Demographic and clinical profile of patients with multiple sclerosis diagnosed over the last 30 years according to different diagnostic criteria.

The aim of this study was to investigate the demographic and clinical characteristics of patients with multiple sclerosis (MS) diagnosed between 1986 and 2015. 333 patients with definite MS were divided into four subgroups according to the following diagnostic criteria: Group A) Poser (n = 145), Group B) McDonald 2000 (n = 66), Group C) McDonald 2005 (n = 62), and Group D) McDonald 2010 (n = 60). We investigated: 1) patient sex and age at diagnosis, 2) symptoms and number of relapses that prompted MS diagnosis, 3) time between first symptoms suggestive of MS and confirmed diagnosis, and 5) Expanded Disability Status Scale (EDSS) score at disease onset. The overall female-to-male ratio was 2.3:1, but in the subgroups it differed significantly (A - 1.9; B - 1.6; C - 4.7; D - 3.6). The mean age at diagnosis (in years) decreased from 39.6 ± 13.3 in Group A to 29.9 ± 9.3 in Group D, p < 0.001. Pyramidal signs remained the most common manifestation regardless of the diagnostic criteria, although an increased trend of visual dysfunction was observed (A - 16%, B - 14%, C - 19%, D - 23,3%; A vs D, p < 0.001). The number of relapses before diagnosis decreased from median 4.0 to 2.5 in Group A and Group D, p < 0.001. Time from the first symptom to diagnosis shortened from 88.9 ± 80.2 months (Group A) to 33.6 ± 68.2 months (Group D), p < 0.0001. Mean EDSS score at diagnosis also decreased: A - 4.4 ± 2.3; B - 3.1 ± 1.7; C - 2.7 ± 1.3; D - 2.8 ± 1.4, p < 0.001. Our study indicates significant differences in demographic and clinical characteristics of MS diagnosed according to the changing criteria.