INTRODUCTION

In recent years we have witnessed significant progress in the search for treatments targeted to influence the pathogenetic process in MS (Hughes 1994; Ebers 1994; Wolinsky 1995; van Oosten et al. 1995). This progress has been hastened by our increased knowledge of MS pathogenesis, by better means of monitoring the disease process, advances in the design of therapeutic trials, and by the introduction of new therapeutic agents. In line with the increasing evidence supporting a crucial role of the immune system in MS pathogenesis, nearly all the therapies discussed in this chapter are targeted at different parts of the immunoregulatory network.

ASSESSING DISEASE EVOLUTION AND THERAPEUTIC EFFECTS

Since the first description of MS, more than 100 different therapies have been applied, and all of them – although based on different etiological and pathophysiological assumptions – have claimed improvements, sometimes by as much as 100% (Schimrigk and Schmitt 1988; Sibley 1992). These contradictory and unsatisfactory results have led to an increasing awareness of the problems associated with the assessment of therapeutic effects in this disease. Committees chaired by Schumacher (1965) and by Brown (1979) defined the main problems as: inprecise diagnosis, a variable and unpredictable disease course with frequent spontaneous remissions, lack of a direct method to assess disease activity, the masking effect of already existing persistent damage on new activity, psychological disturbances, and sometimes hysterical tendencies in some patients.