What is opsoclonus/myoclonus?

Rare: Opsoclonus myoclonus is a rare neurological disorder characterized by unsteady gait, intention tremor myoclonus (brief, shock-like muscle spasms), and opsoclonus (irregular, rapid, horizontal and vertical eye movements). Other symptoms may include dysphasia (difficulty speaking), dysarthria (poorly articulated speech), lethargy, irritability, malaise. It occurs in viral illnesses and tumors.

Random eye movements: The patient experiences constant irregular rapid eye motions in random directions, often in a sudden jerking fashion (myoclonus). This was first described in children with neuroblastomas, but has been rarely associated with problems affecting cerebellar-brainstem connections in other diseases, such as even in multiple sclerosis.