[Paraneoplastic opsoclonus-myoclonus syndrome associated with small-cell lung cancer].

Opsoclonus-myoclonus syndrome was observed in a patient treated for small-cell lung cancer. Opsoclonus presented as anarchic involuntary eye movements associated with myoclonies of the limbs and trunk. Opsoclonus-myoclonus is exceptional and a specific expression among several paraneoplastic manifestations described in small-cell lung cancer. These manifestations develop late after diagnosis of cancer. Presence of anti-neuronal antibodies in the serum (inconstant) is a factor of very poor prognosis.