1. Descriptive Epidemiology of Multiple Sclerosis (MS) Multiple Sclerosis

2. Course of Disease ` ` Acute - Very Rapid Course, Death in a few months ` ` Progressive - Gradually becoming worse, well defined remissions and exacerbations exacerbations ` ` Benign - Exacerbations with very long remissions ` ` Subclinical - No Symptoms, identified at autopsy

3. Progressive Acute

4. Epidemiology : Incidence of MS in Denmark

5. Incidence of MS in Iceland

6. Incidence of MS in Faroe Islands

7. Incidence of MS in Faroe Islands by age

8. Years since 1942: in Faroe Islands

9. Incidence of MS in South Africa

10. Prevalence of MS

11. Unusual Occurrence of MS in Tropical Island

12. Risk Factors : Unusual Stress in 2 Yrs Before Cases Controls p value 79% 54% <0.01

13. Risk factors : Exposed to Animal Illness Cases Controls 43% 19%

14. Risk Factors : Exposed to Canine Distemper Cases Control 17% 6%

15. Physical Activity and MS

16. Immunologic Involvement ` `Autoantibodies ` `Encephalomyelitis developing- -Similar to the administration of rabies virus vaccine ` ` Evidence for a superantigen?

17. Frequency of Viral Infection

18. Concordance Rates in Twins MZ DZ 31/107 13/101 0.29 0.13

19. Prevalence of MS in First Degree Relatives Sibs Parents Offspring 125/10,682 41/6,521 9/1,521 0.0117 0.0063 0.0059

20. DZ Risk versus Sibling Risk DZ Sibling 0.13 0.012

21. HLA Antigens and MS: Northern Europeans

22. Conclusions ` `MS caused by environmental factors, but not clear what they are ` `For MS there is evidence for HLA associations, however, there is more than HLA ` `MS is a multiloci diseaseMS is a multiloci disease