The Dancing Eye Syndrome (DES) is so called because of the very abnormal eye movements which are almost invariably present in this rare condition.
Unlike the oscillating movements of nystagmus, eye movements are chaotic and best described as dancing. They are jerky and correspond with jerky movements which develop in the limbs particularly the arms. These movements give the Dancing Eye Syndrome its other name of opsoclonus-myoclonus, referring respectively to the jerky eye and limb movements. DES was first described in the 1950s by Kinsbourne and Sandifer, Neurologists at Great Ormond Street Children’s Hospital, London. The condition mostly affects children though occasionally infants and adults are also affected.
In the United Kingdom it is probable that there are between 5 and 10 newly affected children recognised each year.
Typically, a previously well child will become irritable and unsteady and have jerky in coordination of the arms and legs. The condition worsens over a couple of weeks or so, the child becoming more miserable and ultimately unable to walk. The illness can be distinguished from the acute unsteadiness and nystagmus that complicates some viral illnesses such as chicken pox. In DES the children are extremely unhappy.
What’s the cause of the condition?
The cause of the condition is not known with certainty but it’s thought to be an auto-immune condition in which antibodies which are normally directed to repelling infections and foreign material introduced into the body, start acting against the body itself. Other auto-immune diseases include, for example, rheumatoid arthritis, and some cases of inflammation of nerves and muscles, the character of the illness depending upon what tissues are attacked.
In the case of DES it is believed that antibodies are directed against areas of the brain concerned with coordination and with personality and learning. In approximately 10 per cent of cases the condition develops as a complication of neuroblastoma, a tumour of childhood which is, in the majority of cases, self-curing. It has been suggested that it is the immune-based process of rejection of the tumour which acts indiscriminately on parts of the brain which are structurally similar to the tumour which is being destroyed. Despite exhaustive studies, there is no evidence that neuroblastoma is present in the majority of children with DES but it is thought that an immune-based process is present in all. Occasionally, viral infections seem to trigger the illness.