Mild 'pre-dementia' affecting almost 1 million annually in U.S.

CHICAGO — A milder type of mental decline that often precedes Alzheimer's disease is alarmingly more common than has been believed, and in men more than women, doctors reported Monday.

Nearly a million older Americans slide from normal memory into mild impairment each year, researchers estimate, based on a Mayo Clinic study of Minnesota residents.

That's on top of the half million Americans who develop full-blown Alzheimer's or other forms of dementia — a problem sure to grow as baby boomers age. The oldest boomers turn 62 this year.

"We're seeing that in fact there's a much larger burgeoning problem out there" of people at risk of developing dementia, said Dr. Ronald Petersen, the Mayo scientist who led the study.

Dr. Ralph Nixon, a New York University psychiatrist and scientific adviser to the Alzheimer's Association, was blunt.

"We're facing a crisis," he said.

There are no treatments now to prevent this mental slide or reverse it once it starts.

But that may be changing. Researchers on Monday reported early, somewhat encouraging results from an experimental nose spray that seemed to improve certain memory measures in a study of mildly impaired people.

The drug, for now just called AL-108, needs testing in a longer, larger study. It is being developed by Allon Therapeutics Inc., based in Vancouver, B.C.

Doctors said it shows the potential for new types of medicines that target the protein tangles that kill nerve cells, instead of targeting the sticky brain deposits that have gotten most of the attention up to now.

The studies were reported at the International Conference on Alzheimer's Disease in Chicago.

Petersen is the scientist who defined mild cognitive impairment, or MCI, as a transition phase between healthy aging and dementia. It is more than "senior moments" like forgetting where you parked the car, but not as severe as having dementia, where you forget what a car is for.

People with it have impaired memory but not other problems like confusion, inattention or trouble putting thoughts into words.

The Alzheimer's Association says more than 5 million Americans have Alzheimer's, but no estimate for this "pre-dementia" has been available until now.