MS diagnosis criteria to be revised and updated

A new version of the McDonald diagnostic criteria for multiple sclerosis (MS) is on the way and is set to include updated MS biomarkers.

A panel of experts presented a draft of these revised criteria at the annual meeting of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) in Copenhagen.

The proposed changes, from the Advisory Committee on Clinical Trials in Multiple Sclerosis, represent the first significant update since 2017. These revisions aim to allow for earlier diagnosis of MS, as well as including biomarkers to improve the accuracy of diagnoses.

One major update is the ability to diagnose MS in people who don’t show symptoms but have signs of the disease on an MRI, previously categorised as having radiologically isolated syndrome (RIS). Montalban explained that in specific cases, RIS could now be classified as MS, signalling a shift towards a biological diagnosis, similar to developments seen in conditions like Alzheimer’s and Parkinson’s.

Optic neuritis, often the first sign of disease in individuals with clinically isolated syndrome, can now be considered one of the key anatomical locations for diagnosing MS if no other explanation is found. The optic nerve can be evaluated using MRI, visual evoked potentials, or optical coherence tomography.

Additionally, the need for ‘dissemination in time’ – which previously helped confirm an MS diagnosis – is no longer a requirement, although it may still be useful. Criteria for ‘dissemination in space’ will also be updated. A quick test for intrathecal kappa free light chains, which has similar diagnostic properties to oligoclonal bands, can now also assist in diagnosing MS.

“The biggest change is that you can now diagnose MS in people without symptoms [those with RIS],” said Daniel Ontaneda, MD, PhD, from the Cleveland Clinic’s Mellen Center for Multiple Sclerosis. He emphasised that this will substantially widen the scope of who can be diagnosed with MS.

To ensure the accuracy of MS diagnoses, paraclinical evidence must be considered, and MS should only be diagnosed after ruling out any other potential explanations. Montalban stressed that abnormal MRI results, showing typical lesions, are necessary for an MS diagnosis.

In some instances, MRI scans may include markers like the central vein sign or paramagnetic rim lesions (PRLs), which, while not essential, can increase the accuracy of a diagnosis. For instance, if a patient shows typical symptoms and lesions, the presence of PRLs, alongside either evidence of progression over time or positive cerebrospinal fluid (CSF) results, can confirm an MS diagnosis.

For patients over 50 or those with conditions like vascular or headache disorders, additional diagnostic factors such as spinal cord lesions, positive CSF, or the central vein sign may be needed to confirm the diagnosis. Testing for myelin oligodendrocyte glycoprotein-immunoglobulin G is recommended for children and adolescents, as the central vein sign in about half of T2 lesions strongly suggests MS in younger patients.

The diagnostic criteria for both relapsing MS and primary progressive MS (PPMS) will follow a similar approach, although PPMS will require proof of progression over at least 12 months. Experts noted that a unified framework should be used for diagnosing both forms of the condition.

Next steps include publishing a paper outlining the revised criteria, as well as a diagnostic algorithm. Additional discussions will cover how to implement these updates and consider both global and patient factors.