Amyotrophic lateral sclerosis in Middle-Finland: an epidemiological study

Amyotrophic Lateral Sclerosis in Southwestern and Eastern Finland

INTRODUCTION

The incidence of amyotrophic lateral sclerosis (ALS) worldwide is approximately 1-2.6/1,000,000 and prevalence is 5-6/100,000. ALS has been suggested to be relatively common in Finland, but epidemiological information on the subject is scarce and outdated.

MATERIAL AND METHODS

Patients with ALS diagnostic codes were identified from mandatory administrative registries in the provinces of Southwestern Finland (population circa 430,000) and North Karelia (population circa 170,000), together comprising 11.7% of the total population of Finland. The diagnoses were verified, and data were extracted by reviewing the patient records. Incidence period was 2010-2018, and the prevalence date was December 31, 2018. Age-standardization was performed using the European Standard Population 2013 (ESP2013).

RESULTS

Overall crude incidence of ALS was 4.2/100,000 person-years in Southwestern Finland (ESP2013: 4.0/100,000) and 5.6/100,000 person-years in North Karelia (ESP2013: 4.8/100,000), while crude prevalences were 11.9/100,000 (ESP2013: 10.5/100,000) and 10.9/100,000 (ESP2013: 9.3/100,000), respectively. Mean age at diagnosis was 65.5-71.6 years in women (higher in Southwestern Finland compared to North Karelia, p = 0.003) and 64.7-67.3 years in men (no difference between provinces, p = 0.39). The diagnosis had been made in 50% before the age of 70 years in Southwestern Finland and before the age of 65 years in 51% in North Karelia. Genetic testing had been conducted in 28% of all patients with the most common findings being SOD1 and C9orf72. After the diagnosis, mean survival was 2.0-2.7 and median survival 1.3-1.4 years. Onset phenotype (p < 0.001), age at diagnosis (p < 0.001), and genotype (p = 0.001) predicted survival. Riluzole had been used by 25% of patients and tracheostomy and invasive ventilation (TIV) had been performed in <1%.

CONCLUSIONS

Both incidence and prevalence of ALS in Finland are among the highest in the world but with some notable differences between the eastern and southwestern parts of the country. Low median life expectancy may be related to the advanced age of patients and the high prevalence of C9orf72 repeat expansion in Finland as well infrequent use of TIV and riluzole.

ALS in Finland

Background and Objectives

To analyze the frequencies of major genetic variants and the clinical features in Finnish patients with amyotrophic lateral sclerosis (ALS) with or without the C9orf72 hexanucleotide repeat expansion.

Methods

A cohort of patients with motor neuron disease was recruited between 1993 and 2020 at the Helsinki University Hospital and 2 second-degree outpatient clinics in Helsinki. Finnish ancestry patients with ALS fulfilled the diagnosis according to the revised El Escorial criteria and the Awaji-criteria. Two categories of familial ALS (FALS) were used. A patient was defined FALS-A if at least 1 first- or second-degree family member had ALS, and FALS-NP, if family members had additional neurologic or psychiatric endophenotypes.

Results

Of the 815 patients, 25% had FALS-A and 45% FALS-NP. C9orf72 expansion (C9pos) was found in 256 (31%) of all patients, in 58% of FALS-A category, in 48% of FALS-NP category, and in 23 or 17% of sporadic cases using the FALS-A or FALS-NP definition. C9pos or SOD1 p.D91A homozygosity was found in 328 (40%) of the 815 patients. We compared demographic and clinical characteristics between C9pos and patients with unknown cause of ALS (Unk). We found that the age at onset was significantly earlier and survival markedly shorter in the C9pos vs Unk patients with ALS. The shortest survival was found in bulbar-onset male C9pos patients, whereas the longest survival was found in Unk limb-onset males. Older age at onset associated consistently with shorter survival in C9pos and Unk patients in both limb-onset and bulbar-onset groups. There were no significant differences in the frequencies of bulbar-onset and limb-onset patients in C9pos and Unk groups. ALS-frontotemporal dementia (FTD) was more common in C9pos (17%) than in Unk (4%) patients, and of all patients with ALS-FTD, 70% were C9pos.

Discussion

These results provide further evidence for the short survival of C9orf72-associated ALS. A prominent role of the C9orf72 and SOD1 variants was found in the Finnish population. An unusually high frequency of C9pos was also found among patients with sporadic ALS. The enrichment of these 2 variants likely contributes to the high incidence of ALS in Finland.

Home invasive mechanical ventilation in Finland in 2015-2019

INTRODUCTION

The prevalence of long-term invasive mechanical ventilation via tracheostomy in chronic respiratory insufficiency is largely unknown. We aimed to clarify prevalence and aetiology of the use of home invasive mechanical ventilation (HIMV) in Finland in 2015-2019.

METHODS

Information on HIMV patients was collected yearly from all Finnish Hospital District patient registries between 1 January 2015 and 1 January 2019. Data included underlying diagnosis, time from diagnosis to HIMV initiation, treatment length, mortality and basic sociodemographic data.

RESULTS

In 2015, we had 107 HIMV patients. During the follow-up we received 34 new patients (24.1%) and 46 patients (32.6%) died. In 2019, we had 95 HIMV patients and the prevalence in Finland was 2.0 in 100 000. The most common diagnoses were motor neurone disease (29.1%) and spinal cord injuries (19.9%). Mean duration of HIMV among all patients on 1 January 2019 was 12.3 years and among deceased patients, 11.2 years. Treatment durations ranged from 7.7 years for motor neurone disease patients to 47.3 years for post-polio syndrome patients. Most patients (81.6%) used HIMV 24 h·day-1.

CONCLUSIONS

HIMV is a rare, long-lasting treatment, most often used in chronic hypoventilation caused by chronic neurological disease. Based on our 4 year follow-up the prevalence of HIMV seems to be diminishing in Finland. Treatment duration and survival vary greatly depending on the underlying diagnosis. Most of the patients were totally dependent on HIMV, requiring 24-h care.

ALS and fertility: does ALS affect number of children patients have?

