Relapsing MS Patients Treated With Dmts Exhibit Highly Variable Disease Progression

Background:  Patterns of disease progression in the "treatment era" of relapsing MS patients (RMS) remain to be defined.

Objectives:  We aimed to characterize three patterns of RMS progression using definitions which categorize patients according to whether rapidly worse aggressive disease occurred at any time, and whether or not EDSS 4.0 was reached.

Methods:  In a single center we retrospectively examined data collected since 1995 on patients newly diagnosed with RMS. Group 1 patients were termed “aggressive MS” (AMS) and experienced rapid progression defined as a change of 2 or more EDSS points in 2 or less years to result in an EDSS of 4.0 or more. Group 2 patients reached EDSS 4.0, but did so with a slower rate of change; this group was termed “intermediate MS” (IMS). Lastly, group 3 patients did not reach EDSS 4.0 or have a change of EDSS of 2 in less than 2 years, this group was termed “Non Aggressive MS” (NAMS). Groups were compared for progression on EDSS scores over time.

Results:  One hundred ninety-six patients were followed an average of 12.1 years and of those patients 2.6% met AMS definition at onset, an additional 11.5% in the first five years of disease duration, followed by 11.8% the next decade. The AMS group remained more disabled at final sustained EDSS, (95% of AMS remained at an EDSS of 4.0 or greater, compared to 68% of the IMS) p = 0.010 using a forward stepwise binomial logistic regression testing for age at onset of MS, gender, disease duration at final sustained EDSS and disease duration at the time meeting definition for AMS or IMS. A lower bound repeated measures ANOVA suggested a significant difference between time and EDSS scores of the IMS, 2.52 (95 % CI 1.87-3.17) and AMS, 4.30 (95%CI 3.67-4.93) groups from year 1 of disease duration to year 15 of disease duration (p = 0.013). Furthermore, 32/41 patients in the AMS reached EDSS 6.0, while 2/22 reached the metric in the IMS group, (p < 0.001) OR= 22.52 (95%CI 5.42-93.59).  Five patients reached EDSS 8.0; all were in the AMS group.

Conclusions:  A transition from relatively mild MS to an aggressive course may begin at any time in the first two decades despite DMTs. Our definition accurately identifies a group of patients who quickly become permanently disabled.