Occupation and motor neuron disease: a New Zealand case–control study

ObjectivesTo assess associations between occupational exposures to pesticides and other chemicals and motor neuron disease (MND).MethodsA population-based case–control study that included 319 MND cases (64% male/36% female) recruited through the...

BackgroundApart from increasing age and a few specific genetic polymorphisms, the aetiology of Motor Neurone Disease is largely unknown. Only 5–10% of cases are familial with the vast majority being...

BackgroundWe have reported previously the results on a New Zealand population based case-control study evaluating occupations as risk factors for MND. The aim of this study was to investigate the...

Our objective was to analyse the coverage of hospital discharge data and the mortality registry (MR) of La Rioja to ascertain motor neuron disease (MND) cases to be included in the Spanish National Rare Diseases Registry. MND cases that occurred in La Rioja during the period 1996–2011 were selected from hospital discharge data and the MR by means of the International Classification of Diseases. Review of the medical histories was carried out to confirm the causes of death reported. Characteristics of the population with MND were analysed. A total of 133 patients with MND were detected in La Rioja during the period 1996–2011; 30.1% were only recorded in the hospital discharges data, 12.0% only in the MR, and 57.9% were recorded by both databases. Medical records revealed a miscoding of patients who had been diagnosed with progressive supranuclear palsy but were recorded in the MR with an MND code. In conclusion, the hospital discharges data and the MR appear to be complementary and are valuable databases for the Spanish National Rare Diseases Registry when MNDs are properly codified. Nevertheless, it would be advisable to corroborate the validity of the MR as data source since the miscoding of progressive supranuclear palsy has been corrected.

Air pollution exposure has been associated with an increased risk of neurodegenerative diseases; however, evidence is limited for motor neuron disease (MND), especially regarding disease progression. To determine whether long-term exposure to air pollution is associated with the risk and prognosis of MND. This population-based, nested case-control study used Swedish health register data of incident MND cases diagnosed between 2015 and 2023 with up to 8 years of follow-up. Participants included patients with MND, 5 age- and sex-matched population controls without MND per patient with MND, and full siblings of the patients with MND. Data were analyzed between November 6, 2024, and November 4, 2025. Mean yearly concentrations of particulate matters of 2.5 µm or less, 10 µm or less, or 2.5 to 10 µm in diameter (PM2.5, PM10, PM2.5-10) and nitrogen dioxide (NO2) were assessed at the residential address using a spatiotemporal model to approximate accumulated air pollution exposure. Association between air pollution and risk of MND was assessed by comparing cases to both population and sibling controls. Flexible parametric survival models estimated the association between air pollution exposure and the risk of mortality (or use of invasive ventilation) after MND diagnosis (case-only analyses). Based on the rate of decline in the ALS Functional Rating Scale-Revised (ALSFRS-R) score and its subscores after diagnosis, patients were classified into fast (upper 25th percentile) or slow (lower 75th percentile) progression. Logistic regression was used to assess air pollution exposure and the risk of fast progression. The study included 1463 patients with MND, 7310 population controls, and 1768 sibling controls. The mean (SD) age for all patients with MND was 67.3 (11.7) years, and 814 (55.6) were male. In the population comparison, long-term air pollution was associated with an increased risk of MND; per IQR increase in the 10-year average level, the odds ratio was 1.21 (95% CI, 1.09-1.34) for PM2.5, 1.30 (95% CI, 1.19-1.42) for PM2.5-10, 1.29 (95% CI, 1.18-1.42) for PM10, and 1.20 (95% CI, 1.12-1.29) for NO2. A higher level of PM10 or NO2 was associated with a higher hazard of mortality, whereas a higher level of all PMs was associated with faster functional decline, particularly motor and respiratory functions, after MND diagnosis. The findings of this case-control study suggest that air pollution, even at relatively low levels typical of Sweden, may contribute both to the risk of developing MND and disease prognosis after MND diagnosis.

Background Although there are no established environmental or occupational risk factors for Motor Neurone Disease, an association with work in “electrical occupations” has been observed in numerous studies. However, the results of investigations using job-exposure matrices for extremely low frequency EMF and for electric shocks have been equivocal. In a population-based case-control study conducted in New Zealand we examined the effect of both electric shocks and ELF-MF. Methods We recruited cases from a voluntary register supplemented by notifications by neurologists. General population controls were selected from the Electoral Roll. A standardised questionnaire was used to obtain demographic and personal data, information on lifestyle factors plus a lifetime occupational history. Odds ratios were estimated for occupation, adjusting for age, gender, ethnicity, SES and smoking using logistic regression. The occupational histories of all participants were linked to job-exposure matrices on ELF-MF exposure and on electric shocks. Results We included 259 cases and 474 controls. There was no association between ELF-MF exposure and MND, with an OR = 1.1 (95% CI: 0.6–2.1) for the high exposure group. For electric shock the risk was elevated (but not statistically significantly) for both the medium OR = 1.3 (0.9–1.9) and high risk OR = 1.3 (0.0–1.9) groups when compared with the reference low risk group. Conclusions We found no strong evidence of elevated risk of MND associated with either ELF-MF or electric shock.

