Sociodemographic and clinical characteristics of people with multiple sclerosis and neuro-myelitis optica spectrum disorder in a central northern region of Chile: A prevalence study

•The prevalence of multiple sclerosis (MS) was 7.18 per 100,000.•The prevalence of neuro-myelitis optica spectrum disorder (NMOSD) was 0.95 per 100,000.•Both diseases are 4 times more common in women; mean diagnosis age was 32.6 years.•86.6% of MS patients had relapsing-remitting MS; 58% reported mild disability.•87.5% of patients with NMOSD use rituximab; 50% presented moderate disability.