Risk factors associated with permanent disability in neuromyelitis optica spectrum disorders

•During their evolution, most NMOSD patients develop permanent disability•Diagnosis ≥ 12 months is the most important risk factor for permanent disability•EDSS ≥ 4.0 and age of onset ≥ 50 years old at first visit are also risk factors•Prompt recognition and treatment of NMOSD is paramount to prevent disability Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system. In NMOSD, a relapse results in increased disability. To assess risk factors associated with permanent disability (PD) in patients with neuromyelitis optica spectrum disorders (NMOSD). We evaluated 34 cases (who developed permanent disability) and 33 controls. The assessment included the following variables: sociodemographic data and characteristics of the disease. Logistic regression analysis was performed to adjust variables associated with PD. fifty-one percent developed PD during follow-up; 15 (22%) developed permanent visual disability, 13 (19%) developed permanent motor disability and 6 (9%) were restricted to wheelchair. Factors associated with PD in the crude analysis were: age at onset ≥ 50 years (OR 3.95, 95% IC 1.12-13.94, p= 0.032), time from onset to diagnosis ≥ 12 months (OR 3.30, 95% IC 1.13-9.64, p= 0.029), time from onset to treatment ≥ 60 months (OR 4.16, 95% IC 1.03-16.85, p= 0.045), EDSS ≥ 4.0 at the first appointment (OR 3.21, 95% IC 1.18-8.76, p= 0.022) and severe relapses during disease evolution (OR 5.72, 95% IC 1.98-16.57, p= 0.001). Factors associated with PD in the adjusted analysis were: age at onset ≥ 50 years (OR 5.82, 95% IC 1.30-26.05, p= 0.021), time from onset to diagnosis ≥ 12 months (OR 5.43, 95% IC 1.47-20.08, p= 0.011) and severe relapses during disease evolution (OR 6.65, 95% IC 1.98-22.31, p= 0.002). Half of patients with NMOSD may develop PD during disease evolution. Age of onset ≥ 50 years, delay to diagnosis ≥12 months and initial EDSS ≥ 4.0 constitute the strongest risk factors for PD.