Opsoclonus myoclonus syndrome (OMS) is a disorder that affects the nerves and muscles. OMS is very rare and occurs due to autoimmune reaction. Opsoclonus refers to dancing eyes which in medical terms is known as Nystagmus. Myoclonus is involuntary contraction and twitching of muscles. The other names for this condition are Kinsbourne syndrome or ‘dancing eye-dancing feet’ syndrome.
As you know OMS is a rare form of neurological disorder and affects 1 out of 10 million people. Most often children below two years of age suffer from this rare disorder, but it can also affect adults.
The ratio of its affection is equal in both the genders. Opsoclonus myoclonus syndrome is known to occur after a viral infection or a tumor, generally a neuroblastoma.
Causes Of Opsoclonus Myoclonus
Almost fifty percent of cases of OMS are because of neuroblastoma. The rest half cases are caused as a result of infections, mostly viral.
Coxsackie virus, E-B virus, can be responsible for the symptoms of OMS. Any child who is suffering from OMS should be searched for tumor in his body even if the cause is viral infection. Since both of them can precipitate the condition.
The rest fifty percent of Opsoclonus myoclonus syndrome is caused by neuroblastoma and ganglio-neuroblastoma. The tumors are present in abdomen and pelvis quiet away from brain.
The question now arises how neuroblastoma can damage the brain cells to cause myoclonus when the tumor is present in faraway place such as abdomen and pelvis. The question still remains unanswered; however some researchers have put forth autoimmune theory. As per this theory, the brain is only the victim.
Symptoms Of Opsoclonus Myoclonus Syndrome
As the name itself suggests,
- Opsoclonus: There is rapid and involuntary movement of the eye in vertical as well as horizontal direction.
- Myoclonus: Contraction and twitching of group of muscles or single muscle.
The disorder usually strikes a normal child. Suddenly, the patient often a child starts to shake and jerk. After a couple of weeks the child may not be able to stand or walk on his own.
- At the peak of the disorder, the child is extremely irritable. He always wants to be carried.
- Screaming at night without any reason, difficulty in sleeping are few other symptoms of OMS.
- If the disorder remains untreated further deterioration of the child’s condition can occur. This includes behavioral problems such as attention deficit, anger and rage, temper tantrums and in the worst case mental retardation.
- Vomiting and drooling are other symptoms of opsoclonus myoclonus syndrome.
Treatment For Opsoclonus Myoclonus
Researchers are still not able to find a definite cure for this disorder because of its rare origin, however there are several drugs that are known to give relief in the symptoms.
- In cases of tumor, removal of tumor possibly increases the chances of survival, especially in children. In adults tumor removal does not benefit.
- ACTH (adenocorticotrophic hormone) is considered to be effective in treating disorders like opsoclonus myoclonus syndrome.
- Use of corticosteroids may reduce the severity of symptoms. In the beginning they have to be given intravenously, and after certain period the dose is gradually reduced and the patient is put on pills.
- Intravenous immunoglobulin is useful for children who show neurological deterioration.
- Chemotherapy may be needed for eliminating the neuroblastoma.
- Children with mildest symptoms have greater chance of recovery from this disorder.