscle involvement is observed. The ALS form with progressive muscle atrophy, where only the lower motoneuron is affected, and primary lateral sclerosis with only upper motoneuron damage are rare. Familiar forms of ALS (FALS) associated with specific genes (the most common is C9orf72) have been discovered. FALS is usually associated with dementia (frontotemporal lobar dementia, FTLD), behavioral disorders, cognitive dysfunction and impairment of executive functions. The diagnosis of ALS is determined by excluding other conditions and utilizing clinical examinations, laboratory and genetic tests and nerve conduction/needle electromyography studies (EMG). Needle EMG records abnormal activities at rest and looks for neurogenic patterns during muscle contraction. Motor evoked potentials after transcranial magnetic stimulation remain the test of choice to identify impairment of upper motor neurons. New biochemical, neurophysiological and morphological biomarkers are extensively studied as early diagnostic and prognostic factors and have implications for clinical trials, research and drug development.

A Rare Case of Amyotrophic Lateral Sclerosis With Asymmetrical Phrenic Nerve Lesion Presenting With Acute Respiratory Failure as an Initial Manifestation

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that causes muscle weakness, disability, and eventually, death. Respiratory failure is the leading cause of death in ALS. It is common in the advanced stages of the disease. However, acute respiratory failure is a presenting symptom in only a small number of patients, such as in our case. Here, we present the case of a 54-year-old woman with ALS presenting with respiratory failure due to unilateral diaphragm paralysis as the first manifestation. Although rare, respiratory muscle function failure can be the first symptom of motor neuron disease. Therefore, a motor neuron disease such as ALS, which leads to respiratory muscle weakness and diaphragm paralysis, should be considered in cases of unexplained acute respiratory failure.

Genetic analysis of ALS cases in the isolated island population of Malta

Genetic isolates are compelling tools for mapping genes of inherited disorders. The archipelago of Malta, a sovereign microstate in the south of Europe is home to a geographically and culturally isolated population. Here, we investigate the epidemiology and genetic profile of Maltese patients with amyotrophic lateral sclerosis (ALS), identified throughout a 2-year window. Cases were largely male (66.7%) with a predominant spinal onset of symptoms (70.8%). Disease onset occurred around mid-age (median age: 64 years, men; 59.5 years, female); 12.5% had familial ALS (fALS). Annual incidence rate was 2.48 (95% CI 1.59–3.68) per 100,000 person-years. Male-to-female incidence ratio was 1.93:1. Prevalence was 3.44 (95% CI 2.01–5.52) cases per 100,000 inhabitants on 31^st December 2018. Whole-genome sequencing allowed us to determine rare DNA variants that change the protein-coding sequence of ALS-associated genes. Interestingly, the Maltese ALS patient cohort was found to be negative for deleterious variants in C9orf72, SOD1, TARDBP or FUS genes, which are the most commonly mutated ALS genes globally. Nonetheless, ALS-associated repeat expansions were identified in ATXN2 and NIPA1. Variants predicted to be damaging were also detected in ALS2, DAO, DCTN1, ERBB4, SETX, SCFD1 and SPG11. A total of 40% of patients with sporadic ALS had a rare and deleterious variant or repeat expansion in an ALS-associated gene, whilst the genetic cause of two thirds of fALS cases could not be pinpointed to known ALS genes or risk loci. This warrants further studies to elucidate novel genes that cause ALS in this unique population isolate.

An overview on amyotrophic lateral sclerosis and cadmium

The present review represents an update about the knowledge of the possible role of Cadmium (Cd) in amyotrophic lateral sclerosis (ALS) initiation and its progression. ALS is a neurodegenerative disease that occurs in adulthood; its etiology is unknown and leads to death within a few years from its appearance. Among the various possible causes that can favor the development of the disease, heavy metals cannot be excluded. Cadmium is a heavy metal that does not play a biological role, but its neurotoxicity is well known. Numerous in vitro studies on cell and animal models confirm the toxicity of the metal on the nervous system, but these data are not accompanied by an epidemiological evidence, and, thus, an unclear correlation between Cd and the onset of the disease can be pointed out. On the other hand, a possible multifactorial and synergic mechanism in which Cd may have a role can explain the ALS onset. More efforts in new clinical, biochemical, and epidemiological studies are necessary to better elucidate the involvement of Cd in this lethal disease.

Multiple-Tissue Integrative Transcriptome-Wide Association Studies Discovered New Genes Associated With Amyotrophic Lateral Sclerosis

Genome-wide association studies (GWAS) have identified multiple causal genes associated with amyotrophic lateral sclerosis (ALS); however, the genetic architecture of ALS remains completely unknown and a large number of causal genes have yet been discovered. To full such gap in part, we implemented an integrative analysis of transcriptome-wide association study (TWAS) for ALS to prioritize causal genes with summary statistics from 80,610 European individuals and employed 13 GTEx brain tissues as reference transcriptome panels. The summary-level TWAS analysis with single brain tissue was first undertaken and then a flexible p-value combination strategy, called summary data-based Cauchy Aggregation TWAS (SCAT), was proposed to pool association signals from single-tissue TWAS analysis while protecting against highly positive correlation among tests. Extensive simulations demonstrated SCAT can produce well-calibrated p-value for the control of type I error and was often much more powerful to identify association signals across various scenarios compared with single-tissue TWAS analysis. Using SCAT, we replicated three ALS-associated genes (i.e., ATXN3, SCFD1, and C9orf72) identified in previous GWASs and discovered additional five genes (i.e., SLC9A8, FAM66D, TRIP11, JUP, and RP11-529H20.6) which were not reported before. Furthermore, we discovered the five associations were largely driven by genes themselves and thus might be new genes which were likely related to the risk of ALS. However, further investigations are warranted to verify these results and untangle the pathophysiological function of the genes in developing ALS.