OBJECTIVE

Amyotrophic Lateral Sclerosis is one major disease in the group of neurodegenerative conditions. As with most other neurodegenerative diseases, clinical signs of the disease usually show among the elderly population, and most commonly around 60-65 years of age. Therefore the disease is not expected to impact the fertility of ALS patients. When examined from an evolutionary medicine and evolutionary biology perspective, there should be no selection pressure on the patient population due to the late onset of ALS. Methods: In this study, we tested the hypothesis that ALS does not affect fertility on a group of patients with ALS that we collected in a multi-center study. We recruited 511 patients diagnosed with ALS according to the revised El Escorial criteria, and 236 control cases without a neurodegenerative disease. We compared the ALS group's number of offspring with the control group in three consecutive generations. Results: No statistically significant difference was found between the number of siblings of ALS and control groups (p = 0.44). A statistically significant difference was found between the number of children of ALS and control groups (p < 0.001), indicating ALS patients had more children than controls. When the number of children is assessed by gender, for women, there was no statistically significant difference between the number of children of ALS and control groups (p = 0.067). Conclusions: This finding supports the view that ALS does not have a negative selection pressure on the patient population's fertility.

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.

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

To evaluate the association between worldwide ALS incidence rates and age, using a dose-response meta-analysis. We reviewed Medline and Embase up to July 2016 and included all population-based studies of newly-diagnosed cases, using multiple sources for case ascertainment. A dose-response meta-analysis was performed. A meta-regression investigated potential sources of heterogeneity. Of 3254 articles identified in the literature, we included 41 incidence studies covering 42 geographical areas. Overall, the fit between observed and predicted age-specific rates was very good. The expected variation of ALS incidence with age was characterized, in each study, by a progressive increase in the incidence from the 40s leading to a peak in the 60s or 70s, followed by a sharp decrease. Cochran's Q test suggested a significant heterogeneity between studies. Overall, estimated patterns of ALS age-specific incidence (at which the peak was reached) were similar among subcontinents of Europe and North America: peak of ALS incidence ranged in these areas between 6.98 and 8.17/100,000 PYFU, which referred to age in the range 71.6-77.4 years. The relationship between age and ALS incidence appeared different for Eastern Asia which was characterized by a peak of ALS incidence at 2.20/100,000 PYFU around 75 years of age. This study confirms the consistency of the age-specific ALS incidence pattern within different subcontinents. Age-specific incidence appears lower in Eastern Asia as compared to Europe and North America.

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

Background

To assess the worldwide variation of amyotrophic lateral sclerosis (ALS) incidence, we performed a systematic review and meta-analysis of population-based data published to date.

Methods

We reviewed Medline and Embase up to June 2015 and included all population-based studies of newly diagnosed ALS cases, using multiple sources for case ascertainment. ALS crude and standardized incidence (on age and sex using the US 2010 population) were calculated. Random effect meta-analysis and meta-regression were performed using the subcontinent as the main study level covariate. Sources of heterogeneity related to the characteristics of the study population and the study methodology were investigated.

Results

Among 3216 records, 44 studies were selected, covering 45 geographical areas in 11 sub-continents. A total of 13 146 ALS cases and 825 million person-years of follow-up (PYFU) were co-nsidered. The overall pooled worldwide crude ALS incidence was at 1.75 (1.55–1.96)/100 000 PYFU; 1.68 (1.50–1.85)/100 000 PYFU after standardization. Heterogeneity was identified in ALS standardized incidence between North Europe [1.89 (1.46–2.32)/100 000 PYFU] and East Asia [0.83 (0.42–1.24)/100 000 PYFU, China and Japan P = 0.001] or South Asia [0.73 (0.58–0.89)/100 000/PYFU Iran, P = 0.02]. Conversely, homogeneous rates have been reported in populations from Europe, North America and New Zealand [pooled ALS standardized incidence of 1.81 (1.66-1.97)/100 000 PYFU for those areas].

Conclusion

This review confirms a heterogeneous distribution worldwide of ALS, and sets the scene to sustain a collaborative study involving a wide international consortium to investigate the link between ancestry, environment and ALS incidence.

Does surgery accelerate progression of amyotrophic lateral sclerosis?

BACKGROUND

Surgery is not a recognised potential amyotrophic lateral sclerosis (ALS) risk factor that might modify the onset or course of ALS.

METHODS

We studied our database of ALS patients, which includes questions concerning surgical procedures. We defined surgery as an operative procedure requiring general or regional anaesthesia, but not local anaesthesia. Patients were classified as G1-no surgery; G2-surgery performed ≥3 months before disease onset; G3-surgery <3 months before disease onset; and G4-surgery after disease onset. The ALS-FRS score was evaluated every 3 months from presentation. The maximal ALS-FRS score was ascribed to disease onset, itself defined as symptom onset.

RESULTS

657 patients with ALS were studied. In G3 there was a positive correlation between onset-region and surgery-region (p=0.032). In G4, 35 (57.6%) patients had surgery, probably due to initial misdiagnosis. The rate of functional change (%) in G4 was significantly greater in the 3-month period immediately after surgery as compared with the 3-month period before (1.46%±1.35 vs. 6.30%±8.10, p=0.005) and the following 3 months (3.30%±3.10, p=0.006).

CONCLUSIONS

The site of surgery before ALS onset correlates with the region of onset of ALS. Patients with slower disease progression are at an increased risk of undergoing surgery, probably as part of initial difficulty in diagnosis. We noted accelerated disease progression during the 3-month period after surgery. Definite diagnosis is important to avoid unnecessary surgical trauma and subsequent more rapid deterioration.

