Affecting one-eighth of people over the age of 65 and one-half of people over the age of 85, Alzheimer's Disease (AD) is the most common form of dementia and the seventh leading cause of death in the United States.

Dr. Yogesh Trehan, a geriatric and internal medicine specialist, describes AD as a progressive and fatal disease, but believes in a brighter future for Alzheimer's patients.

According to Trehan, although commonly mistaken as an exclusively memory-loss disease, AD is actually multi-symptomatic and characterized by language problems, difficulty recognizing objects, trouble with motor tasks (such as running, driving and writing) and struggles with decision making.

When memory loss is present in any of these symptoms, doctors order a set of tests known as the ABCs: Activities (of daily living), Behavior and Cognition. When impairment is found, patients may undergo an evaluation of medical history, a physical exam to assess for diseases related to dementia, and lab and imaging tests.

One such tool is a series of cognition (understanding) tests in which the patient engages in simple activities or games. In the clock-drawing test, the patient is asked to draw a complete circle, place the numbers in the correct positions on the clock, and draw the hands to indicate the time as instructed by the doctor. The results can indicate such factors such as distortion of reality or a change in cognition.

Today, the most commonly used medications offset the depletion of chemicals important for memory and learning, which effectively slows the disease's progress, but research is moving in the direction of prevention.

We understand Alzheimer's because we understand how the depletion of chemicals leads to nerve cell death, says Trehan. According to the Alzheimer's Association, amyloid plaques are the prime suspects for signal blockage in the brain. The presence of plaques and protein tangles interrupts cell communication and leads to cell death. It is hoped that by preventing the buildup of these plaques and tangles, or by dissolving them after they have formed, we can prevent or even cure AD.

Because the greatest risk factor for developing Alzheimer's is age, Trehan says the best line of defense in Alzheimer's prevention is to eat a healthy, balanced diet, exercise regularly and keep the mind active by maintaining hobbies and activities.

- Andrea Stuart, Sutter Delta Medical Center