This study aimed to determine the predictors of disability among Turkish MS patients who has a disease duration of at least 10-years.

Considering the heterogeneity of disease course among patients with multiple sclerosis (MS), identifying predictors of disability would be helpful particularly in terms of treatment decision.

Patients with 10 or more years of disease duration were determined among patients fulfilling McDonald 2017 criteria for MS seen at Istanbul University Cerrahpasa School of Medicine MS Clinic. Data for demographics, symptoms at disease onset, laboratory findings, extended disability status scale (EDSS) score, and treatments were extracted into a standard form. Factors predicting progressions to EDSS 3 and EDSS 6 were analyzed.

During follow-up, 134 (61.2%) and 74 (33.8%) patients reached EDDS-3 and EDDS-6, respectively. Overall, mean duration to EDDS-3 and EDDS-6 were 23.2±1.4 years and 34.7±1.3 years respectively. Patient’s mean age when reached EDSS 6  was 45.2±9.5 years. 84 patients were initially under first line injectable therapies and 44 were using other immunosuppressive / immunomodulatory drugs.  Multivariate analysis identified PPMS course , EDDS-6 status at the end of study period, and onset of disease at a later age (age of onset > median) as significant independent predictors of to reach EDDS-3 at a shorter time. For reaching EDDS-6 earlier, PPMS and SPMS course, presence of paraparesis, and presence of extremity ataxia at disease onset emerged as significant independent predictors.