Searching for Grendel: origin and global spread of the C9ORF72 repeat expansion

Recent advances are uncovering more and more of the genetic architecture underlying amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative condition that affects ~6,000 Americans annually. Chief among these was the discovery that a large repeat expansion in the C9ORF72 gene is responsible for an unprecedented portion of familial and sporadic ALS cases. Much has been published on how this expansion disrupts neuronal homeostasis and how gene-based therapy might be an effective treatment in the future. Nevertheless, it is instructive to look back at the origins of this important mutation. In this opinion piece, we attempt to answer three key questions concerning C9ORF72. First, how many times did the expansion occur throughout human history? Second, how old is the expansion? And finally and perhaps most importantly, how did the expansion spread throughout Europe? We speculate that the expansion occurred only once in the past, that this event took place in the Finnish population and that the Vikings and their descendants were responsible for disseminating this mutation throughout the rest of the continent.

Examining the relationship between head trauma and neurodegenerative disease: A review of epidemiology, pathology and neuroimaging techniques

Traumatic brain injuries (TBI) are induced by sudden acceleration-deceleration and/or rotational forces acting on the brain. Diffuse axonal injury (DAI) has been identified as one of the chief underlying causes of morbidity and mortality in head trauma incidents. DAIs refer to microscopic white matter (WM) injuries as a result of shearing forces that induce pathological and anatomical changes within the brain, which potentially contribute to significant impairments later in life. These microscopic injuries are often unidentifiable by the conventional computed tomography (CT) and magnetic resonance (MR) scans employed by emergency departments to initially assess head trauma patients and, as a result, TBIs are incredibly difficult to diagnose. The impairments associated with TBI may be caused by secondary mechanisms that are initiated at the moment of injury, but often have delayed clinical presentations that are difficult to assess due to the initial misdiagnosis. As a result, the true consequences of these head injuries may go unnoticed at the time of injury and for many years thereafter. The purpose of this review is to investigate these consequences of TBI and their potential link to neurodegenerative disease (ND). This review will summarize the current epidemiological findings, the pathological similarities, and new neuroimaging techniques that may help delineate the relationship between TBI and ND. Lastly, this review will discuss future directions and propose new methods to overcome the limitations that are currently impeding research progress. It is imperative that improved techniques are developed to adequately and retrospectively assess TBI history in patients that may have been previously undiagnosed in order to increase the validity and reliability across future epidemiological studies. The authors introduce a new surveillance tool (Retrospective Screening of Traumatic Brain Injury Questionnaire, RESTBI) to address this concern.

Prognosis and epidemiology of amyotrophic lateral sclerosis: Analysis of a clinic population, 1997-2011

Amyotrophic lateral sclerosis is a disease with highly variable clinical features and prognosis. We analyzed the prognostic indicators of age, sex, bulbar or spinal onset, body mass index (BMI), and forced vital capacity (FVC) for 728 deceased patients from the Emory ALS Clinic. The median overall survival was 29.8 months from symptom onset, 15.8 months from diagnosis, and 14.3 months from the initial clinic visit. While univariate analyses revealed that each of the identified clinical features was strongly associated with patient survival, in multivariable analyses only age, BMI, and FVC measured at the first clinic visit were independent prognostic indicators; bulbar onset and sex were not significantly associated with survival prognosis after adjustment for the other clinical features.

Incidence of amyotrophic lateral sclerosis in the Faroe Islands

OBJECTIVES

The establishment of variations in the incidence of amyotrophic lateral sclerosis (ALS) in the Faroese population from that found in other general populations may point to risk factors for the development of this disease among the Faroese. The aim of this study was to estimate the annual incidence of ALS during the period 1987-2009 and to compare the occurrence of ALS in the Faroe Islands with data from three European countries.

METHOD

All Faroese patients diagnosed with ALS in this period are documented in the current longitudinal prospective study.

RESULTS

The incidence of ALS in the Faroe Islands during the period 1987-2009 is 2.6 (1.7-3.7) per 100,000 annually. The results yielded no strong evidence of a difference (P = 0.09) in the incidence of ALS between Faroe Islands and Europe. The sample population is small, and this, of course, impacts the statistical precision of the findings.

CONCLUSION

The data clearly suggest, however, that the Faroese population is probably not subject to an increased risk of ALS, even though certain risk factors are present in the general population: (i) a fish-based diet contaminated with mercury and polychlorinated biphenyl; (ii) the high occurrence of the recessive carnitine transporter genetic defect; and (iii) the anticipated high degree of inbreeding at the fifth generation.

Trauma and amyotrophic lateral sclerosis: a case-control study from a population-based registry

BACKGROUND AND PURPOSE

Published reports on the association between amyotrophic lateral sclerosis (ALS) and trauma are controversial suggesting the need for a new case-control study done in a large population.

METHODS

A case-control study was undertaken in Italy to assess this association. Cases were patients with newly diagnosed ALS from four population-based registries. For each case, two hospital controls were selected, matched for age, sex, and province of residence, one with a neurological (non-degenerative) disease and one with a non-neurological disease (other than orthopedic or surgical). Traumatic events (defined as accidental events causing injuries requiring medical care) were recorded with details on type, site, timing, severity, and complications. The risks were assessed as odds ratios (ORs) with 95% confidence intervals (CI), crude and adjusted for age, sex, education, interviewee (patient or surrogate), physical activity, smoking, alcohol, and coffee.

RESULTS

The study population comprised 377 patients in each of the three groups. One or more traumatic events were reported by 225 cases (59.7%), 191 neurological controls (50.7%), and 179 non-neurological controls (47.5%) (P < 0.01) (OR 1.63; 95% CI 1.25-2.14) (P < 0.01). The ORs were 3.07 (95% CI 1.86-5.05) for patients reporting 3+ traumatic events and 2.44 (95% CI 1.36-4.40) for severe traumatic events. The ORs remained significant when the analysis was limited to events that occurred 5+ and 10+ years before ALS onset, to incident ALS, and direct informant.

CONCLUSION

Antecedent trauma, repeated trauma, and severe trauma may be risk factors for ALS.

