Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the central nervous system (CNS). It primarily affects the optic nerves and spinal cord. NMOSD is most common among non-white women in their 30s and 40s . It affects approximately 15,000 people in the United States.
Like many autoimmune disorders, there is still much that is unknown about NMOSD, including its exact cause and how to predict attacks. What researchers do know is that it develops when the immune system mistakes normal tissues of the CNS as foreign and attacks the optic nerves and spinal cord, and sometimes the brain and brainstem.
Symptoms of NMOSD include fatigue, pain, muscle weakness, inability to walk, and blindness. Because of shared symptoms, it is often confused with multiple sclerosis (MS).
NMOSD is a severe and progressive disease. Symptoms continue to build with each relapse. According to one study, half of the participants required a wheelchair, and 62% were functionally blind within 5 years of diagnosis .
Sources: Kim, S. H., Mealy, M. A., Levy, M., Schmidt, F., Ruprecht, K., Paul, F., Ringelstein, M., Aktas, O., Hartung, H. P., Asgari, N., Tsz-Ching, J. L., Siritho, S., Prayoonwiwat, N., Shin, H. J., Hyun, J. W., Han, M., Leite, M. I., Palace, J., & Kim, H. J. (2018). Racial differences in neuromyelitis optica spectrum disorder. Neurology, 91(22), e2089–e2099. https://doi.org/10.1212/wnl.0000000000006574
 Understanding NMOSD. (2019, May 3). Genentech. https://www.gene.com/stories/understanding-nmosd