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Neuromyelitis Optica Spectrum Disorder (NMOSD)

Understanding NMOSD

  • We do not know the root cause of the demyelination and inflammation that occurs in NMOSD. However, scientists do understand what happens in the body. The immune system attacks the central nervous system, producing inflammation. The inflammation causes damage and demyelination, which produces the symptoms you experience.

  • relapses— also called flare-ups or attacks. The relapses can be weeks, months or years apart. Between relapses, people may experience some recovery.Relapses, which usually affect the optic nerves or spinal cord, can happen over hours or days. Some people have pain behind their eyes or notice that colors look faint or gray. They may also lose some strength and sensation in the arms, trunk and legs and have bladder or bowel control problems. Relapses require immediate medical attention to prevent worsening and minimize permanent disability.With effective treatments, the risk of relapses is now lower, but relapses can still be debilitating. Doctors recommend early and ongoing treatment to prevent relapses and long-term disability." c-nmssatomrichtext_nmssatomrichtext-host="">
    NMOSD is a relapsing disease. This means that new inflammation in the nervous system produces relapses— also called flare-ups or attacks. The relapses can be weeks, months or years apart. Between relapses, people may experience some recovery.Relapses, which usually affect the optic nerves or spinal cord, can happen over hours or days. Some people have pain behind their eyes or notice that colors look faint or gray. They may also lose some strength and sensation in the arms, trunk and legs and have bladder or bowel control problems. Relapses require immediate medical attention to prevent worsening and minimize permanent disability.With effective treatments, the risk of relapses is now lower, but relapses can still be debilitating. Doctors recommend early and ongoing treatment to prevent relapses and long-term disability.

  • optic neuritis simultaneously or one at a time. This may cause visual impairment. 
  • Transverse myelitis refers to inflammation across both sides of the spinal cord at a single level. It causes weakness and loss of sensation in the legs and, depending how high on the spinal cord the inflammation occurs, occasionally in the arms. Transverse myelitis can also affect bowel and bladder function. Transverse myelitis symptoms tend to be more severe in NMO than in MS, causing more severe symptoms — although that is not always the case.
In most people with NMOSD, blood tests detect specific antibodies (anti-AQP4) that attack Aquaporin-4 (AQP4) in the central nervous system. AQP4 is a protein on astrocytes, a type of cell that helps the nerves in the central nervous system work properly.This attack leads to inflammation and damage to the astrocytes, as well as to the nerve cells and their myelin insulation. The resulting damage disrupts the messages from the brain and spinal cord to the rest of the body, causing weakness, worsened vision or other symptoms." c-nmssatomrichtext_nmssatomrichtext-host="">
NMOSD can cause optic neuritis and transverse myelitis.
  • Both eyes may be affected with optic neuritis simultaneously or one at a time. This may cause visual impairment. 
  • Transverse myelitis refers to inflammation across both sides of the spinal cord at a single level. It causes weakness and loss of sensation in the legs and, depending how high on the spinal cord the inflammation occurs, occasionally in the arms. Transverse myelitis can also affect bowel and bladder function. Transverse myelitis symptoms tend to be more severe in NMO than in MS, causing more severe symptoms — although that is not always the case.
In most people with NMOSD, blood tests detect specific antibodies (anti-AQP4) that attack Aquaporin-4 (AQP4) in the central nervous system. AQP4 is a protein on astrocytes, a type of cell that helps the nerves in the central nervous system work properly.This attack leads to inflammation and damage to the astrocytes, as well as to the nerve cells and their myelin insulation. The resulting damage disrupts the messages from the brain and spinal cord to the rest of the body, causing weakness, worsened vision or other symptoms.

  • Changes in vision (optic neuritis) and symptoms caused by spinal cord inflammation (transverse myelitis) are common in NMOSD.Symptoms caused by optic neuritis include:
    • Loss or blurring of vision in one or both eyes
    • Loss of color vision
    • Eye pain
    Symptoms caused by transverse myelitis include:
    • Weakness, numbness or loss of sensation
    • Loss of muscle function
    • Loss of bowel or bladder control or difficulty emptying the bladder
    • Spasticity (increased muscle tone or stiffness in the arms or legs)
    • Shooting pain or tingling in the neck, back or abdomen
    Other symptoms that commonly occur with an NMOSD relapse include uncontrollable hiccups, nausea and vomiting.

  • NMOSD progresses at variable rates and, as with MS, is unpredictable. Each relapse causes new damage, and, over time, relapses can lead to serious disability.

