Neuromyelitis optica diagnosis in clinically isolated syndromes suggestive of multiple sclerosis

The authors assessed the extent of overlap between current diagnostic criteria of neuromyelitis optica (NMO) and multiple sclerosis (MS) by applying NMO criteria to a large cohort of 320 patients with clinically isolated syndromes (CIS). Twenty-three (7.2%) patients fulfilled NMO absolute criteria at some time and 1 (0.3%) also fulfilled one major supportive criterion. Therefore, even by systematically applying NMO criteria in patients with CIS, NMO diagnosis is reached infrequently.