refers to uncontrolled eye movements
Opsoclonus consists of rapid, involuntary, multivectorial (horizontal and vertical), unpredictable, conjugate fast eye movements without intersaccadic
intervals. It is also referred to as "saccadomania". The movements of opsoclonus may have a very small amplitude
, appearing as tiny deviations from primary position.
Possible etiologies of opsoclonus include neuroblastoma and encephalitis in children, and breast, lung, or ovarian cancer in adults. Other considerations include multiple sclerosis, toxins, or medication effects.
It is frequently presented with myoclonus in opsoclonus myoclonus syndrome.