Multiple sclerosis: a disease or a syndrome?

Multiple sclerosis (MS) is traditionally considered a chronic immune-mediated disease of the central nervous system. However, increasing evidence suggests substantial clinical, radiological, and immunopathological heterogeneity among individuals diagnosed with MS. In recent years, increasing awareness of this heterogeneity has led to a re-evaluation of whether MS represents a single disease entity or a constellation of related yet distinct pathological processes manifesting as a syndrome. This review explores the argument that MS may not represent a single disease entity but rather a syndrome encompassing multiple distinct immunopathological processes. By integrating evidence from diverse clinical phenotypes, radiological signatures, and neuro-immunopathogenic mechanisms, we aim to explore whether MS should be reconsidered and conceptualized as a syndromic entity.