[The epidemiology of Bell's palsy]

Abstract

Aims: Bell's palsy (BP) is a frequent condition with an incidence that varies throughout different countries around the world. The aim of this article is to analyse the incidence of BP in different countries around the world.

Development: Different rates of incidence and prevalence have been reported in the medical literature depending on the geographical regions under study. In most of the series published incidence oscillates between 11 and 40 cases per 100,000 inhabitants per year--although figures as low as 8 and as high as 240 cases per 100,000 inhabitants per year have also been reported. The climate, racial factors, the prevalence of predisposing diseases and the demographic features of the regions studied could be involved in these variations in the appearance of BP. Nevertheless, and although they are estimated to be of little significance, both methodological and diagnostic aspects of BP may also exert a certain influence on the results obtained.

Conclusions: The incidence of BP in the world varies, which may reflect both a different frequency of appearance in the geographical regions studied and differences in the diagnostic criteria employed as well as in the methodology used to collect and analyse data.