Opsoclonus myoclonus syndrome

A rare neurological disorder characterized by rapid, involuntary eye movements and muscle jerks

Opsoclonus myoclonus syndrome (OMS) is a rare neurological disorder that is characterized by a combination of opsoclonus, myoclonus, ataxia, and often severe behavioral changes. It is sometimes referred to as "dancing eyes-dancing feet syndrome" due to the characteristic symptoms of rapid, involuntary eye movements and muscle jerks.

Signs and symptoms

The primary symptoms of opsoclonus myoclonus syndrome include:

• Opsoclonus: This refers to rapid, involuntary, and chaotic eye movements that occur in all directions. These movements are often described as "dancing eyes."
• Myoclonus: This involves sudden, brief, involuntary muscle jerks that can affect any part of the body, often described as "dancing feet."
• Ataxia: A lack of voluntary coordination of muscle movements, which can affect gait and balance.
• Behavioral changes: These can include irritability, sleep disturbances, and cognitive dysfunction.

Causes

Opsoclonus myoclonus syndrome can be associated with several underlying causes, including:

• Paraneoplastic syndrome: OMS is often associated with neuroblastoma in children, where the immune system's response to the tumor mistakenly attacks the nervous system.
• Infections: Certain viral infections, such as those caused by Epstein-Barr virus or Coxsackievirus, can trigger OMS.
• Idiopathic: In some cases, the cause of OMS is unknown.

Pathophysiology

The exact pathophysiology of opsoclonus myoclonus syndrome is not fully understood. It is believed to involve an autoimmune process where the body's immune system attacks the nervous system, particularly affecting the cerebellum and brainstem, which are involved in coordinating movement and balance.

Diagnosis

The diagnosis of opsoclonus myoclonus syndrome is primarily clinical, based on the characteristic symptoms. Additional tests may include:

• Magnetic resonance imaging (MRI): To rule out other neurological conditions.
• Lumbar puncture: To analyze cerebrospinal fluid for signs of inflammation or infection.
• Blood tests: To check for antibodies that may indicate an autoimmune process.

Treatment

Treatment of opsoclonus myoclonus syndrome often involves addressing the underlying cause, if known, and managing symptoms. Common treatments include:

• Immunotherapy: Such as corticosteroids, intravenous immunoglobulin (IVIG), or rituximab to modulate the immune response.
• Symptomatic treatment: Medications such as clonazepam or valproic acid may be used to control myoclonus and ataxia.
• Physical therapy: To improve coordination and balance.

Prognosis

The prognosis of opsoclonus myoclonus syndrome varies depending on the underlying cause and the response to treatment. In some cases, symptoms may resolve completely, while in others, they may persist or recur. Early diagnosis and treatment are crucial for improving outcomes.

Related pages

• Neuroblastoma
• Paraneoplastic syndrome
• Autoimmune disease
• Cerebellum