Evolving the Diagnosis of Multiple Sclerosis: A New Landscape in Light of the 2024 McDonald Criteria

Abstract

Timely and accurate diagnosis of multiple sclerosis (MS) allows for prompt treatment initiation that can alter the disease course and prevent disability accumulation. The 2024 revisions of the McDonald criteria aim to achieve earlier and more precise MS diagnosis by including new neuroimaging and biomarker advances. This review highlights key updates, including revised definitions of dissemination in space and time, along with new MRI features, including the central vein sign and paramagnetic rim lesions. We also describe the role of cerebrospinal fluid biomarkers, including oligoclonal bands and kappa-free light chains. The updated criteria formally incorporate incidental imaging and nonspecific symptom presentations to enable diagnosis before either a first clinical attack or progression of neurological disability. Finally, we explore emerging and promising investigational tools for future incorporation into MS diagnosis, including advanced MRI techniques, fluid biomarkers, and applications of artificial intelligence.