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.