Alzheimer Disease, Amyloid beta-Protein

- Presence of MCI defined as abnormal cognition on objective testing in the absence of dementia or significant functional loss.
- Absence of systemic or other neurological disease that may contribute to cognitive impairment or prevent follow-up over two years.
- Able to give written informed consent.
- Age >/= 60 years of age.

- Mini mental state examination (MMSE) score < 24 at baseline
- Clinical dementia rating (CDR) score > 0.5 at baseline
- Patients who receive regular medication of drugs which may adversely impact cognition (e.g. tricyclic antidepressants, antipsychotics and/or large doses of hypnotics or anxiolytics)
- Existing or history of cancer
- History of severe head trauma, brain surgery or intracranial hematoma with permanent brain lesion
- Lifetime history of major affective disorder, schizophrenia, or schizo-affective disorder
- Contraindications to MRI (Magnetic resonance imaging)
- Relevant history, physical or imaging findings of neurological disease other than MCI and mild depression
- History of severe anaphylactic reaction or high risk of allergic reaction to drugs
- Patient has received another investigational drug in the preceding 14 days