How does HIV change our brains?
Over the past few decades, HIV medications have gotten better, so people are living longer than ever before with HIV. It’s estimated that over a quarter—26%—of people living with HIV are over the age of 55. In San Francisco, more than 58% of people living with HIV are over 50 years old. One concern that people may have is that their memory, or other cognitive abilities, may decline as they get older.
Brandon Imp, from the University of California San Francisco spoke about the cognitive decline that can happen in people who are living with HIV at a recent Positive Force The Doctor Is In event. Here’s what we learned.
What is HIV-associated neurocognitive impairment?
Researchers and clinicians use the term HIV-associated neurocognitive disorder (HAND) to refer to the changes in brain function that are associated with HIV.
People with HAND are affected in the following ways. Their cognition may be affected—with memory loss, difficulty concentrating, mental slowing, and comprehension difficulties. Their motor skills may be affected—with an unsteady gait, poor coordination, and tremors. Or, their behavior may be affected and they may have depression, show apathy or be agitated.
People may be asymptomatic (not report any difficulties but show impairment on cognitive testing), have mild to moderate symptoms, or have dementia (severe impairment).
Why we care about cognitive impairment—even if it’s asymptomatic
People who have asymptomatic impairment don’t report any issues, problems or symptoms—but they do worse on very sensitive testing measures of reaction time, memory or spatial abilities. Detecting these kinds of early impairments may be important for two reasons.
First, people who are asymptomatic are more likely to develop noticeable symptoms of neurocognitive impairment in the future. Detecting impairment before symptoms start makes it more likely that people can compensate and get help when and if noticeable symptoms do appear.
Second, even if people don’t notice or report asymptomatic neurocognitive impairment, it may still interfere with things like medication-taking and HIV management. People may be more likely to forget to take their HIV mediations or other medications, or not remember when they have doctor’s appointments.
How many people are affected
Studies find that about half of people living with HIV have some cognitive impairment on sensitive cognition tests (although many people—especially those who are taking highly-active antiretrovirals—may only have very mild effects with no reported symptoms).
In a group of 436 people living with HIV who were part of the CHARTER study (with an average age of 44 years), slightly less than half (46%) of participants had neurocognitive impairment. (The authors noted that the sample had “many and diverse non-HIV-related comorbid conditions that may confer increased risks for NC [neurocognitive] impairment.”) Other studies have found that the prevalence of cognitive impairment among people living with HIV ranging from 40% to over 60%.
Highly-active antiretroviral therapy helps prevent cognitive impairment
Taking antiretroviral therapy may help prevent cognitive impairment in some cases. It also helps prevent the most severe types. The roll-out of highly-active combination antiretroviral therapy since 1996 has decreased the number of people who experience HIV-related cognitive impairment overall. And, out of all people who do experience HAND, a higher percentage of them are in the asymptomatic or mild stage versus the severe stage.
But, people who take highly active antiretroviral therapy may still develop HIV-related cognitive impairments. Researchers aren’t sure why this is, but they speculate that this may be because brain injury occurs before antiretroviral therapy begins; viral suppression isn’t complete in the central nervous system (the brain and spinal cord); even low levels of virus could result in injury; or, that some antiretroviral drugs could be responsible for the later impairment.
People can get HAND as they get older, but it’s not guaranteed
Both age and HIV can impact cognition, but the effect is not additive. Age doesn’t predict cognitive decline—the variation in cognitive functioning within each age group is as big as the variation in cognitive functioning across different age groups.
But, in general, older people are more likely to have symptomatic cognitive impairment, and a more significant amount of cognitive decline than younger people.
The causes of cognitive impairment
There are a lot of things that may contribute to cognitive impairment. Basically, factors like chronic immune activation or long-term exposure to antiretrovirals can damage the brain and result in the symptoms that appear. Things that researchers believe can contribute to cognitive impairment include:
- Uncontrolled plasma or cerebrospinal fluid HIV;
- Chronic immune activation;
- Long-term exposure to antiretroviral medications;
- Cerebrovascular problems; and,
- Other neurodegenerative diseases.
What you can do to prevent cognitive decline
There are a few key things you can do to prevent or treat cognitive impairment. Getting on, and staying on, an effective antiretroviral therapy is the first step. People who start HIV treatment as soon as they test positive for HIV have better health outcomes later on.
The other things to focus on are keeping other parts of your life healthy. Get plenty of exercise and take care of your body by getting other illnesses and diseases properly treated. Keep your brain stimulated, which you can do in a lot of different ways—it doesn’t have to be by doing crossword puzzles. You could start a new hobby, make new friends, listen to interesting podcasts or do Sudoku.
Mindfulness-based stress reduction may also helpful. This therapy, based on Buddhist and Zen practices, uses meditation, mindfulness techniques and yoga postures to help people let go of negative thoughts and emotions. Reducing stress and anxiety in your life can do a lot to improve both your mental and physical well-being.
Get involved in the research
If you live in the San Francisco Bay Area, you might be interested in joining the UCSF HIV Elders Study. This study is looking at whether mindfulness-based stress reduction, described above, can improve HIV-related cognitive impairment, and/or improve quality of life.
The study is open to people living with HIV who are over 60, have had an undetectable viral load for at least six months, are on antiretroviral therapy and struggle with memory or day-to-day activities.