Personalized Prevention in Mercury-Induced Amyotrophic Lateral Sclerosis: A Case Report

Chronic exposure to low levels of mercury is involved in the development of motor neuron diseases (MND). Genetic alterations may have a crucial role in the onset and progression. We presented a case of a TANK-binding kinase 1 (TBK1)-mutated 54-year-old male worker who developed a MND due to chronic mercury exposure at work. He was employed in a chlor-alkali plant in Central Italy. After two years of employment he had acute mercury intoxication with suggestive neurological symptoms and a high urinary level of the metal. Through years, many episodes of intoxication occurred, but he continued to perform the same job and be exposed to mercury. After yet another episode of intoxication in 2013, he showed fasciculations of the upper limbs and trunk, and electromyographic activity patterns were consistent with amyotrophic lateral sclerosis (ALS). In 2016, a genetic test revealed a mutation of TBK1, an ALS-related gene. This case highlights the important role of genetics in personalized occupational medicine. Occupational physicians should use genetic tests to identify conditions of individual susceptibility in workers with documented frequent episodes of mercury intoxication recorded during health surveillance programs to customize prevention measures in the workplace and act before damage appears.

Predictors of Depression in Caucasian Patients with Amyotrophic Lateral Sclerosis in Romania

Depression remains an underdiagnosed comorbidity which significantly decreases the quality of life in amyotrophic lateral sclerosis (ALS) patients. We aimed to investigate the prevalence of depression in a cohort of ALS patients with more than one year of disease evolution. A total of 50 ALS patients were evaluated with the Beck Depression Inventory II (BDI-II) and cognition, using the Mini-Cog Standardized Instrument (MCSI). The clinical disability was evaluated using the ALS Functional Rating Scale (ALSFRS). The prevalence of depression was 42.8%. A lower BDI-II score was significantly correlated with a higher education level, the spouse as a caregiver, spiritual devotion, and employment status (p < 0.05). A multiple linear regression analysis between the BDI-II score as the dependent variable and various independent variables such as spirituality, caregiver status, educational level, and occupational status revealed that only the type of caregiver (spouse or parent/child) significantly affected the BDI-II total score (p = 0.006). The functional disability significantly correlated with loss of appetite and loss of libido (p < 0.001). A high education, spiritual devotion, high ALSFRS, and the presence of the spouse as the caregiver were associated with the absence of depression.

Amyotrophic lateral sclerosis: a clinical review

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting primarily the motor system, but in which extra-motor manifestations are increasingly recognized. The loss of upper and lower motor neurons in the motor cortex, the brain stem nuclei and the anterior horn of the spinal cord gives rise to progressive muscle weakness and wasting. ALS often has a focal onset but subsequently spreads to different body regions, where failure of respiratory muscles typically limits survival to 2-5 years after disease onset. In up to 50% of cases, there are extra-motor manifestations such as changes in behaviour, executive dysfunction and language problems. In 10%-15% of patients, these problems are severe enough to meet the clinical criteria of frontotemporal dementia (FTD). In 10% of ALS patients, the family history suggests an autosomal dominant inheritance pattern. The remaining 90% have no affected family members and are classified as sporadic ALS. The causes of ALS appear to be heterogeneous and are only partially understood. To date, more than 20 genes have been associated with ALS. The most common genetic cause is a hexanucleotide repeat expansion in the C9orf72 gene, responsible for 30%-50% of familial ALS and 7% of sporadic ALS. These expansions are also a frequent cause of frontotemporal dementia, emphasizing the molecular overlap between ALS and FTD. To this day there is no cure or effective treatment for ALS and the cornerstone of treatment remains multidisciplinary care, including nutritional and respiratory support and symptom management. In this review, different aspects of ALS are discussed, including epidemiology, aetiology, pathogenesis, clinical features, differential diagnosis, investigations, treatment and future prospects.

Phenotypic Suppression of ALS/FTD-Associated Neurodegeneration Highlights Mechanisms of Dysfunction

A fundamental question regarding the etiology of amyotrophic lateral sclerosis (ALS) is whether the various gene mutations associated with the disease converge on a single molecular pathway or act through multiple pathways to trigger neurodegeneration. Notably, several of the genes and cellular processes implicated in ALS have also been linked to frontotemporal dementia (FTD), suggesting these two diseases share common origins with varied clinical presentations. Scientists are rapidly identifying ALS/FTD suppressors that act on conserved pathways from invertebrates to vertebrates to alleviate degeneration. The elucidation of such genetic modifiers provides insight into the molecular pathways underlying this rapidly progressing neurodegenerative disease, while also revealing new targets for therapeutic development.