  • MRI of your brain, optic nerves and spinal cord
  • Spinal tap (lumbar puncture) to examine cerebrospinal fluid
  • Eye scans and vision tests
  • Blood tests, including anti-AQP4 antibody testing
    • Some people who test negative for anti-AQP4 may have a related condition called myelin oligodendrocyte glycoprotein antibody disease (MOGAD)." c-nmssatomrichtext_nmssatomrichtext-host="">
    Healthcare providers consider several things when diagnosing NMOSD, including symptoms, medical history and test results. The diagnosis process may include:
    • Medical history to identify any past or present symptoms that might be caused by NMOSD, MS or another disorder
    • Neurologic exam of your thinking, vision, hearing, sensations, strength, swallowing, reflexes, coordination, walking and balance
    • MRI of your brain, optic nerves and spinal cord
    • Spinal tap (lumbar puncture) to examine cerebrospinal fluid
    • Eye scans and vision tests
    • Blood tests, including anti-AQP4 antibody testing
    Some people who test negative for anti-AQP4 may have a related condition called myelin oligodendrocyte glycoprotein antibody disease (MOGAD).

  • An estimated 4,000 to 8,000 people live with NMOSD in the United States and a quarter-million people worldwide.
    • NMOSD is more common in women (more than 80%) than men.
    • NMOSD occurs in all parts of the world. It is more common among people of African and Eastern Asian descent than in people who are white. NMOSD may be the most common demyelinating disease within the African and Eastern Asian communities.
    • NMOSD can occur at any age — in children as young as 3 and adults as old as 90 — but appears most often between ages 30 and 50.
    " c-nmssatomrichtext_nmssatomrichtext-host="">
    An estimated 4,000 to 8,000 people live with NMOSD in the United States and a quarter-million people worldwide.
    • NMOSD is more common in women (more than 80%) than men.
    • NMOSD occurs in all parts of the world. It is more common among people of African and Eastern Asian descent than in people who are white. NMOSD may be the most common demyelinating disease within the African and Eastern Asian communities.
    • NMOSD can occur at any age — in children as young as 3 and adults as old as 90 — but appears most often between ages 30 and 50.

  • cognitive changes over time, such as changes in memory, reasoning and problem-solving.
  • Disability from NMOSD results from relapses and is rarely progressive. MS can start off as, or develop into, a progressive disease.
  • NMOSD relapses are generally more severe than MS relapses.
  • Doctors use a blood test for NMOSD. It looks for the AQP4-IgG antibody. This is present in about 70% of people with NMOSD.
    • Read about other diseases with symptoms similar to NMOSD and MS." c-nmssatomrichtext_nmssatomrichtext-host="">
    NMOSD and MS share some symptoms, and in fact experts used to think it was a form of MS. But there are key differences:
    • NMOSD relapses may affect both eyes at the same time. MS usually affects one eye at a time.
    • NMOSD usually affects only the optic nerve and spinal cord although lesions may develop in specific areas of the brain such as the brainstem. MS typically affects multiple areas of the brain as well as the spinal cord and optic nerve.
    • Cognitive changes are not typically a symptom of NMOSD. People with MS experience cognitive changes over time, such as changes in memory, reasoning and problem-solving.
    • Disability from NMOSD results from relapses and is rarely progressive. MS can start off as, or develop into, a progressive disease.
    • NMOSD relapses are generally more severe than MS relapses.
    • Doctors use a blood test for NMOSD. It looks for the AQP4-IgG antibody. This is present in about 70% of people with NMOSD.
    Read about other diseases with symptoms similar to NMOSD and MS.

  • medication guide.
  • Inebilizumab-cdon (Uplizna®)
  • Ravulizumab-cwvz (Ultomiris®)
  • Satralizumab-mwge (Enspryng®)
    • Other drugs that are used off-label to prevent relapses include:" c-nmssatomrichtext_nmssatomrichtext-host="">
    There is not currently a cure for NMOSD, but there are effective treatments. The standard of care for an relapse of NMOSD includes:
    • Intravenous (into the vein) high-dose corticosteroids (methylprednisolone) to reduce inflammation of the nervous system
    • Plasma exchange (PLEX) for severe relapses or if no improvement occurs with corticosteroids
    • The goal of PLEX is to lower the level of anti-AQP4 antibodies in the blood.
    PLEX involves removing blood from the body through a needle and tubing. Through a series of steps, the plasma (the liquid part of the blood) is separated from blood cells and replaced with an artificial plasma substitute. The plasma substitute and blood cells are combined and then returned to the body intravenously.The procedure lasts several hours and may be repeated multiple times over a number of days.Because the likelihood of recurrence is very high and relapses are generally severe and often result in permanent disability, ongoing treatment to suppress the immune system is necessary. The U.S. Food and Drug Administration (FDA) has approved 4 drugs specifically for treating anti-AQP4 positive NMOSD:Other drugs that are used off-label to prevent relapses include:

    Resources for People Affected by NMOSD

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