High frequency of the expanded C9ORF72 hexanucleotide repeat in familial and sporadic Greek ALS patients

An intronic expansion of a hexanucleotide GGGGCC repeat in the C9ORF72 gene has recently been shown to be an important cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) in familial and sporadic cases. The frequency has only been defined in a small number of populations where the highest sporadic rate was identified in Finland (21.1%) and the lowest in mainland Italy (4.1%). We examined the C9ORF72 expansion in a series of 146 Greek ALS cases, 10.95% (n = 16) of cases carried the pathological expansion defined as greater than 30 repeats. In the 10 familial ALS probands, 50% (n = 5) of them carried a pathologically large expansion. In the remaining 136 sporadic ALS cases, 11 were carriers (8.2%). None of the 228 Greek controls carried an expanded repeat. The phenotype of our cases was spinal (13/16) or bulbar (3/16) ALS, the familial cases were all spinal ALS and none of our cases had behavioral frontotemporal dementia. Expansions in the C9ORF72 gene therefore represent a common cause of ALS in Greece and this test will be diagnostically very important to implement in the Greek population. The frequency is higher than other populations with the exception of Finland and this may be due to Greece being a relatively isolated population.

Amyotrophic lateral sclerosis: update and new developments

Amyotrophic lateral sclerosis (ALS) is the most common form of motor neuron disease. It is typically characterized by adult-onset degeneration of the upper and lower motor neurons, and is usually fatal within a few years of onset. A subset of ALS patients has an inherited form of the disease, and a few of the known mutant genes identified in familial cases have also been found in sporadic forms of ALS. Precisely how the diverse ALS-linked gene products dictate the course of the disease, resulting in compromised voluntary muscular ability, is not entirely known. This review addresses the major advances that are being made in our understanding of the molecular mechanisms giving rise to the disease, which may eventually translate into new treatment options.

Chromosome 9p21 in amyotrophic lateral sclerosis in Finland: a genome-wide association study

BACKGROUND

The genetic cause of amyotrophic lateral sclerosis (ALS) is not well understood. Finland is a well suited location for a genome-wide association study of ALS because the incidence of the disease is one of the highest in the world, and because the genetic homogeneity of the Finnish population enhances the ability to detect risk loci. We aimed to identify genetic risk factors for ALS in the Finnish population.

METHODS

We did a genome-wide association study of Finnish patients with ALS and control individuals by use of Illumina genome-wide genotyping arrays. DNA was collected from patients who attended an ALS specialty clinic that receives referrals from neurologists throughout Finland. Control samples were from a population-based study of elderly Finnish individuals. Patients known to carry D90A alleles of the SOD1 gene (n=40) were included in the final analysis as positive controls to assess whether our genome-wide association study was able to detect an association signal at this locus.

FINDINGS

We obtained samples from 442 patients with ALS and 521 control individuals. After quality control filters were applied, 318 167 single nucleotide polymorphisms (SNPs) from 405 people with ALS and 497 control individuals were available for analysis. We identified two association peaks that exceeded genome-wide significance. One was located on chromosome 21q22 (rs13048019, p=2·58×10(-8)), which corresponds to the autosomal recessive D90A allele of the SOD1 gene. The other was detected in a 232 kb block of linkage disequilibrium (rs3849942, p=9·11×10(-11)) in a region of chromosome 9p that was previously identified in linkage studies of families with ALS. Within this region, we defined a 42-SNP haplotype that was associated with significantly increased risk of ALS (p=7·47×10(-33) when people with familial ALS were compared with controls, odds ratio 21·0, 95% CI 11·2-39·1) and which overlapped with an association locus recently reported for frontotemporal dementia. For the 93 patients with familial ALS, the population attributable risk for the chromosome 9p21 locus was 37·9% (95% CI 27·7-48·1) and that for D90A homozygosity was 25·5% (16·9-34·1).

INTERPRETATION

The chromosome 9p21 locus is a major cause of familial ALS in the Finnish population. Our data suggest the presence of a founder mutation for chromosome 9p21-linked ALS. Furthermore, the overlap with the risk haplotype recently reported for frontotemporal dementia provides further evidence of a shared genetic cause for these two neurodegenerative diseases.

FUNDING

National Institutes of Health and National Institute on Aging, Microsoft Research, ALS Association, Helsinki University Central Hospital, Finnish Academy, Finnish Medical Society Duodecim, and Kuopio University.

Outcome measures and prognostic indicators in patients with amyotrophic lateral sclerosis

The purpose of the study was to assess frequency and predictors of disability measures in ALS. One hundred and fourteen newly diagnosed patients resident in eight administrative districts of Lombardy, Italy (population 4,947,554), included in a population-based registry, were followed for 2570 person-months (mean 22.5 months). The cumulative time-dependent risk of wheelchair, percutaneous endoscopic gastrostomy, and assisted ventilation was estimated according to the Kaplan-Meier method. Predictors of disability (age, sex, disease duration at diagnosis, type of onset, El-Escorial diagnosis) were assessed with the Cox proportional hazard function. During follow-up, 29 patients (25.4%) became wheelchair bound, 51 (44.7%) received gastrostomy, and 47 (41.2%) received assisted ventilation. The median time to loss of ambulation was 46.7 months (95% CI 36.5-56.8). The median time to gastrostomy and assisted ventilation was 31.1 months (95% CI 26.8-35.4) and 34.6 months (95% CI 29.6-39.6), respectively. Spinal onset ALS was the only predictor of loss of ambulation. Predictors of gastrostomy were older age, definite ALS, and shorter disease duration. Shorter disease duration was the only predictor of assisted ventilation. In conclusion, patients with ALS differ in terms of measures and predictors of disability. These factors are sources of bias and confounding in randomized clinical trials.

Good practice in the management of amyotrophic lateral sclerosis: clinical guidelines. An evidence-based review with good practice points. EALSC Working Group

The evidence base for diagnosis and management of ALS is still weak, and curative therapy is lacking. Nonetheless, early diagnosis and symptomatic therapy can profoundly influence care and quality of life of the patient and relatives, and may increase survival time. This review addresses the current optimal clinical approach to ALS. The literature search is complete to December 2006. Where there was lack of evidence but consensus was clear we have stated our opinion as good practice points. We conclude that a diagnosis of ALS can be achieved by early examination by an experienced neurologist. The patient should be informed of the diagnosis by the consultant. Following diagnosis, a multi-diciplinary care team should support the patient and relatives. Medication with riluzole should be initiated as early as possible. PEG is associated with improved nutrition and should be inserted early. The operation is hazardous in patients with VC <50%: RIG may be a better alternative. Non-invasive positive pressure ventilation improves survival and quality of life but is underused in Europe. Maintaining the patient's ability to communicate is essential. During the course of the disease, every effort should be made to maintain patient autonomy. Advance directives for palliative end of life care are important and should be discussed early with the patient and relatives if they so wish.

