Opsoclonus myoclonus and ataxia syndrome with supraventricular tachycardia.

Pediatric opsoclonus-myoclonus and ataxia syndrome (OMAS) is a neurologic disorder characterized by disturbances in eye movement, muscle jerks, ataxia, sleep, and mood. In approximately 50% of cases, it is a paraneoplastic syndrome associated with a neuroblastoma. In the remaining cases, it is believed that the tumor is occult, has involuted, or there is a preceding immune-stimulating event. While neuroblastomas can be associated with other paraneoplastic syndromes, supraventricular tachycardia (SVT) is rarely reported in the literature, and to our knowledge, this is the first case of SVT secondary to idiopathic OMAS. Confounding treatment toxicity, including intravenous immunoglobulin and other immunomodulatory drugs, should be screened for possible cardiovascular side effects in OMAS patients. The development of cardiac arrhythmias during OMAS treatment is not a contraindication to therapy. In these patients, arrhythmias should be controlled with vagal maneuvers or antiarrhythmics as needed while OMAS treatment is completed.