The purpose of our study is to investigate CSF and blood biomarkers among the subjects with mild cognitive impairment (MCI) and Alzheimer's disease (AD) as well as normal controls.

Alzheimer's disease is the most prevalent cause of dementia. A biomarker is a variable that are measured in vivo and indicate specific features of disease related molecular mechanisms and pathologic changes, including amyloid processing and aggregation, tau hyperphosphorylation, accumulation of neurofibrillary tangles, synaptic dysfunction, neurodegeneration, and loss of brain tissue.

We examine serum oligomeric beta-amyloid 42 and CSF monomeric beta-amyloid 42, total tau and phosphorylated tau, as well as PiB-PET, FDG-PET and brain MRI in 90 participants (30 normal controls, 30 patients with mild cognitive impairment, 30 patients with Alzheimer's disease).

Inclusion Criteria:

1. Signed and dated written informed consent obtained from the subject or the subject's legally acceptable representative ( if applicable) in accordance with the local regularities.
2. Both male and female, aged > 50 and <90, if women, must have no childbearing potential
3. Controls did not have subjective memory complaints or any of 28 diseases and did not have a history suggestive of a decrease in cognitive function (stroke or transient ischemic attack, seizures, Parkinson's disease, multiple sclerosis, cerebral palsy, Huntington's disease, encephalitis, meningitis, brain surgery, vascular surgery of the brain, diabetes requiring insulin control, improperly managed hypertension, cancer diagnosed within the past 3 years excluding skin cancer, shortness of breath while sitting still, use of home oxygen, heart attack with changes in memory, walking, or solving problems lasting at least 24 hours afterwards, kidney dialysis, liver disease, hospitalization for mental or emotional problems in the past 5 years, current use of medications for mental or emotional problems, alcohol consumption greater than 3 drinks each day, drug abuse in the past 5 years, treatment for alcohol abuse in the past 5 years, unconsciousness for more than one hour other than during surgery, overnight hospitalization due to head injury, illness causing a permanent decrease in memory or other mental functions, trouble with vision that prevents reading ordinary print even with glasses, or difficulty understanding conversations because of hearing even with a hearing aid)
4. The controls also had scores that were at least one standard deviation above the mean scores of the respective age- and education-matched population on the K-MMSE and an average score of 0.42 or less on the Korean Instrumental Activities of Daily Living (K-IADL)

Exclusion Criteria:

-