MONDAY, March 31 (HealthDay News) -- Cerebral microbleeds -- brain lesions that are deposits of iron from red blood cells that have leaked out of small blood vessels -- are more common in people over age 60 than previously believed, according to a Dutch study.

"We found a three- to fourfold higher overall prevalence of cerebral microbleeds compared to other studies," Dr. Monique M.B. Breteler, of the Erasmus MC University Medical Center in Rotterdam, said in a prepared statement. "These findings are of major importance, since cerebral microbleeds likely reflect cerebrovascular pathology and may be associated with an increased risk of cerebrovascular problems."

The researchers used MRI to check the brains of 1,062 healthy women and men, average age 70, and found that 250 of them had cerebral microbleeds.

The prevalence of microbleeds increased with age, from 18 percent of people aged 60 to 69, to 38 percent in people over age 80. The researchers also found that microbleeds were more common in people with the e4 allele of the APOE gene, which is known to increase the risk of Alzheimer's disease and of cerebral amyloid angiopathy.

"We also found that the risk factors for cerebral microbleeds appear to vary according to the location of the microbleed," Breteler said. "Our results show people with high blood pressure and a history of smoking had microbleeds in a different location in the brain than people with the APOE e4 allele, suggesting different causes for microbleeds in different locations."

The study is published in the April 1 issue of Neurology.

More information

The American Association of Neurological Surgeons has more about cerebrovascular disease.

SOURCE: American Academy of Neurology, news release, March 31, 2008