Epidemiology of amyotrophic lateral sclerosis in the province of Modena, Italy. Influence of environmental exposure to lead.

A retrospective study of all admissions to the University of Modena Neurological Department from 1976-1986; 51 cases of amyotrophic lateral sclerosis (ALS) were found. ALS mean annual incidence was 0.78/100,000 inhabitants, while prevalence was 2.35/100,000. Mean age at onset was 61.43 years, mean and median duration of illness were, respectively, 28.83 and 24.5 months, and survival at 5 years post-onset was 24.4%. A tendency to higher incidence and prevalence of ALS in the ceramic district, when compared with those of the rest of the province was found. However, the small number of cases did not allow any conclusive statistical correlation between environmental exposure to lead and frequency of ALS.