The International Panel on Diagnosis of Multiple Sclerosis is considering potential revisions to its 2017 McDonald criteria for the diagnosis of multiple sclerosis, but no formal changes are expected soon, according to Dr. Jeffrey Cohen at the ACTRIMS lecture presented at the 28th European Charcot Foundation meeting, November 25, 2020.
The Panel has been considering three key research areas for incorporation into the MS diagnostic criteria:
1. Neurofilament-light (NfL): A number of studies have reported that NfL levels in CSF are prognostic of MS in patients with clinically isolated syndrome (Arrambide et al. Neurology 2016;87:1076-1084) or radiologically isolated syndrome (Matute-Blanch et al. Brain 2018;141:1085-1109). For example, in the study by Arrambide and colleagues, higher cNfL levels were predictive of an MS diagnosis by McDonald criteria but the value was small (hazard ratio 1.009 for every 100 ng/L increment). Other measures (e.g. oligoclonal banding, T2 lesions) appeared to have better diagnostic and prognostic value. The Panel concluded that NfL has limited utility as a diagnostic biomarker at this time. Additional information is needed on the usefulness of longitudinal assessments.
2. Optic nerve involvement to demonstrate dissemination in space: The MAGNIMS group proposed that optic nerve involvement be included as an additional item to meet DIS criteria (Filippi et al. Lancet Neurol 2016;15:292-303). A subsequent study of CIS patients with and without optic neuritis found that DIS criteria that included optic nerve involvement were more sensitive but less specific than McDonald 2017 criteria (Brownlee et al. Neurology 2018;91:e1130-e1134). While the inclusion of asymptomatic optic nerve involvement did not appear to be useful in that study, a subsequent OCT study has proposed cut-off values to establish the presence of asymptomatic and symptomatic optic nerve lesions based on inter-eye differences in retinal nerve fibre layer (RNFL) and ganglion cell + inner plexiform layer thickness (Nolan-Kenney et al. Ann Neurol 2019;85:618-629). The Panel concluded that this area of research deserves further consideration.
Central vein sign: A consensus statement by the North American Imaging in MS (NAIMS) Cooperative said that while the presence of the central vein sign (CVS) in lesions can be useful in differentiating MS from mimics, its prognostic value is unknown and further efforts were needed to refine and standardize this assessment (Sati et al. Nat Rev Neurol 2016;12:714-722). A subsequent study reported high specificity but only moderate sensitivity in differentiating MS from mimics (e.g. NMOSD, SLE, migraine/cluster headache, diabetes/small-vessel disease) (Sinnecker et al. JAMA Neurol 2019;76:1446-1456). The Panel concluded that the CVS shows promise, but it is unclear how it would be incorporated into the current diagnostic criteria. For example, it is not known if a diagnostic criterion should be based on the number of CVS lesions or the proportion of CVS lesions. Additional research will also be needed to determine the optimal techniques and image acquisition protocols.