Amyotrophic lateral sclerosis in Sweden, 1991-2005

Characterization, epidemiology, and factors associated with evolution and survival in patients with amyotrophic lateral sclerosis in southeastern Spain, 2008-2021: a population-based study

OBJECTIVE

To describe the epidemiology, characteristics, and factors associated with the evolution and survival in patients with amyotrophic lateral sclerosis (ALS) in a region of southeastern Spain.

METHODS

An observational study was carried out in people with a diagnosis of ALS in the period 2008-2021 who were registered in the Information System of Rare Diseases of the Region of Murcia (SIER). We calculated crude and standardized incidence rate (SIR) using European Standard Population of 2013 and point prevalence. The Kaplan-Meier method and the log-rank test were used to estimate and compare survival curves.

RESULTS

We identified 374 cases. The mean age at diagnosis was 66.5 ± 11.7 and 50.3% persons were spinal onset. Mean time from the onset of symptoms to diagnosis was 0.9 ± 1.0 years. The global SIR was 1.95/100,000 person-years (95%CI: 1.77-2.12), which was higher in men (ratio 1.34), and the point prevalence in 2021 was 4.57 per 100,000 (95% CI: 4.46-4.68). There were 297 deaths with a mean age of 69.8 ± 10.8. The median survival from clinical onset was 2 years (95%CI: 1.0-3.0). Factors associated with lower survival were bulbar onset (p < 0.001), older age at the onset of symptoms (p < 0.001), and the absence of riluzole treatment (p = 0.003).

CONCLUSIONS

This study is one of few to evaluate the epidemiological, characteristics, and prognostic factors of ALS in Spain, with findings similar to previous population studies. The use of population-based registries offers reliable information on the magnitude, or evolution in these patients.

The epithelial barrier theory and its associated diseases

The prevalence of many chronic noncommunicable diseases has been steadily rising over the past six decades. During this time, over 350,000 new chemical substances have been introduced to the lives of humans. In recent years, the epithelial barrier theory came to light explaining the growing prevalence and exacerbations of these diseases worldwide. It attributes their onset to a functionally impaired epithelial barrier triggered by the toxicity of the exposed substances, associated with microbial dysbiosis, immune system activation, and inflammation. Diseases encompassed by the epithelial barrier theory share common features such as an increased prevalence after the 1960s or 2000s that cannot (solely) be accounted for by the emergence of improved diagnostic methods. Other common traits include epithelial barrier defects, microbial dysbiosis with loss of commensals and colonization of opportunistic pathogens, and circulating inflammatory cells and cytokines. In addition, practically unrelated diseases that fulfill these criteria have started to emerge as multimorbidities during the last decades. Here, we provide a comprehensive overview of diseases encompassed by the epithelial barrier theory and discuss evidence and similarities for their epidemiology, genetic susceptibility, epithelial barrier dysfunction, microbial dysbiosis, and tissue inflammation.

Increased incidence of motor neuron disease in Sweden: a population-based study during 2002-2021

BACKGROUND

Motor neuron diseases (MND), with amyotrophic lateral sclerosis constituting most cases, are rare conditions of unknown etiology. There have been reports of an increase in incidence during the latter half of the twentieth century in various Western countries, including Sweden. This study provides updated data on the incidence of MND in Sweden during the last 20 years.

METHODS

Data was obtained from the Swedish National Patient Register on individuals diagnosed with MND from 2002 to 2021 and analysed in relation to group level data for the entire Swedish population. Incidence rates were calculated and presented in relation to year, age, sex, and region.

RESULTS

In the early 2000s, there was a crude incidence rate of 3.5-3.7 per 100,000 person-years, which then increased to 4.0-4.6 from 2008 onward. Age standardization to the starting year (2002) partially mitigated this increase. The incidence rate was greater among men compared to women and was highest within the age range of 70 to 84 years. There were indications of a higher incidence rate in the northernmost parts of the country, although the difference was not statistically significant.

CONCLUSIONS

The incidence rate of MND in Sweden now seems to have surpassed 4 cases per 100,000 person-years. This is higher when compared to both other European countries and previous Swedish studies. It remains to be determined if this increase reflects an actual increasing incidence of MND in Sweden or is due to other factors such as better registry coverage.

Analysis of the spatial distribution of amyotrophic lateral sclerosis in Virginia

Objective: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that is usually fatal. Environmental exposures have been posited in the etiology of ALS, but few studies have modeled the spatial risk of ALS over large geographic areas. In this paper, our goal was to analyze the spatial distribution of ALS in Virginia and identify any areas with significantly elevated risk using Virginia ALS Association administrative data. Methods: We used Bayesian hierarchical spatial regression models to estimate the relative risk for ALS in Virginia census tracts, adjusting for several covariates posited to be associated with the disease. We used an intrinsic conditional autoregressive prior to allow for spatial correlation in the risk estimates and stabilize estimates over space. Results: Considerable variation in ALS risk existed across Virginia, with greater relative risk found in the central and western parts of the state. We identified significantly elevated relative risk in a number of census tracts. In particular, Henrico, Albemarle, and Botetourt counties all contained at least four census tracts with significantly elevated risk. Conclusions: We identified several areas with significantly elevated ALS risk across Virginia census tracts. These results can inform future studies of potential environmental triggers for the disease, whose etiology is still being understood.

Epidemiology of amyotrophic lateral sclerosis in the north east Tuscany in the 2018–2021 period

Background

The incidence of Amyotrophic Lateral Sclerosis (ALS) varies among different geographical areas and seems to increase over time. This study aimed to examine the epidemiologic data of ALS in the north-east Tuscany and compare the results with those of similar surveys.

Methods

Data from ALS cases diagnosed in Florence and Prato Hospitals were prospectively collected from 1st June 2018 to 31st May 2021.

Results

The age- and sex-adjusted incidence rate of ALS in cases per 100,000 population was 2.71 (M/F ratio: 1.21), significantly higher as compared to that reported in the 1967-1976 decade in the same geographical area (0.714). The age- and sex-adjusted incidence rate among resident strangers was similar to that of the general population (2.69). A slightly higher incidence rate (4.36) was observed in the north-east area of Florence province, which includes the Mugello valley. The mean prevalence was of 7.17/100,00. The mean age at diagnosis was 69.7 years, with a peak between 70 and 79 years among men and a smoother age curve among women.

