Relation Of Geographical And Meteorological Factors To Occurrence Of Multiple Sclerosis In Czechoslovakia

In Czechoslovakia a part of the territory situated between 48–49°. No latitude, with about 1.4 million inhabitants, was studied as to the prevalence of multiple sclerosis. The territory studied was divided into a part having a yearly mean temperature of 10° C and an altitude of 0–137 m and another part with a yearly mean temperature of 8° C and an altitude of 145–500 m. The prevalence of multiple sclerosis in both geographical territories was compared. Moreover, the seasonal incidence of multiple sclerosis was investigated and the incidence of the disease in the warmer (April-September) and the colder (October-March) halves of the year was compared. The prevalence was significantly higher in the region having a lower mean temperature and a greater altitude. This relation was more conspicuous when the place of birth rather than the place of residence was taken into account. No significant difference was found for frequency of onset of the disease between the warmer and the colder part of the year.