<qa>  What is the purpose of this study?The purpose of this study is to evaluate the feasibility of giving four weekly doses of Rituximab anti-CD20 antibody in the treatment of children with refractory neuroblastoma associated opsoclonus-myoclonus. Patients must have continued symptoms of opsoclonus, myoclonus and or ataxia despite surgical resection and a minimum of one month of steroid therapy. Evaluations include clinical symptoms of opsoclonus-myoclonus and ataxia as well as detailed evaluation of learning and development. 