Carmustine, Etoposide, Cytarabine, Melphalan, and Antithymocyte Globulin Followed by Peripheral Blood Stem Cell Transplant in Treating Patients With Autoimmune Neurologic Disease That Did Not Respond to Previous Therapy

This phase II trial studies the side effects and how well carmustine, etoposide, cytarabine and melphalan together with antithymocyte globulin before a peripheral blood stem cell transplant works in treating patients with autoimmune neurologic disease that did not respond to previous therapy. In autoimmune neurological diseases, the patient's own immune system 'attacks' the nervous system which might include the brain/spinal cord and/or the peripheral nerves. Giving high-dose chemotherapy, including carmustine, etoposide, cytarabine, melphalan, and antithymocyte globulin, before a peripheral blood stem cell transplant weakens the immune system and may help stop the immune system from 'attacking' a patient's nervous system. When the patient's own (autologous) stem cells are infused into the patient they help the bone marrow make red blood cells, white blood cells, and platelets so the blood counts can improve.