People who will go on to develop dementia may lose awareness of their memory lapses two to three years before dementia sets in, new research suggests.
The study, published Aug. 26 in the online edition of Neurology, also found that several dementia-related changes in the brain are associated with the decline in memory awareness.
“Our findings suggest that unawareness of one’s memory problems is an inevitable feature of late-life dementia, driven by a buildup of dementia-related changes in the brain,” study author Robert S. Wilson said in a news release from the American Academy of Neurology. Wilson is a neuroscientist at Rush University Medical Center in Chicago. “Lack of awareness of memory loss is common in dementia, but we haven’t known much about how common it is, when it develops, or why some people seem more affected than others. Most studies of memory unawareness in dementia have focused on people who have already been diagnosed. In contrast, this new study began following older adults before they showed signs of dementia.”
Wilson and his colleagues analyzed data from 2,092 older adults participating in three ongoing studies that have each followed older adults for 10 years or more. When the study began, participants were an average age of 76 and showed no signs of memory or cognitive impairment. They were given yearly tests of memory and thinking abilities. Participants were also asked how often they had trouble remembering things, and how they would rate their memory compared to 10 years earlier.
During the study, 239 participants were diagnosed with dementia. For those individuals, memory awareness was stable until it declined sharply an average of 2.6 years before dementia set in. This followed several years of memory decline.
“Although there were individual differences in when the unawareness started and how fast it progressed, virtually everyone had a lack of awareness of their memory problems at some point in the disease,” Wilson said.
Researchers were surprised to see that memory unawareness began earlier in younger participants than in older participants. Researchers suggest it may happen because older people were more likely to expect memory loss as a normal part of aging.
Wilson and his colleagues also examined the brains of 385 participants who died during the study to look for seven types of brain changes commonly seen in dementia. They identified three changes that were associated with the rapid decline in memory awareness: The presence of tau proteins or tangles; areas of brain damage caused by the loss of blood flow; and changes in a protein associated with the formation of abnormal protein clumps and tangles in the brain. As those brain changes build up, affected people lose awareness that their memory is failing.
“This study underscores the importance of family members looking for help from doctors and doctors getting information from friends or family when making decisions about whether a person has dementia, since people may be unable to give reliable reports about the history of their own memory and thinking abilities,” Wilson said.
If you’re worried about someone you love, contact St. Elizabeth Physicians in Crestview Hills or call (859) 957-0052 for more information.
