Clustering during childhood of multiple sclerosis patients

Previous studies investigating the possibility of space-time clustering in multiple sclerosis (MS) used time and place of onset of the disease or time and place of birth of the MS patient as the testing point. However, immigration studies have shown that the risk of MS is determined during childhood and thus, ‘exposure’ probably occurred at sometime between birth and age 15. In this study it was possible to study space-time clustering at any …