Conclusions

ALS epidemiological features in north-east Tuscany are in line with other Italian and European Centers. The dramatic increase of the local disease burden over the last decades probably reflects better ascertainment methods and health system.

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.

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.

High incidence of amyotrophic lateral sclerosis in the Faroe Islands 2010-2020

The Faroese population isolate harbors epidemiological and genetic characteristics that likely differ from outbred populations. This population-based register study found that the Faroese 2010-2020 crude incidence of amyotrophic lateral sclerosis (ALS) was 4.9/100,000 person-years (95% confidence interval [CI], 3.3-7.0) and the age- and sex-standardized incidence (US 2010 Census Population) was 4.1/100,000 person-years (95% CI, 2.7-6.0), which is a 68% increase from the 1987-2009 estimate. The 2020 crude prevalence was 9.5/100,000 (95% CI, 3.0-19.6) in a population of 52,912 inhabitants. Incidence and prevalence estimates of ALS in the Faroes are high and further research is warranted to uncover the genetic or environmental determinants of ALS in this population.

Amyotrophic Lateral Sclerosis After Exposure to Manganese from Traditional Medicine Procedures in Kenya

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neuron loss and widespread muscular atrophy. Despite intensive investigations on genetic and environmental factors, the cause of ALS remains unknown. Recent data suggest a role for metal exposures in ALS causation. In this study we present a patient who developed ALS after a traditional medical procedure in Kenya. The procedure involved insertion of a black metal powder into several subcutaneous cuts in the lower back. Four months later, general muscle weakness developed. Clinical and electrophysiological examinations detected widespread denervation consistent with ALS. The patient died from respiratory failure less than a year after the procedure. Scanning electron microscopy and X-ray diffraction analyses identified the black powder as potassium permanganate (KMnO4). A causative relationship between the systemic exposure to KMnO4 and ALS development can be suspected, especially as manganese is a well-known neurotoxicant previously found to be elevated in cerebrospinal fluid from ALS patients. Manganese neurotoxicity and exposure routes conveying this toxicity deserve further attention.

Geographical clusters of amyotrophic lateral sclerosis and the Bradford Hill criteria

With the aim of shedding further light on the role of environmental factors in amyotrophic lateral sclerosis (ALS) etiology, we hereby conducted a historical narrative review to critically appraise the published reports on ALS geographical clusters using the modern interpretation of the Bradford Hill criteria for causation. Our research hypothesis was that the more criteria were met, the greater was the evidence supporting a causal association. We found that cluster studies that met the greatest number of Bradford's Hill criteria regarded the non-protein amino acid β-N-methylamino-L-alanine (L-BMAA) and exposure to metals and minerals, but the evidence for causation was at best moderate and was poor for other environmental factors. This defective picture might be attributed not only to the methodological approach adopted by published studies, but also to the inherent difficulties in the application of Bradford Hill criteria, due to the complexity of the disease phenotype and the underlying pathogenic mechanisms.

ALS incidence and population aging in Northern Italy

Objective: Data on and increase of the incidence of amyotrophic lateral sclerosis (ALS) are conflicting and reflect the use of differing populations and designs. We investigated the incidence of ALS using data from a large population-based registry (SLALOM) in two three-year periods using the same diagnostic criteria and equal methods of case ascertainment. Methods: The registry is based in Lombardy, a 10 million population area of Northern Italy. Using different sources of cases (hospital discharge and ambulatory records, regional claims and prescription records) from nine Lombardy provinces (population, 5,485,163), all patients with newly diagnosed ALS during the periods 1998-2000 and 2008-2010 were included. Results: A total of 235 and 440 newly diagnosed patients were traced during the two study periods. The corresponding incidence rates were, respectively, 1.61 and 2.72 per 100,000 person-years. Data varied with age, sex and province by a significant increase was found only in men aged 65 through 74 years. Conclusions: Based on our findings, the increased incidence of ALS with time is real and can be largely interpreted as a reflection of the advancing age of the general population.

Incidence, Prevalence, and Geographical Clustering of Motor Neuron Disease in the Netherlands

OBJECTIVE

To assess time trends in motor neuron disease (MND) incidence, prevalence, and mortality and to investigate geographic clustering of MND cases in the Netherlands from 1998 to 2017, we analyzed data from the Netherlands Personal Records database, the Netherlands MND Center, and the Netherlands Patient Association of Neuromuscular Diseases.

METHODS

In this prospective cohort study, Poisson regression was used to assess time trends in MND risk. We calculated age- and sex-standardized, observed, and expected cases for 1,694 areas. Bayesian smoothed risk mapping was used to investigate geographic MND risk.

RESULTS

We identified 7,992 MND cases, reflecting an incidence of 2.64 (95% confidence interval [CI] 2.62-2.67) per 100,000 person-years and a prevalence of 9.5 (95% CI 9.1-10.0) per 100,000 persons. Highest age-standardized prevalence and mortality rates occurred at a later age in men than in women (p < 0.001). Unadjusted mortality rates increased by 53.2% from 2.57 per 100,000 person-years in 1998 to 3.86 per 100,000 person-years in 2017. After adjustment for age and sex, an increase in MND mortality rate of 14.1% (95% CI 5.7%-23.2%, p < 0.001) remained. MND relative risk ranged from 0.78 to 1.43 between geographic areas; multiple urban and rural high-risk areas were identified.

CONCLUSIONS

We found a significant national increase in MND mortality from 1998 through 2017, explained only partly by an aging Dutch population, and a geographic variability in MND risk, suggesting a role for environmental or demographic risk factors.

Season-of-birth phenomenon in health and longevity: epidemiologic evidence and mechanistic considerations

In many human populations, especially those living in regions with pronounced climatic differences between seasons, the most sensitive (prenatal and neonatal) developmental stages occur in contrasting conditions depending on the season of conception. The difference in prenatal and postnatal environments may be a factor significantly affecting human development and risk for later life chronic diseases. Factors potentially contributing to this kind of developmental programming include nutrition, outdoor temperature, infectious exposures, duration of sunlight, vitamin D synthesis, etc. Month of birth is commonly used as a proxy for exposures which vary seasonally around the perinatal period. Season-of-birth patterns have been identified for many chronic health outcomes. In this review, the research evidence for the seasonality of birth in adult-life disorders is provided and potential mechanisms underlying the phenomenon of early life seasonal programming of chronic disease and longevity are discussed.

