A Look At Alzheimer's

(CBS/AP)  It was November 1994, when former President Ronald Reagan addressed a simple, handwritten letter to the nation, which began:

"My fellow Americans, I have recently been told that I am one of the millions of Americans who will be afflicted with Alzheimer's disease."

From that time until his death on June 5, 2004, President Reagan made few public appearances.

About 4 million Americans have Alzheimer's, and the numbers will increase as better medical care helps people escape other major killers, such as heart disease. The Alzheimer's Association estimates the total will be 14 million by the middle of this century unless a cure or prevention is found.

Dr. Sam Gandy of the Alzheimer's Association explains, "Alzheimer's is caused, at least in some cases, by mistakes in the DNA, in genes. And in those cases, the disease begins by buildup of a gooey material called amyloid, which builds up in the brain and is poisonous, especially to the nerve cells responsible for thinking."

Although aging is the biggest known risk factor, Dr. Gandy says, "We know in some cases that high cholesterol, diabetes, obesity even, mental inactivity can increase the risk for Alzheimer's."

The disease begins in parts of the brain that regulate memory and thinking skills, but eventually it spreads to other areas. This attack on the brain can be fatal, although victims often die first of other things.

Alzheimer's can be broken down into three stages, beginning with stage 1, known as mild. "The symptoms of mild Alzheimer's disease include the loss of ability to form and retrieve new memories, confusion and often changes in personality, disorientation as well," Dr. Gandy explains.

The second stage is known as the moderate stage. "As the disease progresses, the outer shell of the brain that's responsible for thinking dies and degenerates. As that occurs, patients become often more difficult to handle by their care-givers," Dr. Gand says. "Caring for someone with Alzheimer's disease is a 24-hour-a-day, seven-day-a-week job. It's very exhausting. By the second stage, often behavioral problems can be so disruptive that the family will become exhausted and admit the patient to an assisted living or a nursing home situation."

Stage 3 is described as severe. "It's severe Alzheimer's that is hidden from the world," Dr. Gandy says. "As the disease progresses, the person affected becomes progressively more and more bed-bound, spending more time in the bed and less time interacting with the environment. And at the end of the disease, the patient is totally inactive, bed-bound, and has no awareness of his or her environment."

Alzheimer's is an especially democratic illness that has taken prominent people from all walks of life, including former British Prime Minister Harold Wilson, singer Perry Como, actress Rita Hayworth and former Secretary of State Cyrus Vance, as well.

In recent years, Nancy Reagan has been among those leading the effort to fund research into embryonic stem cells as a possible treatment for Alzheimer's and other diseases. Asked if we see a cure in this lifetime, Dr. Gandy says, "I think the progress we've made is very promising, especially for finding ways to delay or prevent the disease."