Human salivary Raman fingerprint as biomarker for the diagnosis of Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease leading to progressive and irreversible muscle atrophy. The diagnosis of ALS is time-consuming and complex, with the clinical and neurophysiological evaluation accompanied by monitoring of progression and a long procedure for the discrimination of similar neurodegenerative diseases. The delayed diagnosis strongly slows the potential development of adequate therapies and the time frame for a prompt intervention. The discovery of new biomarkers could improve the disease diagnosis, as well as the therapeutic and rehabilitative effectiveness and monitoring of the pathological progression. In this work saliva collected from 19 patients with ALS, 10 affected by Parkinson’s disease, 10 affected by Alzheimer’s disease and 10 healthy subjects, was analysed using Raman spectroscopy, optimizing the parameters for detailed and reproducible spectra. The statistical multivariate analysis of the data revealed a significant difference between the groups, allowing the discrimination of the disease onset. Correlation of Raman data revealed a direct relationship with paraclinical scores, identifying multifactorial biochemical modifications related to the pathology. The proposed approach showed a promising accuracy in ALS onset discrimination, using a fast and sensitive procedure that can make more efficient the diagnostic procedure and the monitoring of therapeutic and rehabilitative processes in ALS.

[Calculation of the prevalence of progressive muscular atrophy among adults in China based on urban medical insurance data from 15 provinces]

OBJECTIVE

To analyze the characteristics of patients with progressive muscular atrophy (PMA) and calculate the prevalence of PMA in China in 2016.

METHODS

A retrospective analysis based on China's urban employee basic medical insurance data and the urban residence basic medical insu-rance data from January 1, 2016 to December 31, 2016 was carried out. Children under 18 years old were excluded. Patients with progressive muscular atrophy were identified by disease names and codes. Subgroup analyses by gender, region and age were carried out to calculate the gender-specific, region-specific and age-specific prevalences. Age-adjusted national prevalence was estimated based on 2010 Chinese census data. Sensitivity analyses were done by only considering the observed cases and by excluding the top 10% provinces regarding the missing rate of diagnostic information, respectively.

RESULTS

A total of 996.09 million person-years were included in this study, with 518.41 million person-years in males and 477.67 million person-years in females. The age and gender distribution of the study population was similar to that of the 2010 Chinese census data, therefore the study population was nationally representative. The prevalence of PMA in China in 2016 was 0.28 per 100 000 person-years (95%CI: 0.24-0.33), with 0.21 per 100 000 person-years (95%CI: 0.16-0.26) and 0.35 per 100 000 person-years (95%CI: 0.28-0.42) for females and males, respectively. Regional disparity existed in the Chinese PMA prevalence, with the lowest prevalence in Southwest region (0.11 per 100 000 person-years, 95%CI: 0.07-0.15) and the highest prevalence in Northwest region (3.47 per 100 000 person-years, 95%CI: 0.80-7.99). Age trend in the PMA prevalence was not obvious, but the prevalence among those aged 70 years and older was relatively higher. The age-adjusted prevalence based on 2010 Chinese census data was 0.29 per 100 000 person-years (95%CI: 0.27-0.31). The national prevalences calculated by only considering the observed cases and by excluding the top 10% provinces regar-ding the missing rate of diagnostic information were 0.17 per 100 000 person-years (95%CI: 0.14-0.20) and 0.24 per 100 000 person-years (95%CI: 0.20-0.28), respectively.

CONCLUSION

This study is to calculate the prevalence of PMA among adults in urban China, which can provide basic statistics for the enactment of PMA related medical policies, and clues for the studies on the mechanisms of PMA.

Exciting Complexity: The Role of Motor Circuit Elements in ALS Pathophysiology

Amyotrophic lateral sclerosis (ALS) is a fatal disease, characterized by the degeneration of both upper and lower motor neurons. Despite decades of research, we still to date lack a cure or disease modifying treatment, emphasizing the need for a much-improved insight into disease mechanisms and cell type vulnerability. Altered neuronal excitability is a common phenomenon reported in ALS patients, as well as in animal models of the disease, but the cellular and circuit processes involved, as well as the causal relevance of those observations to molecular alterations and final cell death, remain poorly understood. Here, we review evidence from clinical studies, cell type-specific electrophysiology, genetic manipulations and molecular characterizations in animal models and culture experiments, which argue for a causal involvement of complex alterations of structure, function and connectivity of different neuronal subtypes within the cortical and spinal cord motor circuitries. We also summarize the current knowledge regarding the detrimental role of astrocytes and reassess the frequently proposed hypothesis of glutamate-mediated excitotoxicity with respect to changes in neuronal excitability. Together, these findings suggest multifaceted cell type-, brain area- and disease stage- specific disturbances of the excitation/inhibition balance as a cardinal aspect of ALS pathophysiology.