Phenotypic and genotypic features of patients diagnosed with ALS in the city of Sakarya, Turkey

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease leading to motor neuron damage. In this study, the clinical, demographic, and genetic features of ALS patients in the city of Sakarya, Turkey, were investigated. Patients with an established diagnosis of ALS according to the Awaji criteria were included. Age, sex, age at onset of ALS, initial complaints, consanguineous marriage, and genetic features were retrospectively investigated. Conventional genetic analysis and NGS were used for molecular evaluation of patients. A total of 55 probands (10 familial, 45 sporadic) in whom ALS was suspected due to their phenotypic features were included. Thirty-two patients were male (58.2%), and 23 were female (41.8%); their mean ages were 62.65 ± 13 years. The mean age of onset for 37 familial patients from 10 families was 49.9 years. Two cases had juvenile-onset. Fourteen (25.5%) bulbar-onset versus 40 (72.7%) limb-onset patients were detected; one patient had both. Six (10.9%) patients showed marked frontotemporal dementia. Twenty-nine (52.7%) patients died during the follow-up period. Genetic analysis identified causative variants in eleven cases, carrying variants in six different ALS genes (C9orf72, SOD1, VCP, SPG11, TBK1, and SH3TC2). Genetic investigations have revealed more than 40 genes to be involved in the pathogenesis of ALS. Our relatively small study cohort restricted to one province of Turkey, however, prone to migration, consists of 10/55 familial ALS cases, which harbor two rare (SH3TC2-p.Met523Thr and TBK1-p.Glu643del) and two novel (SPG11-p.Lys656Valfs*11 and VCP-p.Arg191Pro) mutations contributing to the literature.

Muscleblind acts as a modifier of FUS toxicity by modulating stress granule dynamics and SMN localization

Mutations in fused in sarcoma (FUS) lead to amyotrophic lateral sclerosis (ALS) with varying ages of onset, progression and severity. This suggests that unknown genetic factors contribute to disease pathogenesis. Here we show the identification of muscleblind as a novel modifier of FUS-mediated neurodegeneration in vivo. Muscleblind regulates cytoplasmic mislocalization of mutant FUS and subsequent accumulation in stress granules, dendritic morphology and toxicity in mammalian neuronal and human iPSC-derived neurons. Interestingly, genetic modulation of endogenous muscleblind was sufficient to restore survival motor neuron (SMN) protein localization in neurons expressing pathogenic mutations in FUS, suggesting a potential mode of suppression of FUS toxicity. Upregulation of SMN suppressed FUS toxicity in Drosophila and primary cortical neurons, indicating a link between FUS and SMN. Our data provide in vivo evidence that muscleblind is a dominant modifier of FUS-mediated neurodegeneration by regulating FUS-mediated ALS pathogenesis.

Are rises in Electro-Magnetic Field in the human environment, interacting with multiple environmental pollutions, the tripping point for increases in neurological deaths in the Western World?

Whilst humans evolved in the earth's Electro-Magnetic-Field (EMF) and sun-light, both being essential to life but too much sun and we burn. What happens if background EMF rise to critical levels, coinciding with increasing environmental pollutants? Two of the authors can look back over 50 clinical years and appreciate the profound changes in human morbidity across a range of disparate conditions - autoimmune diseases, asthma, earlier cancer incidence and reduced male sperm counts. In particular have been increased autism, dyslexia, Attention Deficit Hyperactivity Disorder and neurological diseases, such as Amyotrophic Lateral Sclerosis, Multiple Sclerosis, Parkinson's Disease, Early Onset Dementia, Multiple System Atrophy and Progressive Supranuclear Palsy. What might have caused these changes-whilst genetic factors are taken as given, multiple environmental pollutants are associated with neurological disease although the mechanisms are unclear. The pace of increased neurological deaths far exceeds any Gompertzian explanation - that because people are living longer they are more likely to develop more age-related problems such as neurological disease. Using WHO global mortality categories of Neurological Disease Deaths (NDD) and Alzheimer's and Dementia deaths (Alz), updated June 2018, together they constitute Total Neurological Mortality (TNM), to calculate mortality rates per million for people aged 55-74 and for the over-75's in twenty-one Western countries. Recent increases in American people aged over-75's rose 49% from 1989 to 2015 but US neurological deaths increased five-fold. In 1989 based on Age-Standardised-Deaths-Rates America USA was 17th at 324 pm but rising to 539 pm became second highest. Different environmental/occupational factors have been found to be associated with neuro-degenerative diseases, including background EMF. We briefly explore how levels of EMF interact upon the human body, which can be described as a natural antennae and provide new evidence that builds upon earlier research to propose the following hypothesis. Based upon recent and new evidence we hypothesise that a major contribution for the relative sudden upsurge in neurological morbidity in the Western world (1989-2015), is because of increased background EMF that has become the tipping point-impacting upon any genetic predisposition, increasing multiple-interactive pollutants, such as rises in petro-chemicals, hormone disrupting chemicals, industrial, agricultural and domestic chemicals. The unprecedented neurological death rates, all within just twenty-five years, demand a re-examination of long-term EMF safety related to the increasing background EMF on human health. We do not wish to 'stop the modern world', only make it safer.

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.

The Swedish motor neuron disease quality registry

OBJECTIVE

We set up the Swedish Motor Neuron Disease (MND) Quality Registry to assure early diagnosis and high-quality health care for all MND patients (mainly amyotrophic lateral sclerosis, ALS), and to create a research base by prospectively following the entire MND population in Sweden.

METHODS

Since 2015, the MND Quality Registry continuously collects information about a wide range of clinical measures, biological samples, and quality of life outcomes from all MND patients recruited at the time of MND diagnosis in Sweden and followed at each clinic visit approximately every 12 weeks. The Registry includes an Internet based patient own reporting portal that involves patients in the registration of their current symptoms and health status.

RESULTS

As of 20th January 2017, the MND Quality Registry included 99% of the MND patients of the Stockholm area (N = 194), consisting mostly of ALS patients (N = 153, 78.9%), followed by patients labeled as MND due to a neurophysiology finding but not fulfilling the criteria for ALS (N = 20, 10.3%), primary lateral sclerosis (N = 13, 6.7%), and progressive spinal muscular atrophy patients (N = 8, 4.1%). A higher proportion of these patients were women (N = 100, 52%), and women and men had a similar age at symptoms onset (59 years).

