Skip Ribbon Commands
Skip to main content

Neuromyelitis Optica Spectrum Disorder

Neuromyelitis Optica Spectrum Disorder - What it is

​Neuromyelitis optica spectrum disorder (NMOSD) is a chronic immune mediated condition, in which the body’s immune system mistakenly attacks the central nervous system. People with NMOSD often develop inflammation of the nerves of the eyes or optic nerves (optic neuritis), of the spinal cord (transverse myelitis), or sometimes of the brain.

Neuromyelitis Optica Spectrum Disorder - Symptoms

​Possible symptoms of NMOSD include:

  • Vision loss in one or both eyes
  • Weakness or numbness in the legs or arms   
  • Uncontrollable vomiting and hiccups
  • Difficulty with or loss of bladder and bowel control
  • Difficulty walking
  • Painful spasms
  • Uncontrollable itching

NMOSD has an unpredictable course and many people with NMOSD develop attacks (relapses) which may occur months or years apart. Disability can be cumulative with repeated attacks, leading to worsening disability over time e.g. difficulty with walking and long-lasting visual loss.

Previously, NMOSD was thought to be a subtype of multiple sclerosis (MS) as both the conditions have similar symptoms. We now know that NMOSD is a separate condition. Attacks in NMOSD are often more severe and the effects might be permanent after each attack.

Neuromyelitis Optica Spectrum Disorder - How to prevent?

Neuromyelitis Optica Spectrum Disorder - Causes and Risk Factors

​In most patients, this autoimmune condition is caused by an autoantibody called aquaporin-4-immunoglobulin G (AQP4-IgG antibody). NMOSD may develop in association with other autoimmune disorders.

NMOSD usually develop in adulthood, between the ages of 30 and 65. It can also rarely affect children and the elderly. Women are more commonly affected than men.

While NMOSD can affect people of all races and ethnic backgrounds, those of African and Asian descents may develop the disorder at a higher rate.

Neuromyelitis Optica Spectrum Disorder - Diagnosis

​NMOSD can be diagnosed by a combination of detailed medical history, clinical examination and tests. Some of these tests include:

  • Blood tests

- Detecting AQP4-IgG antibody in the blood helps to differentiate between NMOSD and MS as well as other similar immune-mediated neurological conditions

  • Lumbar puncture (spinal tap)
- To remove a small amount of fluid from the spinal column
- This test might help to differentiate NMOSD from MS or other conditions which can mimic NMOSD
  • Magnetic Resonance Imaging (MRI)

- Imaging of the brain, optic nerves and spinal cord to detect areas of inflammation or damage

Neuromyelitis Optica Spectrum Disorder - Treatments

​There is currently no cure for NMOSD but there are treatment options for acute attacks, relapse prevention, and symptom relief.

  • Acute treatment

Early treatment after an attack is essential to minimize the risk of permanent damage. The most common drugs are corticosteroids. High dose intravenous (IV; given through the vein) methylprednisolone is usually given over 3 to 5 days, followed by a slow tapering course of oral prednisolone.

Plasma exchange (plasmapheresis) may be recommended as first or second treatment, especially for patients who did not respond substantially to corticosteroids. Plasma exchange involves removal of harmful antibodies and other immune factors in the blood stream by mechanically separating the blood cells from the fluid (plasma) via a specialized machine.

  • Long-term relapse prevention

There are drugs available for the prevention of relapses. Your neurologist may recommend azathioprine, mycophenolate mofetil, rituximab, or tocilizumab. While these drugs have been demonstrated in small clinical trials, observation studies, and clinical practice to be effective in preventing NMOSD relapses and are commonly used, they are currently not approved by the U.S. Food and Drug Administration (FDA).

Drugs which have been shown to be effective in reducing relapses in adults with NMOSD who have AQP4-IgG antibodies and are approved by the U.S. FDA include eculizumab, inebilizumab, and satralizumab. However, these monoclonal antibodies may not be readily available in every country.

  • Symptomatic management

After a relapse, people with NMOSD may continue to have symptoms such as weakness, walking difficulty, visual impairment, bowel and bladder issues, and pain. Medications can be prescribed to address these symptoms.

Additionally, physiotherapy and occupational therapies are often required to optimize functional status e.g. to improve mobility.

Neuromyelitis Optica Spectrum Disorder - Preparing for surgery

Neuromyelitis Optica Spectrum Disorder - Post-surgery care

Neuromyelitis Optica Spectrum Disorder - Other Information

The information provided is not intended as medical advice. Terms of use. Information provided by SingHealth

Discover articles,videos, and guides afrom Singhealth's resources across the web. These information are collated, making healthy living much easier for everyone.