Neuromyelitis Optica

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What is neuromyelitis optica?

Neuromyelitis optica (NMO) is an autoimmune disease of the central nervous system (CNS) that mainly affects the optic nerves and spinal cord. It is sometimes referred to as NMO spectrum disorder or NMOSD.

In NMO, the body's immune system mistakenly attacks healthy cells and proteins in the body, most often those in the spinal cord and eyes. Symptoms include:

  • Optic neuritis, which causes pain in the eye and vision loss
  • Transverse myelitis, which causes weakness or paralysis of arms and legs
  • Numbness
  • Loss of bladder and bowel control
  • Severe nausea and vomiting, with hiccups from involvement of a part of the brain that controls vomiting

    The disease is caused by abnormal autoantibodies that bind (attach) to a protein called aquaporin-4, activating other parts of the immune system and causing inflammation and damage to cells. This also results in the loss of myelin (the fatty substance that acts as insulation around nerve fibers and helps nerve signals move from cell to cell) in the brain and spinal cord.

    NMO is different from multiple sclerosis (MS). Attacks are usually more severe in NMO than in MS, and NMO is treated differently than MS. Most individuals with NMO experience clusters of attacks days to months or years apart, followed by partial recovery during periods of remission. Women are more often affected by NMO than men. African Americans are at greater risk of the disease. The onset of NMO varies from childhood to adulthood, with two peaks, one in childhood and the other in adults in their 40s.

    There is no cure for NMO. The U.S. Food and Drug Administration (FDA) has approved three drug treatments (eculizumab, inebilizumab-cdon, and satralizumab-mwge) which can reduce the risk of relapses in adults who are anti-aquaporin-4 antibody positive.

    NMO relapses and attacks are often treated with corticosteroid drugs and plasma exchange (also called plasmapheresis, a process used to remove harmful antibodies from the bloodstream). Immunosuppressvie drugs used to prevent attacks include mycophenolate mofetil, rituximab, and azathioprine. Pain, stiffness, muscle spasms, and bladder and bowel control problems can be managed with medications and therapies.

    Individuals with major disability may require physical and occupational therapy, along with social services professionals to address complex rehabilitation needs. Most individuals with NMO have an unpredictable, relapsing course of disease with attacks occurring months or years apart. Disability is cumulative, the result of each attack damaging new areas of the central nervous system.

    Learn About Clinical Trials
    Clinical trials are studies that allow us to learn more about disorders and improve care. They can help connect patients with new and upcoming treatment options.

    How can I or my loved one help improve care for people with neuromyelitis optica?

    Consider participating in a clinical trial so clinicians and scientists can learn more about NMO and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

    All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

    For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with NMO at

    Where can I find more information about neuromyelitis optica?

    Information may be available from the following resources:

    Order publications from the NINDS Catalog
    The NINDS Publication Catalog offers printed materials on neurological disorders for patients, health professionals, and the general public. All materials are free of charge, and a downloadable PDF version is also available for most publications.