LAUSR

BACKGROUND Validation of the 2017 revised McDonald criteria was based on data from Caucasians. Among North Africans, Multiple Sclerosis prevalence, clinical phenotype and differential diagnosis are different. Hence, verifying the relevance of the latest revised criteria applied in North Africans was recommended. The aim of our study was to investigate the applicability and reliability of the revised 2017 McDonald criteria, compared to the 2010 version, with the relevance to the diagnosis of Multiple sclerosis in a Tunisian cohort. METHODS Data from patients, with a typical clinically isolated syndrome, were re-analyzed retrospectively. Also, clinical, immunological and imaging characteristics were reviewed, according to the 2010, then 2017, McDonald criteria. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value were evaluated to analyze the impact of the new criteria in everyday clinical practice. RESULTS A total of 98 patients were included. Eighty-eight patients developed a definite Multiple Sclerosis, while ten had a different diagnosis. With relevance to the 2010 criteria, 41 patients (42%) were diagnosed with Multiple Sclerosis, after the first clinical attack. The 2017 revised criteria allowed to diagnose 32 more cases (73 patients = 74%). Sensitivity of the 2017 criteria was higher (77% versus 44%), but specificity was lower (33% versus 63%). CONCLUSIONS Compared to the 2010 version, the 2017 McDonald criteria highlighted higher sensitivity, but lower specificity for Tunisians.