The McDonald criteria maintained a scheme for diagnosing MS based solely on clinical grounds but also proposed for the first time that when clinical evidence is lacking, magnetic resonance imaging (MRI) findings can serve as surrogates for dissemination in space (DIS) and/or time (DIT) to diagnose MS.[5] The criteria try to prove the existence of demyelinating lesions, by image or by their effects, showing that they occur in different areas of the nervous system (DIS) and that they accumulate over time (DIT). The McDonald criteria facilitate the diagnosis of MS in patients who present with their first demyelinating attack and significantly increase the sensitivity for diagnosing MS without compromising the specificity.[5]