Epidemiology of multiple system atrophy: a prevalence and pilot risk factor study in Aquitaine, France.

We investigated the prevalence of multiple system atrophy (MSA) in Gironde, France, through a network of 120 public and private specialists and assessed the relationship between some environmental factors and MSA in a case-control study involving 50 MSA patients, 50 Parkinson's disease (PD) patients and 50 healthy controls. The occupational exposure to pesticides was evaluated through a job-exposure matrix. On prevalence day (November 1, 1998), the crude prevalence of MSA in Gironde was 1.94/100,000 inhabitants. We found no significant relationship between occupational exposure to pesticides and MSA. PD patients were significantly less frequently ever-smokers than controls and the same tendency was observed for MSA patients. We also described the clinical features that heralded the disease among this nonselected population.