Opsoclonus-Myoclonus Syndrome
Opsoclonus-Myoclonus Syndrome
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Authors: Douglas Nordli, MD, Mayo Clinic Florida/Nemours Jacksonville; Alison L. Christy, MD, PhD , Providence Pediatric Neurology at St. Vincent Medical Center – Portland, Oregon

Reviewed: October 2021


Opsoclonus-myoclonus syndrome (OMS) is a very rare autoimmune disorder involving:

  • Abnormal eye movements (opsoclonus)
  • Muscle jerks (myoclonus)
  • Poor balance and coordination (ataxia)

Sometimes OMS occurs after an illness. Other times, it is caused by the body’s response to a tumor.


Disorder Overview


The immune system is made up of immune cells. Immune cells usually fight off threats from the outside, such as viruses, bacteria, and fungi. In autoimmune diseases, immune cells attack the healthy cells of the body.

Immune cells also attack tumors that are growing in the body. This is a normal way that the body prevents cancer. When immune cells attack a certain type of tumor called a neuroblastoma, this inflammation may accidentally affect the rest of the body. This can cause an autoimmune response to cells in the brain. When a tumor causes OMS, it is called paraneoplastic (para: alongside; neoplastic: relating to cancer) OMS.

OMS can also occur as non-paraneoplastic autoimmune disease. In these cases, it is usually triggered by a viral illness.


Main Symptoms of OMS

The main symptoms of OMS are opsoclonus, myoclonus, and ataxia.

  • Opsoclonus means having rapid, disorganized eye movements, or “dancing eyes”
  • Myoclonus means having quick, lightning bolt-like muscle jerks in the body
  • Ataxia means having poor balance and coordination and frequent falling

Sometimes OMS is called opsoclonus-myoclonus-ataxia syndrome (OMAS).

Other Symptoms of OMS

Some children will develop other problems that show a disturbance in the way the brain functions. These can include:

  • Abnormal behavior, such as rage or irritability
  • Difficulty talking
  • Sleep problems

When OMS is associated with a neuroblastoma tumor, children may also have other symptoms of the tumor. These can include:

  • Dark circles around the eyes
  • Bulging eyes
  • Bone pain
  • Swollen belly, or the feeling of a painless lump in the belly
  • Fever
  • Weight loss
  • Easy bruising or bleeding
  • High blood pressure
  • Fatigue



A neuroblastoma is a type of tumor that starts to grow from immature nerve cells. It is often found in the adrenal glands. The adrenal glands are located on top of the kidneys, in the back part of the upper abdomen.

Neuroblastomas often start growing in infants. They are usually diagnosed in the first five years of life. Neuroblastoma is the most common cancer of infancy.

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When a neuroblastoma is not present, it can be difficult to determine why a child has developed OMS. However, OMS can be caused by the body’s response to a virus.

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Clinical Diagnosis

OMS is a clinical diagnosis. This means that physicians will make the diagnosis of OMS from:

  • A thorough health history
  • A physical exam of the child

It can be helpful if parents have video of the concerning events. This can help physicians confirm the diagnosis.

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Neuroblastoma Testing

Some tests can look for the specific type of tumor associated with OMS, the neuroblastoma. These include:

  • Urine tests. Urine can be tested for two chemicals that are often high when this tumor is present:
    • Vanillylmandelic acid (VMA)
    • Homovanillic acid (HMA)
  • Pictures of the chest, abdomen, and pelvis can look for a tumor.
    • A specific medicine, like I-methyl-iodobenzylguanine (MIBG), may be given during imaging to locate a neuroblastoma.

Because neuroblastomas can be small and hard to find, these tests may need to be repeated in a few months.

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Testing to Confirm OMS

Other tests may be used to rule out other causes of brain dysfunction. These tests will be normal if OMS is the cause of the symptoms. These can include:

  • Lumbar puncture. A lumbar puncture can test the fluid that surrounds the brain and spine. It can be used to look for an active brain infection, like:
    • Meningitis
    • Encephalitis
  • Magnetic resonance imaging (MRI). Pictures of the brain or spinal cord taken with MRI may show other abnormalities in the nervous system.

Sometimes a blood test can help confirm an OMS diagnosis. Some children with OMS will have high levels of immune proteins called antibodies in their blood. However, antibody blood tests are not always useful. They are not a primary way to make a diagnosis.

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There are two types of treatments used in OMS:


Sometimes, OMS may be treated with steroids, ACTH, IV immunoglobulin, or other immunosuppressing drugs that can halt the body’s immune response.

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If a neuroblastoma is the cause, it will usually be removed by a surgeon.

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The prognosis of OMS can vary from patient to patient. The outcome will depend on:

  • The underlying cause of OMS
  • The patient’s response to treatment

Some children will end up with continuing disabilities. Disabilities may include:

  • Attention difficulties
  • Speech difficulties
  • Learning difficulties

Children with long-term effects may benefit from speech therapy or additional support in school.



OMSLife Foundation
The mission of the OMSLife Foundation is to raise awareness of opsoclonus-myoclonus syndrome, maintain a support network for caregivers, and fund research for a cure. They connect patients to OMS specialists throughout the world, provide caregiver conferences and a bi-annual medical conference, and fund research of OMS. OMSLife hosts Opsoclonus Myoclonus Syndrome Support Group, a private Facebook group with over 1,500 members.

The Opsoclonus Myoclonus Syndrome Support Network
Currently, there is no website for Opsoclonus Myoclonus Syndrome Support Network. However, co-founder Sandra Greenberg, parent of a child with OMS, is available to provide support and networking information for patients and families of patients with OMS. Sandra can be reached at [email protected].

Child Neurology Foundation (CNF) solicits resources from the community to be included on this webpage through an application process. CNF reserves the right to remove entities at any time if information is deemed inappropriate or inconsistent with the mission, vision, and values of CNF. 


ClinicalTrials.gov for Opsoclonus-Myoclonus Syndrome (birth to 17 years)

These are clinical trials that are recruiting or will be recruiting. Updates are made daily, so you are encouraged to check back frequently.

ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world. This is a resource provided by the U.S. National Library of Medicine (NLM), which is an institute within the National Institutes of Health (NIH). Listing a study does not mean it has been evaluated by the U.S. Federal Government. Please read the NLM disclaimer for details.  

Before participating in a study, you are encouraged to talk to your health care provider and learn about the risks and potential benefits. 

The information in the CNF Child Neurology Disorder Directory is not intended to provide diagnosis, treatment, or medical advice and should not be considered a substitute for advice from a healthcare professional. Content provided is for informational purposes only.  CNF is not responsible for actions taken based on the information included on this webpage. Please consult with a physician or other healthcare professional regarding any medical or health related diagnosis or treatment options. 


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