These mental lapses, also called cognitive fluctuations, are common in a type of dementia called dementia with Lewy bodies, but researchers previously did not know how frequently they occurred in people with Alzheimer’s disease and, equally important, what effect fluctuations might have on their thinking abilities or assessment scores.
The study involved 511 people with an average age of 78. Researchers interviewed the participant and a family member, evaluated the participants for dementia and tested their memory and thinking skills.
People with three or four of the following symptoms met the criteria for having mental lapses: • Feeling drowsy or lethargic all the time or several times per day despite getting enough sleep the night before • Sleeping two or more hours before 7 p.m. • Having times when the person’s flow of ideas seems disorganized, unclear, or not logical • Staring into space for long periods
A total of 12 percent of the people with dementia in the study had mental lapses. Of 216 people with very mild or mild dementia, 25 had mental lapses. Of the 295 people with no dementia, only two had mental lapses.
Those with mental lapses were 4.6 times more likely to have dementia than those without mental lapses. People with mental lapses also tended to have more severe Alzheimer’s symptoms and perform worse on tests of memory and thinking skills than people who did not have lapses.
“When older people are evaluated for problems with their thinking and memory, doctors should consider also assessing them for these mental lapses,” said senior study author James E. Galvin, MD, MPH, of Washington University School of Medicine in St. Louis, who is a member of the American Academy of Neurology.
The study was supported by the National Institute on Aging.
The American Academy of Neurology, an association of more than 22,000 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Parkinson’s disease, ALS (Lou Gehrig’s disease), dementia, West Nile virus, and ataxia. For more information about the American Academy of Neurology, visit http://www.aan.com.