September 12, 2006
Some older men and women who complain of "senior moments" may be losing brain cells along with their memory, according to a new study. Researchers found that seniors who complained of memory loss, despite scoring normally on standard memory tests, showed a measurable decrease in the density of their gray matter, a part of the brain essential for thinking and memory. The memory complaints may be an early sign of mild cognitive impairment, or MCI, an early-stage form of serious memory loss that may lead to full-blown Alzheimer's disease.
"Significant memory loss complaints may indicate a very early 'pre-MCI' stage of dementia for some people," said study author Andrew Saykin, PsyD, Professor of Psychiatry and Radiology at Dartmouth Medical School in Lebanon, New Hampshire. "This finding is important because early detection will be critical as new disease modifying medications are developed in an effort to slow and ultimately prevent Alzheimer's disease." The findings were published in Neurology, the scientific journal of the American Academy of Neurology, a major medical organization for physicians who treat Alzheimer's disease and other nervous system disorders.
The researchers looked at 120 people over the age of 60. They found that people who complained of significant memory problems but still had normal performance on memory tests had reduced gray matter density in their brains, even though they weren't diagnosed with Alzheimer's disease or mild cognitive impairment. When compared to healthy individuals, people who complained of significant memory problems had a three-percent reduction in gray matter density in an area known to be important for memory; there was a four-percent reduction among individuals diagnosed with MCI.
While normal aging, MCI, and Alzheimer's disease have been associated with the loss of gray matter in the brain, this is believed to be the first study to quantitatively examine the severity of cognitive complaints in older adults and directly assess the relationship to gray matter loss. Saykin says the findings highlight the importance of cognitive complaints in older adults, and suggest that those who complain of significant memory problems should be evaluated and closely monitored over time. Memory complaints, a cardinal feature of MCI, which confers high risk for Alzheimer's disease, are reported in 25- to 50-percent of the older adult population.
For more on memory loss, MCI, and the diagnosis of Alzheimer's disease, visit www.ALZinfo.org.
A.J. Saykin, Psyd; H.A. Wishart, Ph.D.; L.A. Rabin, Ph.D., et al: "Older Adults with Cognitive Complaints Show Brain Atrophy Similar to that of Amnestic MCI." Neurology 67: September 12, 2006, pages 834-842. Press release: American Academy of Neurology.