The Safety and The Efficacy Evaluation of NEUROSTEM®-AD in Patients With Alzheimer's Disease

Inclusion Criteria: * Korean men and women who are age 50 or older * Dementia as determined by DSM-IV criteria * Probable alzheimer's disease as determined by NINCDS-ADRDA criteria * K-MMSE score in the range of 10 to 24 * Positive result of PIB-PET imaging (SUV \> 1.5,when comparing the result for the cerebellum with the result for the frontal lobe) * Voluntarily participating subject who sign the consent form Exclusion Criteria: * Subject with psychological diseases (i.e. depression, schizophrenia, bipolar disorder, etc) * Subject with dementia caused by other than Alzheimer's disease (i.e. infection of central nervous system, Creutzfeld-Jacob disease, severe head trauma, Pick's disease, Huntington's disease, and Parkinson's disease) * Subject with vascular dementia as determined by the clinical criteria of DSM IV and the imaging criteria of Erkinjuntii * Subject with severe white matter hyperintensities (WMH); Severe WMH is defined that length of the deep white matter is 25 mm or longer and length of the periventricular capping/banding is 10 mm or longer. * Subject who have had stroke in 3 months. * Subject with liver disease (two times higher than normal range of ALT/AST) * Subject with severe kidney failure (1.5mg/dL of serum creatinine or more) * Pregnant women or lactating women * Hemoglobin \< 9.5g/dL for men, \< 9.0 g/dL for women; Total WBC count \< 3000/mm3; Total bilirubin ≥ 3 mg/dL * Subject who is suspect to have active lung diseases, based on check X-ray result from Visit 1 * Women of childbearing age who reject to practice contraception * Subject who have been excluded in the subject selection process for this study before * A platelet count \< 150,000/mm3; PT ≥ 1.5; INR or aPTT ≥ 1.5 X control * Subject with cancer * History of alcohol or drug abuse * Subject who cannot undergo MRI, CT, or PET screening * Subject who cannot undergo anesthesia or stereotactic brain injection * Subject who is determined inappropriate by the investigators