Stem Cell Transplantation for Stiff Person Syndrome (SPS)

Non-myeloablative regimens (as the investigators use herein) are designed to maximally suppress the immune system without destruction of the bone marrow stem cell compartment. When using a non-myeloablative regimen recovery occurs without infusion of stem cells and the stem cells are autologous. While not necessary for recovery, stem cell infusion may shorten the interval of neutropenia and attendant complications. Thus in reality there is no transplant only an autologous supportive blood product. Based on our encouraging results of non-myeloablative hematopoietic stem cell transplantation, for patients with multiple sclerosis and chronic inflammatory demyelinating polyneuropathy, the investigators will investigate the role of non-myeloablative hematopoietic stem cell transplantation for patients with SPS who require assistance to ambulate.

Pre-study Testing 1. History and physical 2. Electrocardiogram (EKG) 3. Dobutamine stress echocardiogram 4. High-resolution computed tomography of the chest (HRCT) 5. Blood draw for laboratory tests- these tests will include a complete blood count, evaluating liver and kidney function, assessing immune system, tissue typing, and checking for certain germs that can cause infections, including a pregnancy test for females and prostate-specific antigen (PSA) for male as well as testing for HIV 6. Pulmonary Function Test (PFT) 7. Electromyography (EMG) 8. Magnetic Resonance Imaging (MRI) of the Abdomen and Pelvis 9. Magnetic Resonance Imaging (MRI) of the Spinal Cord 10. Magnetic Resonance Imaging (MRI) of the Brain with Gadolinium (only if PERM of cerebellar ataxia) 11. Colonoscopy 12. Mammogram (if female) 13. Timed ambulation 14. Quality of Life Questionnaires \[ Short Form (36) Health Survey (SF36) and Barthel Index\] 15. Chronic Pain Acceptance Questionnaire (CPAQ) 16. Rankin Functional Scale 17. Modified Ashworth Scale 18. Purkinje Cell Cytoplasmic Antibody, Type 1 (PCA-1), Purkinje Cell Cytoplasmic Antibody, Type 2 (PCA-2) antibody (only if cerebellar ataxia) 19. Spinocerebellar ataxia (SCA) 1, 2, 3, 4, 5, 6, 7, 8 genes (only if ataxia) Study Treatment Stem Cell Collection: Cyclophosphamide 2.0 gm/m2 will be given on day 0, G-CSF 5-10 mcg/kg/day subcutaneous (SQ) will start on day +5 and will continue until apheresis is discontinued. Apheresis will begin when the absolute neutrophil count (ANC) \> 1.0 x 109/L and continue until \>2.0 x 106 cluster of differentiation 34 (CD34)+ cells/kg patient weight are cryopreserved. A 10-15 liter apheresis will be performed unless stopped earlier for clinical judgment of toxicity (e.g., numbness, tetany). A maximum of four apheresis will be performed.