DISTRIBUTION OF MULTIPLE SCLEROSIS IN FINLAND, WITH SPECIAL REFERENCE TO SOME GEOLOGICAL FACTORS

Abstract

The prevalence studies provided data on persons in receipt of a national pension in Finland for multiple sclerosis, and the mortality figures were obtained from the cause-of-death statistics. The method employed is discussed. A prevalence rate of 18.6/100,000 inhabitants and annual mortality rate of 0.7/100,000 was established. Taking into consideration the points raised in the discussion, the true prevalence was estimated to be at least 40/100,000 inhabitants and the true mortality at least 1.0/100,000 inhabitants per annum. Multiple sclerosis occurred fairly evenly in the central hospital districts throughout Finland. But the prevalence was somewhat higher in the districts of Central Ostrobothnia, Seinajoki and Turku. in some districts variations in local distribution of prevalence and mortality rates could be noticed. Comparison of the prevalence of multiple sclerosis with the Precambrian map of Finland gave findings both for and against such a correlation. Further evidence is required before a stand can be taken on Warren''s theory. No positive correlation was established between the incidence of multiple sclerosis and the known lead deposits in Finland.