Amyotrophic Lateral Sclerosis in South-East England: A Population-Based Study

BACKGROUND/AIMS

We aimed to estimate the incidence and prevalence of amyotrophic lateral sclerosis (ALS) in the South East of England. The reported incidence of ALS varies between 0.44 and 3.2 per 100,000 person years. This can partly be explained by differences in design and diagnostic criteria used. There is little population data concerning England, particularly the South East.

METHODS

A population study of South-East England (total population: 2,890,482) was carried out and multiple sources including our tertiary centre and district general hospitals were used for complete case ascertainment.

RESULTS

Between 1 January 2002 and 30 June 2006 we identified 138 people (76 males; 62 females) with a new diagnosis of ALS, giving a crude incidence of 1.06 per 100,000 person years. The projected age- and gender-adjusted annual incidence rate for England and Wales was 1.10 (95% CI 0.80-1.40). 142 people were alive on 30 June 2006, giving a point prevalence of 4.91 per 100,000 population.

CONCLUSION

Our incidence and prevalence rates are similar to those reported in comparable studies from other countries. This argues against the role of a specific exogenous factor in the aetiology of ALS in South-East England.

Ethnic variation in the incidence of ALS: a systematic review

BACKGROUND

The findings of recent genetic polymorphism studies in ALS suggest that the influence of genetic risk factors for the disease may vary by ethnicity. It is now widely accepted that the incidence of ALS is uniform across Caucasian populations, but whether racial variation across other ethnicities exists remains unknown.

METHOD

Systematic review of the known literature on the incidence, prevalence, and mortality of ALS across all ethnicities. To facilitate comparison, studies were grouped according to the type of data presented and examined for sources of case ascertainment and inclusion criteria.

RESULTS

The literature search identified 61 publications. Lower standardized incidence rates were observed in Asian than Caucasian populations. Within the United States, several incidence and mortality studies have identified lower ALS frequency among African American and Hispanic populations than among non-Hispanic Caucasians. These observations are supported by the other data sources.

CONCLUSIONS

The incidence of ALS may be lower among African, Asian, and Hispanic ethnicities than among whites. We conclude with proposals for a prospective epidemiologic study concentrating on non-Caucasian populations.

Changes in the incidence of amyotrophic lateral sclerosis in Wakayama, Japan

In the 1960s, the incidence of amyotrophic lateral sclerosis (ALS) in the Kozagawa and Koza areas in Wakayama prefecture was much higher than that in other areas of the world. However, between 1980 and 1993, a gradual decrease in the incidence of the disease in these areas was reported. To ascertain whether the decreased incidence has persisted, we conducted a retrospective epidemiological study, and determined the average annual incidence of ALS in Wakayama prefecture from 1998 to 2002. The number of ALS cases encountered during the period was 134 (male 79, female 55). The crude average annual incidence in Wakayama prefecture in total was 2.50 (male 3.08, female 1.99) per 100,000. In the Kozagawa and Koza areas in Wakayama prefecture, where the senility rate rapidly increased in recent years, the average annual incidence of ALS in the present research was 10.56 (male 14.14, female 7.66). When the crude rate was standardized for both age and sex to the Japanese population in 1990, the expected value was 5.24 (male 7.34, female 3.18), which was lower than that of our previous survey. The prevalence in Wakayama prefecture at 31 December 2002 was 11.31 (male 14.40, female 8.53). In Kozagawa and Koza areas, the crude prevalence was 52.81 (male 70.70, female 38.28). These results indicated that the incidence of ALS in Wakayama prefecture, especially for females, steadily decreased compared to that in previous reports. However, a high incidence of ALS persisted among males in Wakayama prefecture, especially in the Kozagawa and Koza areas. Some environmental factors and gender specificity may be related to the decreased incidence of ALS in focus areas.

EFNS task force on management of amyotrophic lateral sclerosis: guidelines for diagnosing and clinical care of patients and relatives. An evidence-based review with good practice points

Despite being one of the most devastating diseases known, there is little evidence for diagnosing and managing patients with amyotrophic lateral sclerosis (ALS). Although specific therapy is lacking, correct early diagnosis and introduction of symptomatic and specific therapy can have a profound influence on the care and quality of life of the patient and may increase survival time. This document addresses the optimal clinical approach to ALS. The final literature search was performed in the spring of 2005. Consensus recommendations are given graded according to the EFNS guidance regulations. Where there was lack of evidence but consensus was clear we have stated our opinion as good practice points. People affected with possible ALS should be examined as soon as possible by an experienced neurologist. Early diagnosis should be pursued and a number of investigations should be performed with high priority. The patient should be informed of the diagnosis by a consultant with a good knowledge of the patient and the disease. Following diagnosis, the patient and relatives should receive regular support from a multidisciplinary care team. Medication with riluzole should be initiated as early as possible. PEG is associated with improved nutrition and should be inserted early. The operation is hazardous in patients with vital capacity < 50%. Non-invasive positive pressure ventilation improves survival and quality of life but is underused. Maintaining the patients ability to communicate is essential. During the entire course of the disease, every effort should be made to maintain patient autonomy. Advance directives for palliative end of life care are important and should be fully discussed early with the patient and relatives respecting the patients social and cultural background.

Survival of Patients with Amyotrophic Lateral Sclerosis in a Population-Based Registry

OBJECTIVE

To evaluate the survival of patients with amyotrophic lateral sclerosis (ALS) in an Italian population and to assess the effects of selected prognostic indicators on survival.

