Reframing Multiple Sclerosis as a Spectrum of Progression

This academic review proposes a unified spectrum model for multiple sclerosis (MS) that challenges traditional, rigid phenotype classifications like RRMS, SPMS, and PPMS. The authors argue that disability often accumulates through progression independent of relapse activity (PIRA) and "smouldering" disease processes, which frequently occur silently long before a formal progressive diagnosis. By integrating the role of neurologic reserve and biological ageing, the text explains how the clinical transition to progressive states reflects a declining capacity to compensate for ongoing tissue injury rather than a brand-new disease mechanism. This shift toward a biology-aware framework aims to facilitate earlier recognition of worsening and move treatment strategies beyond a simple focus on suppressing acute relapses. Ultimately, the source advocates for longitudinal, multidimensional monitoring to better address the continuous pathological evolution that shapes long-term neurological decline across the entire MS continuum.