NMOSD tends to be a relapsing disease, characterized by attacks (also called flare-ups or exacerbations) with periods of recovery (also called remissions) in between. These attacks can be debilitating and cause permanent damage, so treatment is geared toward both reversing recent symptoms and preventing future attacks, according to the Mayo Clinic. NMOSD happens when your immune system targets myelin, a substance that forms a protective layer around nerves. It’s unknown what causes this autoimmune attack. NMOSD is also known as neuromyelitis optica (NMO) and Devic’s disease. Symptoms of optic neuritis may include the following:
Blurry vision or loss of vision in one or both eyesPain in one or both eyesLoss of color vision
Usually, only one eye is affected in episodes of optic neuritis due to NMOSD, according to the National Organization for Rare Disorders (NORD). Symptoms of transverse myelitis may include the following:
Weakness or paralysis in your legs or armsMuscle spasms or stiffness, which may be painfulNumbness or loss of sensation throughout your bodyNeck or back stiffnessPain in your back, arms, or legsNausea or vomitingHeadacheHiccupsBladder or bowel problemsDifficulty sleeping
Transverse myelitis due to NMOSD may cause symptoms below a certain level on your body — from your neck down to your feet, for example, or from your waist down to your feet, indicating the level at which the spinal cord is inflamed — and possibly on only one side of your body, NORD notes. In children, NMOSD can cause confusion, seizures, or coma, according to the Mayo Clinic. About 90 percent of people with NMOSD have the relapsing form of the disease with periodic attacks and recovery in between, according to the Oregon Health & Science University (OHSU) Brain Institute. But some people have what’s known as the monophasic form of NMOSD, meaning they experience just one attack. In all autoimmune disorders including NMOSD, the immune system mistakenly attacks your body’s own healthy tissue the way it normally attacks outside invaders like bacteria or viruses. Some people with NMOSD report having an upper respiratory infection before the onset of their symptoms, but this possible connection isn’t well understood. Only about 3 percent of people with NMOSD report having relatives with the condition, according to NORD. But about 50 percent of people with NMOSD have another autoimmune disease or a family history of autoimmune diseases. The following groups are known to be at higher risk for NMOSD:
WomenPeople ages 30 to 50People of Asian or African descentPeople with another autoimmune disease
Women are about 4 to 10 times more likely than men to have relapsing NMOSD, the most common form of the condition. But men and women are equally likely to experience monophasic NMOSD, or a single episode, according to NORD. While people of Asian or African descent are disproportionately likely to have NMOSD in Western countries like the United States, there are still more people of European descent with NMOSD, the OHSU Brain Institute notes. Your doctor may refer you to a neurologist for a neurological examination. This specialized exam may include evaluating your vision, hearing, speech, swallowing, muscle strength, coordination, sensation, and balance, as well as your cognitive performance, per Mayo Clinic. You may also have your vision examined separately by an eye specialist. A neurologist or your primary care doctor may order or perform the following tests:
Magnetic resonance imaging (MRI) This imaging test uses strong magnets and radio waves to create detailed images of your brain, spinal cord, and optic nerves. Damaged areas called lesions may be visible in these areas.Blood tests Your doctor may order tests that look for certain antibodies, or proteins involved in attacking nerves in NMOSD. Two of these antibodies are known as NMO-IgG (also known as AQP4-IgG) and MOG-IgG, and testing for them can help rule out other conditions that may cause symptoms similar to those of NMOSD.Lumbar puncture (spinal tap) This procedure involves inserting a needle into your lower back to take a small amount of spinal fluid for testing. Tests performed on your spinal fluid will look at levels of certain cells and proteins, which can help distinguish NMOSD from other conditions.Evoked potentials This type of testing evaluates your brain’s response to stimuli such as touch, sounds, or sights. It involves attaching electrodes to your scalp or other areas, and then giving you predetermined stimuli.
Testing for the NMO-IgG antibody can be especially useful, since about 70 percent of people with NMOSD have it, according to the OHSU Brain Institute. In people who don’t have NMO-IgG, the other antibody listed above, MOG-IgG, is present in about half of cases, according to NORD. Periods of recovery between attacks can last for weeks, months, or even years, depending on individual differences and the treatments people receive, according to the OHSU Brain Institute. In anyone with NMOSD, the likelihood of future attacks without treatment is high, and there is no point in time when you’re considered cured of the condition. That means you’ll need ongoing treatment to suppress your immune system and prevent future attacks, according to the National Multiple Sclerosis Society.
Treating NMOSD Attacks
An NMOSD attack is a medical emergency that requires prompt treatment, the Children’s Hospital of Philadelphia notes. You’re likely to receive the initial care for an NMOSD attack in a hospital. There are two main treatments for an NMOSD attack:
CorticosteroidsPlasma exchange
The standard first treatment for an NMOSD attack in its early stages is a corticosteroid medication, typically delivered by IV for about five days, according to the Mayo Clinic. You’ll then be tapered off the medication over several days. The standard corticosteroid treatment used for NMOSD is methylprednisolone. As your first or second treatment, depending on individual factors, you may undergo plasma exchange. In this procedure, blood is pumped out of your body and separated into blood cells and plasma (fluid). Your cells are then mixed with a replacement solution and returned to your body. The goal of plasma exchange in NMOSD is to remove harmful antibodies from your blood — the ones involved in your immune system’s attack on the myelin protecting your nerves. Plasma exchange may begin before or after your corticosteroid treatment has been completed, the OHSU Brain Institute notes. Plasma exchange may be an effective treatment for some people who don’t respond to corticosteroid treatment, according to NORD.
