Overview
Introduction
Multiple sclerosis is diagnosed by pattern, not by a single confirmatory test.
Multiple sclerosis is diagnosed by pattern, not by a single confirmatory test. The clinician must establish objective evidence of central nervous system demyelination, demonstrate dissemination in space and time or use an accepted substitute, and exclude a better explanation. The 2024 McDonald revisions, published in 2025, update the framework used in Canada and support a more unified approach across relapsing and progressive courses and across the lifespan. NP assessment, diagnostic workup, relapse decisions, and safety surveillance for disease-modifying therapies. Apply provincial NP authority, the current Health Canada product monograph, and local MS-neurology pathways when initiating or monitoring treatment.