Even seemingly healthy patients show signs of damage, study finds

In disturbing news for HIV patients, research now provides visual evidence that the AIDS virus ravages some parts of the brain, even in those who follow powerful drug regimens to remain healthy.

By using high-tech scanners, researchers from two American universities found that the brains of HIV patients were 15 percent thinner in areas that control language, planning and movement. It didn't matter if the patients were on a drug regimen known as HAART, which often allows infected individuals to keep the virus from destroying the immune system.

"The drugs clearly aren't stopping the destruction of brain tissue," said study co-author Paul M. Thompson, a neuroscience researcher at the University of California , Los Angeles .

An estimated 40 million people worldwide are infected with the AIDS virus -- about 1 percent of those aged 15 to 49 -- and many don't have access to the antiviral medicines that have turned HIV infection into a largely treatable condition for many in the developed world.

A large percentage of HIV patients suffer from neurological problems; one study put the number at 40 percent.

In the new study, Thompson and his colleagues from UCLA and the University of Pittsburgh used magnetic resonance imaging (MRI) to create three-dimensional brain /images of 40 subjects. Of those, 26 were HIV patients and 14 were healthy "controls."

The thickness of the brain in three areas -- the primary sensor, motor and premotor cortices -- was 15 percent lower in HIV patients. The other three-quarters of the brain were unaffected, the study found.

"Now you can catch AIDS red-handed," said Thompson, who added that the study, appearing in this week's online issue of the Proceedings of the National Academy of Sciences , was the first of its kind. "You can see the damage it inflicts on the brain in great detail."

What does this mean for HIV patients? They're likely to suffer from brain damage, Thompson said, "although it may not get to the degree where you experience noticeable symptoms."

The next step is to determine how to stop the disease from attacking the brain. But, while the virus can penetrate the brain, drugs typically can't because of a natural barrier that protects the organ from foreign materials in the blood.

"The brain becomes a kind of sanctuary where the drugs can't follow," Thompson said.

Dr. Nick Fox, a professor of neurology at University College London, who's familiar with the findings, said the new research sends an important message to health-care professionals about the need to remember about HIV's effects on the brain.