Paraneoplastic opsoclonus associated with squamous cell carcinoma of the tongue.

Opsoclonus is a pathological eye movement phenomenon in hich the eyes experience involuntary, arrhythmic, rapid, multidiectional, conjugate movements. It occurs in all eye positions and uring smooth pursuit, and can also persist during sleep. It is diferentiated from nystagmus in that there is no slow eye movement hase, and it differs from ocular flutter because the eye movement s multidirectional and not confined to the horizontal. Opsoclonus an be accompanied by tremors, cerebellar ataxia, myoclonic jerks, r encephalopathy. In addition to paraneoplastic etiologies, it is ometimes autoimmune, but frequently without an identifiable ntibody [1].