Earlier diagnosis requires more than new criteria

A new open-access paper Application of the 2024 McDonald Criteria: Earlier Diagnosis and Avoiding Misdiagnosis of Multiple Sclerosis in a Global Setting, published in Neurology, examines how the updated 2024 McDonald criteria for diagnosing multiple sclerosis (MS) can be applied in healthcare settings around the world, helping healthcare professionals diagnose MS earlier while avoiding misdiagnosis.

The paper was developed by an international group of MS experts and explores both the opportunities created by the revised criteria and the practical considerations involved in applying them across diverse healthcare settings.

Diagnosing MS can be complex. There is no single test that can confirm whether a person has MS. Instead, healthcare professionals use a combination of medical history, neurological examination, MRI findings, laboratory tests and other evidence to determine whether the signs and symptoms are consistent with MS and not another condition.

Earlier diagnosis is important because it enables people with MS to access treatment and support sooner, plan for the future, and achieve the best possible long-term outcomes. Delays in diagnosis can leave people living with uncertainty for months or even years. During this time, they may struggle to access appropriate treatment, support services and information about managing their condition. An accurate diagnosis can provide clarity, open the door to specialist care and help people make informed decisions about their future.

“Where a person lives should not determine how quickly they receive an accurate MS diagnosis. This paper highlights exciting advances in the diagnosis of MS, while also reminding us of the importance of ensuring that healthcare systems around the world are equipped to translate those advances into better outcomes for people affected by MS.”

Rachel King, Senior International Evidence Manager at MSIF and lead for the Atlas of MS

What is the new paper about?

The 2024 revisions to the McDonald criteria introduced new pathways to diagnosing MS, incorporating advances in scientific understanding and diagnostic tools. The new publication provides practical guidance on how the criteria can be implemented across diverse healthcare systems while maintaining diagnostic accuracy and minimising the risk of misdiagnosis.

The paper was written not only for MS specialists, but also for healthcare professionals, trainees and others involved in diagnosing and caring for people with MS. By providing practical guidance on the updated criteria, the authors aim to support wider understanding and appropriate implementation across a range of healthcare settings.

The authors highlight that while updated criteria may make earlier diagnosis possible for many people, their implementation in clinical practice will require appropriate diagnostic testing, specialist expertise, and training.

While earlier diagnosis has many benefits, accuracy remains essential. A misdiagnosis may lead to unnecessary treatment, anxiety and delays in identifying the person’s actual condition. The paper therefore explores how the updated criteria can support earlier diagnosis while maintaining diagnostic confidence.

“The updated McDonald criteria reflect important advances in our understanding of MS and have the potential to accelerate diagnosis for many people. Our goal with this paper was to provide a practical framework for implementing the criteria responsibly across diverse healthcare systems, while balancing the benefits of earlier diagnosis with the need to minimise misdiagnosis.”

Professor Andrew Solomon, Chair of MSIF’s International Medical and Scientific Expert Group (IMSEG), University of Vermont, USA, lead author of the study.

Why does this matter?

Advances in diagnostic criteria can create new opportunities for earlier diagnosis, but their impact depends on whether healthcare systems have the people, expertise and resources needed to put them into practice.

Access to the specialists, tests and technologies needed for MS diagnosis varies considerably around the world. As diagnostic approaches evolve, understanding how new criteria can be applied across different healthcare settings is essential to help ensure that advances in diagnosis benefit people with MS regardless of where they live.

“The updated criteria create exciting opportunities for earlier diagnosis of MS. It also introduces new tools and biomarkers to improve diagnostic accuracy. However, healthcare systems vary considerably in terms of available resources, expertise and diagnostic technologies. Supporting healthcare professionals to apply and implement the criteria appropriately within their local context will be key to ensuring these advances benefit people with MS, regardless of where they live.”

Dr Shanthi Viswanathan, Deputy Chair of MSIF’s International Medical and Scientific Expert Group (IMSEG), Tunku Abdul Rahman Neuroscience Institute, Kuala Lumpur Hospital, Malaysia, and co-author of the study.

Previous research from the Atlas of MS has shown that many countries continue to face substantial barriers to early diagnosis. These include limited awareness of MS, shortages of trained healthcare professionals, and challenges accessing diagnostic equipment and investigations.

Recent Atlas of MS research has also demonstrated significant global inequalities in access to key diagnostic tests used in MS diagnosis, raising concerns that advances in diagnostic criteria may not benefit everyone equally.

What are the implications for MS diagnosis globally?

The publication reinforces an important message: advances in diagnostic criteria alone are not enough to improve MS diagnosis globally. Successful implementation of the updated criteria will depend on how they are integrated into routine clinical practice across diverse healthcare settings.

The paper highlights the need for healthcare professionals to understand how the updated criteria can be applied appropriately while maintaining diagnostic accuracy and avoiding misdiagnosis.

Previous Atlas of MS research provides important context for these implementation challenges. Atlas data have identified barriers to diagnosis in many countries, including limited awareness of MS, shortages of trained healthcare professionals, challenges accessing diagnostic equipment and tests, and barriers to adopting newer diagnostic criteria.

Addressing these challenges may help support implementation of the updated criteria and improve access to timely and accurate diagnosis worldwide. Areas that MSIF has identified as important for strengthening MS diagnosis include:

• Training and education for healthcare professionals
• Access to MRI and other diagnostic technologies, including laboratory testing
• National approaches to implementing diagnostic guidance and best practice
• Raising awareness of MS symptoms among healthcare professionals and the public

These priorities closely align with MSIF’s ongoing work to improve access to timely and accurate diagnosis worldwide. Improving diagnosis requires more than advances in diagnostic criteria. It also requires healthcare systems that are equipped to put those advances into practice. By helping clinicians understand how the updated criteria can be applied across diverse healthcare settings, this publication is an important contribution to ongoing global efforts to improve timely and accurate MS diagnosis.

Further information

• Read the paper in Neurology: Application of the 2024 McDonald Criteria: Earlier Diagnosis and Avoiding Misdiagnosis of Multiple Sclerosis in a Global Setting 
• Learn more about the 2024 revisions to the McDonald criteria
• Learn more about improving MS diagnosis: Improve MS Diagnosis
• Read about global barriers to MS diagnosis: Global barriers to MS diagnosis – MS International Federation
• Read about global access to diagnostic testing: Global gaps in MS diagnostic testing risk delaying diagnosis for many – MS International Federation