Multiple Roles of Transforming Growth Factor Beta in Amyotrophic Lateral Sclerosis

Transforming growth factor beta (TGFB) is a pleiotropic cytokine known to be dysregulated in many neurodegenerative disorders and particularly in amyotrophic lateral sclerosis (ALS). This motor neuronal disease is non-cell autonomous, as it affects not only motor neurons but also the surrounding glial cells, and the target skeletal muscle fibers. Here, we analyze the multiple roles of TGFB in these cell types, and how TGFB signaling is altered in ALS tissues. Data reported support a crucial involvement of TGFB in the etiology and progression of ALS, leading us to hypothesize that an imbalance of TGFB signaling, diminished at the pre-symptomatic stage and then increased with time, could be linked to ALS progression. A reduced stimulation of the TGFB pathway at the beginning of disease blocks its neuroprotective effects and promotes glutamate excitotoxicity. At later disease stages, the persistent activation of the TGFB pathway promotes an excessive microglial activation and strengthens muscular dysfunction. The therapeutic potential of TGFB is discussed, in order to foster new approaches to treat ALS.

CRISPR/Cas9-Mediated Gene Correction to Understand ALS

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease caused by the death of motor neurons in the spinal cord and brainstem. ALS has a diverse genetic origin; at least 20 genes have been shown to be related to ALS. Most familial and sporadic cases of ALS are caused by variants of the SOD1, C9orf72, FUS, and TARDBP genes. Genome editing using clustered regularly interspaced short palindromic repeats/CRISPR-associated system 9 (CRISPR/Cas9) can provide insights into the underlying genetics and pathophysiology of ALS. By correcting common mutations associated with ALS in animal models and patient-derived induced pluripotent stem cells (iPSCs), CRISPR/Cas9 has been used to verify the effects of ALS-associated mutations and observe phenotype differences between patient-derived and gene-corrected iPSCs. This technology has also been used to create mutations to investigate the pathophysiology of ALS. Here, we review recent studies that have used CRISPR/Cas9 to understand the genetic underpinnings of ALS.

Minimizing the Diagnostic Delay in Amyotrophic Lateral Sclerosis: The Role of Nonneurologist Practitioners

Introduction

Amyotrophic lateral sclerosis (ALS), usually fatal in a few years, is a neurodegenerative disorder where the diagnostic delay, although variable according to the studies, remains too long. The main objective of this study was to determine the average time to diagnose ALS and the role of each physician, general practitioner (GP), or specialist (neurologist or not) involved in the management of these patients. The secondary objective was to propose some simple schemes to quickly identify an ALS suspicion with the aim to reduce this delay. Patients and Methods. This retrospective study evaluated the diagnostic delay (and other intermediate delays) of 90 ALS patients registered in the ALS Center of Bordeaux (France) in 2013. The main clinical signs encountered (and their order of appearance) were studied.

Results

The average diagnostic delay was 17 months, with a median diagnostic delay of 12 months. The average diagnostic delay was 2.7 months between the first symptoms and the first complaint to GP, followed by an additional 6.5 month delay before the patient's first visit to a neurologist. This period could be shortened, especially if GP performed additional tests quickly (p=0.01), as the time spent consulting various specialists often extends this crucial step. Overall, diagnostic delay accounted for 40% of the total duration of the disease progression.

Conclusion

In relation to total survival time, the diagnostic delay of ALS appears to be proportionately very long, sometimes longer than that observed in previous studies (because it also included the total delay to diagnostic or treatment initiation). The rapid execution of useful additional tests by the first medical doctor, often GP (with the help of a neurologist), considerably reduces the diagnostic delay. The central role of GP seems to be crucial in the management of patients with ALS. The main objective is, of course, to initiate appropriate treatment and care as soon as possible. Finally, based on our results, we also provide a short practical diagram to help nonneurologist practitioners to quickly discuss the diagnosis of ALS in case of some specific symptoms (“red flags”).

Identification of Amyotrophic Lateral Sclerosis Based on Diffusion Tensor Imaging and Support Vector Machine

Objectives: White matter (WM) impairments involving both motor and extra-motor areas have been well-documented in amyotrophic lateral sclerosis (ALS). This study tested the potential of diffusion measurements in WM for identifying ALS based on support vector machine (SVM). Methods: Voxel-wise fractional anisotropy (FA) values of diffusion tensor images (DTI) were extracted from 22 ALS patients and 26 healthy controls and served as discrimination features. The revised ALS Functional Rating Scale (ALSFRS-R) was employed to assess ALS severity. Feature ranking and selection were based on Fisher scores. A linear kernel SVM algorithm was applied to build the classification model, from which the classification performance was evaluated. To promote classifier generalization ability, a leave-one-out cross-validation (LOOCV) method was adopted. Results: By using the 2,400~3,400 ranked features as optimal features, the highest classification accuracy of 83.33% (sensitivity = 77.27% and specificity = 88.46%, P = 0.0001) was achieved, with an area under receiver operating characteristic curve of 0.862. The predicted function value was positively correlated with patient ALSFRS-R scores (r = 0.493, P = 0.020). In the optimized SVM model, FA values from several regions mostly contributed to classification, primarily involving the corticospinal tract pathway, postcentral gyrus, and frontal and parietal areas. Conclusions: Our results suggest the feasibility of ALS diagnosis based on SVM analysis and diffusion measurements of WM. Additional investigations using a larger cohort is recommended in order to validate the results of this study.