Occupational exposures to magnetic fields and neurodegenerative disease risks

Motor neurone disease (MND) was studied in relation to various determinants in a case-control study covering nine counties in southern Sweden. A questionnaire about occupational exposures, medical history, lifestyle factors etc was given to all cases in the age range 45-79 and to a random sample of 500 population controls in the same age range. The questionnaires were answered by 92 cases and 372 controls, a response rate of 85% and 75% respectively. Among men high Mantel-Haenszel odds ratios (MHORs) were obtained for electricity work (MHOR = 6.7, 95% confidence interval (95% CI) 1.0-32.1), welding (MHOR = 3.7, 95% CI 1.1-13.0), and impregnating agents (MHOR = 3.5, 95% CI 0.9-13.1). Heritability with regard to a neurodegenerative disease or thyroid disease seemed to predispose to a risk of developing MND (OR = 2.1, 95% CI 1.0-4.3). The highest OR was found for the combination of such heritability, exposure to solvents, and male sex (OR = 15.6, 95% CI 2.8-87.0), a combination that occurred for seven cases and three controls. Hereditary factors and external exposures had a different distribution among cases with the spinal type of MND than among cases with involvement of the pyramidal tract or bulbar paresis also.

ObjectiveTo map the international methods used to measure energy expenditure of adults living with motor neuron disease (MND) and to highlight discrepancies when indicating hypermetabolism in the MND literature.BackgroundA decline in the nutritional status of patients is associated with exacerbated weight loss and shortened survival. Assessments of energy expenditure, using a variety of methods, are important to ensure an adequate energy intake to prevent malnutrition-associated weight loss. Assessments of energy expenditure are also commonly used to indicate hypermetabolism in MND, although these approaches may not be optimal.MethodsA protocol based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews Guidelines was developed. Three electronic databases (Medline [Ovid], CINAHL [EBSCO], and Web of Science) were exhaustively searched. Identified publications were systematically screened according to predefined PICOS eligibility criteria. The primary outcome was the identification of methods used to measure energy expenditure in MND. The secondary outcome was the identification of applications of energy expenditure assessments to indicate hypermetabolism in MND.ResultsThirty-two observational primary research publications were identified. Thirteen (40.6%) were longitudinal in design, with data on repeated measurements of energy expenditure presented in 3 (9.4%). Thirteen (40.6%) were case-control studies, of which 11 use a matched control group. Pulmonary function was used to assess eligibility in 10 publications. Energy expenditure was measured using indirect calorimetry (IC) in 31 studies. Discrepancies in the durations of fasted, measurement, and washout periods were observed. Of all included publications, 50% used assessments of resting energy expenditure to identify hypermetabolism. Bioelectrical impedance analysis was used to assess body composition alongside energy expenditure in 93.8% of publications.ConclusionsResting energy expenditure is most frequently measured using an open-circuit IC system. However, there is a lack of a standardized, validated protocol for the conduct and reporting of IC and metabolic status in patients with MND.

ObjectiveTo confirm the symptoms and signs for motor neuron disease (MND) in the Red Flag tool; to quantify the extent to which the key symptoms and signs are associated with...

Military and risk of motor neurone disease: A French nationwide case-control study

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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.

To determine the accuracy of (1) hospital discharge data and (2) death certificates, coded as motor neuron disease (MND). Comparison of data from The Scottish Motor Neuron Disease Register (SMNDR) with routinely collected Scottish Hospital In-Patient Statistics (SHIPS) and death certificate coding. Scotland UK. 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). 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'. (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%. 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.

ObjectivesTo assess whether sports, physical trauma and emotional trauma are associated with motor neurone disease (MND) in a New Zealand case–control study (2013–2016).MethodsIn total, 321 MND cases and 605 population controls were interviewed collecting information on lifetime histories of playing sports, physical trauma (head injury with concussion, spine injury) and emotional trauma (14 categories). ORs were estimated using logistic regression adjusting for age, sex, ethnicity, socioeconomic status, education, smoking status, alcohol consumption and mutually adjusting for all other exposures.ResultsHead injury with concussion ≥3 years before diagnosis was associated with MND (OR 1.51, 95% CI: 1.09–2.09), with strongest associations for two (OR 4.01, 95% CI: 1.82–8.86), and three or more (OR 2.34, 95% CI: 1.00–5.45) head injuries. Spine injury was not associated with MND (OR 0.81, 95% CI: 0.48–1.36). Compared to never playing sports, engaging in sports throughout childhood and adulthood increased MND risk (OR 1.81, 95% CI: 1.01–3.25), as was more than 12 years playing football/soccer (OR 2.35, 95% CI: 1.19–4.65). Reporting emotionally traumatic events in more than three categories was associated with MND (OR 1.88, 95% CI: 1.17–3.03), with physical childhood abuse the only specific emotional trauma associated with MND (OR 1.82, 95% CI: 1.14–2.90), particularly for those reporting longer abuse duration (OR(5–8 years) 2.26, 95% CI: 1.14–4.49; OR(>8 years) 3.01, 95% CI: 1.18–7.70). For females, having witnessed another person being killed, seriously injured or assaulted also increased MND risk (OR 2.68, 95% CI: 1.06–6.76).ConclusionsThis study adds to the evidence that repeated head injury with concussion, playing sports in general, and playing football (soccer) in particular, are associated with an increased risk of MND. Emotional trauma, that is physical abuse in childhood, may also play a role.