Which are the symptoms of Opsoclonus myoclonus syndrome?

Opsoclonus myoclonus syndrome (OMS) is a rare neurological disorder that primarily affects children but can also occur in adults. It is characterized by a combination of involuntary eye movements (opsoclonus) and sudden, brief muscle contractions (myoclonus). OMS is also known by other names such as dancing eyes-dancing feet syndrome, Kinsbourne syndrome, or opsoclonus-myoclonus-ataxia (OMA) syndrome.

Opsoclonus refers to the rapid, involuntary, and irregular eye movements that occur in all directions. These eye movements are often described as "dancing" or "jumping" eyes. They can be continuous or intermittent and may worsen with attempts to fixate on an object or follow a moving target. Opsoclonus can cause significant visual disturbances and may lead to difficulties with coordination and balance.

Myoclonus refers to sudden, brief, shock-like muscle contractions that can affect various parts of the body. In OMS, myoclonus typically involves the trunk, limbs, and face. These muscle jerks can be spontaneous or triggered by certain stimuli such as noise, touch, or emotional stress. Myoclonus can be mild or severe, and it may significantly impact a person's ability to perform daily activities.

In addition to opsoclonus and myoclonus, individuals with OMS may experience a range of other symptoms, which can vary in severity and duration. These symptoms may include:

• Ataxia: Lack of coordination and unsteady movements, often affecting balance and gait.


• Behavioral changes: Irritability, mood swings, anxiety, and sleep disturbances.


• Language and speech difficulties: Slurred speech, difficulty articulating words, or language regression in children.


• Cognitive impairment: Problems with attention, concentration, memory, and learning.


• Motor delays: Developmental delays in achieving motor milestones, such as sitting, crawling, or walking.


• Autonomic dysfunction: Disturbances in the autonomic nervous system, leading to issues with blood pressure, heart rate, and body temperature regulation.


• Generalized weakness: Reduced muscle strength and fatigue.


• Emotional instability: Emotional lability, including episodes of uncontrollable laughter or crying.


• Sleep disturbances: Insomnia, frequent awakenings, or excessive daytime sleepiness.

The exact cause of OMS is still unknown, but it is believed to be an autoimmune-mediated disorder. In some cases, OMS may be associated with an underlying tumor, most commonly a neuroblastoma, a type of cancer that develops from immature nerve cells. Therefore, it is crucial to thoroughly evaluate individuals diagnosed with OMS to rule out any underlying malignancies.

OMS is typically diagnosed based on the presence of opsoclonus, myoclonus, and other associated symptoms. Additional tests, such as blood work, neuroimaging (MRI or CT scans), and lumbar puncture, may be performed to identify any underlying causes or to assess the extent of neurological involvement.

Treatment for OMS aims to control symptoms, improve quality of life, and address any underlying causes. The management of OMS often involves a multidisciplinary approach, including neurologists, oncologists (if a tumor is present), immunologists, and rehabilitation specialists. Treatment options may include:

• Immunotherapy: The use of medications to modulate the immune system, such as corticosteroids, intravenous immunoglobulin (IVIG), or rituximab.


• Tumor removal: If an associated tumor is identified, surgical removal or other appropriate treatments may be necessary.


• Physical and occupational therapy: These therapies can help improve coordination, balance, and motor skills.


• Speech therapy: To address any speech and language difficulties.


• Psychological support: OMS can have a significant impact on emotional well-being, so counseling or therapy may be beneficial for both the affected individual and their family.

While the prognosis for OMS varies depending on the underlying cause and individual factors, many individuals with OMS experience improvement in symptoms over time. However, some may continue to have long-term neurological and cognitive deficits. Regular follow-up with healthcare professionals is essential to monitor progress, adjust treatment plans, and provide ongoing support.