Preventing Future NMOSD Attacks
For a long time, there were no long-term treatments approved specifically for NMOSD, and drugs approved for other conditions were used off-label to help prevent future NMOSD attacks along with corticosteroids, NORD notes. Since 2020, there have been three approved long-term treatments for NMOSD in people who test positive for the antibody NMO-IgG:
Eculizumab (Soliris)Inebilizumab (Uplizna)Satralizumab (Enspryng)
These drugs are designed to suppress your immune system’s attack on nerve cells in a targeted way. For people who don’t test positive for NMO-IgG or who need further treatments to prevent NMOSD attacks, other treatment options include:
Azathioprine (Azasan, Imuran)Mycophenolate mofetil (Cellcept)Prednisone, a corticosteroidRituximab (Rituxan)
Typically, azathioprine or mycophenolate mofetil is prescribed along with a corticosteroid, according to NORD. Rituximab may be helpful for people who don’t respond to other drugs meant to prevent future NMOSD attacks.
Treating Symptoms of NMOSD
A number of treatments may be prescribed or recommended to treat specific symptoms of NMOSD such as muscle spasms, pain, and loss of bladder or bowel control. Depending on your needs, you may be referred to work with a specialist in rehabilitative medicine, physical therapy, psychiatry, or another field of medicine, according to Penn Medicine. You may also benefit from joining a support group, particularly if you experience permanent vision loss or paralysis from NMOSD. For muscle stiffness or spasms, you may benefit from medications or from regular exercises and stretching to help keep your muscles flexible, the OHSU Brain Institute notes. Wearing a splint on your ankle, wrist, or elbow may also help you deal with daily tasks. For bladder or bowel problems, medications may be helpful if you experience constipation or frequent urination. Getting enough fiber in your diet and regular exercise can help with digestive problems. NMOSD can cause long-term nerve pain, which medications can help relieve. You may also benefit from alternative therapies like acupuncture or meditation, as well as from mental health services to deal with the psychological toll of chronic pain. Pain isn’t the only aspect of NMOSD that can lead to mental health challenges, such as depression — so can vision loss, loss of mobility, or any other symptom that interferes with your daily life. Let your doctor know if you’re having trouble dealing with sadness, stress, or other difficult feelings related to your NMOSD symptoms or diagnosis. But a major goal of NMOSD treatment is to prevent recurring attacks of the condition. It’s important to continue taking medications prescribed for this purpose, even if you don’t experience any ongoing or new symptoms. If you experience recurring attacks of NMOSD even though you’re taking a medication designed to prevent these attacks, you and your healthcare team may decide to reevaluate your treatment.
Visual impairment, including blindnessWeakness or paralysis in one or both arms or legsMuscle stiffness or spasmsLoss of bladder or bowel controlFatigueDepressionDifficulty breathing
NMOSD can lead to greater physical disability over time, especially due to weakness in your arms or legs. Some people with breathing problems will need to start using a ventilator for breathing assistance. To help deal with long-term disability related to NMOSD, it’s important to work with relevant health professionals — who may include neurologists, physical or occupational therapists, and social service providers. You’ll also benefit from a support network that may include your family, friends, and organized support groups. The U.S. National Library of Medicine offers a more specific estimate of the prevalence of NMOSD, at 1 to 2 per 100,000 people worldwide. In the United States, that would mean there are about 3,320 to 6,640 people living with NMOSD. The National Multiple Sclerosis Society estimates that there are between 4,000 and 8,000 people living with NMOSD in the United States, and more than 250,000 worldwide, with women accounting for more than 80 percent of cases. Research on several aspects of NMOSD is ongoing, including at the National Institute of Neurological Disorders and Stroke (NINDS), where scientists are trying to gain a better understanding of how the immune system destroys the protective myelin layer in certain autoimmune diseases. On a more practical level, researchers are investigating ways to repair spinal cord damage due to loss of myelin, including through cell transplantation (replacing damaged cells with healthy cells). According to a research review published in August 2021, promising areas of research related to NMOSD include identifying more biomarkers (proteins or cells found in the blood or spinal fluid) that could lead to new and better treatments for the condition, ways to predict an attack ahead of time, and better ways to monitor a person’s response to treatments. A key part of the process of diagnosing NMOSD involves distinguishing it from MS. That’s critically important, because the two conditions are treated differently, and standard treatments for MS have not been shown to work for NMOSD, according to the Cleveland Clinic. Here are some key differences between NMOSD and MS, according to the National Multiple Sclerosis Society:
NMOSD attacks tend to be more severe and damaging than MS attacks.NMOSD attacks may affect both eyes at the same time, while MS attacks typically do not.NMOSD usually affects mostly the optic nerves and spinal cord, with more limited brain involvement. MS typically affects multiple areas of the brain.MS is more likely than NMOSD to lead to cognitive changes in areas such as memory, reasoning, and problem solving.NMOSD typically leads to disability only through damage from attacks of the disease. MS can start as, or become, a progressive disease in which there is ongoing worsening disability.
Guthy-Jackson Charitable Foundation This organization supports research, advocacy, and education efforts related to NMOSD. It also offers updates on ongoing research, as well as information on local support groups. Siegel Rare Neuroimmune Association This group is for people with rare neuroimmune (neurological autoimmune) disorders, including NMOSD, as well as a handful of related conditions. On the website, you can read about programs and services for people with these conditions and their caregivers, research updates, online support meetings, and more. National Organization for Rare Disorders (NORD) On this organization’s website, you can find detailed information about NMOSD and other rare disorders as well as guidance on health insurance coverage, financial assistance programs, and advocacy opportunities.
