Researchers at the University of California-Los Angeles have paired a brain-imaging tool and stroke risk assessment to identify signs of cognitive decline early on in individuals who don’t yet show symptoms of dementia.
Previous research has established a clear connection between stroke risk and cognitive decline, the researchers said. People with a higher risk of stroke traditionally perform worse on tests of memory, attention and abstract reasoning.
The UCLA study found that stroke risk, coupled with amyloid beta plaques and neurofibrillary tau tangles, may influence cognitive decline.
“The findings reinforce the importance of managing stroke risk factors to prevent cognitive decline even before clinical symptoms of dementia appear,” said first author Dr. David Merrill, an assistant clinical professor of psychiatry and biobehavioral sciences at the Semel Institute for Neuroscience and Human Behavior at UCLA.
For the study, the team assessed 75 people who were healthy or had mild cognitive impairment. Average age of the participants was 63.
Each person underwent neuropsychological testing and physical assessments to calculate their stroke risk using the Framingham Stroke Risk Profile, which examines age, gender, smoking status, systolic blood pressure, diabetes, use of blood pressure medications, and other factors.
Each participant was then injected with a chemical marker called FDDNP, which binds to deposits of amyloid beta plaques and neurofibrillary tau tangles, the types of protein debris in the brain that are markers of Alzheimer’s disease.
The researchers then used positron emission tomography (PET) to examine images of the brains. This allowed them to pinpoint where these abnormal proteins accumulate, the researchers noted.
The researchers found that greater stroke risk was significantly related to lower performance in several cognitive areas, including language, attention, information-processing speed, memory, problem-solving and verbal reasoning.
The researchers also observed that FDDNP binding levels in the brain correlated with cognitive performance.
For instance, participants who had greater difficulties with problem-solving and language displayed higher levels of the marker in areas of their brain that control those cognitive activities.
“Our findings demonstrate that the effects of elevated vascular risk, along with evidence of plaques and tangles, is apparent early on, even before vascular damage has occurred or a diagnosis of dementia has been confirmed,” said the study’s senior author, Dr. Gary Small, director of the UCLA Longevity Center and a professor of psychiatry and biobehavioral sciences.
The researchers say that several individual factors in the stroke assessment stood out as predictors of decline in cognitive function, including age, systolic blood pressure and use of blood pressure medications.
The next step will be studies with a larger sample size to confirm and expand the findings, according to Small.
The study was published in the Journal of Alzheimer’s Disease.