The prevalence of parkinsonism in Italy: an epidemiological survey of the disease in general practice. The Italian General Practitioner Study Group (IGPSG).

The prevalence and characteristics of parkinsonism have been assessed in two separate geographic areas in Italy (Arcisate and San Giovanni Rotondo). A total of 28,377 patients of 23 general practitioners (GPs) were the reference population. Fifty-eight patients were traced by the GP as having typical parkinsonian features or being treated with antiparkinson drugs. Among 53 subjects, 21 of them untreated, parkinsonism was subsequently confirmed neurologically. The overall crude prevalence rate was 1.87 cases per 1,000 (Arcisate 1.81; San Giovanni Rotondo 2.01). The age- and sex-adjusted prevalence rates were 1.84 in Arcisate and 2.04 in San Giovanni Rotondo. After exclusion of drug-related parkinsonism, the rates were 1.48 and 1.90, respectively. Even with some inconsistencies within the two study areas, the prevalence tended to be higher in San Giovanni Rotondo, to prevail in women, and to increase significantly with age. Presumed etiological factors for parkinsonism were recorded in 34% of the cases (mostly drugs). In two thirds of the cases the disease ran a mild course. The present study shows that the GP proves a valuable reference for surveys of parkinsonism in Italy.