Residential exposure to ultra high frequency electromagnetic fields emitted by Global System for Mobile (GSM) antennas and amyotrophic lateral sclerosis incidence: A geo-epidemiological population-based study

International audienceAmyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of unknown etiology. Mobile communication antennas have increased over the last few decades. Consequently, there has been a steady increase in environmental exposure to ultra high frequency electromagnetic fields (UHF-EMFs) emitted by Global System for Mobile (GSM) communication antennas, which raises concerns about possible health risks in the general population. We aimed to evaluate the relationship between residential exposure to UHF-EMFs generated by GSM antennas and the risk of ALS in general population. A geo-epidemiological population-based study was performed in Limousin (France). ALS incident cases were identified through a register (FRALim, 2000-2012 period). A model to estimate UHF-EMF exposure was developed based on the distance and the power of GSM antennas. Exposure to multiple emissions from multiple directions was considered. A non-cumulative and a cumulative model were established. A geographic information system integrated the raster model of exposure, and the residential distribution of observed and expected cases. A generalized linear model was performed to test the association. Overall, 312 ALS cases were included. We estimated exposures below 1.72 V/m in urban areas and below 1.23 V/m in rural areas for 90% of the population. A gradient effect between UHF-EMF exposure and ALS incidence was apparent with a statistically significant trend. A significant increased risk of ALS was observed between the non-exposure category and the highest exposure category, with a relative risk of 1.78 (95% CI: 1.28-2.48) in the non-cumulative model and 1.83 (95% CI: 1.32-2.54) in the cumulative model. Our results suggest a possible association between residential UHF-EMF exposure and ALS. Ecological studies are a means of generating hypotheses. Further studies are needed to clarify the potential role of EMFs on neurodegeneration

Clinical features and prognosis of amyotrophic lateral sclerosis in Africa: the TROPALS study

International audienceOBJECTIVE:We describe and compare the sociodemographic and clinical features, treatments, and prognoses and survival times of patients with amyotrophic lateral sclerosis (ALS) in Africa.METHODOLOGY:We conducted a multicentre, hospital-based cohort study in Africa. Patients with ALS diagnosed in the neurology departments of participating hospitals from 2005 to 2017 were included. Subgroup analysis was performed by subcontinent. Survival analyses were conducted using the Cox proportional hazards model.RESULTS:Nine centres from eight African countries participated. A total of 185 patients with ALS were included: 114 from Northern Africa, 41 from Western Africa and 30 from Southern Africa. A male predominance (male to female ratio 2.9) was evident. The median age at onset was 53.0 years (IQR 44.5-64.0 years). The onset was bulbar in 22.7%. Only 47 patients (26.3%) received riluzole, mainly in Northern and Western Africa. The median survival from the time of diagnosis was 14.0 months (95% CI 10.7 to 17.2 months). The median survival was longer in Northern Africa (19.0 months, 95% CI 10.8 to 27.2 months) than in Western (4.0 months, 95% CI 0.8 to 7.1 months) and Southern (11.0 months, 95% CI 5.6 to 16.4 months) Africa (Breslow test, p<0.0001). Both subcontinental location and riluzole treatment independently affected survival.CONCLUSION:More African patients with ALS were male and younger and exhibited a lower proportion of bulbar onset compared with patients with ALS from Western nations. Survival was consistent with that in Western registers but far shorter than what would be expected for young patients with ALS. The research improves our understanding of the disease in Africa