CONCLUSIONS

Main strengths of the MND Quality Registry are its clinical, quantitative, qualitative, and prospective nature, providing the researchers potential means of identifying appropriate candidates for clinical trials and other research projects, as well as assuring to the patients an effective and adequate time spent on-site with the healthcare professionals.

Late age onset of amyotrophic lateral sclerosis is often not considered in elderly people

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease causing an upper and lower motor neuron loss. It is neurology textbook knowledge that the mean age of onset is about 60 years. However, recent investigations show an increasing incidence in older persons. We therefore evaluated whether ALS is potentially not considered in elderly people with ALS symptoms, respectively, not recognized.

MATERIALS AND METHODS

We included retrospectively all patients with ALS diagnoses after work-up that were admitted to our neurological and geriatric departments from 2007 to 2010 and collected their clinical data. The diagnosis of ALS was based on the El Escorial criteria. Patients were grouped into three categories according to age (<50, between 50 and 70, >70), and differences in clinical and/ or biographical factors were investigated.

RESULTS

We identified 35 patients (18 men and 17 women) with a median age at onset of 71.5 years (range: 36-87 years). When establishing the diagnosis, 51% were older than 70 years, 40% (14/35) between 50 and 70, and only 9% younger than 50. Only in 46 per cent of patients who were sent to our departments with ALS symptoms ALS was considered by the referring physician.

CONCLUSION

Late age onset of ALS seems to be more common than formerly assumed and is presumably under-recognized in elderly patients. ALS needs to be considered as a differential diagnosis in older patients. Potential factors accounting for older people being underdiagnosed with ALS relate to frequent presentation with symptoms like dysphagia, frailty or general weakness for other reasons.

Risk factors in Swedish young men for amyotrophic lateral sclerosis in adulthood

Recent research suggests that the incidence of amyotrophic lateral sclerosis (ALS) may be on the rise. Since ALS becomes predominant in later life, most studies on causal factors are conducted in middle-aged or older populations where potentially important influences from early life can usually not be adequately captured. We aimed to investigate predictors in young Swedish men for ALS in adulthood. Therefore, we performed a prospective cohort study of young men (aged 16-25, n = 1,819,817) who enlisted 1968-2005 and took part in comprehensive conscription examinations. Incident cases of ALS (n = 526) during up to 46 years of follow-up were identified in the National Hospital Register and Swedish Cause of Death Register. Those who developed ALS had lower BMI (body mass index) at conscription than their peers (p = 0.03). The risk of ALS during follow-up was calculated with Cox proportional hazards models. No associations were found with physical fitness, erythrocyte sedimentation rate, or non-psychotic mental disorders. Low overall muscle strength compared to high overall muscle strength [hazard ratio (HR) 1.36; 95% confidence interval (CI) 1.01-1.83] and low BMI (a one-unit increase HR 0.96; 95% CI 0.93-0.99) and lower erythrocyte volume fraction (a one-unit increase HR 0.96; 95% CI 0.92-0.998) were the statistically significant predictors for ALS in adjusted models. These findings provide novel epidemiologic evidence of a prospective association between low overall muscle strength and erythrocyte volume fraction in young men and ALS risk.

Secular Trends of Amyotrophic Lateral Sclerosis: The Piemonte and Valle d'Aosta Register

Importance

This study reports the long-term epidemiologic trends of amyotrophic lateral sclerosis (ALS) based on a prospective register.

Objective

To examine the 20-year epidemiologic trends of ALS in the Piemonte and Valle d'Aosta regions of Italy.

Design, Setting, and Participants

The Piemonte and Valle d'Aosta Register for ALS (PARALS) is an epidemiologic prospective register that covers 2 Italian regions (population of 4 476 931 inhabitants according to the 2011 census) from January 1, 1995, through December 31, 2014. Case ascertainment is based on multiple sources (neurologic departments, hospital discharge archives, and mortality records). Incidence rates are age and sex standardized for the Italian population of the 2011 census. Age-period-cohort (APC) analysis was performed using a Poisson regression model.

Main Outcomes and Measures

The primary study outcomes were long-term incidence and prevalence rates of ALS using a prospective design and their determinants.

Results

During the study period, a total of 2702 patients (mean [SD] age at onset, 65.7 [11.1] years; 1246 [46.1%] female and 1456 [53.9%] male) received a diagnosis of ALS between 1995 and 2014, corresponding to a crude annual incidence rate of 3.03 per 100 000 population (95% CI, 2.85-3.23) and an adjusted incidence rate of 2.78 per 100 000 population (95% CI, 2.57-2.96). The age-adjusted incidence rate increased in the 2 decades of the study (1995-2004: 2.66; 95% CI, 2.50-2.83; 2005-2014: 2.89; 95% CI, 2.71-3.07; P = .04), mostly in women. The adjusted rate ratio of men to women decreased from 1.27:1 (1995-2004) to 1.17:1 (2005-2014). The analysis of deviance for the APC regression models indicated that the drift variable is relevant in explaining the variation of ALS incidence rates over time in the overall population (change in deviance, 4.6553; P = .03) and in women (change in deviance, 3.8821; P = .05) but not in men (change in deviance, 0.77215; P = .38). A total of 479 patients with ALS were alive and had not undergone tracheostomy at the prevalence day (December 31, 2014), corresponding to a crude prevalence rate of 10.54 per 100 000 population (95% CI, 9.64-11.52).

Conclusions and Relevance

During the 1995 to 2014 period, the crude and adjusted incidences of ALS increased in Piemonte and Valle d'Aosta, mostly in women. The APC model revealed that the increase of ALS incidence is attributable to a birth cohort effect in women, with a peak in the 1930 cohort. The different increase of ALS incidence in men and women points to an effect of exogenous factors with a differential effect on the 2 sexes, acting on a genetic background.

Characteristics and Prognosis of Oldest Old Subjects with Amyotrophic Lateral Sclerosis

BACKGROUND

Amyotrophic Lateral Sclerosis (ALS) is an age-related neurodegenerative disease with unclear characteristics and prognosis in the oldest old (80 years and over). The aim of this study was to compare the oldest old and younger ALS patients in terms of clinical and socio-demographic characteristics, and prognosis.

