How HIV Affects the Brain
HIV infection is known to cause several side effects as it invades the body. Because of advances in medicine, along with our overall understanding of what HIV is and how the virus works inside the human body, we have been able to prolong the side effects that was so disastrously prevalent in the 1980s and 1990s: death due to a completely compromised immune system. As we are now able to keep the virus essentially ineffective, even though we are still not able to eradicate it from the body, infected individuals are now able to live much longer than before, and many die of other natural causes before they develop AIDS from their HIV infection. With people now living longer than they were able to before, researchers have noticed slow-showing side effects that an elongated HIV infection can cause. One of the more feared, as well as least understood, side effects of HIV is its negative effects on a person’s mental abilities. To learn how HIV affects the brain, researchers out of Washington University in St. Louis have looked at one of the two leading theories on the subject.
The two leading theories on how HIV affects the brain are: 1) the early immune system’s responses to the infection which triggers a series of effects that slowly impair memory and mental function; 2) how the disease and co-infections commonly seen with HIV affect the brain independently of the HIV infection. The research team decided to focus on the co-infection theory, as they saw ways to judge whether these infections were indeed affecting the brain instead of HIV itself. Through statistical elimination, they determined the only co-infection which is common enough to affect so many HIV-infected individuals is hepatitis C. So, they looked at the effects of hepatitis C and the possibilities it has in affecting a brain when it is co-infected along with HIV. Knowing that this virus predominately attacks the liver led researcher David Clifford, MD, to rule out this theory, because he believes hepatitis C does not affect the brain in any directly negative manner. The study included almost 1,600 HIV infected individuals who roughly 400 were co-infected with hepatitis C. These patients were given two exams – one written and one physical – to determine any differences they may have in their cognitive and mental abilities. The exams looked at how the patients expressed themselves, made decisions, learned and retained new information, and controlled their body. The results were that there was no distinction between those co-infected with hepatitis C and those who were only infected with HIV. This lack of distinction was made even more impressive, according to Clifford, because those who were co-infected with hepatitis C were almost all older, had less of an education, and generally had lower reading and math scores than the others. They now feel the leading theory – that the immune system’s initial reactions of inflammation of the bowels and brain – is the correct one, and are working to prove this.