One factor coming under increased study is cerebral microbleeds, experienced by nearly 20 percent of people by age 60 and nearly 40 percent by age 80. Research into these small areas of brain bleeding, caused by a breakdown of miniscule blood vessels, is shedding light on how the condition may contribute to these neurological changes.

With microbleeds common in older individuals, physicians need to take it into consideration when treating other brain-related issues, said Dr. Mark Fisher, professor of neurology, anatomy & neurobiology, and pathology & laboratory medicine at UC Irvine. This is especially important with stroke prevention measures, which often involve medications that interfere with blood clotting and could exacerbate microbleeds. Stroke risk escalates with age, especially after 55, making stroke one of the leading causes of disability and death in the elderly.

In two current papers published online in Frontiers in Neurology and Stroke, Fisher writes about the brain's intricate system to protect itself against hemorrhaging. This system seems to break down as we get older, resulting in microbleeds that develop spontaneously and become increasingly common with aging.

"The next step in stroke prevention will require that we address both blood clotting and protection of the blood vessels," he said. "This seems to be the best way to reduce the risk of microbleeds when it's necessary to limit blood clotting for stroke prevention."

In his Stroke article, Fisher describes how newer medications interfere with blood clotting (to protect against stroke) while at the same time protecting the blood vessel wall (to help prevent bleeding). And in Frontiers in Neurology, he suggests that MRI screening be used more strategically to identify patients with microbleeds, allowing their physicians to adjust treatments accordingly.

"With the prevalence of microbleeds, it's important that we better understand this neurological factor as we develop and proceed with brain-related treatments for the elderly," Fisher said. "Identifying and controlling microbleeds may be an important step in a therapeutic approach to maximize brain health during the process of aging. This is a critical issue requiring further study."