Risk factors of multiple system atrophy: a case-control study in French patients.

Multiple system atrophy (MSA) is a rare sporadic progressive neurodegenerative disorder. MSA risk factors are poorly known. The objectives of this case-control study were to study environmental risk factors associated with MSA. Cases were recruited through five French referral centers. Controls matched for age, gender, and living area were recruited from healthy relatives of inpatients free of any parkinsonian syndrome of the same centers. Subjects were interviewed about exposure to environmental factors (pesticides, solvents, etc.), occupation and food habits, and use of anti-inflammatory drugs. Odds ratios and 95% confident intervals (OR [95% CI]) were computed using conditional logistic regression. Seventy-one cases and 71 matched controls were included. Low education level was more frequent in cases than in controls. Controls drank more alcohol than did cases (OR = 0.5 [0.2-1.1]) and the risk of MSA decreased with increasing alcohol consumption (P = 0.04). Controls ate fish and sea food more often and drank more tea than cases. Aspirin intake was more frequent among controls than did cases (OR = 0.5 [0.2-1.0]) and the risk of MSA decreased with the frequency of intake (P = 0.0002). MSA was not associated to exposure to pesticides, solvents, and other toxics neither to occupations, except plant and machine operators and assemblers (OR = 10.0 [2.1-47.5]) where the risk of MSA increased with number of years in this occupation (P = 0.004). This case-control study provided new findings about risk factors of MSA. On another hand, it did not confirm the previously reported association between MSA and exposure to pesticides.