The status of Willie Alexander, a 74-year-old Clinton man suffering from Alzheimer's disease, was incorrectly described by police in Tuesday's editions. Alexander returned home within two days of his disappearance from Landover Mall in July. (Published 1/28/88)

An 80-year-old Fairfax County man who had Alzheimer's disease and had been missing since Thursday was found dead Sunday evening less than a mile from where he had apparently walked away from the family automobile, police said yesterday.

Passers-by discovered the body of George H. Stiff in the Huntley Meadows Park and Wildlife Preserve in southern Fairfax County. Stiff's daughter, Clara Wilson, said her father was "just sitting there against a log, just sitting there, like he was waiting . . . . "

Stiff apparently had been wandering outside in chilly weather. His wife Clara had left him in the car outside a friend's home while she was inside to discuss getting a companion to help care for her husband, Wilson said.

Northern Virginia Medical Examiner James C. Beyer said that Stiff died of exposure and hypothermia.

"He was totally unharmed, untouched," Wilson said. Stiff had had several strokes in addition to Alzheimer's, Wilson said.

Stiff is the third person apparently having Alzheimer's known to have wandered away in the Washington area in recent months.

One of the other two, a Prince George's County man, has not been found.

Alzheimer's, which afflicts 2.5 million to 3 million Americans, is a degenerative brain disorder that affects memory, speech and reasoning.

There is no cure or effective treatment.

In recent years, the number of people afflicted with the disease has climbed dramatically because people are living longer, according to Dr.Andrew Monjan, acting director of neuroscience and neuropsychology at the National Institute on Aging.

Police officers in the District, Maryland and Virginia said they have received dozens of calls about missing elderly people who are disoriented and confused. Police said most of these people are discovered in a short time. In recent months, however A 71-year-old Bethesda womanwith Alzheimer's symptoms was found in a Lord & Taylor store in the District, where she apparently had spent Christmas week. Police had been searching for Brigitte Pierre for seven days when they found her in a stairwell at the store. When discovered, Pierre told them she had little if any memory of her whereabouts for the week. A 74-year-old Clinton man with Alzheimer'swandered away from Landover Mall in July, according to Prince George's County police. The man, Willie Alexander, is still missing.

As a person ages, the likelihood of contracting Alzheimer's disease increases. About 7 percent of people age 65 and older get the disease, and about 20 to 25 percent of those 85 and older have it, Monjan said.

The number of Americans 65 and older grew twice as fast as the rest of the population in the past two decades, and those 85 and older are expected to increase sevenfold by the middle of the next century, according to a report by the Senate Special Committee on Aging.

In 1985, there were 28.5 million Americans 65 and older, according to the U.S. Census Bureau, and there were 2.7 million Americans 85 years and older.

"For a number of years it was considered a rare disorder of the elderly," said Monjan.

"But in the last 10 to 15 years, we found that many things we considered part of the normal aging process . . . getting forgetful and losing your memory, were due to a pathological disease."

Fairfax police said that on Thursday and Friday, 35 officers searched within a three-mile radius of the Spring Drive home where Stiff was last seen.

Officer Judy Dailey, a department spokesman, said officers searched sections of Huntley Meadows, a 1,262-acre wetland, and used a helicopter and dog in the effort.

Wilson, who said her father was only three-quarters of a mile from the Spring Drive home, said she was "very, very puzzled" about why the search did not find him.

A World War II veteran and a retired education specialist at the former Department of Health, Education and Welfare, Stiff had lived in Fairfax for 36 years. He began showing the effects of Alzheimer's about four years ago, Wilson said.