Men with impaired brain function may be at higher risk of suffering a stroke, even if these impairments are quite minor, a new study published today in the journal Neurology hints.

Several studies have suggested a link between seriously impaired cognitive function and stroke, Dr. Bernice Wiberg of Uppsala University in Sweden and her colleagues note in their report.

To better understand what types of mental decline might predict stroke risk, they gave 930 70-year-old men tests of mental function, and then followed them for 13 years. At the study’s outset, none of the men had suffered a stroke or “mini-stroke” known as a transient ischemic attack.

During follow-up, 166 of the men had a stroke or a mini-stroke, and 105 had brain injury as a result of the stroke.

The researchers found that the longer a man took to complete a task known as the Trail Making Test B, the greater his risk of brain injury due to stroke. This particular test requires a person to connect 25 consecutive “dots” consisting of numbers alternating with letters (1, A, 2, B, etc.) and is a measure of a person’s visual attention skills and ability to switch among different tasks.

The men who took the longest to complete the test (around 2.5 to 4 minutes) were more than three times as likely to have stroke-related brain injury as those who did it the quickest (in 43 seconds to about 1.5 minutes).

“Our results support the idea that cognitive decline regardless of whether a person has dementia may predict risk of stroke,” Wiberg noted in a statement from the American Academy of Neurology.

“The Trail Making Test B is a simple and cost-effective test that, with more research, could be used to identify those persons for whom stroke prevention measures should be considered,” the researcher added.

Stroke is the leading cause of disability and death among older people, making early identification of those at high risk of stroke “extremely important,” Wiberg said.

SOURCE: Neurology, February 2, 2010.