Using Mendelian randomization to understand and develop treatments for neurodegenerative disease

Common neurodegenerative diseases are thought to arise from a combination of environmental and genetic exposures. Mendelian randomization is a powerful way to leverage existing genetic data to investigate causal relationships between risk factors and disease. In recent years, Mendelian randomization has gathered considerable traction in neurodegenerative disease research, providing valuable insights into the aetiology of these conditions. This review aims to evaluate the impact of Mendelian randomization studies on translational medicine for neurodegenerative diseases, highlighting the advances made and challenges faced. We will first describe the fundamental principles and limitations of Mendelian randomization and then discuss the lessons from Mendelian randomization studies of environmental risk factors for neurodegeneration. We will illustrate how Mendelian randomization projects have used novel resources to study molecular pathways of neurodegenerative disease and discuss the emerging role of Mendelian randomization in drug development. Finally, we will conclude with our view of the future of Mendelian randomization in these conditions, underscoring unanswered questions in this field.

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.

Increasing Patient Self-Enrollment in the National Amyotrophic Lateral Sclerosis Registry: Lessons Learned From a Direct to Provider Campaign

Objective:

To conduct educational and promotional outreach activities to general neurologists and to increase self-enrollment of persons with amyotrophic lateral sclerosis (ALS) in the National ALS Registry (Registry).

Methods:

A multicomponent project to educate neurologists and increase Registry self-enrollment was delivered. Project components consisted of phone calls, mailings, train-the-trainer presentations, and key informant interviews. Project-specific metrics, continuing education enrollment, and Registry self-enrollment data were analyzed to measure project efficacy.

Results:

Mailings were sent to 1561 neurologists in 6 states during 2015 to 2016. Sixty-five percent of responding neurologists remembered the mailing 3 months after receipt. Of providers who saw patients with ALS in the 3-month period, 60% read the provider guide, 22% distributed a patient guide, and 15% advised a patient to self-enroll. No changes in self-enrollment rates were observed.

Conclusion:

Targeted mailings to providers can be used to educate them about the Registry; however, most providers did not distribute materials to patients with ALS. Increases in providers receiving Registry material did not lead to increases in patient self-enrollment.

Practice Implications:

General neurologists have competing priorities, and they see patients with ALS infrequently. Neurologists could be the appropriate channel to distribute Registry information to patients, but they are not the appropriate resource to assist patients with self-enrollment. Engaging the support staff of busy specialists can help increase research response rates and information distribution. The lessons learned from this project can be applied to other rare conditions and disease specialists.

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.

Antioxidant Alternatives in the Treatment of Amyotrophic Lateral Sclerosis: A Comprehensive Review

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that produces a selective loss of the motor neurons of the spinal cord, brain stem and motor cortex. Oxidative stress (OS) associated with mitochondrial dysfunction and the deterioration of the electron transport chain has been shown to be a factor that contributes to neurodegeneration and plays a potential role in the pathogenesis of ALS. The regions of the central nervous system affected have high levels of reactive oxygen species (ROS) and reduced antioxidant defenses. Scientific studies propose treatment with antioxidants to combat the characteristic OS and the regeneration of nicotinamide adenine dinucleotide (NAD+) levels by the use of precursors. This review examines the possible roles of nicotinamide riboside and pterostilbene as therapeutic strategies in 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.

Clinical and Lifestyle Factors and Risk of Amyotrophic Lateral Sclerosis: A Population-Based Case-Control Study

Background: Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease of the motor neurons. The etiology of ALS remains largely unknown, particularly with reference to the potential environmental determinants. Methods: We performed a population-based case-control study in four provinces from both Northern and Southern Italy in order to assess non-genetic ALS risk factors by collecting through tailored questionnaires information about clinical and lifestyle factors. We estimated ALS risk by calculating odds ratio (OR) with its 95% confidence interval (CI) using unconditional logistic regression models adjusted for sex, age and educational attainment. Results: We recruited 230 participants (95 cases and 135 controls). We found a possible positive association of ALS risk with trauma, particularly head trauma (OR = 2.61, 95% CI 1.19–5.72), electric shock (OR = 2.09, 95% CI 0.62–7.06), and some sports, although at a competitive level only. In addition, our results suggest an increased risk for subjects reporting use of private wells for drinking water (OR = 1.38, 95% CI 0.73–2.27) and for use of herbicides during gardening (OR = 1.95, 95% CI 0.88–2.27). Conversely, there was a suggestion of an inverse association with overall fish consumption (OR = 0.27, 95% CI 0.12–0.60), but with no dose-response relation. Consumption of some dietary supplements, namely those containing amino acids and, in the Southern Italy population, vitamins and minerals such as selenium, seemed associated with a statistically imprecise increased risk. Conclusions: Our results suggest a potential etiologic role a number of clinical and lifestyle factors with ALS risk. However, caution is needed due to some study limitations. These include the small sample size and the low number of exposed subjects, which affect statistical precision of risk estimates, the potential for exposure misclassification, and the uncertainties about mechanisms underpinning the possible association between these factors and disease risk.

Causal association of type 2 diabetes with amyotrophic lateral sclerosis: new evidence from Mendelian randomization using GWAS summary statistics

BACKGROUND

Associations between type 2 diabetes (T2D) and amyotrophic lateral sclerosis (ALS) were discovered in observational studies in both European and East Asian populations. However, whether such associations are causal remains largely unknown.

