Objective: To study if there are different patterns of clinical activity--measured by the annual exacerbation rate (AER)--among relapsing-remitting multiple sderosis (RRMS), "early" secondary multiple sclerosis (SPMS) and "late" SPMS.
Methods: A prospective 5-year follow-up study in 80 MS patients has been carried out, calculating the AER and the mean expanded disability status scale (EDSS) change rate (MCR).
Results: A significant difference on the AER, among RRMS, early SPMS and late SPMS, has been found.
Conclusions: The SPMS has a high clinical inflammatory activity before and during its transformation from a RRMS.