Phase 2 Study to Examine Grape Seed Extract as an Anti-Oligomerization Agent in Alzheimer's Disease (AD)

Inclusion Criteria: * NINCDS/ADRDA criteria for probable AD * MMSE between 12-26 * Treatment with a cholinesterase inhibitor or an NMDA (N-methyl-D-asparate) antagonist with stable dose for at least 12 weeks * Home monitoring available for supervision of medications * Caregiver available to accompany patient to all visits and willing to participate in study as informant * Fluent in English or Spanish * Medical stability for this study as confirmed by review of records, internist's physical exam, neurological exam, and laboratory tests * Stable doses of non-excluded medication * No evidence of hepatic insufficiency * Able to swallow oral medications * Ability to participate in the informed consent process Exclusion Criteria: * History of hypotension or unstable hypertension * Active hepatic or renal disease * Use of another investigational drug within the past two months * History of clinically significant stroke * History of seizure or head trauma with disturbance of consciousness within the past two years * Major mental illness including psychotic disorders, bipolar disorder, or major depressive episode that is not in remission for less than 12 months * Women of child-bearing age unless using effective birth control or at least one year post-menopausal or surgically menopausal * Any ferrous or metallic materials which are contraindicated for MRI Medication Exclusions * Current use of drugs with significant anticholinergic or antihistaminic properties