[Predictors of disability in a cohort with neuromyelitis optica spectrum]

Disability in neuromyelitis optica spectrum disorder (NMOSD) is common and can be severe.

To determine factors associated with increased disability in NMOSD.

Observational, analytical, ambispective study in a cohort of patients with NMOSD between January 2015 and July 2021, using a secondary source to review variables and the expanded disability status scale (EDSS) after onset and a primary source, with a telephone survey for the final EDSS and missing data. Major disability was defined as occurring when the EDSS score was = 6. The analysis was performed by means of logistic regression with SPSS 25®.

A total of 125 patients were analysed. The average age at onset was 41 (standard deviation: 14) years, with a female-to-male ratio of 8:1. Of the total sample, 87% (109) were positive for anti-aquaporin antibodies. Optic neuritis (44.8%) and transverse myelitis (39.2%) were the most frequent clinical manifestations at onset. Altogether 71.2% of patients received acute treatment at their first relapse. Mean chronic treatment initiation was 12 months (interquartile range: 3-60) and 44% had difficulties with immunosuppression compliance. Of the total number of patients, 80.8% had relapses and 44% had a final EDSS score = 6. The median baseline-to-final EDSS score was 1 (interquartile range: 0-3), often towards disability accumulation. An association was found between a relapsing course (odds ratio = 3.73; p = 0.011) and a high baseline EDSS (odds ratio = 1.54; p = 0.0001) with increased disability. In the multivariate analysis, with a higher baseline EDSS and a relapsing course disability was 1.6 and 5.3 times more likely to occur, respectively.

Disease relapses and high EDSS after the first episode are predictors of disability in NMOSD.