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

## TL;DR

This paper reviews updated diagnostic criteria for multiple sclerosis, emphasizing new imaging and biomarker tools to enable earlier and more accurate diagnosis.

## Contribution

The paper introduces the 2024 McDonald criteria updates, incorporating new MRI features and biomarkers for earlier MS diagnosis.

## Key findings

- The revised McDonald criteria include central vein sign and paramagnetic rim lesions as new MRI features for MS diagnosis.
- Cerebrospinal fluid biomarkers like oligoclonal bands and kappa-free light chains are now formally included in diagnostic criteria.
- The updated criteria allow diagnosis before a first clinical attack or disability progression, using incidental imaging and nonspecific symptoms.

## 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.