AIDS can continue to damage some types of brain tissue even when patients are receiving highly active antiretroviral therapy, according to a study published on Tuesday in the Proceedings of the National Academy of Sciences, London's Daily Telegraph reports. Paul Thompson, a researcher at the David Geffen School of Medicine at the University of California-Los Angeles and colleagues from the University of Pittsburgh used a 3-D magnetic resonance imaging technique on the brains of 26 people diagnosed with AIDS and 14 HIV-negative people (Highfield, Daily Telegraph, 10/11). The researchers found that the AIDS patients had 10% to 15% thinner brain tissue in regions that control movement, language and feeling. The tissue loss shown in the brain imaging of the AIDS patients correlated with motor and cognitive defects that the patients showed in multiple brain function tests. In addition, the extent of the tissue loss seemed to be related to patients' CD4+ T cell counts (BBC News, 10/11). In addition, AIDS patients who were taking HAART had no significant difference in tissue loss compared with AIDS patients who were not taking the therapy. "Even though antiretroviral drugs rescue the immune system, AIDS is still attacking the brain," Thompson said, adding, "A protective blood barrier prevents drugs from entering the brain, transforming it into a reservoir where HIV can multiply and attack cells unchecked." According to the study, some areas of the brain were not affected by AIDS (Daily Telegraph, 10/11). At least two in five people living with HIV/AIDS are expected to "suffer from cognitive impairments, ranging from minor deficits to dementia," the BBC News reports. Rod Watson of the Terrence Higgins Trust, the largest HIV/AIDS charity in Europe, said, "This study tracking any cognitive decline is interesting but small. We'd need more solid evidence on how HIV can affect the brain in different individuals before we looked at offering neuroprotective drugs" (BBC News, 10/11).