Chapter 11 Multiple Sclerosis

Abstract

This chapter discusses the clinical aspects of multiple sclerosis. Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system that has variable and unpredictable courses. The evaluation of the effect and efficacy of therapies in MS has, thus, always been a difficult task. The presumed but unspecified immune-mediated cause of MS has led to an attempt to develop therapies that can modify the immune response. The design of the clinical trials conducted in MS has usually included a group of patients receiving placebo, looking for differences in behavior among the various groups of patients tested using several outcome measures. The standard methods used to assess MS activity, and therefore to judge the potential therapeutic efficacy of new components, are commonly the Kurtzke expanded disability status scale (EDSS), a measure of the neurologic handicap, the exacerbation rate, and magnetic resonance imaging (MRI). MRI studies are complementary to clinical assessments, because serial MRI studies of the brain have proven that frequent asymptomatic disease activity occurs in relapsing-remitting MS and in MS in general. This observation reflects that there are many more active lesions in the brain than clinical relapses. Consequently, the clinical measure of MS poorly reflects MS activity, although the desired efficacy of developing treatments deals mostly with the possibility of interfering with the progression of neurologic handicap. The therapeutic strategies used, developed, and tested in clinical trials in MS generally deal with three different objects: (1) the treatment of acute relapses, (2) the prevention of acute relapses, and (3) the prevention of disease progression, measured using MRI techniques and the assessment of the neurologic handicap (EDSS).