Opsoclonus myoclonus (OMS), also known as Dancing Eyes-Dancing Feet Syndrome and Kinsbourne syndrome, is a rare disorder that affects the eyes and muscles and causes other disturbances.

In young children, it is most often caused by a tumor that triggers the immune system to mistakenly attack the nervous system, with an onset that can be described as abrupt and severe. In adults, the condition is caused most often in response to lung or breast cancers. It can also occur on its own or following a bacterial or viral infection. OMS is generally not a fatal disorder.

Symptoms include:

• Opsoclonus (irregular, rapid eye movements)
• Myoclonus (brief, shock-like muscle spasms) in the arms or legs
• Unsteady, trembling gait (manner of walking)
• Ataxia (including difficulty walking and with balance)
• Tremor of the hand

• Difficulty speaking
• Difficulty eating or sleeping
• Behavioral changes, including rage attacks
• Lack of coordination
• Hypotonia (decreased muscle tone)

Doctors diagnose OMS when the person has three of the four following symptoms:

• A rare type of cancer that affects the nerve tissue
• Uncontrolled eye movement
• Myoclonus and/or ataxia
• Issues with behavior or sleep disturbance

A blood exam can detect certain antibodies in individuals with OMS.

Treatment includes corticosteroids or the hormone ACTH, intravenous immunoglobulin therapy (in which antibodies from hundreds of donors are pooled together and injected into a person to fight the immune response), and medications to treat other symptoms. Some people recover fully while others continue to display symptoms, and some people with the disorder may have a relapse of neurological symptoms.

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.

About 20-40% of adults with opsoclonus myoclonus syndrome (OPS) are found to have cancer somewhere in their body. In these cases, it is believed the cancer cells trigger (cause) an immune response which ends up mistakingly attacking other non-cancerous cells in the body (paraneoplastic syndrome).

Non-paraneoplastic (non-cancer related) adult onset OPS has been linked to various infections, including Lyme disease, enterovirus, West Nile virus, Epstein Barr virus, HIV, salmonella, cytomegalovirus, and after Rubella vaccination or a streptococcal infection. Similar to paraneoplastic cases, it is believed the virus triggers an abnormal immune response. Although in many cases of non-paraneoplastic OPS a cause can not be found (idiopathic), most medical researchers believe the likely cause is an undetected viral infection triggering the immune system.

Signs and symptoms of opsoclonus-myoclonus syndrome (OMS) may include:

• 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.

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

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.

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.

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. 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. Adults may be less likely to respond to immunological treatment compared with children.
• Trazodone: Used to treat sleep problems and associated rage attacks.