Strategies to Delay the Onset of Clinically Definite Multiple Sclerosis in Patients with Monosymptomatic Presentations of Optic Neuritis, Brainstem Syndromes or Myelopathy

Abstract

Converging lines of evidence suggest that it is now possible definitively to test strategies to delay the onset of clinically definite multiple sclerosis (CDMS) in patients who experience first attacks of optic neuritis, brainstem syndromes or myelitis. It has been demonstrated that brain magnetic resonance imaging (MRI) can identify patients with monosymptomatic presentations who subsequently are at high risk to develop CDMS. There is also evidence to suggest that the development of CDMS following isolated optic neuritis can be delayed by administering intravenous corticosteroids. A study to investigate this question further in monosymptomatic patients is now particularly relevant for several reasons. It has been shown that treatment can have a beneficial effect on the course of early relapsing-remitting MS and in vitro data from studies of experimental allergic encephalomyelitis (an animal model of multiple sclerosis) provide a potential explanation for why treatment at the time of an initial monosymptomatic event (e.g. optic neuritis) might have greater efficacy than treatment once CDMS is well established. In this chapter we will review evidence supporting the need for such a study as well as aspects of study design that must be properly addressed to assure its successful completion.