METHODS

ALS incident cases from the register of ALS in Limousin (FRALim), diagnosed between January 2000 and July 2013, were included. Descriptive and comparative analyses by age group were carried out. For time to event univariate analysis, Kaplan-Meier estimator and log rank test were used. Univariate and multivariate survival analyses were carried out with Cox's proportional hazard model.

RESULTS

Out of 322 patients, 50 (15.5%) were aged 80 or over ("oldest old" ALS) at the time of diagnosis. Among them, the male:female gender-ratio was 1.27, and 32.6% had a bulbar onset (not different from subjects aged less than 80 years). With increasing age, there was a worsening of the clinical state of the patients at time of diagnosis in terms of weight loss, forced vital capacity, ALSFRS-R and manual muscular testing. Access to ALS referral centres decreased with age, and the use of riluzole tended to be lower in the oldest old group. The median survival of oldest old patients appeared to be 10 months shorter than that of subjects aged less than 80 years (7.4 vs. 17.4 months).

CONCLUSION

The survival of oldest old ALS patients is particularly short. It relates to prognostic features at baseline and to an independent effect of advanced age.

The Epidemiology of Neuromuscular Diseases

Neuromuscular disorders as a group are linked by anatomy with significant differences in pathogenetic mechanisms, clinical expression, and time course of disease. Each neuromuscular disease is relatively uncommon, yet causes a significant burden of disease socioeconomically. Epidemiologic studies in different global regions have demonstrated certain neuromuscular diseases have increased incidence and prevalence rates over time. Understanding differences in global epidemiologic trends will aid clinical research and policies focused on prevention of disease. There is a critical need to understand the global impact of neuromuscular diseases using metrics currently established for communicable and noncommunicable diseases.

Nationwide incidence of motor neuron disease using the French health insurance information system database

OBJECTIVE

There are no estimates of the nationwide incidence of motor neuron disease (MND) in France. We used the French health insurance information system to identify incident MND cases (2012-2014), and compared incidence figures to those from three external sources.

METHODS

We identified incident MND cases (2012-2014) based on three data sources (riluzole claims, hospitalisation records, long-term chronic disease benefits), and computed MND incidence by age, gender, and geographic region. We used French mortality statistics, Limousin ALS registry data, and previous European studies based on administrative databases to perform external comparisons.

RESULTS

We identified 6553 MND incident cases. After standardisation to the United States 2010 population, the age/gender-standardised incidence was 2.72/100,000 person-years (males, 3.37; females, 2.17; male:female ratio = 1.53, 95% CI1.46-1.61). There was no major spatial difference in MND distribution. Our data were in agreement with the French death database (standardised mortality ratio = 1.01, 95% CI = 0.96-1.06) and Limousin ALS registry (standardised incidence ratio = 0.92, 95% CI = 0.72-1.15). Incidence estimates were in the same range as those from previous studies.

CONCLUSIONS

We report French nationwide incidence estimates of MND. Administrative databases including hospital discharge data and riluzole claims offer an interesting approach to identify large population-based samples of patients with MND for epidemiologic studies and surveillance.

Epidemiology of amyotrophic lateral sclerosis in Southern Germany

The objective of this study is to determine the current distribution of clinical phenotypes and to estimate future trends of ALS incidence in Western societies. We report on a clinical-epidemiological registry with a capture-recapture rate of >80% and population-based case-control study in ALS patients in South Western Germany. 1163 incidents of ALS were registered. Clinical and neuropsychological data were prospectively collected from 699 cases. The mean age at onset was 66.6 (SD = 11.6) years in prospective cases (N = 699). The site of onset was more frequently bulbar (34.1%) than lumbosacral (30.7%), cervical (27.0%), or thoracic (3.1%). Cognitive deficits (ranging from 27.5 to 42.1%, depending on the screening instrument) and behavioral changes (29%) were frequently detected. The incidence rate dropped markedly after 79 years of age, and bulbar onset as well as cognitive impairment were more frequent in ALS cases >75 years. The mean survival time of ALS cases from first paresis was 31 months. The age-standardized incidence rate (ASR) of ALS in 2012/2013 was found to be 2.4 (95% CI 2.2-2.7) per 100,000 person-years (resulting in an ASR of 3.1/100,000 with 100% coverage). Based on the predicted age distribution of the German population, the incidence of ALS was estimated to be 4.5/100,000 for men and 3.3/100,000 for women in the year 2050. ALS prevalence will rise to about 9.2-9.8/100,000 person-years in Germany in 2050. An increased proportion of patients with bulbar onset and/or cognitive deficits can be used as basic epidemiologic data on ALS for future health care decisions.

Incidence of amyotrophic lateral sclerosis in the province of Novara, Italy, and possible role of environmental pollution

OBJECTIVE AND METHODS

Based on nationwide death certificates, a cluster of amyotrophic lateral sclerosis (ALS) has been reported in the area of Briga (Novara province, northern Italy), known for its severe environmental contamination. We further investigated this finding, by following up with the collection of recent incidence ALS data in 2002-2012 of Novara province, also to assess the possible long-term effects of environmental pollution in that area.

RESULTS

In the whole Novara province we identified 106 ALS cases, of which 35 were from the Briga area. Incidence rates of Novara province were 3.98, 5.14 and 2.97 for the total population, males and females, respectively, compared with the Briga area where they were 4.65, 4.27 and 4.98, respectively. The ratio of observed-to-expected ALS cases in the Briga area, using incidence of the rest of Novara province as a reference, was 1.17 (95% CI 0.81-1.62), with a value of 0.83 (95% CI 0.47-1.37) in males and 1.68 (95% CI 1.03-2.60) in females.

CONCLUSIONS

Overall, our study did not confirm previous findings of an excess ALS incidence in an area characterised by severe environmental heavy metal pollution, and it suggests the need to interpret with caution clusters identified through mortality data.

Drivers: A Biologically Contextualized, Cross-Inferential View of the Epidemiology of Neurodegenerative Disorders

Background:

Sutherland et al. (2011) suggested that, instead of risk factors for single neurodegenerative disorders (NDDs), there was a need to identify specific “drivers”, i.e., risk factors with impact on specific deposits, such as amyloid-β, tau, or α-synuclein, acting across entities.

Objectives and Methods:

Redefining drivers as “neither protein/gene- nor entity-specific features identifiable in the clinical and general epidemiology of conformational NDDs (CNDDs) as potential footprints of templating/spread/transfer mechanisms”, we conducted an analysis of the epidemiology of ten CNDDs, searching for patterns.

