Cognitive fluctuations include: feeling drowsy or lethargic all the time or several times per day, sleeping two or more hours before 7 p.m., having times when the flow of one's ideas seems disorganized, unclear or illogical and staring into space for long periods. This sounds like fairly typical behaviour in older (and not-so-old) people but researchers at Washington University School of Medicine in St Louis have found that it could be linked to an increased risk of Alzheimer's disease. The researchers' study included 511 older adults with memory problems who had an average age of 78. 12% of the sample had three symptoms of cognitive fluctuations and these people were 4.6x more likely to be diagnosed with Alzheimer's. Of the 216 people diagnosed with very mild or mild dementia 25 had cognitive fluctuations whereas of the 295 with no dementia only two did. People with cognitive fluctuations also did worse on tests of memory and thinking than those without.
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