LATAM-Panorama-NMOSD: Epidemiological, Clinical, and Paraclinical Features of Neuromyelitis Optica Spectrum Disorder...

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune neurological disease. NMOSD is more common in non-Caucasian populations, with some Latin American and Caribbean (LAC) populations having some of the highest reported prevalences globally. Previous research suggests that populations in the LAC region may present with distinctive clinical and paraclinical features. However, despite these potential population-specific differences, such characteristics remain poorly defined and understudied.

Following the PRISMA guidelines and the PROSPERO registration (CRD42024598746), a systematic review was conducted in October 2024 to evaluate the epidemiological, clinical, and paraclinical characteristics of NMOSD in Latin America. The outcomes of interest included age at onset, female-to-male ratio, mean disease duration, mean Expanded Disability Status Scale (EDSS) score, seropositivity for aquaporin-4 antibodies, and the prevalence proportion of NMOSD. Studies were included based on predefined inclusion and exclusion criteria. Risk of bias was assessed for all studies using the JBI critical appraisal tools. Pooled single-group summary estimates were calculated using a random effects model. Forest plots were generated to visualize the pooled results. Data analysis was performed using STATA version 18.

A systematic search of PubMed and Embase was conducted. A total of 303 studies were screened, 74 articles underwent full-text evaluation, and 33 studies were included for data extraction and analysis. An overall population of 5,105 patients was analyzed. The mean age at onset was 36.08 years (95% CI: 34.77-37.39). The female-to-male ratio was approximately 4:1, with a pooled proportion of females of 0.81 (95% CI: 0.79-0.83). The mean disease duration was 6.57 years (95% CI: 5.13-8.01), with a mean Expanded Disability Status Scale score of 4.27 (95% CI: 3.87-4.67). The proportion of patients seropositive for aquaporin-4 antibodies was 0.64 (I² = 85.81%, 95% CI: 0.59-0.69). The pooled prevalence proportion of NMOSD in Latin America was 3.03 per 100,000 inhabitants (95% CI: 0.87-5.20), with high heterogeneity in prevalence estimates among the included studies.

The prevalence of NMOSD in Latin America is highly heterogeneous. The clinical and paraclinical characteristics of patients with NMOSD included in this study are consistent with those reported in other regions globally.