Results:

We identified seven potential drivers, each of which was shared by at least two CNDDs: 1) an age-at-exposure-related susceptibility to Creutzfeldt-Jakob disease (CJD) and several late-life CNDDs; 2) a relationship between age at onset, survival, and incidence; 3) shared genetic risk factors for CJD and late-life CNNDs; 4) partly shared personal (diagnostic, educational, behavioral, and social risk factors) predating clinical onset of late-life CNDDs; 5) two environmental risk factors, namely, surgery for sporadic CJD and amyotrophic lateral sclerosis, and Bordetella pertussis infection for Parkinson’s disease; 6) reticulo-endothelial system stressors or general drivers (andropause or premenopausal estrogen deficiency, APOEɛ4, and vascular risk factors) for late-life CNDDs such as dementia/Alzheimer’s disease, type-2 diabetes mellitus, and some sporadic cardiac and vascular degenerative diseases; and 7) a high, invariant incidence ratio of sporadic to genetic forms of mid- and late-life CNDDs, and type-2 diabetes mellitus.

Conclusion:

There might be a systematic epidemiologic pattern induced by specific proteins (PrP, TDP-43, SOD1, α-synuclein, amyloid-β, tau, Langerhans islet peptide, and transthyretin) or established combinations of these.

Isolated rapid eye movement sleep without atonia in amyotrophic lateral sclerosis

OBJECTIVE

The aim of this study was to quantitatively analyze, with the most recent and advanced tools, the presence of periodic leg movements during sleep (PLMS) and/or rapid eye movement (REM) sleep without atonia (RSWA), in a group of patients with amyotrophic lateral sclerosis (ALS), and to assess their eventual correlation with the clinical severity of the disease.

METHODS

Twenty-nine ALS patients were enrolled (mean age 63.6 years) along with 28 age-matched "normal" controls (mean age 63.8 years). Functional impairment due to ALS was evaluated using the ALS-Functional Rating Scale-Revised (ALS-FRS) and the ALS severity scale (ALSSS). Full video polysomnographic night recordings were obtained, and PLMS were analyzed by considering their number/hour of sleep and periodicity index, the distribution of intermovement intervals, and the distribution during the night. The characteristics of the chin electromyogram (EMG) amplitude during REM sleep were analyzed by means of the automatic atonia index and the number of chin EMG activations (movements).

RESULTS

The ALS patients showed longer sleep latency than the controls, together with an increase in number of stage shifts, increased sleep stage 1, and decreased sleep stage 2. None of the leg PLMS parameters were different between the ALS patients and controls. The REM atonia index was significantly decreased in the ALS patients, and the number of chin movements/hour tended to increase. Both REM atonia index and number of chin movements/hour correlated significantly with the ALS-FRS; REM atonia was higher and chin movements were less in ALS patients with more preserved function (higher scores on the ALS-FRS).

CONCLUSION

Abnormal REM sleep atonia seemed to be a genuine effect of ALS pathology per se and correlated with the clinical severity of the disease. It is unclear if this might constitute the basis of a possible risk for the development of REM sleep behavior disorder or represent a form of isolated RSWA in ALS.

Predictors of health-related quality of life in people with amyotrophic lateral sclerosis

BACKGROUND

Knowledge of factors influencing health-related quality of life (HRQL) in people with amyotrophic lateral sclerosis (ALS) is important because some factors might be amenable to intervention.

OBJECTIVES

The aim was to describe and explore the effects of disease severity, fatigue, anxiety, depression, frequency of social and lifestyle activities, coping capacity and mechanical ventilator use on HRQL in people with ALS.

METHODS

Sixty people with ALS were enrolled in this cross-sectional study. Data were collected with questionnaires during home visits. The Sickness Impact Profile and the EuroQol Visual Analogue Scale were used to assess HRQL. Multivariate regression analyses explored associations between HRQL and independent factors.

RESULTS

Low frequency of social and lifestyle activities, and severe disease, were associated with worse HRQL, explaining 57% of total variance in the Sickness Impact Profile physical score. Severe disease, weak coping capacity and anxiety and/or depression were associated with worse HRQL, explaining 33% of total variance in Sickness Impact Profile psychosocial score. Fatigue and mechanical ventilator use were associated with worse HRQL, explaining 17% of variance in the EuroQol Visual Analogue Scale.

CONCLUSION

Knowledge and understanding of how frequency of social and lifestyle activities, disease severity, coping capacity, anxiety and/or depression, fatigue and ventilator use contribute to and predict self-rated HRQL can optimize person-centred care and support.

Screening of Drugs Inhibiting In vitro Oligomerization of Cu/Zn-Superoxide Dismutase with a Mutation Causing Amyotrophic Lateral Sclerosis

Dominant mutations in Cu/Zn-superoxide dismutase (SOD1) gene have been shown to cause a familial form of amyotrophic lateral sclerosis (SOD1-ALS). A major pathological hallmark of this disease is abnormal accumulation of mutant SOD1 oligomers in the affected spinal motor neurons. While no effective therapeutics for SOD1-ALS is currently available, SOD1 oligomerization will be a good target for developing cures of this disease. Recently, we have reproduced the formation of SOD1 oligomers abnormally cross-linked via disulfide bonds in a test tube. Using our in vitro model of SOD1 oligomerization, therefore, we screened 640 FDA-approved drugs for inhibiting the oligomerization of SOD1 proteins, and three effective classes of chemical compounds were identified. Those hit compounds will provide valuable information on the chemical structures for developing a novel drug candidate suppressing the abnormal oligomerization of mutant SOD1 and possibly curing the disease.

Etiologic Framework for the Study of Neurodegenerative Disorders as Well as Vascular and Metabolic Comorbidities on the Grounds of Shared Epidemiologic and Biologic Features

Background: During the last two decades, protein aggregation at all organismal levels, from viruses to humans, has emerged from a neglected area of protein science to become a central issue in biology and biomedicine. This article constitutes a risk-based review aimed at supporting an etiologic scenario of selected, sporadic, protein-associated, i.e., conformational, neurodegenerative disorders (NDDs), and their vascular- and metabolic-associated ailments.

Methods: A rationale is adopted, to incorporate selected clinical data and results from animal-model research, complementing epidemiologic evidences reported in two prior articles.