METHODS

We employed a two-sample Mendelian randomization approach to evaluate the causal relationship of T2D with the risk of ALS in both European and East Asian populations. Our analysis was implemented using summary statistics obtained from large-scale genome-wide association studies with ~660,000 individuals for T2D and ~81,000 individuals for ALS in the European population, and ~191,000 individuals for T2D and ~4100 individuals for ALS in the East Asian population. The causal relationship between T2D and ALS in both populations was estimated using the inverse-variance-weighted methods and was further validated through extensive complementary and sensitivity analyses.

RESULTS

Using multiple instruments that were strongly associated with T2D, a negative association between T2D and ALS was identified in the European population with the odds ratio (OR) estimated to be 0.93 (95% CI 0.88-0.99, p = 0.023), while a positive association between T2D and ALS was observed in the East Asian population with OR = 1.28 (95% CI 0.99-1.62, p = 0.058). These results were robust against instrument selection, various modeling misspecifications, and estimation biases, with the Egger regression and MR-PRESSO ruling out the possibility of horizontal pleiotropic effects of instruments. However, no causal association was found between T2D-related exposures (including glycemic traits) and ALS in the European population.

CONCLUSION

Our results provide new evidence supporting the causal neuroprotective role of T2D on ALS in the European population and provide empirically suggestive evidence of increasing risk of T2D on ALS in the East Asian population. Our results have an important implication on ALS pathology, paving ways for developing therapeutic strategies across multiple populations.

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.

Induced pluripotent stem cell-based Drug Repurposing for Amyotrophic lateral sclerosis Medicine (iDReAM) study: protocol for a phase I dose escalation study of bosutinib for amyotrophic lateral sclerosis patients

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a progressive and severe neurodegenerative disease caused by motor neuron death. There have as yet been no fundamental curative medicines, and the development of a medicine for ALS is urgently required. Induced pluripotent stem cell (iPSC)-based drug repurposing identified an Src/c-Abl inhibitor, bosutinib, as a candidate molecular targeted therapy for ALS. The objectives of this study are to evaluate the safety and tolerability of bosutinib for the treatment of patients with ALS and to explore the efficacy of bosutinib on ALS. This study is the first clinical trial of administered bosutinib for patients with ALS.

METHODS AND ANALYSIS

An open-label, multicentre phase I dose escalation study has been designed. The study consists of a 12-week observation period, a 1-week transitional period, a 12-week study treatment period and a 4-week follow-up period. After completion of the transitional period, subjects whose total ALS Functional Rating Scale-Revised (ALSFRS-R) score decreased by 1-3 points during the 12-week observation period receive bosutinib for 12 weeks. Three to six patients with ALS are enrolled in each of the four bosutinib dose levels (100, 200, 300 or 400 mg/day) to evaluate the safety and tolerability under a 3+3 dose escalation study design. Dose escalation and maximum tolerated dose are determined by the safety assessment committee comprising oncologists/haematologists and neurologists based on the incidence of dose-limiting toxicity in the first 4 weeks of the treatment at each dose level. A recommended phase II dose is determined by the safety assessment committee on completion of the 12-week study treatment in all subjects at all dose levels. The efficacy of bosutinib is also evaluated exploratorily using ALS clinical scores and biomarkers.

ETHICS AND DISSEMINATION

This study received full ethical approval from the institutional review board of each participating site. The findings of the study will be disseminated in peer-reviewed journals and at scientific conferences.

TRIAL REGISTRATION NUMBER

UMIN000036295; Pre-results, JMA-IIA00419; Pre-results.

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.

Retrospective longitudinal study of ALS in Cyprus: Clinical characteristics, management and survival

Introduction

Amyotrophic lateral sclerosis (ALS) is a rare, progressive neurodegenerative disease. There is heterogeneity of clinical phenotypes while a clinical characterization of ALS in Cyprus is still lacking. The aim of this 30-year retrospective study of ALS in Cyprus is to determine the demographic characteristics of patients, the clinical features of the disease, the uptake of supportive therapies and factors influencing survival.

Methods

All ALS patients seen at the Cyprus Institute of Neurology and Genetics from January 1985 until July 2015 were included. Medical records of eligible patients were used for data extraction and compilation of an ALS database. Clinical features were compared between gender categories using univariate tests, while survival was assessed using Kaplan-Meier curves. Cox proportional hazards models were used to identify prognostic factors for survival.

Results

One hundred and seventy-nine ALS patients were included in the study, of whom 7 had a positive family history. Most clinical characteristics of ALS did not differ from what is observed in other European countries. However, some clinical characteristics were unique to our population, such as an increased acceptability and utilisation of supportive treatments such as gastrostomy.

Conclusions

Overall, clinical characteristics of patients with ALS in the Republic of Cyprus do not differ from other European counties. Our study demonstrates a high acceptance and utilisation of supportive interventions enhancing survival, in the context of a multidisciplinary approach offered in the single tertiary centre that services the whole Cypriot ALS population. The findings of this paper are of value to the health professionals treating ALS in Cyprus.

