Revised McDonald criteria allow earlier and more precise MS diagnosis

The revised McDonald criteria allow for the diagnosis of MS in certain cases in asymptomatic individuals who have radiologically isolated syndrome (RIS). Dissemination in time (DIT) should no longer be required. Also, optic nerve imaging for diagnosis may serve as a fifth anatomical location.

The draft revision of the McDonald diagnostic criteria for MS is an initiative of the International Advisory Committee on Clinical Trials in MS, presided by Prof. Xavier Montalban (Vall d'Hebron University Hospital, Spain). He presented the most important upcoming revisions to the 2017 version of the McDonald criteria [1,2]. Prof. Montalban stressed the importance of these criteria as they impact the patient-clinician dialogue, treatment decisions (although diagnostic criteria do not equal treatment guidelines), clinical trials, and the prognosis of MS.

The first and most fundamental change Prof. Montalban mentioned, was that RIS can be considered MS in specific situations. This allows for the diagnosis of MS in asymptomatic individuals. “This means we are moving towards a biological diagnosis, which is happening as well in other neurodegenerative conditions such as Alzheimer's and Parkinson's disease.” A patient with RIS may be diagnosed with MS if he fulfils the criteria for both DIT and dissemination in space (DIS) —damage in at least 2 of 5 anatomical locations in the nervous system.

The other proposed revisions include:

• DIT is no longer required.
• The optic nerve may serve as a fifth anatomical location to demonstrate DIS —assessed by MRI, visual evoked potential, or optical coherence tomography— if no better explanation for optic nerve pathology can be found.
• Updated DIS criteria: DIS criteria are fulfilled when 2 out of 5 topographies show typical lesions, whether these are symptomatic or not.
• Criteria for the diagnosis of primary progressive MS and relapsing MS are now the same.
• Paraclinical evidence is needed to diagnose MS.
• Kappa-free light chain is a diagnostic marker for MS.
• Central vein sign and a paramagnetic rim lesion are added as optional tools to help diagnose MS in certain situations.
• Stricter features should be used to diagnose MS in individuals >50 years of age with headache disorders (including migraine) or with vascular disorders.
• Laboratory tests are recommended to confirm the diagnosis in children and adolescents.

 

1. Montalban X. Revised McDonald criteria 2023. Scientific Session 1, ECTRIMS 2024, 18–20 September, Copenhagen, Denmark.
2. Thompson AJ, et al. Lancet Neurol. 2018;17(2):162-73.

 

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Posted on 18 November 202425 November 2024