Diseases associated with multiple sclerosis and epilepsy. A population cohort study of 159,200 middle-aged, urban, native Swedes observed over 10 years (1970-79).

A defined general population of 159,200 male and female native Swedes born in the period 1911-1940 from an urban catchment area of the then only general hospital, was followed over a decade (1970-79) with regard to in-patient hospitalization for all kinds of diagnoses. As a part of this population cohort study, multiple sclerosis cases (n = 351) and epilepsy cases (n = 648) were studied for association with other diseases. Unexpectedly, a cluster of diseases encompassing tuberculosis, bronchial asthma, diabetes mellitus and myocardial infarction, among the diseases associated with multiple sclerosis, also forms a gradient; this suggests a quantitative rather than a qualitative multifactorial model of disease for the understanding of the pathogenesis of MS. In epilepsy, heterogeneity was suggested as being mainly linked to the presence or absence of co-existing alcoholism. Brain tumours in cases of epilepsy were found almost exclusively in the latter subset and prevailing among younger people independent of sex (with an almost 100-fold excess rate of that disease combination as expected by chance only).