A new article published in The Lancet Neurology1 proposes modifications to the widely used McDonald criteria for the diagnosis of MS. We explain how the current McDonald criteria are used in clinical practice and the implications of the proposed changes.
Historically, it was difficult to diagnose multiple sclerosis. Doctors had to rely on clinical indicators because lesions could not be detected in a living brain.2,3
Magnetic resonance imaging (MRI) has revolutionized diagnosis. Using MRI, the brain lesions indicative of MS can be visualized, helping doctors to distinguish between MS and other inflammatory conditions with potentially similar clinical symptoms.
The 2010 McDonald diagnostic criteria for MS are shown in the figure below.4 Neurologists consider both clinical (blue) and MRI (green) evidence when reaching a diagnosis of MS (orange). In particular, neurologists look for lesions in multiple brain regions (dissemination of lesions in space) or brain lesions that have developed at different times (dissemination of lesions in time).
Since the McDonald criteria were last updated in 2010, MRI technology has advanced and new data have been published on the use of MRI to diagnose MS. On the basis of this new evidence, a group of clinical and imaging experts in MS diagnosis and treatment (MAGNIMS) have now proposed 10 modifications to the McDonald criteria. Most notably, this group recommends extending the area of the CNS that is imaged and examined for lesions so that it includes the whole spinal cord and the optic nerve. This would increase the likelihood of detecting more than one lesion on an MRI scan and so could enable earlier diagnosis of MS.
1. Filippi M, Rocca MA, Ciccarelli O et al. MRI criteria for the diagnosis of multiple sclerosis: MAGNIMS consensus guidelines. Lancet Neurol 2016;15:292–303.
2. Schumacher GA, Beebe G, Kibler RF et al. Problems of experimental trials of therapy in multiple sclerosis: report by the panel on the evaluation of experimental trials of therapy in multiple sclerosis. Ann N Y Acad Sci 1965;122:552–68.
3. Poser CM, Paty DW, Scheinberg L et al. New diagnostic criteria for multiple sclerosis: guidelines for research protocols. Ann Neurol 1983;13:227–31.
4. Polman CH, Reingold SC, Banwell B et al. Diagnostic criteria for multiple sclerosis: 2010 revisions to the McDonald criteria. Ann Neurol 2011;69:292–302.