Opsoclonus-myoclonus syndrome associated with a nasopharyngeal tumor in an adult: a case report.

Introduction: Opsoclonus-myoclonus syndrome is a rare autoimmune syndrome usually seen in children and very rarely in adults. It typically presents with a triad of opsoclonus, myoclonus and ataxia, and is most often associated with a tumor or after an infection or vaccination. Around half of all adult cases are paraneoplastic in origin, and isolated case reports include associations with lung, breast and ovarian cancers.