BACKGROUND

Median survival of ALS patients has been reported to range between 12 and 23 months from diagnosis and between 23 and 36 months from onset of symptoms. Although several negative prognostic factors have been identified, the overall picture still needs clarification.

METHODS

We included patients enrolled in an Italian ALS Regional Register (population 4,529,003) during the calendar year 1998. The diagnosis was confirmed by an ad hoc committee using the original El Escorial criteria. Each case was regularly followed up until death or December 31, 2002, whichever came first. Survival was assessed with the Kaplan-Meier method in the whole sample, by level of diagnostic certainty, and by selected prognostic indicators (age, sex, bulbar or spinal onset, and disease duration). Multivariate analysis was done with the Cox proportional hazard function.

RESULTS

The sample comprised 79 patients (33 female; 46 male) aged 28-85 years (mean age 64.4 years). Onset of symptoms was bulbar in 30% of cases. Mean symptom duration at diagnosis was 13.3 months. ALS was definite in 43%, probable in 29%, possible in 6%, and suspected in 22%. By December 31, 2002, 56 cases (71%) had died. The cumulative probability of surviving after diagnosis was 78% at 12 months, 56% at 24 months, and 32% at 48 months. Median survival from onset was 39.2 months and from diagnosis 30.6 months. Multivariate analysis confirmed definite ALS at diagnosis and older age as adverse prognostic factors.

CONCLUSIONS

Survival of ALS patients in the present sample was slightly longer than previously reported. Better palliative care and supportive treatment may explain the difference. Older age and the presence of definite ALS at diagnosis are poor prognostic predictors.

Clinical and epidemiological features of motor neuron disease in south-western Greece

OBJECTIVE

To evaluate the epidemiological and clinical features of motor neuron disease (MND) in a region (835,000 inhabitants) of south-western Greece.

PATIENTS AND METHODS

The medical records of all patients diagnosed with adult-onset MND at the Department of Neurology of the University Hospital of Patras from 1990 to 2003 were reviewed.

RESULTS

Overall 133 patients were identified, corresponding to a mean annual incidence rate of 1.13/100,000 population with male preponderance. Eighty-five of them were males (63.9%) and 48 (36.1%) females with a mean age of 61.4 +/- 13.3 years. The most common type of MND was amyotrophic lateral sclerosis (ALS) being identified in 111 (83.5%) patients, whereas 19 cases (14.3%) were classified as progressive spinal muscular atrophy (PSMA) and three (2.2%) cases as progressive bulbar palsy (PBP). The mean age at onset was 60.3 +/- 13.5 years, while the mean delay between age at onset and age at diagnosis was 1.3 +/- 1.1 years. The symptoms at onset involved the lower limbs in 76 (57.2%) cases, upper limbs in 32 (24%) cases, bulbar region in 22 (16.5%) cases and respiratory muscles in three (2.3%) cases. The mean survival time after onset of disease was 20.4 +/- 8.3 months for ALS patients, 15.3 +/- 4.5 months for PBP and 38.1 +/- 26.4 months for PSMA patients.

CONCLUSIONS

There was no statistically significant difference in the results of the considered epidemiological parameters of our study to those reported by other similar studies. The study of the patients with MND showed a predominance of ALS patients. No potentially causative clinical associations were found and no relation between socioeconomic factors, occupational exposure and the disease was noted.

Validation of bioelectrical impedance analysis in patients with amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurologic disease with an unfavorable prognosis that may be accompanied by malnutrition or overweight. Nutritional status is difficult to evaluate in these patients because of their physical limitations and the asymmetry of their disease involvement. Bioelectrical impedance analysis (BIA), which enables bedside analysis of body compartments, has not been adequately validated for use in patients with ALS.

OBJECTIVE

We compared reference measures of fat-free mass (FFM(a)), obtained by dual-energy X-ray absorptiometry, with FFM obtained by BIA and by the skinfold-thickness technique.

DESIGN

We measured FFM(a) in 32 ALS patients. Anthropometric measures included weight, height, skinfold thickness, and arm and wrist circumferences. The fat mass obtained from the skinfold-thickness measures enabled us to calculate FFM. BIA was performed by measuring the bioimpedances at 5, 50, and 100 kHz of each side of the body and from one side to the other. FFM was calculated by using the instrument's internal software and by using 3 standard equations. The concordance between the methods was evaluated by the Bland-Altman test.

RESULTS

Two of the 16 measured FFM values were not significantly different from FFM(a). However, the risk of dispersion was too high to be acceptable in practice. An equation was then developed by using multivariate analysis, with impedance at 50 kHz. This equation was validated in a second population of 15 ALS patients and with the use of 2 successive measurements performed on 18 patients.

CONCLUSION

BIA is a simple technique that is valid for use in ALS patients, both for a single exam measure and for longitudinal monitoring, with the use of an adapted equation and a frequency of 50 kHz.

Estimation of the amyotrophic lateral sclerosis incidence by capture-recapture method in the Limousin region of France

Amyotrophic lateral sclerosis (ALS) is a rapidly fatal degenerative neurological disease categorized among motor neuron diseases. In the literature, the incidence of ALS varies between 0.7 and 2.4 per 100, 000 inhabitants. A study using the capture-recapture method (multiple records system analysis) was undertaken in Limousin (France) ascertaining all patients having onset of definite or probable ALS during the period 1994-1995. Three information sources able to identify these new ALS cases were selected: the first source was a computerized database of the Neurology Department of the University Hospital of Limoges; the second source consisted of the neurologists of the Limousin region and neighboring provinces (county-sized regions); the third source grouped the hospitals of the Limousin region and neighboring provinces (county-sized regions). During this period, 46 new cases of ALS were seen, corresponding to an observed mean annual incidence of 3.2 (+/-0.6) per 100,000 inhabitants. After standardization for age, the annual incidence was 2.5 per 100,000 inhabitants. The number of new cases estimated by the capture-recapture method was 70, corresponding to an estimated mean annual incidence of 4.9 (+/-1.0) for 100,000 inhabitants. Hence, statistical modeling utilizing partially overlapping information sources permitted a more exhaustive compendium of the new cases of ALS and may be a truer reflection of actual disease incidence than has been previously reported.