The Role of Altered BDNF/TrkB Signaling in Amyotrophic Lateral Sclerosis

Brain derived neurotrophic factor (BDNF) is well recognized for its neuroprotective functions, via activation of its high affinity receptor, tropomysin related kinase B (TrkB). In addition, BDNF/TrkB neuroprotective functions can also be elicited indirectly via activation of adenosine 2A receptors (A_2aRs), which in turn transactivates TrkB. Evidence suggests that alterations in BDNF/TrkB, including TrkB transactivation by A_2aRs, can occur in several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Although enhancing BDNF has been a major goal for protection of dying motor neurons (MNs), this has not been successful. Indeed, there is emerging in vitro and in vivo evidence suggesting that an upregulation of BDNF/TrkB can cause detrimental effects on MNs, making them more vulnerable to pathophysiological insults. For example, in ALS, early synaptic hyper-excitability of MNs is thought to enhance BDNF-mediated signaling, thereby causing glutamate excitotoxicity, and ultimately MN death. Moreover, direct inhibition of TrkB and A_2aRs has been shown to protect MNs from these pathophysiological insults, suggesting that modulation of BDNF/TrkB and/or A_2aRs receptors may be important in early disease pathogenesis in ALS. This review highlights the relevance of pathophysiological actions of BDNF/TrkB under certain circumstances, so that manipulation of BDNF/TrkB and A_2aRs may give rise to alternate neuroprotective therapeutic strategies in the treatment of neural diseases such as 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.

Spinal Cord Imaging in Amyotrophic Lateral Sclerosis: Historical Concepts-Novel Techniques

Amyotrophic lateral sclerosis (ALS) is the most common adult onset motor neuron disease with no effective disease modifying therapies at present. Spinal cord degeneration is a hallmark feature of ALS, highlighted in the earliest descriptions of the disease by Lockhart Clarke and Jean-Martin Charcot. The anterior horns and corticospinal tracts are invariably affected in ALS, but up to recently it has been notoriously challenging to detect and characterize spinal pathology in vivo. With recent technological advances, spinal imaging now offers unique opportunities to appraise lower motor neuron degeneration, sensory involvement, metabolic alterations, and interneuron pathology in ALS. Quantitative spinal imaging in ALS has now been used in cross-sectional and longitudinal study designs, applied to presymptomatic mutation carriers, and utilized in machine learning applications. Despite its enormous clinical and academic potential, a number of physiological, technological, and methodological challenges limit the routine use of computational spinal imaging in ALS. In this review, we provide a comprehensive overview of emerging spinal cord imaging methods and discuss their advantages, drawbacks, and biomarker potential in clinical applications, clinical trial settings, monitoring, and prognostic roles.

Epidemiology of ALS in Korea using nationwide big data

OBJECTIVE

This study aimed to determine the incidence, prevalence and survival time of Korean patients with amyotrophic lateral sclerosis (ALS) using National Health Insurance Service (NHIS) data.

METHODS

Using NHIS data, the Korean nationwide health dataset, we identified patients with motor neuron diseases who were first diagnosed with a KCD-6 code (G12.20-G12.28; modified from ICD-10 codes) between 2011 and 2015. ALS (G12.21 code) epidemiological characteristics, including annual incidence, prevalence, mortality rates and survival time, were analysed and compared with sociodemographic variables.

RESULTS

New patients with ALS (n=3049) were enrolled over 5 years. The mean annual incidence was 1.20/100 000, and the sex ratio was 1.60 (male:female). The mean age at the time of diagnosis was 61.4 years. The prevalence rate was 3.43/100 000 in 2015. In this period, riluzole was prescribed to 53.6% of patients with ALS. Furthermore, 20.3% of patients with ALS underwent tracheostomy. When analysed for age and socioeconomic status, ALS prevalence rate was 10.71 in the aged group (≥60) in 2015 and was lowest in the middle-income group compared with that in the high-income and low-income groups. The estimated mean survival time in this population was 50.0 months, and the 3-year and 5-year mortality rates were 52.1% and 63.7%, respectively.

CONCLUSIONS

This study is the first nationwide survey for epidemiological characteristics of ALS in Korea using national data. The use of these data substantially advances the understanding of Korean and Asian ALS epidemiology and its relationship with socioeconomic status, age and sex.

Dysregulated mitochondrial Ca2+ and ROS signaling in skeletal muscle of ALS mouse model

Amyotrophic lateral sclerosis (ALS) is a devastating neuromuscular disease characterized by motor neuron loss and prominent skeletal muscle wasting. Despite more than one hundred years of research efforts, the pathogenic mechanisms underlying neuromuscular degeneration in ALS remain elusive. While the death of motor neuron is a defining hallmark of ALS, accumulated evidences suggested that in addition to being a victim of motor neuron axonal withdrawal, the intrinsic skeletal muscle degeneration may also actively contribute to ALS disease pathogenesis and progression. Examination of spinal cord and muscle autopsy/biopsy samples of ALS patients revealed similar mitochondrial abnormalities in morphology, quantity and disposition, which are accompanied by defective mitochondrial respiratory chain complex and elevated oxidative stress. Detailing the molecular/cellular mechanisms and the role of mitochondrial dysfunction in ALS relies on ALS animal model studies. This review article discusses the dysregulated mitochondrial Ca2+ and reactive oxygen species (ROS) signaling revealed in live skeletal muscle derived from ALS mouse models, and a potential role of the vicious cycle formed between the dysregulated mitochondrial Ca2+ signaling and excessive ROS production in promoting muscle wasting during ALS progression.

