Can HIV Cause Brain Disease?

Despite the availability of antiretroviral therapy, neurologic disorders occur frequently in HIVers and increase the risk of death, a study in Canada finds. This may reflect late diagnosis and entry into care, so efforts to identify people with HIV earlier are vital, according to AIDS expert Julio Montaner.

Researchers examined 1,651 HIV-positive patients receiving care at the Southern Alberta Clinic from 1998 to 2008. Of them, 404 (24.5%) had one or more neurologic disorders, and 41% of people with AIDS exhibited neurologic disease. Most prevalent were symptomatic distal sensory polyneuropathy (10%) and HIV-associated neurocognitive disorder (6.2%, says Chris Power, a professor at the universities of Alberta and Calgary, and colleagues.

Patients with at least one neurologic disorder exhibited higher mortality rates (17.6% versus 8%), and especially AIDS-related deaths (9.7% versus 3.2%), compared with those without neurologic disorders. The highest mortality hazard ratio was associated with opportunistic infections of the central nervous system, followed by HIV-associated neurocognitive disorder and any neurologic disorder.

"It's actually quite disturbing in the sense that he's reporting a significant number of people who are presenting with neurological disease related to HIV," says Montaner, director of the British Columbia Center for Excellence in HIV/AIDS. "An astonishing amount of the pathology that is being presented is actually preventable if we implement an aggressive strategy of what we call seek and treat."

Power says the problem may be that antiretroviral medications do not make it through to the nervous system in sufficient amounts to offset the consequences of HIV on the brain. Only a fraction makes it through, he says, noting that some are better than others. One solution, he suggests, might be to fine-tune existing therapies in order to enhance levels in the nervous system.

The study, "Neurologic Disease Burden in Treated HIV/AIDS Predicts Survival," was published in the journal Neurology.