Amyotrophic lateral sclerosis in Catalonia: a population based study.

Our objective was to determine the incidence and clinical-epidemiological characteristics of an ALS cohort patient in Catalonia (Spain). We conducted a population based registry for a three-year period (1999-2001) in Catalonia (6,361,365 inhabitants) using several sources of information. The original El Escorial diagnostic criteria (1994) for ALS were applied for the classification of patients.