Steadiness of amyotrophic lateral sclerosis in the province of Parma, Italy, 1960-1990

Abstract
A clinical and epidemiological study on amyotrophic lateral sclerosis (ALS) was conducted in the province of Parma, Italy, from 1960–1990. A total of 121 cases were collected from hospital records. The average annual incidence was 0.98 per 100000 inhabitants, with a male/female ratio of 1.1. Age-specific incidence was maximal in the age group 60–69 years. No difference between rural and urban areas was found. Prevalence on October 26th, 1981 was 2.5 per 100000. Mean age at onset was 60 years, with no significant sex difference. Mean duration of the disease was 30 (sd 21.4) months. Bulbar forms were significantly (p<0.05) shorter than conventional forms, with a mean duration of 23.4 (sd 21.4) months. Age at onset did not influence prognosis. A comparison of three decades was made, to verify whether possible variations of the disease had occurred with time. From our data a definite stability was found in such epidemiological parameters as incidence, prevalence, mean duration and mortality of ALS in the period.