A study of mental decline in the years earlier to diagnosis of Alzheimer’s disease suggests that altering the focus of testing could possibly permit physicians to detect signs of the disease three years in advance.
Present cognitive testing characteristically seems to focus on periodic memory, or the ability to remember things like word lists or facts from a reading. However, scientists at Washington University School of Medicine in St. Louis discovered that a different group of mental abilities known as visuospatial skills seems to begin to worsen up to three years prior to diagnosis. Apparently, these skills are tested with tasks such as connecting the dots or utilizing a guide in order to build a structure with blocks.
For the purpose of the study, Galvin along with his coauthors was believed to have examined long-term data from volunteers at the Memory and Aging Project at Washington University’s Alzheimer’s Disease Research Center (ADRC).
For about three decades, study experts have daily been carrying out wide testing of volunteers in order to discover the factors associated with the normal, healthy retention of mental function in seniors. The latest study was noted to analyze data on 444 volunteers aged 60 to 101 that were assembled between 1979 and 2006.
Scientists appear to have classified cognitive testing results into a global measure of cognitive abilities in addition to three specific types of mental skills. Supposedly, these specific types included episodic memory, visuospatial skills and working memory.
“We may need to rethink what we look for as the earliest signs of mental change associated with Alzheimer’s disease. If we can better recognize the first signs of disease, we can start treating patients earlier and hopefully with new treatments we can slow or perhaps even stop their progress into dementia,” says senior author James Galvin, M.D., a Washington University neurologist who is also on staff at Barnes-Jewish Hospital.
Additionally, these types seem to have assessed the ability to manipulate facts from memory, such as repeating a list of numbers backwards. The study authors found that declines in episodic memory and working memory appear to have become apparent one year before volunteers were diagnosed with Alzheimer’s disease.
Also, losses in the composite assessment of cognitive abilities seemed to be detectable two years prior to diagnosis. Moreover, visuospatial skills were observed to have begun to decay three years earlier. Galvin claimed that the losses in visuospatial skills were chiefly noticeable if testing tasks were timed.
The study experts also analyzed the data with the help of a novel model that not only tracks the speed of decline in a mental ability but also the acceleration of the decline. They discovered that episodic memory’s decline seemed to have accelerated more slowly as compared to both visuospatial skills and working memory which declined fastest.
The new perspective may possibly allow doctors to identify signs of Alzheimer’s earlier, but more information will be required in order to make a firm diagnosis. In order to make that possible, study experts at the ADRC appear to be trying to take what they’ve learned in the latest study and associate it with biomarkers.
Biomarkers are known to be physical changes associated with preclinical Alzheimer’s disease. These include tests such as scanning the brain for amyloid plaques or analyzing the levels of proteins in the cerebrospinal fluid.
Galvin further stated that, “The new findings raise the question of what changes are occurring in the brain during the one- to three-year period prior to diagnosis. Patients have had plaques in their brain for years, and suddenly their cognitive abilities begin to deteriorate. Is a threshold being crossed where brain cell death begins to occur or really starts to pick up speed?”
Galvin was of the opinion that amyloid brain plaques could begin building in patients 10 years or more before clinical symptoms become visible. Also, amyloid brain plaques are known to be a primary characteristic of Alzheimer’s disease.
The study authors plan to apply their latest approach for assessing mental decline to other dementias including Lewy body dementia. The form of dementia seems to be associated with Parkinson’s disease.
The findings of the study have been published in the journal, Archives of Neurology.