NMOSD is caused by an autoimmune attack on the nervous system. In more than 80% of cases, IgG autoantibodies against aquaporin-4 (anti-AQP4+) are the cause, and in 10–40% of the remaining cases, IgG antibodies against MOG are the cause. The cause of the remaining cases is still unknown, and it is likely heterogeneous. Why autoimmunity develops is largely unknown. Multiple genetic and environmental factors are known to increase the risk of developing NMOSD. The strongest risk factor is being female, especially in AQP4-IgG-positive NMOSD. Multiple human leukocyte antigen (HLA) alleles are associated with NMOSD. NMO was associated in the past with many systemic diseases. Some researchers have pointed out that some other cases could be paraneoplastic. It appears that lupus can produce NMO-IgG autoantibodies, leading to cases of lupus-derived NMO. The discovery of NMO-IgG (anti-AQP4) has opened a new avenue of research into the causes.
Neuromyelitis optica spectrum disorder
Alexander disease
Corneal-cerebellar syndrome
Leber's hereditary optic neuropathy
Subacute myelo-optic neuropathy
Canavan disease
Grinker myelinopathy
Toxic and nutritional optic neuropathy