Researchers have found that those who will develop dementia may stop realizing they are having memory problems around two or three years before the disease' actual onset.
In a study published in the journal Neurology, researchers suggest that unawareness of memory problems is characteristic of late-life dementia, which is brought about by dementia-related brain changes building up. According to Robert Wilson, one of the authors of the study, a lack of awareness that memory loss is occurring is actually common in dementia cases but it is not known just how common.
While most studies tackling memory unawareness associated with dementia have focused on subjects who are already diagnosed, this current study started assessing older adults before they showed signs of the disease.
The study involved 2,092 participants part of three ongoing studies designed to follow older adults for over 10 years. At the start of the study, the average age for the participants was 76 years old and all of the participants had not shown any signs of cognitive or memory impairment. Aside from being given annual tests that measured thinking and memory abilities, the participants were also question about how often they would have trouble remembering things and what rating would they give their memory compared to 10 years earlier.
There were 239 participants diagnosed with dementia during the course of the study. For these participants, memory awareness started dropping sharply 2.6 years on average before the disease developed. Afterwards, several years of decline in memory was reported.
Wilson also said that while differences were present individually in when and how fast the unawareness progressed, all affected still exhibited lack of awareness that their memory is waning at some point in their disease.
Surprisingly, however, memory unawareness began earlier for younger participants than those older. The researchers suggest that that reporting may have been skewed in older participants since they expect memory loss as a usual part of aging.
The researchers examined the brains as well of 385 participants who died during the study, assessing for seven types of dementia-related brain changes. They discovered that changes in a protein called TDP-43, brain damage areas, and the presence of tangles or tau proteins were associated with a fast decline in awareness involving memory quality.
The study received support from the Illinois Department of Public Health and the National Institute on Aging. Other authors include: Julie Schneider, David Bennett, Aron Buchman, Joel Sytsma, Lisa Barnes, Lei Yu and Patricia Boyle.
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