Multiple Sclerosis Relapses: Epidemiology, Outcomes and Management. A Systematic Review.

Relapses (episodic exacerbations of neurological signs or symptoms) are a defining feature of relapsing-remitting multiple sclerosis (MS), the most prevalent MS phenotype. While their diagnostic value relates predominantly to the definition of clinically definite MS, their prognostic value is determined by their relatively high associated risk of incomplete remission resulting in residual disability. The mechanisms governing a relapse incidence are unknown, but numerous modifiers of relapse risk have been described, including demographic and clinical characteristics, many of which represent opportunities for improved disease management. Also relapse phenotypes have been associated with patient and disease characteristics and an individual predisposition to certain phenotypic presentations may imply individual neuroanatomical disease patterns. While immunomodulatory therapies and corticosteroids represent the mainstay of relapse prevention and acute management, respectively, their effect has only been partial and further search for more efficient relapse therapies is warranted. Other areas of research include pathophysiology and determinants of relapse incidence, recurrence and phenotypes, including the characteristics of the relapsing and non-relapsing multiple sclerosis variants and their responsiveness to therapies.