Overview of Treatment Trials: Early Baseline Clinical and MRI Data of the PROMiSe Trial

Abstract

Primary progressive multiple sclerosis (PPMS) is the least common clinical disease phenotype exhibited by MS patients. Current international consensus definitions of the various disease phenotypes demand that patients with PPMS have a progressive disease from onset and a clinical course without discernible attacks [1]. Some minor amount of improvement or worsening is allowed, but episodes that fit most modern trial definitions of acute relapses eliminate patients from this subtype and consign them to either secondary progressive or progressive relapsing MS categories, depending upon whether the attack occurred prior to or following the onset of their progressive neurologic dysfunction. Approximately 15% of MS patients have a progressive disease at onset, but nearly one-third of these will experience a clinical relapse. Thus, only 10% of all MS patients have PPMS. It is likely that some of these patients fail to recall remote episodes of neurologic dysfunction that may or may not have been attended by physicians or resulted in a formal diagnosis. Such cases of cryptic secondary progressive or “transitional” MS [2] may contaminate to some extent any cohort of rigorously defined PPMS patients. Further complicating our understanding of this clinical phenotype is the common use of the term “chronic progressive MS” to describe patient cohorts with secondary progressive, progressive relapsing, or PPMS.