Findings: Theory is formulated assuming an underlying conformational transmission mechanism, mediated either by horizontal transfer of mammalian genes coding for specific aggregation-prone proteins, or by xeno-templating between bacterial and host proteins. We build a few population-based and experimentally-testable hypotheses focusing on: (1) non-disposable surgical instruments for sporadic Creutzfeldt-Jakob disease (sCJD) and other rapid progressive neurodegenerative dementia (sRPNDd), multiple system atrophy (MSA), and motor neuron disease (MND); and (2) specific bacterial infections such as B. pertussis and E. coli for all forms, but particularly for late-life sporadic conformational, NDDs, type 2 diabetes mellitus (T2DM), and atherosclerosis where natural protein fibrils present in such organisms as a result of adaptation to the human host induce prion-like mechanisms.

Conclusion: Implications for cohort alignment and experimental animal research are discussed and research lines proposed.

Geographic Variation of Amyotrophic Lateral Sclerosis Incidence in New Jersey, 2009-2011

Few analyses in the United States have examined geographic variation and socioeconomic disparities in amyotrophic lateral sclerosis (ALS) incidence, because of lack of population-based incidence data. In this analysis, we used population-based ALS data to identify whether ALS incidence clusters geographically and to determine whether ALS risk varies by area-based socioeconomic status (SES). This study included 493 incident ALS cases diagnosed (via El Escorial criteria) in New Jersey between 2009 and 2011. Geographic variation and clustering of ALS incidence was assessed using a spatial scan statistic and Bayesian geoadditive models. Poisson regression was used to estimate the associations between ALS risk and SES based on census-tract median income while controlling for age, sex, and race. ALS incidence varied across and within counties, but there were no statistically significant geographic clusters. SES was associated with ALS incidence. After adjustment for age, sex, and race, the relative risk of ALS was significantly higher (relative risk (RR) = 1.37, 95% confidence interval (CI): 1.02, 1.82) in the highest income quartile than in the lowest. The relative risk of ALS was significantly lower among blacks (RR = 0.57, 95% CI: 0.39, 0.83) and Asians (RR = 0.63, 95% CI: 0.41, 0.97) than among whites. Our findings suggest that ALS incidence in New Jersey appears to be associated with SES and race.

Comparative Incidence of Conformational, Neurodegenerative Disorders

Background

The purpose of this study was to identify incidence and survival patterns in conformational neurodegenerative disorders (CNDDs).

Methods

We identified 2563 reports on the incidence of eight conditions representing sporadic, acquired and genetic, protein-associated, i.e., conformational, NDD groups and age-related macular degeneration (AMD). We selected 245 papers for full-text examination and application of quality criteria. Additionally, data-collection was completed with detailed information from British, Swedish, and Spanish registries on Creutzfeldt-Jakob disease (CJD) forms, amyotrophic lateral sclerosis (ALS), and sporadic rapidly progressing neurodegenerative dementia (sRPNDd). For each condition, age-specific incidence curves, age-adjusted figures, and reported or calculated median survival were plotted and examined.

Findings

Based on 51 valid reported and seven new incidence data sets, nine out of eleven conditions shared specific features. Age-adjusted incidence per million person-years increased from ≤1.5 for sRPNDd, different CJD forms and Huntington's disease (HD), to 1589 and 2589 for AMD and Alzheimer's disease (AD) respectively. Age-specific profiles varied from (a) symmetrical, inverted V-shaped curves for low incidences to (b) those increasing with age for late-life sporadic CNDDs and for sRPNDd, with (c) a suggested, intermediate, non-symmetrical inverted V-shape for fronto-temporal dementia and Parkinson's disease. Frequently, peak age-specific incidences from 20–24 to ≥90 years increased with age at onset and survival. Distinct patterns were seen: for HD, with a low incidence, levelling off at middle age, and long median survival, 20 years; and for sRPNDd which displayed the lowest incidence, increasing with age, and a short median disease duration.

Interpretation

These results call for a unified population view of NDDs, with an age-at-onset-related pattern for acquired and sporadic CNDDs. The pattern linking age at onset to incidence magnitude and survival might be explained by differential pathophysiological mechanisms associated with specific misfolded protein deposits.

The Epidemiology of Amyotrophic Lateral Sclerosis in New Hampshire, USA, 2004-2007

BACKGROUND/AIMS

Trends in disease incidence and mortality can provide clues to disease etiology. Previously, we described a town in New Hampshire (N.H.), USA, with 25 times the expected incidence rate of amyotrophic lateral sclerosis (ALS). This study aimed to describe the incidence and mortality of ALS across the state to assess rates relative to other states and industrialized nations.

METHOD

A retrospective review of records from regional ALS centers, clinics and ALS organizations was conducted to obtain demographics and diagnostic details for patients diagnosed with ALS or primary lateral sclerosis in N.H. from January 2004 to December 2007. Data on mortality from review of death certificates were obtained for a similar time frame.

RESULTS

We identified 113 N.H. residents diagnosed with ALS in 2004-2007, yielding an age-standardized incidence rate ranging from 1.3 to 2.2 per 100,000 of the population per year. During the same period, the standardized mortality rate per 100,000 varied from 2.6 to 3.5. ALS was more common among men (ratio 1.6:1), who were more likely than women to have an earlier age at onset (59 ± 14.2 vs. 65 ± 11.8 years, p = 0.01).

CONCLUSION

While localized areas in N.H. with high ALS incidence rates have been reported previously, the overall incidence and mortality rates of ALS in N.H. are similar to those in other industrialized nations.

Risk factors for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. It is typically fatal within 2-5 years of symptom onset. The incidence of ALS is largely uniform across most parts of the world, but an increasing ALS incidence during the last decades has been suggested. Although recent genetic studies have substantially improved our understanding of the causes of ALS, especially familial ALS, an important role of non-genetic factors in ALS is recognized and needs further study. In this review, we briefly discuss several major genetic contributors to ALS identified to date, followed by a more focused discussion on the most commonly examined non-genetic risk factors for ALS. We first review factors related to lifestyle choices, including smoking, intake of antioxidants, physical fitness, body mass index, and physical exercise, followed by factors related to occupational and environmental exposures, including electromagnetic fields, metals, pesticides, β-methylamino-L-alanine, and viral infection. Potential links between ALS and other medical conditions, including head trauma, metabolic diseases, cancer, and inflammatory diseases, are also discussed. Finally, we outline several future directions aiming to more efficiently examine the role of non-genetic risk factors in ALS.

