The Albert Einstein College of Medicine researchers said in up to 20 percent of people infected with HIV, the virus manages to escape from the bloodstream and cross into the brain, resulting in HIV-associated dementia and other cognitive disorders.

The Yeshiva University scientists said their findings might lead to the development of strategies for preventing HIV from entering the brain.

"Previous research has suggested that it's not individual HIV viruses that get into the brain, but rather HIV-infected immune cells known as monocytes," said Dr. Harris Goldstein, senior author of the study. "Using an animal model, we wanted to find out first of all whether being infected with HIV enables monocytes to do what they don't usually do -- escape from blood vessels and enter brain tissue."

They discovered that being infected with HIV somehow gives monocytes the capacity to cross an intact blood brain barrier, said Goldstein.

The study is detailed in the Journal of Virology.