Opsoclonus-myoclonus syndrome (OMS) is an autoimmune neurological disorder. Its name describes its symptoms: opsoclonus is jiggling eye movements and myoclonus means involuntary muscle twitching. It is also known as Kinsbourne syndrome or "dancing-eyes-dancing-feet."
Opsoclonus-myoclonus syndrome results from an autoimmune disorder in which the body's antibodies are responding to either a viral infection or a tumor called a neuroblastoma. In either case, the antibodies end up attacking the brain cells as well, and this causes the damage that produces the symptoms.
Opsoclonus-myoclonus syndrome occurs most often in children. Toddlers are the age group in which neuroblastoma most often develops; about four percent of these children will develop OMS.
If the child has a tumor, the tumor is usually surgically removed. Sometimes this improves the OMS symptoms. In adults, tumor removal often does not help and the symptoms may even get worse. Early recognition and treatment is best.
People with the greatest chance of returning to normal after treatment are those who have the mildest symptoms. Those with more severe symptoms may have relief of their muscle twitching but have difficulty with coordination. Other problems that come from brain injury, such as learning and behavior problems, attention-deficit hyperactivity disorder (ADHD), and obsessive-compulsive disorder, may occur, and these may need their own treatments. Children with the most severe OMS symptoms may have permanent brain damage that may cause physical and mental disabilities.
Many questions remain about opsoclonus-myoclonus syndrome. It is not known how long children with OMS need to be treated.