"'Silent strokes' that cause small areas of brain damage have been tied to memory and thinking problems, but it has been difficult to study these 'silent strokes' due to the cost and inconvenience of obtaining brain MRIs," said study author Brendan J. Kelley, MD, of the University of Cincinnati and a member of the American Academy of Neurology. "With this study, we found that a quick, seven-question test can be a cost-effective tool to help identify people at increased risk of developing dementia."

For the research, 23,830 people from the REGARDS study with an average age of 64 with no memory problems who had never had a stroke completed the stroke symptoms questionnaire at the start of the study and every six months for at least two years. The questionnaire asks about symptoms of stroke or transient ischemic attack (TIA), or a "mini-stroke" where symptoms resolve quickly with no permanent damage. The participants' memory and thinking skills were also tested yearly. During the study, 7,223 people had stroke symptoms.

The study found that people who had stroke symptoms were more likely to develop memory and thinking problems. Caucasians who had stroke symptoms were twice as likely to develop cognitive problems (11 percent) as Caucasians who did not have stroke symptoms (5 percent). African-Americans who had stroke symptoms were nearly 70 percent as likely to develop thinking problems (16 percent) as African-Americans who did not have stroke symptoms (about 10 percent).

"Our study highlights the importance of discussing stroke-like symptoms with your family doctor, even if they don't last long. These symptoms can be a warning sign that a person is at increased risk of stroke or problems with thinking or memory," said Kelley.

The REGARDS study was supported by the National Institute of Neurological Disorders and Stroke, National Institutes of Health and Department of Health and Human Services.