Prevalence varies by region, ranging from 0.5 to 10 cases per 100,000 people. Unlike MS, prevalence has not been found to be related to latitude. NMO is more common in women than men, with women comprising over two-thirds of patients and more than 80% of those with the relapsing form of the disease. A retrospective study found that prevalence of<unk> s (NMOSD) was 1.5% among a random sample of neurological patients, with a MS:NMOSD ratio of 42:7. Among 13 NMOSD patients, 77% had long spinal cord lesions, 38% had severe<unk> neuritis, and 23% had brain or brainstem lesions. Only 56% had clinically definite NMO at follow-up. NMO is more common in Asians than Caucasians. In fact, Asian<unk> spinal multiple sclerosis (OSMS) (which constitutes 30% of the cases of MS in Japan) has been suggested to be identical to NMO (differences between OSMS and classic MS in Japanese patients). In the indigenous populations of tropical and subtropical regions, MS is rare; but when it appears, it often takes the form of OSMS. The majority of NMO patients have no affected relatives, and it is generally regarded as a nonfamilial condition.
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