Decreasing impact of late relapses on disability worsening in secondary progressive multiple sclerosis

Mult Scler. 2020 Jul;26(8):924-935. doi: 10.1177/1352458519848090. Epub 2019 May 16.

Abstract

Background: Changes in relapse activity during secondary progressive multiple sclerosis (SPMS) need to be accurately characterized in order to identify patients who might benefit from continuing disease-modifying therapies.

Objective: To describe relapse occurrence in patients with SPMS during long-term follow-up and assess its impact on disability worsening.

Methods: This retrospective cohort study included 506 patients. We assessed the influence of relapses on time from SPMS onset to an Expanded Disability Status Scale score of 6 (EDSS 6), and on irreversible worsening of EDSS scores across different periods.

Results: The annualized relapse rate (ARR) decreased with patient's age (mean reduction of 43% per decade) and SPMS duration (mean reduction of 46% every 5 years). Post-progression relapses were associated with shorter time from secondary progressive (SP) phase onset to EDSS 6 (hazard ratio (HR) = 1.29, 95% confidence interval (CI) = (1.01, 1.64)). Relapse occurrence during the first 3 years and 3-5 years after SP onset was associated with an increased risk of irreversible EDSS worsening (OR = 3.12 (1.54, 6.31) and 2.04 (1.16, 3.58)). This association was no longer significant after 5 years.

Conclusion: The occurrence of relapses was a marker of short-term disability progression during early SPMS, but did not have decisive impact in later SPMS.

Keywords: Multiple sclerosis; long-term follow-up; natural history; relapses; secondary progressive.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Disease Progression*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Multiple Sclerosis, Chronic Progressive
  • Recurrence
  • Retrospective Studies
  • Severity of Illness Index*
  • Time Factors