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.

Disability and Contextual Factors in Patients with Amyotrophic Lateral Sclerosis - A Three-Year Observational Study

Background:

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by muscle weakness and wasting. Observational natural history studies can give information on body function/structure impairments, activity limitations and participation restrictions, i.e. disability. Information needed to plan and develop care and support.

Objective:

To describe and explore disease severity and impairments, activity limitations, participation restrictions and contextual factors over time. In specific, to explore concurrent presence of cognitive impairment, fatigue, anxiety, depression and pain, and whether these impairments were related to disease severity.

Methods:

In this three-year observational study, 60 patients with ALS were included at baseline. Follow-ups were performed every 6 months unless participants had deceased or declined participation. Data was collected from medical records, and by study-specific and standardized questionnaires administrated during home visits.

Results:

Regardless of disease severity; fatigue, anxiety, depression and pain were present in patients with ALS at each data collection. Approximately one-third experienced two or more of these impairments concurrently, i.e. at the same time point. Cognitive impairment could not be assessed in many patients due to their physical impairments. Disease severity was not associated with fatigue, anxiety, depression or pain.

Conclusions:

Patients with ALS need, throughout the course of the disease, to be regularly screened for commonly present impairments, activity limitations and participation restrictions so that person-centered interventions can be applied at the right time.

Amyotrophic lateral sclerosis and anesthesia: a case series and review of the literature

PURPOSE

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that leads to death due to respiratory failure. This report describes the perioperative characteristics of ALS patients who underwent procedures with anesthesia at our institution.

METHODS

We reviewed perioperative records of ALS patients who underwent procedures with anesthesia from January 1, 2014, through December 31, 2015.

RESULTS

Seventy-eight patients underwent 89 procedures (71 procedures with monitored anesthesia care and 18 with general anesthesia), including 45 gastrostomy tube placements and 18 bone marrow biopsies. Three patients had prolonged duration of postoperative intubation related to preexisting respiratory muscle weakness, and one patient with bilateral pneumothorax required tracheal reintubation for respiratory distress. Four patients had prolonged duration of hospitalization. Three patients were hospitalized for ALS-related complications, and one patient was hospitalized for respiratory distress when pneumoperitoneum developed after gastrostomy tube placement. Three of these patients died of complications attributable to ALS within 30 days of the procedure. Twenty-nine (32.6%) procedures required minimal sedation (e.g., bone marrow biopsy, cataract surgery) and were performed on an ambulatory basis.

CONCLUSION

When caring for patients with ALS, the perioperative team must be prepared to treat potentially complex medical conditions that may not be directly related to the procedure and anesthetic management. However, minor procedures performed with minimal sedation may be safely performed on an ambulatory basis.

CSF and blood biomarkers in amyotrophic lateral sclerosis: protocol for a systematic review and meta-analysis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a highly progressive and debilitating neurodegenerative disease, which usually leads to the death of affected individuals within a few years after the onset of symptoms. ALS is currently incurable and very little is known about its pathophysiology. Finding validated biomarkers will help us to advance our understanding of ALS etiology and find better strategies for early diagnosis and management of the disease. The main aim of the present systematic review is to evaluate the concentration of 11 frequently reported biomarkers for ALS in peripheral blood and CSF of patients diagnosed with ALS compared with controls.

METHODS

This systematic review protocol has been established according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol (PRISMA-P) 2015 guideline. We will include all types of observational studies with human subjects that investigated the concentrations of intended biomarkers (amyloid beta (Aβ-42), tau and phosphorylated tau (p-Tau), neurofilaments, S100β, cystatin C, progranulin (PGRN), glial fibrillary acidic protein (GFAP), monocyte chemoattractant protein-1 (MCP-1), brain-derived neurotrophic factor (BDNF), TAR DNA-binding protein-43 (TDP43), YKL-40, and CHIT1 in CSF or peripheral blood of ALS patients for initial assessment. Also, we will include case series with a minimum of 10 cases and clinical trials which have measured baseline biomarker levels. Case studies, case reports, reviews, letters, and animal and in vitro studies will be excluded. Multiple electronic databases including Cochrane Library, MEDLINE (PubMed), ISI Web of Science, and EMBASE will be searched to find all eligible articles published since 1980. No language restriction will be applied. All titles and abstracts retrieved by searching information sources will be evaluated independently by two authors against the eligibility criteria. The following information will be extracted from each included study by two independent authors: bibliographic details (first author, study title, year of publication, country), demographics and clinical information (number of patients and controls, type of ALS and controls, study design, age, gender, specimen, biomarkers levels, ALS functional rating scale Revised (ALSFRS-R), duration of disease), and measurements (method, value type, biomarkers levels). We will use the extracted mean and standard deviation (SD) of biomarkers concentrations to calculate the standardized mean difference (SMD) and 95% confidence intervals (CI). The primary outcome measures are the mean difference of biomarker levels between ALS patients and controls, different types of ALS, and ALS patients with genetic mutations.

DISCUSSION

We will systematically review the literature and analyze studies of biomarker level in CSF and peripheral blood of patients with ALS and controls. The results will help us to identify biomarkers with possible diagnostic and prognostic value.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017078127.