How many times do you find yourself saying, "I must have Alzheimer's disease" after misplacing your car keys, forgetting a phone number or missing an important appointment? Joking about future memory decline may no longer be a laughing matter.
For the first time, UCLA researchers have documented a link between a person's self-awareness of memory failure and subsequent decline in brain function, particularly in a region of the brain critical to learning and recall. The study results were presented at the First Annual Dementia Congress in Chicago, Ill., sponsored by the Alzheimer's Association and the UCLA Center on Aging.
Researchers at the UCLA Neuropsychiatric Institute identified 39 individuals — age 50 years and older — with mild, age-related memory complaints. Under the direction of Dr. Gary Small, the Parlow-Solomon Professor on Aging at UCLA and director of the UCLA Center on Aging, researchers performed standardized assessments of memory performance and ratings of self-perceived memory performance. To determine possible declines in brain activity over time, each volunteer received a positron emission tomography (PET) scan upon entering the study and again two years later.
"We found that several subjective measures, including perceived change in memory ability and frequency of using memory aids — such as lists and reminders — predicted a decline in brain function two years later," said Small.
The average decline in brain activity changes — in one of the key memory centers for people aware of these memory changes — was significantly greater in people who were aware of memory loss compared with those who noted only minimal memory decline. Previous studies by the UCLA group have shown that PET scans indicating decreased brain function can predict future memory decline and can increase the accuracy of the diagnosis of Alzheimer's disease, particularly early in the disease course.
Self-awareness of memory performance predicted brain activity decline in these memory centers regardless of the patient's genetic risk for Alzheimer's disease.
"The findings suggest that self-awareness of memory ability may be an important factor to consider in assessing mild objective memory losses," added Small. Researchers are currently following these subjects to better understand the pre-symptomatic course of Alzheimer's disease and determine whether these patterns of subjective memory loss will eventually progress to Alzheimer's disease.
Alzheimer's disease often begins with mild memory lapses, then gradually advances to dementia — a progressive deterioration of memory, language and most mental functions. Alzheimer's patients eventually become bedridden and require constant care. Recent research now suggests that a much larger number of people suffering from milder forms of cognitive impairment may have an opportunity to protect the brain from further decline since environmental factors and lifestyle choices, rather than genetic risk, are the greatest determinants of lifelong brain health and fitness.