Amyotrophic lateral sclerosis and occupational heavy metal exposure: a case-control study

A retrospective case-control study of occupational heavy metal exposure was conducted using 66 amyotrophic lateral sclerosis (ALS) patients and 66 age- and sex-matched controls. Cases were ascertained primarily through a neurology support and research clinic. The self-administered questionnaire probed potential exposure to nine heavy metals: aluminum, lead, lead alkyl, magnesium, manganese, mercury, mercury alkyl, nickel and selenium. Using McNemar's test and a Mantel Haenszel extended analysis, no association was found between heavy metal exposure and the pathogenesis of ALS in this patient population. Demographic factors, fracture history, immunizations, travel and other variables were similar in ALS patients and controls.     

Amyotrophic lateral sclerosis and history of skeletal fracture: a case-control study

A retrospective case-control study was conducted, using 66 amyotrophic lateral sclerosis (ALS) patients and 66 closely matched controls. Cases were ascertained primarily through a neurology clinic. A self-administered questionnaire probed for history of skeletal fractures. Using McNemar's test, no association was found between history of skeletal fracture and pathogenesis of ALS. No predilection for the head, neck, or spine was demonstrated. The extremities accounted for most fracture sites in cases and controls. Among cases, 68% of the fractures occurred before diagnosis, 58% occurring more than 10 years before diagnosis of ALS.     

Amyotrophic lateral sclerosis in Middle-Finland: an epidemiological study

ABSTRACT- Amyotrophic lateral sclerosis (ALS) was diagnosed in 36 patients in Middle-Finland Central Hospital District during 1976–1981. The annual incidence of ALS was 2.4 per 100,000 population and the prevalence rate was 6.4 per 100,000 population. The age-specific incidences of ALS were similar for men and women with a maximum of 14/100,000/year in the age group 60–69 years. The initial symptoms originated in 37% of the patients from bulbar and in 63% from spinal levels. Bulbar onset was more common in patients aged 60 years or more compared with younger patients. Patients with bulbar onset had a significantly poorer prognosis than those with spinal onset, which explained the poorer prognosis of older patients.
4 matched controls were chosen for each ALS patient from the files of the Central Hospital. There was no difference between the patients and the controls with respect to previous injuries, surgical operations, malignant neoplasms, or exposure to domestic animals. An earlier observation that evacuees from Karelia ceded to USSR after World War II should have a prevalence twice that of the remaining population was not substantiated.     

Amyotrophic lateral sclerosis: an introduction

Amyotrophic lateral sclerosis (ALS) is a progressive, neurodegenerative disease that results in the degeneration of lower and upper motor neurones in the brain and the spinal cord. Early onset and modern therapies, including assisted ventilation, improve survival in this disease, although its cause remains uncertain. Amongst the possible causes are deficiency of nerve growth factor, deficient glutamate re-uptake, autoimmunity and mutation of superoxide dismutase 1 gene. Additional factors may be industrial pollutants and occupational exposure to chemicals associated with welding and soldering. The criteria for the diagnosis of ALS, proposed by the World Federation of Neurology, are presented together with a review of the clinical features of the disease.

     

Amyotrophic lateral sclerosis: possible role of environmental influences

This treatise briefly discusses the genetic features of ALS and reviews environmental exposures in sporadic ALS. At least 10 genetic foci are responsible for cases of familial motor neuron disease and more are yet to be discovered. Research into sporadic ALS suggests that abundant factors apparently participate in the disease process. A singular cause and unifying disease and nerve dysfunction in polyneuropathies, a multitude of genetic, toxic, autoimmune, infectious, and systematic processes seem to be at play. The ALS syndrome likely will not be dissimilar.     

Amyotrophic lateral sclerosis in southern Greece: an epidemiologic study.

All amyotrophic lateral sclerosis cases hospitalized over a 25-year period in the University Department of Neurology in Athens were surveyed, with emphasis given to the occupation of the patients and the geographic distribution of the disease. The results showed an overrepresentation of farmers among patients and an aggregation of cases in the region of Cephalonia. These findings might suggest that environmental factors could be involved in the etiology of the disease.     

Amyotrophic lateral sclerosis in Palermo, Italy: an epidemiological study

The incidence, prevalence and natural course of ALS were determined in the population of the province of Palermo, Italy. The average annual incidence calculated for the years 1973 through 1984, was 044./100.000 inhabitants. The prevalence rate on prevalence day December 31, 1984, was 1.67/100.000 population. The male/female ratio was 1.38. The mean age at onset was 54.3±11.02. The most common clinical form was the conventional one (61.4%); the bulbar form was more frequent among females than males. The mean duration of the disease was 33.7±35.8 months. The longest duration belongs to the pseudopolyneuritic form. The median survival was 36 months: 16 months for the bulbar, 36 months for the conventional and 51 months for the pseudopolyneuritic form.

