From the specialties

Revised diagnostic criteria for multiple sclerosis

Norwegian
    Einar August Høgestøl, Piotr Sowa, Trygve Holmøy, Lars Bø, Gro Owren Nygaard, Stig Wergeland
    See All Articles
    Einar August Høgestøl

    e.a.hogestol@medisin.uio.no

    Einar August Høgestøl, senior consultant at the Department of Neurology, Akershus University Hospital, head of the research group Imaging Studies in MS, and associate professor at the University of Oslo

    The author has completed the ICMJE form and declares the following conflicts of interest: he has received project funding from the Norwegian MS Association, the Odd Fellow Order and South-Eastern Norway Regional Health Authority, speaker fees from Biogen and Merck, and consultancy fees from Sanofi-Genzyme.

    See All Articles
    Piotr Sowa

    Piotr Sowa, head of unit at the Department of Neurology, Oslo University Hospital, Ullevål

    The author has completed the ICMJE form and declares the following conflicts of interest: he has received speaker fees from RegUt Central Norway Regional Health Authority, and is deputy chair of the Norwegian Society of Neuroradiology.

    See All Articles
    Trygve Holmøy

    Trygve Holmøy, senior consultant at the Department of Neurology, Akershus University Hospital, head of the Division of Medicine and Laboratory Sciences, and professor at the University of Oslo

    The author has completed the ICMJE form and declares the following conflicts of interest: he has received speaker fees from Biogen, Roche, Merck, Novartis, Amgen, Alexion and the Norwegian MS Association.

    See All Articles
    Lars Bø

    Lars Bø, senior consultant at the Department of Neurology, Haukeland University Hospital, professor at the University of Bergen and head of the Norwegian Multiple Sclerosis Competence Centre

    The author has completed the ICMJE form and declares no conflicts of interest.

    See All Articles
    Gro Owren Nygaard

    Gro Owren Nygaard, senior consultant at the Department of Neurology, Oslo University Hospital, Ullevål and researcher at the University of Oslo

    The author has completed the ICMJE form and declares no conflicts of interest.

    See All Articles
    Stig Wergeland

    Stig Wergeland, senior consultant at the Department of Neurology, Haukeland University Hospital and clinical head of the Norwegian MS Registry and biobank

    The author has completed the ICMJE form and declares the following conflicts of interest: he is involved in a study initiated by Merck, which covers the associated costs for his institution, and has received speaker fees from Biogen, Novartis and Janssen-Cilag.

    ()

    sporsmal_grey_rgb
    Article

    Biomarkers are given greater emphasis in the revised diagnostic criteria for multiple sclerosis.

    The diagnosis of multiple sclerosis (MS) is based on clinical symptoms and findings, characteristic MRI changes of the central nervous system and cerebrospinal fluid findings. The revised McDonald diagnostic criteria for MS place greater emphasis on biomarkers. In the absence of a more likely alternative explanation, an MS diagnosis may now be established on the basis of MRI findings and cerebrospinal fluid analyses in patients without clinical MS symptoms or findings (1).

    Historically, clinical evidence of MS has been required because non-specific symptoms such as headache and fatigue are common, and MRI abnormalities in these patients can raise suspicion of MS but are more often due to other causes. To differentiate MS from monophasic conditions such as acute disseminated encephalomyelitis or isolated myelitis, previous diagnostic frameworks required evidence of new relapses or new MRI lesions demonstrating dissemination in time. In the revised McDonald criteria, this mandatory requirement has been removed and replaced by an updated framework that emphasises the overall clinical evaluation alongside paraclinical evidence, such as cerebrospinal fluid and MRI biomarkers (1).

    MRI findings and cerebrospinal fluid analysis

    MRI findings and cerebrospinal fluid analysis

    Three key changes have been introduced regarding MRI in MS. First, the optic nerves are now defined as an anatomical location for MS, in addition to the periventricular, juxtacortical/cortical, infratentorial and spinal cord regions (2). Lesions of the optic nerves can be detected using MRI, optical coherence tomography or visual evoked potentials (2, 3).

    Second, the central vein sign and paramagnetic rim lesions on MRI are now recognised as biomarkers for MS. These elements are not always required, but are particularly emphasised in patients over 50 years of age or with vascular risk factors when cerebrospinal fluid findings are normal, typical clinical MS signs are absent or MRI lesions are limited to only one or two typical anatomical locations for MS (2).

    Finally, elevated levels of kappa free light chains in cerebrospinal fluid can now be used as a simpler and faster alternative to oligoclonal IgG bands (1).

    Improving diagnostic precision

    Improving diagnostic precision

    The revised diagnostic criteria will reduce the frequency of ambiguous diagnoses, such as 'clinically isolated syndrome' or 'radiologically isolated syndrome' (1). They may also lead to earlier diagnosis and initiation of treatment, potentially improving prognosis (4).

    The risk of misdiagnosis or overdiagnosis is low. The revised criteria are unlikely to lead to an MS diagnosis in patients previously considered healthy; they are more likely to clarify the diagnosis in patients who had previously been given an uncertain or provisional diagnosis. Diagnostic precision is expected to improve as the new criteria are implemented by radiologists and neurologists throughout Norway.

    Comments  ( 2 )
    Dette kommentarfeltet modereres, men kommentarer blir ikke redaksjonelt behandlet ut over å sikre at de følger retningslinjer for vårt kommentarfelt.
    Skriv Kommentar
    Published: 8 December 2025
    Tidsskr Nor Legeforen 8 December 2025 Vol. 145.
    doi:
    10.4045/tidsskr.25.0592

    Received 4.10.2025, first revision submitted 19.10.2025, accepted 4.11.2025.
    Copyright: ©️️ Tidsskriftet 2026
    PlumX
    Published: 8 December 2025
    Tidsskr Nor Legeforen 2025 Vol. 145.
    doi: 10.4045/tidsskr.25.0592

    Received 4.10.2025, first revision submitted 19.10.2025, accepted 4.11.2025.
    Copyright:
    ©️️ Tidsskriftet 2026
    Plum Print visual indicator of research metrics PlumX Metrics
    PDF
    Print
    Reply to article

    Recent Articles

    Nyeste ledige stillinger fra legejobber.no

    Se alle stillinger

    Motta vårt nyhetsbrev! Hold deg oppdatert om ny forskning og medisinske nyheter.

    Meld deg på