“Opsoclonus” is an unusual disorder of eye movement in which both eyes dart involuntarily (dancing eyes). “Myoclonus” simply means brief muscle jerks and “ataxia” indicates incoordination.
Myoclonus occurs most when movement is attempted, worsens with agitation or stimulation, but may be present at rest. The patient may appear tremulous (polyminimyoclonus) or have gross jerking. Face, eyelids, limbs, fingers, head and trunk are involved. During the peak of the illness, sitting or standing is difficult or impossible. Patients also have trouble speaking, eating, or sleeping, and exhibit drooling, rage attacks, head tilt, or other abnormalities.
Around half of cases is caused by the cancer Neuroblastoma. Children with OMS tend to have a higher survival rate of the cancer than children without although complete remission from the neurological effects of OMS is difficult to achieve.