Association between diabetes and amyotrophic lateral sclerosis in Sweden

BACKGROUND AND PURPOSE

Energy metabolism is altered in patients with amyotrophic lateral sclerosis (ALS) but the role of diabetes is largely unknown.

METHODS

A population-based case-control study was conducted of 5108 ALS cases and 25,540 individually matched population controls during 1991-2010. Information on ALS and pre-existing diabetes was retrieved from the Swedish Patient Register to explore the association of ALS with diabetes overall and with insulin-dependent or non-insulin-dependent diabetes specifically. Variation of the association by diabetes duration and age was also studied.

RESULTS

In total, 224 ALS cases (4.39%) and 1437 controls (5.63%) had diabetes before the index date, leading to an overall inverse association between diabetes and ALS risk [odds ratio (OR) 0.79, 95% confidence interval (CI) 0.68-0.91]. The association was strong for non-insulin-dependent diabetes (OR 0.66, 95% CI 0.53-0.81) but not for insulin-dependent diabetes (OR 0.83, 95% CI 0.60-1.15) and varied as a function of diabetes duration, with the strongest association observed around 6 years after first ascertainment of diabetes. The association was age-specific; the inverse association was noted only amongst individuals aged 70 or older. In contrast, for younger individuals (<50 years), pre-existing insulin-dependent diabetes was associated with a higher ALS risk (OR 5.38, 95% CI 1.87-15.51).

CONCLUSIONS

Our study suggests that there is an association between diabetes and ALS, and highlights the importance of taking into account age, insulin dependence and diabetes duration. Future studies should explore whether the association is independent of body mass index.

Aspirin use associated with amyotrophic lateral sclerosis: a total population-based case-control study

Background

The association of aspirin use and nonsteroid anti-inflammatory drug (NSAID) use with amyotrophic lateral sclerosis (ALS) risk is unclear. This study determined whether use of any individual compound is associated with ALS risk by conducting a total population-based case-control study in Taiwan.

Methods

A total of 729 patients with newly diagnosed ALS who had a severely disabling disease certificate between January 1, 2002, and December 1, 2008, comprised the case group. These cases were compared with 7290 sex-, age-, residence-, and insurance premium-matched controls. Drug use by each Anatomical Therapeutic Chemical code was analyzed using conditional logistic regression models. False discovery rate (FDR)-adjusted P values were reported in order to avoid inflating false positives.

Results

Of the 1336 compounds, only the 266 with use cases exceeding 30 in our database were included in the screening analysis. Without controlling for steroid use, the analysis failed to reveal any compound that was inversely associated with ALS risk according to FDR criteria. After controlling for steroid use, we found use of the following compounds to be associated with ALS risk: aspirin, diphenhydramine (one of the antihistamines), and mefenamic acid (one of the NSAIDs). A multivariate analysis revealed that aspirin was independently inversely associated with ALS risk after controlling for diphenhydramine, mefenamic acid, and steroid use. The inverse association between aspirin and ALS was present predominately in patients older than 55 years.

Conclusions

The results of this study suggested that aspirin use might reduce the risk of ALS, and the benefit might be more prominent for older people.

Quantification of neurotoxin BMAA (β-N-methylamino-L-alanine) in seafood from Swedish markets

The neurotoxin β-N-methylamino-L-alanine (BMAA) produced naturally by cyanobacteria, diatoms and dinoflagellates can be transferred and accumulated up the food chain, and may be a risk factor for neurodegenerative diseases. This study provides the first systematic screening of BMAA exposure of a large population through the consumption of seafood sold in metropolitan markets. BMAA was distinguished from known isomers by liquid chromatography tandem mass spectrometry after acidic hydrolysis and derivatization. Using deuterium-labeled internal standard, BMAA was quantified as 0.01–0.90 μg/g wet weight of tissues in blue mussel, oyster, shrimp, plaice, char and herring, but was undetectable (<0.01 μg/g) in other samples (salmon, cod, perch and crayfish). Provided that the content of BMAA detected is relevant for intake calculations, the data presented may be used for a first estimation of BMAA exposure through seafood from Swedish markets, and to refine the design of future toxicological experiments and assessments.

A fruitful endeavor: modeling ALS in the fruit fly

For over a century Drosophila melanogaster, commonly known as the fruit fly, has been instrumental in genetics research and disease modeling. In more recent years, it has been a powerful tool for modeling and studying neurodegenerative diseases, including the devastating and fatal amyotrophic lateral sclerosis (ALS). The success of this model organism in ALS research comes from the availability of tools to manipulate gene/protein expression in a number of desired cell-types, and the subsequent recapitulation of cellular and molecular phenotypic features of the disease. Several Drosophila models have now been developed for studying the roles of ALS-associated genes in disease pathogenesis that allowed us to understand the molecular pathways that lead to motor neuron degeneration in ALS patients. Our primary goal in this review is to highlight the lessons we have learned using Drosophila models pertaining to ALS research. This article is part of a Special Issue entitled ALS complex pathogenesis.

Osteoporosis in neurodegeneration

Osteoporosis affects bone microarchitecture and reduces bone mass. There are more than 200 million people with osteoporosis worldwide, and the prevalence is slowly increasing. The highest prevalences are found in Scandinavia and USA, also slowly increasing. A parallel increase in neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, Amyotrophic lateral sclerosis, and multiple sclerosis has been noted since the middle of this century. Osteoporosis is more common in patients with each of these neurodegenerative conditions than in the general population. Several metals with neurotoxic properties accumulate in bone and can substitute for calcium in hydroxyapatite, the main mineral component of bone. Especially cadmium, but also lead, aluminum and arsenic affect bone mineral density negatively. Metals with neurotoxic properties have also been found in brain and cerebrospinal fluid from patients with Alzheimer's disease, Parkinson's disease, Amyotrophic lateral sclerosis, and multiple sclerosis, and markers for neurodegeneration such as amyloid beta peptide and amyloid precursor protein have been detected in bone tissue from patients with osteoporosis. A common mechanism contributing to the pathogenesis of both neurodegeneration and osteoporosis can be suspected. The hypothesis that neurodegenerative disorders are associated with osteoporosis is presented and discussed.