Permanent disability, found in 51% of patients with NMOSD at follow-up, was attributed mainly to age of disease onset, delay in diagnosis, and initial EDSS score.
In a recent cohort study on Mexican patients with neuromyelitis optica spectrum disorder (NMOSD), findings showed that the strongest predictors of permanent disability was an age of onset greater than or 50 years old of age.1 This was the first study assessing risk factors in Mexican patients with NMOSD through the use of a multivariable analysis.
During the follow-up of the study, there were 51% of patients with NMOSD who developed permanent disability.1 Specifically, 22% of patients developed permanent visual disability (N=15),19% developed permanent motor disability (n = 13), and 9% were restricted to a wheelchair (n = 6).
Senior investigator, Miguel Ángel Macías Islas, PhD, full professor, department of neurosciences, University of Guadalajara, and colleagues, investigated the risk factors associated with permanent disability in a cohort of 34 patients with NMOSD who developed permanent disability and 33 controls. Sociodemographic data and characteristics of NMOSD were assessed and a logistic regression analysis was conducted to adjust the variables related to permanent disability.
In the crude analysis, the factors that were associated with permanent disability were age of at least 50 years at onset (OR 3.95; 95% IC, 1.12-13.94; P =.032), more than 12 months of time from onset to diagnosis (OR 3.30; 95% IC 1.13-9.64; P =.029), minimum of 60 months in time from onset to treatment (OR 4.16, 95% IC, 1.03-16.85, P = .045), Expanded Disability Status Scale (EDSS) scores of at least 4.0 at the first appointment (OR, 3.21; 95% IC, 1.18-8.76; P =.022) and severe relapses during disease evolution (OR, 5.72, 95% IC 1.98-16.57, P =.001).
Macías Islas et al wrote, “In our cohort, age of onset [at least] 50 years old had a 5-fold risk of PD. The age of onset [at least] 50 years old is associated with motor and sensory disability.” In a previous study, 63% patients with age of onset at least50 years old of age with APQ4- IgG positive who had an EDSS score of 6.0, reported their age and score as risk for requiring assistance to walk.2
A cross-sectional study showed that retinal measurements in patients with “potential” neuromyelitis optica spectrum disorder were similar to those with definite neuromyelitis optica spectrum disorder.
Similarly, in the adjusted analysis, factors that were associated with permanent disability included age at onset of at least 50 years (OR 5.82; 95% IC, 1.30-26.05, P =.021), time from onset to diagnosis at least 12 months (OR 5.43; 95% IC, 1.47-20.08; P =.011) and severe relapses during disease evolution (OR 6.65; 95% IC ,1.98-22.31; P =.002).
“In Mexican Mestizos, NMOSD seems to be more aggressive compared to other races. However, there is a wide diversity of ethnicity under the terms Hispanic, Mestizo and/or Latin American. Some studies suggests that NMOSD have more aggressive course in mixed population,” Macías Islas et al noted.1
The limitations of this study included the information bias from using the clinical charts, which, could avoid recognizing some other relevant risk factors in some patients. Another limitation was that the patients were recruited from a tertiary-care center, which means they potentially could have more comorbidities compared to patients with NMOSD in a secondary-care hospital. This could explain the high rate of permanent disability.
“Future studies including patients from secondary-care hospitals, university hospitals, and private practices are required to include a wider spectrum of the disease,” Macías Islas and colleagues noted. “This information is required to design healthcare strategies to recognize and treat patients with NMOSD early and aggressively to decrease the rates of [permanent disability] and their effect on both the patients and society.”1