Genetic factors in the early diagnosis of ALS

The frequency of familial amyotrophic lateral sclerosis (ALS) is usually reported as 5-10% of all ALS cases. This figure is probably an underestimate, primarily due to inadequate recording of family history in the patients' charts, and to the not infrequent occurrence of reduced disease penetrance in pedigrees with familial ALS. The true familial ALS frequency may be at least double this. Familial ALS is heterogenetic. The only known ALS-causing gene is the CuZn-superoxide dismutase gene (CuZn-SOD). Mutations in this gene account for a fifth of all familial ALS cases and a few percent of apparent sporadic ALS cases. Genetic testing for CuZn-SOD mutations can help confirm a diagnosis of ALS, especially in cases with atypical features that have been reported in some cases with CuZn-SOD mutations. Genetic testing should only be performed after thorough clinical examination and in cases with a proven or uncertain family history of ALS. It is not warranted in cases with no proven family history for three generations, unless the patient shows the characteristic phenotype associated with recessive inheritance of the D90A CuZn-SOD mutation.

Motor neurone disease in South Estonia. Diagnosis and incidence rate

The current study evaluated the diagnostic standards of MND and epidemiological markers of MND in Estonia. A total of 108 patients were referred to the University Hospital from 1986 to 1995 with the first suggested diagnosis or final diagnosis of amyotrophic syndrome, amyotrophic lateral sclerosis (ALS), progressive bulbar paralysis (PBP) or progressive muscular atrophy (PMA). In addition neurologists of the region and the National Society of Neuromuscular disorders were contacted. Some 94 patients satisfied the diagnostic criteria. The annual incidence rate in South Estonia and in the city of Tartu ranged from 0.5 to 2.8 per 100,000. The mean annual incidence rate in Tartu is 1.98 and in South Estonia in general 1.3. The highest incidence rate was 8.3 for men in the age group 60 to 64 years and 7.49 in the age group 70-74; among female patients the highest incidence rate -4.6 was in the age group from 65 to 69.

Epidemiology of motor neuron disease in the Kii Peninsula of Japan, 1989-1993: active or disappearing focus?

During the period 1989-1993, the incidence and migration patterns of patients with motor neuron diseases (MND) in Wakayama Prefecture, including one of the high-incidence Kii Peninsula foci ('Kozagawa focus'), were surveyed to determine whether the focus had truly disappeared or not. Overall, the crude average annual incidence was 1.43 per 100000 population; when age-adjusted to the 1990 Japanese population, it was 1.25 (1.85 for males and 0.61 for females). The average annual age- and sex-specific incidence steadily increased to a peak between 60 and 69 years and dropped after 70. Geographically, the rates varied in the five regions of Wakayama Prefecture from 0.38 to 2.48. The areas with high incidence were distributed in the central and southernmost regions; the highest was in the Kozagawa focus with 9.54 (two ALS cases within five years; 4193 base population, 1990). During the study period, four emigrants from Kozagawa had developed MND one to four decades after leaving the focus. Although the remarkable clustering of MND was thought to have disappeared, the southern Kii Peninsula remains a high-risk area for MND, especially if one interprets the data so as to include the emigrants. In general, the age at onset has increased in the past 20 years from 56.5 to 61.7; male predominance is observed.

Epidemiological and clinical characteristics of ALS in Belgrade, Yugoslavia

We present the results of the first epidemiological study of ALS in Belgrade. The distribution of 58 newly discovered cases in a 7-year survey period (1985-1991) showed that the average annual age-adjusted incidence rate was 0.42 per 100,000 population (95% confidence interval, 0.18-0.83). The rate for males was 1.5 times higher than the rate for females. The greatest age-specific average incidence rate was observed in patients between 60 and 64 (3.66 per 100,000 population; 95% confidence interval, 2.17-5.78). The actual age-adjusted prevalence rate on December 31, 1991 was 1.07 per 100,000 (95% confidence interval, 0.71-1.71). The mean age at onset of the disease was 56.2 +/- 9.8 and it ranged from 24 to 74. We studied the natural course of the disease through the mean duration and cumulative probability of survival. The mean duration of the disease was 27.7 +/- 18.2 months. The cumulative probability of survival was 27% for the whole population in a 5-year interval. Elderly patients and those with bulbar signs at onset had a poorer prognosis. Patients under 49 at onset and those with the spinal form of the disease survived longer.

Neurodegenerative diseases: occupational occurrence and potential risk factors, 1982 through 1991

OBJECTIVES

To identify potential occupational risk factors, this study examined the occupational occurrence of various neurodegenerative diseases.

METHODS

Death certificates from 27 states in the National Occupational Mortality Surveillance System were evaluated for 1982 to 1991. Proportionate mortality ratios were calculated by occupation for presenile dementia, Alzheimer's disease, Parkinson's disease, and motor neuron disease.

RESULTS

Excess mortality was observed for all four categories in the following occupational categories: teachers; medical personnel; machinists and machine operators; scientists; writers/designers/entertainers; and support and clerical workers. Clusters of three neurodegenerative diseases were also found in occupations involving pesticides, solvents, and electromagnetic fields and in legal, library, social, and religious work. Early death from motor neuron disease was found for firefighters, janitors, military personnel, teachers, excavation machine operators, and veterinarians, among others.

CONCLUSIONS

Neurodegenerative disease occurs more frequently in some occupations than in others, and this distribution, which may indicate occupational risk factors, should be further investigated.

Clinical epidemiology of amyotrophic lateral sclerosis

The introduction of palliative therapies in amyotrophic lateral sclerosis (ALS) will alter the epidemiology of ALS as it is known now. Although incidence rates will remain unchanged in the near future, prevalence rates will likely increase dramatically. Better understanding of the age-specific presentation of motor neuron diseases worldwide will shed light on the vexing questions concerning the variable incidence rates in some countries and apparent incidence gradients in North America and Europe.

