Recent Descriptive Surveys on Multiple Sclerosis in Sardina and in the Province of Ferrara, Italy

Abstract

The Italian findings from small populations, which seem to deny the zonal concept for multiple sclerosis (MS) distribution in Europe and the more widely held interpretation of the gradient of latitude, although appealing, must certainly be reviewed with caution (Kurtzke, 1983). In fact, since MS is a disease with particular characteristics, studies based only on prevalence rather than incidence are likely to be biased by several geographic variables such as natural evolution of the disease, migratory flux, of assistance level, and accessibility to neurological centers. These problems make it difficult to compare prevalence rates for different years and areas. Moreover, owing to the size of the populations investigated, the high prevalence rates in the intensive surveys show very wide confidence intervals, which could reduce the precision rate in measuring the true frequency of MS in Italy. In particular, the large confidence intervals, due to the very few cases do not allow us to reject the idea that the true MS rate is below 30 per 100,000.