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Sommario Questa indagine si prefigge di valutare l'incidenza, la prevalenza ed il decorso naturale della Sclerosi Laterale Amiotrofica nella provincia di Palermo nel periodo compreso tra il 1973 ed il 1984. L'incidenza annuale media è di 0,44/100.000 abitanti; il tasso di prevalenza al 31 Dicembre 1984 è di 1,67/100.000 abitanti. Il rapporto M/F risulta di 1,38; l'età media di esordio è di 54,3±11,01. La forma tipica è quella più comune (61,4%), mentre la forma bulbare è la più frequente tra i soggetti di sesso femminile. La durata media di malattia è di 33,7±35,8 mesi, sopravvivendo maggiormente i pazienti affetti dalla forma pseudopolineuritica. La sopravvivenza media è di 36 mesi. Una analisi differenziata per le singole forme evidenzia una sopravvivenza media di 16 mesi nella forma bulbare, di 36 mesi nella forma tipica e di 51 mesi nella forma pseudopolineuritica.

     

Amyotrophic lateral sclerosis a population study

Summary A country-wide study of the frequency of amyotrophic lateral sclerosis (ALS) was undertaken in Israel for the period 1960–1970. Israel was chosen for this study because of its excellent medical facilities and detailed demographic information. Moreover, the population includes representative groups from all parts of the world for comparison of frequency. A wide variety of motor system disease was screened in all hospitals, clinics, and chronic care facilities in the country, death certificates were reviewed and physicians with a neurological practice were contacted to derive a tentative list of cases. Only those who fit strict clinical diagnostic criteria or had autopsy confirmation were included in estimates of prevalence and incidence.On January 1, 1965, the mid-point of the study, 62 patients with ALS were living in Israel. The age-adjusted prevalence of ALS on that date was 3 per 100000 population. The average annual age-adjusted incidence for the period 1960–1970 was 0.78 per 100000 population (0.86 in males, 0.46 in females; ratio 1.9:1). There was no appreciable change in trend of incidence over the study interval. Age-specific incidence rates were similar in native-born inhabitants of Israel, immigrants from Europe and immigrants from Afro-Asian countries. The range in age-adjusted incidence among subgroups of immigrants to Israel from various countries was 0.25 to 1.20 per 100000 population but small numbers precluded testing the statistical significance of these rather narrow differences.Mean age at onset was 55.4 years for males and 52.4 years for females. The mean age at death was 60.2 for males and 58.0 for females. The average annual mortality from ALS was 0.58 per 100000 population. There were no familial aggregates of ALS in Israel and autopsy data showed no neurofibrillary changes, granulovacuolar or inclusion bodies.There are only a few other population studies of ALS in different regions of the world. The average annual incidence in these other studies ranged from 0.4 to 1.4 per 100000 population. Thus, the incidence in Israel falls within this narrow range. The present study lends further support to the impression that ALS has a remarkably uniform geographic distribution with Guam and the Kii peninsula of Japan being the only known areas with significantly high rates. If an environmental factor contributes to the pathogenesis of ALS, the factor must also have a uniform geographic distribution.Supported in part by the Minneapolis Veterans Administration Hospital.     

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.     

Amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive, degenerative disease of the motor system characterized by signs and symptoms of upper and lower motor dysfunction. This results in the presence of focal amyotrophies and pareses affecting voluntary muscles. Patients die after a few years, in most cases by respiratory failure. ALS is the most frequent motor neuron disease; however, its etiology and pathogenesis are only known in fragments. Its genetic basis is only partially understood and major gaps remain in the understanding of its pathogenesis with the basic principle of selective vulnerability and potentially resulting therapeutic consequences.     

Amyotrophic lateral sclerosis mimic syndromes: a population-based study

BACKGROUND: The Irish ALS Register is a population-based register of the epidemiological characteristics of amyotrophic lateral sclerosis (ALS) in the republic of Ireland. OBJECTIVE: To describe the clinical and demographic details of those patients included in the Irish ALS Register who were incorrectly diagnosed as having ALS (patients who were ultimately rediagnosed as having an "ALS mimic syndrome"). METHODS: The medical records of each patient referred to the register are routinely reviewed and, where possible, patients are examined by our group during their illness. RESULTS: Between January 1, 1993, and December 31, 1997, 32 patients (representing 7.3% of 437 referrals) were rediagnosed as having a condition other than ALS. The median age at onset for these 32 patients was 56.0 years (range, 19.5-85.8 years) for men and 53.5 years (range, 39.5-70.4 years) for women. Twenty-nine patients (91%) presented with symptoms referable to the limbs, and the remainder presented with symptoms involving the bulbar musculature. Multifocal motor neuropathy was the most common condition mistaken for ALS, accounting for 7 cases (22%), followed closely by Kennedy disease (4 cases [13%]). Factors leading to diagnostic revision included evolution of atypical symptoms, results of specific investigations, and failure of symptoms to progress. Twenty-seven (84%) of the patients with an ALS mimic syndrome fulfilled the El Escorial criteria for either "suspected" or "possible" ALS, 4 (13%) met the criteria for probable ALS, and 1 (3%) had definite ALS. CONCLUSIONS: The application of the El Escorial diagnostic criteria may facilitate early recognition of non-ALS cases. Misdiagnosis of ALS remains a common clinical problem despite the increased availability of investigations and a greater awareness among neurologists of potential diagnostic pitfalls.