A 20 month-old girl with cerebellar ataxia and opsoclonus associated with neuroblastoma is reported from the Pediatric Neurology Unit, Tel Aviv Medical Center, Israel. Ataxia, present since 1 year of age, and irregular, “jerky“ eye movements, noted on admission, became worse over a 2 month observation period. An abdominal mass found at 20 months and removed at operation was a ganglioneuroblastoma. Following surgery, steroids for 3 weeks, and chemotherapy 1 year, blood pressure returned to normal immediately and the ataxia and opsoclonus disappeared within 6-7 weeks. At a 2 year follow-up, the neurological and general examinations were normal. 
COMMENT. Opsomyoclonus or “dancing eye syndrome“, also known as myoclonic encephalopathy of infancy, is frequently of undetermined etiology. It may follow viral infection and it is sometimes associated with occult malignancies, notably neuroblastoma. Normal urinary catecholamines do not exclude the presence of tumor and repeat evaluations including radiographs of abdomen and chest are indicated. The acute stage of the dancing eye syndrome usually responds best to ACTH followed after a few weeks by prednisone. Steroids may need to be continued for several months.