2017 revisions of McDonald criteria shorten the time to diagnosis of multiple sclerosis in clinically isolated syndromes

Objectives: To investigate the impact of the 2017 revisions of McDonald criteria on the diagnosis of multiple sclerosis (MS) in a cohort of patients with clinically isolated syndrome (CIS) and dissemination in space (DIS) of demyelinating lesions. Methods: We retrospectively analyzed 137 patients with CIS + DIS from two Italian MS centers. Results: Application of the 2017 revisions of McDonald criteria in our cohort led to a diagnosis of MS in 82.5% of the patients who could have not been diagnosed with MS according to the previous criteria at the time of the first demyelinating event. After a follow-up of 3.8 ± 2.9 years, 85.8% of these patients eventually satisfied also the previous (2010) criteria. Conclusions: Application of the 2017 revisions of McDonald criteria results in an earlier diagnosis of MS in a large percentage of CIS patients destined to convert to MS.