Temporal variation of onset of relapses in multiple sclerosis is not seasonal: results from the MSBase registry

S OF INVITED LECTURES AND FREE PAPERS Neurology Asia December 2008 200 Conclusions: A temporal variation in onset of relapses is present in both northern and southern hemispheres. However, peak relapse incidence does not occur in the same season relapses are more common in spring in the northern hemisphere and autumn in the southern hemisphere. The highest incidence of relapses in the northern hemisphere is at the end of spring in the month of June, not spring onset in this large cohort.