Study to Determine The Effect of a Drug Called Neupogen on Stroke Recovery

Inclusion Criteria: * Patient is between 45 and 85 years of age * Patient is of either gender * The qualifying stroke is ischemic with a total NIH Stroke Score less than 18. * The stroke involves the non-dominant hemisphere including the cerebral cortex and results in hemiparesis. The inclusion of sub-cortical strokes will be permitted if the size is of 3 cm or greater. Patients suffering strokes involving the dominant hemisphere resulting in mild dysphasia are also eligible. * The stroke is classified as a partial anterior cerebral syndrome by the Oxfordshire Criteria. * NIHSS at baseline evaluation with: \*Level of consciousness is not impaired as defined by an NIHSS between 0 and 1 on question 1a and * Hemiparesis as defined by * an NIHSS between 1 and 4 on questions 5 and/or * an NIHSS between 1 and 4 on questions 6. * Be able to start the experimental treatment a minimum of 3 days and a maximum of 10 days after the initial presentation with the stroke, * Patient or surrogate gives informed consent, * The patient is fluent in either French or English. Exclusion Criteria: * Patient with hemorrhagic stroke, * Patients with a pre-morbid modified Rankin score \> 2 (Appendix 3b), * Patients with pre-morbid dementia by DSM-IV criteria. * Patients with a known allergic reaction to G-CSF or a component of G-CSF. * Patients with one or more significant co-morbidities expected to limit lifespan to less than 12 months. Examples include but are not limited to: * \> CHF Class II NYHA * Known prior or ongoing malignancy except non-melanomatous skin cancer. * Acute or chronic infections (HIV, TB, etc.. ) * Other significant cardiac, renal, hepatic or pulmonary dysfunction. * Patients with organ dysfunction that would preclude tests required for this study. Examples include but are not limited to: \*Serum Cr \> 200 μmol/L that would prevent administration of contrast dye. * Patients with a known history of bone marrow dysfunction, such as myeloid leukemia or myeloproliferative state that would prevent treatment with G-CSF. * Patients with metal implants that would preclude MRI examination including but not limited to patients with * pacemakers, * ear implants, and * aneurysm brain clips. * Patients with: * a history compatible with a thrombophilic state or * with a pre-existing known thrombophilic state. * Patient unwilling or unable to comply with trial requirements. * Patients with an ongoing history of illicit drug use. * Female patients of child-bearing potential. * Patients exposed to other investigational drugs in the last 3 months. * Patients with known or suspected sickle cell disease, * Patients with splenic enlargement or an illness that results in splenic enlargement (For example, but not limited to myeloproliferative syndromes, hairy cell leukaemia, malaria, hepatic cirrhosis…), * Patients with an ongoing history of alcohol abuse, * Patients with a known or suspected history of allergy to intravenous contrast agents used for CT scans, * Patients that have received a chemotherapy agent within the previous 5 years (For example, but not limited to cyclophosphamide, anthracycline, methotrexate, fluorouracil…) * Patients that have received a therapy within the previous 5 years that interferes with hematopoiesis or circulating blood cells (For example, but not limited to Lithium, Campath….) * Patients that have received a cytokine within the last 6 months or are currently receiving a cytokine treatment (For example, but not limited to Erythropoietin, Granulocyte Macrophage Colony Stimulating Factor, Keratinocyte Growth Factor, Kit Ligand…)