Purpose of the study: Patients with mild Alzheimer's Disease will be given three different
drugs over a 4-month period to try to increase the blood flow to their brains, and improve
blood vessel and brain function. Each drug can help to open the blood vessels in the brain,
and together they may be more effective than each drug alone. The hypothesis is that small
blood vessels secrete substances that maintain the integrity of the brain, and may prevent
loss of nerve cells leading to Alzheimer's Disease