RealTalk MS – Episode 416

The Updated McDonald Diagnostic Criteria for MS
With Dr. Andrew Solomon
Host: Jon Strum
Release Date: August 18, 2025

Overview

This episode features a deep dive into the just-announced 2024 update to the McDonald diagnostic criteria for Multiple Sclerosis (MS). Host Jon Strum welcomes Dr. Andrew Solomon, neurologist and chair at the Larner College of Medicine, to break down why the criteria matter, what has changed, and how these updates will impact MS diagnosis moving forward. Alongside the main interview, Jon highlights recent advances in understanding MS onset and progression, and how patient voices are shaping future MS treatments.

Key Discussion Points & Insights

1. Diagnosing MS: The Evolving Landscape

• The McDonald Criteria Background
  • Since 2001, the McDonald criteria have been the international gold standard for MS diagnosis, updated periodically as science advances ([00:18]).
  • Updates occurred in 2005, 2010, 2017, and now 2024 ([00:18], [14:40]).

2. The Silent Beginnings of MS (Prodromal Phase)

• Research Highlight ([01:20]–[07:40])
  • Recent findings from Dr. Helen Tremlett’s team indicate MS may begin up to 14–15 years before the appearance of classic symptoms.
  • People who develop MS visit doctors more often years ahead of symptom onset—especially for vague symptoms and mental health concerns.
• Memorable Moment
  • "If we're going to uncover the cause or causes of MS, we need to start at the actual beginning, which, based on the evidence in this study, occurs 14 or 15 years before the onset of the first physical symptoms." – Jon Strum ([06:53])
• Future Possibilities
  • Technological advances, like AI-enhanced MRI, may one day lead to identifying MS before symptoms and intervening even earlier.

3. MS Disease Progression Trends

• Italian Registry Study ([07:40]–[09:51])
  • Fewer people with relapsing-remitting MS are progressing to secondary progressive MS, attributed to better and earlier use of disease-modifying therapies (DMTs).
  • "The improvement in the overall decline in secondary progressive MS diagnoses was attributed to the fact that today’s disease modifying therapies are effective at delaying progression, along with additional factors..." – Jon Strum ([08:54])

4. Patient Advocacy and Drug Development ([09:51]–[13:06])

• Shaping Tomorrow Together Initiative
  • Efforts to integrate patient voices directly into the FDA’s MS drug review and approval.
  • Encouragement to participate in a comprehensive MS experiences survey and join the October 29 livestream event.

Main Interview: Dr. Andrew Solomon on the 2024 McDonald Criteria

Why Diagnostic Criteria Matter ([15:33])

• Dr. Solomon:
  • "There are some diseases where we have a very good test... but for MS, we rely on a variety of assessments, like a recipe... based on a lot of research that helps us get to the diagnostic criteria."
  • Having criteria ensures consistency in diagnosis and research, so that new treatments can be meaningfully tested.

Key Changes in the 2024 Criteria ([17:07])

• "This criteria makes a lot more changes than previous criteria." – Dr. Solomon ([17:07])
  • Earlier Diagnosis: More diagnostic pathways allow patients to be diagnosed sooner.
  • Built-in Safeguards: Added "guardrails" to minimize misdiagnosis.
  • Embracing New Technology: Integration of new testing options, imaging methods, CSF analysis, and optic nerve assessments.
• Benefits: Prompt diagnosis enables earlier intervention, improving long-term outcomes.

The Update Process and Development ([18:45])

• Criteria revised by a global committee of experts, patient advocates, and organizations like the National MS Society and European Committee for Treatment and Research in MS.
• Companion papers, focused on practical guidance, will accompany the main release.
• "There are entire papers devoted to teaching providers how to implement these changes." – Dr. Solomon ([19:49])

Impact on Patients and Healthcare Providers

1. Impact on Diagnostic Journey ([20:36])

• The new criteria should reduce the time and number of tests needed for diagnosis in many cases.
• "Some patients will receive a diagnosis earlier and without so much monitoring and testing..." – Dr. Solomon ([21:01])

2. Retrospective Application ([22:07])

• A new diagnosis will not invalidate previous diagnoses.
• "Anybody who received a diagnosis of MS by prior diagnostic criteria... would still fulfill our current diagnostic criteria." – Dr. Solomon ([22:13])

3. Effect on Ongoing Care ([22:49])

• The criteria do not affect treatment recommendations for already-diagnosed patients.
• "Once that diagnosis is made, the criteria really don’t have anything to do with treatment recommendations..." – Dr. Solomon ([22:49])

4. Spreading the Word ([23:12])

• Education is a priority: conferences, publications, toolkits, and outreach are planned to ensure providers learn and use the updates.
• Providers will require some training to effectively utilize new diagnostic techniques ([23:57]).

5. Timeline for Adoption ([24:25], [24:31])

• Criteria will be available immediately upon publication (expected September 2025).
• Patients are encouraged to discuss the updated criteria with their healthcare team, especially if diagnosis is unclear.
• "If patients have a provider where they feel there are barriers... a referral to an MS specialist could be a way to get an evaluation using the current criteria..." – Dr. Solomon ([25:00])

6. Patients Asking About the Update ([25:20])

• It's absolutely appropriate, and even recommended, that patients ask their healthcare provider about the updated criteria.
• "Every provider is obligated to explain to patients why they do or do not think they have a particular diagnosis... patients should feel that they have the ability to ask those kind of questions..." – Dr. Solomon ([25:52])

Notable Quotes & Memorable Moments

• On why criteria matter:
  "What the purpose of a diagnostic criteria is, so that when doctors give a diagnosis like MS, that we’re all talking about the same thing." – Dr. Andrew Solomon ([15:36])

• On the significance of the 2024 update:
  "There’s more pathways to the diagnosis of MS for patients that will allow them to be diagnosed earlier, which is great." – Dr. Andrew Solomon ([17:18])

• On patient advocacy:
  "This is truly a once in a lifetime chance for the MS community to come together to make a difference in future MS treatments." – Jon Strum ([12:47])

• On patient-provider dialogue:
  "Patients should feel that they have the ability to ask... whether or not the 2024 criteria was part of their thinking..." – Dr. Andrew Solomon ([25:52])

Timestamps for Important Segments

• Background on McDonald Criteria: [00:18], [14:40]
• Prodromal Phase Research (MS may start earlier than thought): [01:20]–[07:40]
• Trends in Progression to Secondary Progressive MS: [07:40]–[09:51]
• Patient voice/FDA advocacy: [09:51]–[13:06]
• Interview: Why diagnostic criteria are needed: [15:33]
• Major changes in the 2024 criteria: [17:07]
• Update process and global collaboration: [18:45]
• Impact on diagnostic journey: [20:36]
• Previous diagnoses and treatment: [22:07], [22:49]
• Training and rollout: [23:12]
• When providers may begin using criteria: [24:25]
• Empowering patients to ask about the update: [25:20]

Tone & Style

The episode is conversational, clear, and practical, focusing on breaking down complex medical updates into actionable and understandable insights for people living with MS, their loved ones, and caregivers. Dr. Solomon’s explanations are reassuring, practical, and encouraging. Jon’s hosting style is informative, empathetic, and empowering, urging listeners to be proactive and involved in their care.

Summary

The latest update to the McDonald diagnostic criteria for MS stands to bring profound positive changes—potentially allowing faster, more accurate diagnoses, earlier treatment, and better outcomes for those affected by MS. The episode makes clear that patients and providers alike are encouraged to keep pace with these advances, and patient voices will be increasingly central in shaping the MS landscape.