Michel Druet-Cabanac

Introduction Amyotrophic lateral sclerosis (ALS) is the most common motor neurone disease. It occurs in two forms: (1) familial cases, for which several genes have been identified and (2) sporadic cases, for which various hypotheses have been formulated. Notably, the β-N-methylamino-L-alanine (L-BMAA) toxin has been postulated to be involved in the occurrence of sporadic ALS. The objective of the French BMAALS programme is to study the putative link between L-BMAA and ALS. Methods and analysis The programme covers the period from 1 January 2003 to 31 December 2011. Using multiple sources of ascertainment, all the incident ALS cases diagnosed during this period in the area under study (10 counties spread over three French regions) were collected. First, the standardised incidence ratio will be calculated for each municipality under concern. Then, by applying spatial clustering techniques, overincidence and underincidence zones of ALS will be sought. A case–control study, in the subpopulation living in the identified areas, will gather information about patients’ occupations, leisure activities and lifestyle habits in order to assess potential risk factors to which they are or have been exposed. Specimens of drinking water, food and biological material (brain tissue) will be examined to assess the presence of L-BMAA in the environment and tissues of ALS cases and controls. Ethics and dissemination The study has been reviewed and approved by the French ethical committee of the CPP SOOM IV (Comité de Protection des Personnes Sud-Ouest & Outre-Mer IV). The results will be published in peer-reviewed journals and presented at national and international conferences.

Background and purpose: The main objective of establishing theFrench register of amyotrophic lateral sclerosis (ALS) in theLimousin region (FRALim), was to assess the incidence ofALS, in this ageing region ofEurope, over a 12‐year period (2000–2011).Methods: Patients were included if they lived inLimousin at the time of diagnosis ofALSaccording toElEscorial revised criteria and were identified by at least one of the following sources: (i) theFrench national body coordinatingALSreferral centres; (ii) public and private hospitals in the region; (iii) health insurance data related to long‐term diseases.Results: TheFRALim register identified 279 incident cases (2000–2011). The crude andEuropean population standardized incidences ofALSwere as high as 3.19/100 000 person‐years of follow‐up (95%CI2.81–3.56) and 2.58/100 000 person‐years of follow‐up (95%CI2.27–2.89) respectively. Median age at onset was 70.8 years (interquartile range 63.1–77.1). The standardized sex incidence ratio (male/female) was 1.3 overall, but 1.1 under the age of 65 years, 1.7 between 65 and 75 years and 1.9 above 75 years. The exhaustiveness of the register has been estimated at 98.4% (95%CI95.6–99.4) by capture–recapture analysis.Conclusion: It was possible for the first time in France to monitor accurately the incidence ofALSover a long time period. It appears to be in the upper range of data reported in western countries. Patterns displayed here might anticipate the epidemiology ofALSin ageing western countries.