PREVALENCE AND INCIDENCE OF MULTIPLE-SCLEROSIS IN THE CITY OF MONREALE, ITALY

The prevalence and incidence of multiple sclerosis (MS) in the city of Monreale, southern Italy were ascertained 10 years after a preliminar y study in the same area. The study was undertaken in a population of 26,256 people. The patients were classified according to Poser's crite ria. The prevalence of MS on 31 December 1991 was 72.4 per 100,000 pop ulation. The incidence of MS for the period 1981-1991 was 3.3/100,000 per year. The mean period between onset and diagnosis of MS was 4.9 ye ars for those patients found during this survey and 9.2 years for thos e in the first study. This study shows an increase of MS prevalence in Monreale city and a high incidence. The findings parallel the reducti on of the lag time between onset and diagnosis.