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Disease Profile

Opsoclonus-myoclonus syndrome

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

Age of onset

Infancy

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ICD-10

G25.3

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

Opsoclonus myoclonus syndrome; OMS; Kinsbourne syndrome;

Categories

Eye diseases; Nervous System Diseases

Summary

Opsoclonus-myoclonus syndrome (OMS) is a rare disorder that affects the nervous system. Symptoms include rapid, multi-directional eye movements (opsoclonus), quick, involuntary muscle jerks (myoclonus), uncoordinated movement (ataxia), irritability, and sleep disturbance. The onset of OMS is usually abrupt and often severe. The disease may become chronic.[1] OMS typically occurs in association with tumors (neuroblastomas), or following a viral or bacterial infection.[2][3][4] Treatment may include corticosteroids or ACTH (adrenocorticotropic hormone). When there is a tumor present, treatment may include chemotherapy, surgery, and/or radiation. In some cases, when the underlying cause of OMS is treated, symptoms improve.[1][2][3]

Symptoms

Signs and symptoms of opsoclonus-myoclonus syndrome (OMS) may include:[2][3]

  • Unsteady, trembling gait (manner of walking)
  • Sudden, brief, shock-like muscle spasms (myoclonus). While it occurs most when trying to move and worsens with agitation or stimulation, it can also be present at rest. Myoclonus can make a person appear nervous or shaky, or have jerking movements. The face, eyelids, limbs, fingers, head and trunk may be involved. When the illness is at its worst, sitting or standing is difficult or impossible.
  • Irregular, rapid eye movements (opsoclonus)

Other symptoms may include difficulty speaking or inability to speak, difficulty eating or sleeping, excessive drooling, lack of coordination, rage attacks, head tilt, a decrease in muscle tone, and/or general feeling of discomfort or illness.[2][3]

Children may appear to be nervous, irritable, or lethargic while adults may have mental clouding (encephalopathy).[3]

Cause

Opsoclonus-myoclonus syndrome is often associated with the presence of a tumor (such as neuroblastoma) and referred to as a paraneoplastic syndrome. In other cases, it is associated with a viral infection (such as influenza, Epstein-Barr, hepatitis C, HIV,or Coxsackie B) or a bacterial infection (such as as streptococcal, Lyme disease, or mycoplasma). In some cases, the cause is unknown.[2][3]

Diagnosis

A diagnosis of OMS is mostly based on the presence of the characteristic signs and symptoms. In some cases, laboratory tests for certain antibodies and/or for abnormal white blood cells may also be done.[3]

The diagnosis is based on the presence of any 3 out of the 4 following criteria:

  1. Rare type of cancer that affects the nerve tissue (neuroblastoma)
  2. Uncontrolled eye movement (opsoclonus)
  3. A movement disorder with sudden muscle contractions (myoclonus) and/or lack of coordination (ataxia)
  4. Behavioral and/or sleep disturbance

In adults with OMS, a blood exam may show Hu anti-neuronal nuclear antibodies (anti-Hu) but not in children. The most efficient methods for detecting a neuroblastoma (which is present in many affected people) are MRI with contrast and helical (or spiral) CT scanning.[4]

Treatment

There are no official treatment recommendations for OMS. Management may involve: 

  • Surgery, chemotherapy, and/or radiation: When there is a tumor present, treatment such as surgery for tumor removal, chemotherapy, or radiation may be required.[2] In children, the removal of the neuroblastoma does not always improve neurologic symptoms. Some adults with paraneoplastic OMA do not have more neurologic symptoms with the removal pf the neuroblastoma or after its treatment.
  • Corticosteroids or ACTH (adrenocorticotrophic hormone), human intravenous immunoglobulins (IVIG), or immunosuppressive agents such as immuran, cyclophosphamide, mycophenolate mofetil, and rituximab. In many cases, a combination of medications leads to the best result.[2][3][5] Adults may be less likely to respond to immunological treatment compared with children.[5]
  • Trazodone: Used to treat sleep problems and associated rage attacks.

Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Social Networking Websites

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

        In-Depth Information

        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Opsoclonus-myoclonus syndrome. Click on the link to view a sample search on this topic.

          References

          1. Pranzatelli MR. Opsoclonus-Myoclonus Syndrome. National Organization for Rare Disorders (NORD). 2009; https://rarediseases.org/rare-diseases/opsoclonus-myoclonus-syndrome/.
          2. NINDS Opsoclonus Myoclonus Information Page. National Institute of Neurological Disorders and Stroke (NINDS). https://www.ninds.nih.gov/Disorders/All-Disorders/Opsoclonus-Myoclonus-Information-Page.
          3. Pranzatelli MR. What is the Opsoclonus-Myoclonus Syndrome?. Opsoclonus-Myoclonus U.S.A. And International web site. https://www.omsusa.org/pranzatelli-Brochure1.htm.
          4. Opsoclonus-myoclonus syndrome. Orphanet. November, 2014; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=1183.
          5. Dalmau J and Rosenfeld MR. Opsoclonus myoclonus ataxia. UpToDate. May 3 2016; https://www.uptodate.com/contents/opsoclonus-myoclonus-ataxia.

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