Opsoclonus–myoclonus–ataxia syndrome in children

Opsoclonus–myoclonus–ataxia syndrome is a rare neuroimmunologic disorder typically presenting in previously healthy infants and toddlers. It is characterized by a clinical triad of (1) erratic saccadic intrusions; (2) myoclonus and/or ataxia; (3) behavioral features, typified by developmental plateauing, irritability and insomnia. About half of cases are associated with an underlying neuroblastoma and diagnostic imaging is essential once OMAS is suspected. A thorough workup, including serum, urine, and cerebrospinal fluid studies is critical to identify underlying biomarkers of OMAS itself or neuroblastoma. Historically, many children had relatively poor long-term outcomes, with residual neurologic and/or neuropsychiatry sequelae typical. More recent concepts have emphasized combined immunotherapy regimens that offer hope for better outcomes in children with this remarkable, challenging disease.