Multiple sclerosis diagnosis and management are undergoing significant changes, and clinicians are being urged to catch up. The 2024 revisions to the McDonald diagnostic criteria now allow neurologists to identify MS earlier and with greater precision — without waiting for neurological worsening to confirm the diagnosis.

On the treatment side, the field has largely shifted away from the traditional escalation approach (start with lower-efficacy drugs, move up if needed) toward early high-efficacy therapy. This means more patients are being started on infusion or injection-based treatments right after diagnosis, with the goal of not just reducing relapses but also slowing long-term disease progression.

Key Takeaways:

• The 2024 McDonald criteria added the optic nerve as a fifth CNS site for dissemination in space, and incorporated biomarkers like kappa free light chain index and MRI markers (central vein sign, paramagnetic rim lesions) to improve diagnostic specificity
• Patients with radiologically isolated syndrome can now be diagnosed with MS if they meet dissemination criteria — no clinical symptoms required
• Ocrelizumab remains the only FDA-approved therapy for progressive MS; BTK inhibitors are an emerging class under active investigation due to their superior CNS penetration
• Relapsing and progressive MS are increasingly viewed as a spectrum of one disease, not two separate entities

Why it matters: Earlier diagnosis means earlier treatment, which translates to less disability over time. As the field moves toward more aggressive upfront therapy, clinicians need to stay current on both the evolving diagnostic landscape and the growing pipeline of therapies targeting disease progression.