Published Oct. 10 by the online Proceedings of the National Academy of Sciences, the research offers a new way to measure the impact of AIDS on the living brain, and reveals that the brain is still vulnerable to infection when patients are receiving highly active antiretroviral therapy (HAART).
"Two big surprises came out of this study," explained Paul Thompson, Ph.D., first author and associate professor of neurology at the David Geffen School of Medicine at UCLA. "First, that AIDS is selective in how it attacks the brain. Second, drug therapy does not appear to slow the damage. The brain provides a sanctuary for HIV where most drugs cannot follow."
Thompson's laboratory used a new 3-D brain-mapping technique developed at UCLA to analyze the MRIs of 26 people diagnosed with AIDS, and then compared the scans to those of 14 HIV-negative people. The brain scans measured the thickness of gray matter in various regions of the cerebral cortex.
The University of Pittsburgh diagnosed and scanned the AIDS patients; all 26 subjects had lost at least half of their T-cells, the immune cells targeted by HIV. None had experienced AIDS-related dementia, and 13 were on HAART.
The striking differences between the AIDS patients' and the control subjects' brain scans were easy to see on the detailed 3-D images. Areas of tissue loss glowed red and yellow, while intact regions shone blue and green.
The researchers were surprised to discover that AIDS consistently injured the brain's motor, language and judgment centers, but left other areas alone. Specific patterns of tissue damage directly correlated with patients' physi
Contact: Elaine Schmidt
University of California - Los Angeles