Opsoclonus is associated with -

Ans. is 'a' i.e., Neuroblastoma o Opsolonus is seen primarily in Neuroblastoma.o Neuroblastoma is embryonal cancer of peripheral sympathetic nervous system,o Thirst most common childhood cancer (lst - leukemia, 2nd - Brain tumor),o MC diagnosed neoplasm in infancy.o Arises in abdomen either in adrenal gland or retroperitoneal sympathetic ganglion,o Superior cervical ganglion involvement produce Horner syndrome,o Can present as Paraneoplastic as ataxia or opsomvoclonus.o Optoclonus also seen sometimes in encephalitis.