When you think of cognitive problems and stroke, you probably think of the cognitive decline that can occur as a result of post-stroke brain damage. But new research suggests that cognitive decline and memory problems can occur before stroke, too — and may be a sign that stroke risk is increasing.
In general, problems with cognitive function indicate poor neurological health and impaired brain function. A decline in cognitive ability and memory in older people not only signals deteriorating neurological and physical health, but can specifically indicate increasing stroke risk. According to the CDC, 800,000 people have a stroke every year in the U.S.; every four minutes, someone in the U.S. dies from a stroke. The more researchers can learn about the signs of an impending stroke, the more strokes doctors will be able to prevent with medication and lifestyle recommendations.
Cognitive Decline and Increased Stroke Risk in Older Adults
According to researchers at Chicago’s Rush University Medical Center, cognitive decline could be a sign of an impending stroke in adults over age 65. While it’s well-known that strokes can cause cognitive decline, few studies have examined the role that a decline in cognitive functions can play in causing stroke. The Rush University researchers wanted to know if cognitive decline, generally considered a marker of worsening neurological health, could be considered a risk factor for stroke in older adults.
The researchers investigated information about the cognitive functioning of 7,217 men and women older than 65 years of age. In addition to measuring the study participants’ cognitive function, the researchers also monitored the study participants for strokes. They administered four tests of cognitive function every three years. The tests measured long and short-term memory, attention, and awareness.
The researchers found a startling relationship between reduced cognitive function and stroke risk, discovering that those who performed poorly on their cognitive skills tests were 61 percent more likely than those who performed well to have a stroke at some point after the test. Among those who demonstrated poor cognitive function before a stroke, cognitive function continued to deteriorate almost twice as quickly as it did prior to stroke. They were also more likely to die following their strokes. Of those who demonstrated poor cognitive skills and who had strokes, 78 percent died during the follow-up period. The researchers believe not only that cognitive decline can raise stroke risk, but that once a stroke occurs, it can drastically speed up the decline that was already occurring.
Poor Memory May Indicate Increasing Stroke Risk in the Educated
While cognitive skills tests may be one way to identify older people who may be in need of stroke-preventing medications like Plavix, a Dutch study recently published in the journal Stroke suggests that at least one group of people may be capable of pinpointing their own cognitive problems. Researchers at Erasmus University Rotterdam have found that people who are highly educated — which, for the purposes of this study, means people with university or vocational training in a field — are better able to spot deterioration in their own cognitive function.
For the purposes of the study, researchers following 9,152 people over age 55 from 1990 to 2012. First, the study participants filled out a questionnaire regarding any memory complaints they may have had. Then, they took a Mini-Mental State Examination or MMSE, a test that seeks to identify cognitive impairment.
At follow-up in 2012, the researchers found that 1,134 of the study participants had had strokes — 663 ischemic, 99 hemorrhagic, and 372 unspecified. The researchers found that a high score on the MMSE did not correlate with increased stroke risk. However, they did find that participants who complained of memory problems seemed to be more likely to suffer a stroke. The researchers expanded the study at this point, to discover whether they could find the same association between memory complaints an increased stroke risk among people with less education — those who had completed only primary education or who had started, but not completed, higher education.
The researchers found that the association between subjectively experienced memory problems and increased stroke risk existed only in the highly educated group. Those with advanced university or vocational training were 39 percent more likely to suffer a stroke if they complained about memory problems beforehand. The study authors believe that perhaps more educated people are more in tune with their cognitive performance than those with less education, so that they’re more likely to notice and be troubled by even the most subtle changes in memory. However, the study participants were limited to white Europeans living in a specific part of one city; further research would need to be conducted on a more diverse pool of cohorts in order to better understand the relationship between the experience of subjective memory problems and increased stroke risk.
Cognitive decline is an all-too-frequent consequence of stroke, but researchers are now discovering that it can precede stroke, too. If you or someone you care about begins to demonstrate signs of memory problems or other cognitive decline, talk to your doctor about preventative measures. Early treatment can help reverse the damage done by stroke, but the prevention is the best cure of all.