Steadiness of amyotrophic lateral sclerosis in the province of Parma, Italy, 1960-1990

A clinical and epidemiological study on amyotrophic lateral sclerosis (ALS) was conducted in the province of Parma, Italy, from 1960-1990. A total of 121 cases were collected from hospital records. The average annual incidence was 0.98 per 100,000 inhabitants, with a male/female ratio of 1.1. Age-specific incidence was maximal in the age group 60-69 years. No difference between rural and urban areas was found. Prevalence on October 26th, 1981 was 2.5 per 100,000. Mean age at onset was 60 years, with no significant sex difference. Mean duration of the disease was 30 (sd 21.4) months. Bulbar forms were significantly (p < 0.05) shorter than conventional forms, with a mean duration of 23.4 (sd 21.4) months. Age at onset did not influence prognosis. A comparison of three decades was made, to verify whether possible variations of the disease had occurred with time. From our data a definite stability was found in such epidemiological parameters as incidence, prevalence, mean duration and mortality of ALS in the period.

Motor neuron disease: a disease of old age

There is little information dealing specifically with motor neuron disease (MND) in the elderly. Given current epidemiological trends, geriatricians will be increasingly called upon to diagnose and manage this condition. We report four patients who presented within a six month period to a geriatric medical unit, and place this experience in the perspective of 229 patients from a population-based study of adult-onset MND in Scotland in 1989 and 1990. In 1990 Scotland had a crude annual incidence of MND of 2.25/100,000; the figure for those over 65 is four times greater. MND is more common in men, but the sex ratio was nearly equal over the age of 65. The risk of presenting with bulbar palsy was greater in women, and even higher in elderly women. This, together with increasing age, is the most important negative prognostic factor in MND. Problems with the diagnosis and management of MND in the elderly are highlighted.

The prognosis of adult-onset motor neuron disease: a prospective study based on the Scottish Motor Neuron Disease Register

The Scottish Motor Neuron Disease Register (SMNDR) is a prospective, collaborative, population-based project which has been collecting data on incident patients since 1989. In this report we present the clinical features of 229 patients with motor neuron disease (218 sporadic and 11 familial) diagnosed in 1989 and 1990 and compare their prognosis with previous studies of survival. The overall 50% survival from symptom onset was 2.5 years (95% CI, 2.2-3.0) and 5-year survival 28% (95% CI, 20-36%). The presence of progressive bulbar palsy (PBP), either at presentation or developing during the course of the illness, significantly reduced survival and was the most important prognostic indicator. Patients who survived longer than 5 years from symptom onset did not have PBP as part of their presenting illness. The prognosis was worse for women, and this was in part related to the higher frequency of PBP in older women, but age was also an independent adverse risk factor. Differences in survival between this and previous series can probably be explained on the basis of variation in case definition and ascertainment methods.

Amyotrophic lateral sclerosis in Sardinia, Italy: an epidemiologic study

The authors carried out an epidemiologic study on amyotrophic lateral sclerosis in Sardinia for the years 1957 through 1990. The duration of the disease and survival were significantly shorter in bulbar form. The distribution of ALS in various areas of the island was found to be not at all homogeneous. Mean yearly incidence showed no significant variations in the decades 1971-80 and 1981-90. In the last decade, an increase of bulbar forms was observed.

Utility of Scottish morbidity and mortality data for epidemiological studies of motor neuron disease

OBJECTIVES

To determine the accuracy of (1) hospital discharge data and (2) death certificates, coded as motor neuron disease (MND).

DESIGN

Comparison of data from The Scottish Motor Neuron Disease Register (SMNDR) with routinely collected Scottish Hospital In-Patient Statistics (SHIPS) and death certificate coding.

SETTING

Scotland UK.

PATIENTS

1) 379 adults (> 15 years) discharged for the first time from a Scottish hospital in 1989-90 and (2) 281 deaths in the same period assigned to the International Classification of Diseases (ICD)-9, category 335 (MND).

MAIN OUTCOME MEASURES

The sensitivity and positive predictive value of a diagnosis of MND as retrieved by (1) the Information and Statistics Division of the Common Services Agency for the Scottish Health Service for morbidity data and (2) the Registrar General's office for mortality data, using the SMNDR as the 'gold standard'.

RESULTS

(1) Thirty per cent of adult patients identified as having MND by SHIPS did not have this disease and 23% of patients with MND did not appear on SHIPS. The sensitivity of a diagnosis of MND, as retrieved by SHIPS, was 84% and the positive predictive value was 70% overall. Miscoding of patients with pseudobulbar palsy caused by cerebrovascular disease was the major source of false positive error. The incidence of adult onset sporadic MND was over estimated by SHIPS by a factor of 1.6. (2) Mortality data were more accurate, with a false negative rate of 6% and a positive predictive value of 90%.

CONCLUSIONS

Coded hospital discharge data are an inaccurate record of a diagnosis of MND and cannot, in their present form, be used as a reliable measure of disease incidence in Scotland. Greater care is required in the preparation of discharge summaries and coding if these data are to be useful for health care planning and epidemiological research. SHIPS is, however, an important source of information to achieve a complete sample of patients with MND. There is also a problematic false positive rate for mortality data but this source more closely approximates true incidence.

Duration of amyotrophic lateral sclerosis is age dependent

Since 1985, we prospectively followed 246 patients with ALS. The relationship between the age of developing neurological impairment and disease duration was analyzed in 138 patients (86 men and 52 women) who died. Mean disease duration was 4.0 +/- 3.8 years for men and 3.2 +/- 2.5 years for women. There was an inverse, exponential, relationship between onset age and duration (goodness-of-fit P > 0.05). Mean duration at onset age < or = 40 years was 8.2 +/- 5.0 years compared with 2.6 +/- 1.4 years for patients aged 61 to 70 years (P > 0.001). The ratio of young (< or = 40 years) men to women was 3.6:1. When matched for age, disease duration was the same for patients with bulbar and nonbulbar onsets. We conclude that onset age, but not sex, is the most significant predictor determining disease duration in ALS. Longer survival in younger patients probably reflects their greater neuronal reserve.