Dementia and Other Cognitive Disorders
People with HIV can have many co-occurring (comorbid) conditions. One serious comorbid condition is dementia. Dementia is a broad term for changes in a person’s memory, motor function, personality, coordination, and more. Any of the brain’s functions and anything it controls can be impacted by dementia.
Dementia can be caused by a wide variety of different causes. Some conditions directly impact neurons (the cells that carry information in the brain). These include Alzheimer’s disease and Parkinson’s disease. Infections from bacteria, fungi, and viruses like HIV can cause dementia. Dementia can also be caused by changes in blood flow in the brain, including strokes, brain bleeds, or long-term, severe high blood pressure.
A spectrum of cognitive disorders related to HIV
There are many different types of dementia and other similar cognitive disorders that can result from HIV. These disorders have also received several different names over the years. Essentially, dementia related to HIV is a spectrum of disorders and symptoms. Some experts call the overarching issue HIV-associated neurocognitive disorder (HAND).
HAND can then be broken down into less severe cognitive disorders, including minor neurocognitive disorder (MND) and more severe disorders, like HIV-associated dementia (HAD).1
HIV-associated dementia (HAD)
HAD is often referred to as AIDS dementia complex (ADC) or HIV encephalopathy. While these acronyms can be confusing, they are referring to one large spectrum of dementia-related disorders and are classified based on how severe a person’s symptoms are.1
Severe HAD used to be much more common before the creation of antiretroviral therapy (ART). People with CD4 counts lower than 200 were the most likely to develop HAD. Now, with ART, HAD and other serious forms of dementia are decreasing.1,2
Minor cognitive motor disorder (MCMD)
A less severe version of HAD, called minor cognitive motor disorder (MCMD), has become one of the most common versions of HIV-related dementia and may be more manageable. As many as 40 percent of people with HIV may have some neurological issues, whether they are minor or severe.1,2
Causes of dementia and other cognitive disorders
The exact way that HIV causes dementia is a topic of intense research. However, there are a few theories.
Some experts believe that HIV may infect neurons in the brain late in the progression of the infection or when a person’s viral load is very high. This could cause direct damage and lead to dementia-related symptoms.
Some believe that other cells in the brain in combination with a person’s own immune system response (including their inflammatory signals and chemicals) are what might cause damage to the brain and lead to dementia. Others believe that HIV may carry proteins that are directly toxic to the brain.
Of course, it could be a combination of all of these factors or something yet to be discovered. Thankfully, severe dementia is decreasing among those living with HIV due to ART and better control of the virus.1-3
However, people living with HIV are still susceptible to other causes of dementia, including:1-3
- Blood flow changes
- Conditions like Parkinson’s disease or Alzheimer’s
- Brain injuries
- General age-related changes
Now that people who are living with HIV are living longer than ever before, other causes of dementia may become more of an issue. While we cannot do much to prevent or avoid many of the risk factors for these conditions, keeping control of the virus with ART can help reduce the risk of infections that can cause dementia.
Dementia symptoms and diagnosis
The symptoms of dementia can be hard to spot. They are often slow to develop and progress. Early on, symptoms may be so mild that the person experiencing them, their loved ones, and even their doctor may have a hard time noticing them. When symptoms do appear, they often include:1,3
- Slowed thinking and issues with concentration and memory
- Weakness of muscles, slow movement, and coordination problems
- Personality changes including apathy, depression, or delusions
A doctor makes a diagnosis of dementia based on a variety of factors. They often will perform a clinical exam, perform basic mental status tests, and possibly order imaging studies of the brain like CT or MRI. They may also look for common causes of dementia, including testing the blood for infections, vitamin deficiencies, and HIV viral load. Some people may need to undergo a spinal tap for diagnosis. This involves taking a small sample of spinal fluid from the back using a needle and analyzing it for viruses, abnormal proteins, blood, and more.
When symptoms are very mild and testing does not show an obvious cause but a doctor is still suspicious of HIV-associated dementia, neuropsychological testing may be helpful. This is a more in-depth mental examination that can detect small changes in mental status.1,3
Stages of HIV-associated dementia
HIV-associated dementia is often broken out into 5 stages with various characteristics:1
Stage 0 to 0.5 – Essentially normal. A person has minimal or no symptoms and no impairment in their overall functioning.
Stage 1 – Mild impairment. A person can do most things on their own unless the action is especially demanding. They are able to walk on their own without assistance. People with stage 1 may benefit from neuropsychological testing. They have some impairment, but it is hard to detect.
Stage 2 – Moderate impairment. A person is able to take care of themselves on a basic level but are unable to work or perform intensive tasks. May need assistance walking using a cane or other assistive device.
Stage 3 – Severe impairment. A person is unable to have or follow a full conversation. They may also have severe motor function issues and be unable to walk without assistance.
Stage 4 – A nearly comatose state. A person is unable to understand or communicate much at all; may be incontinent or paraplegic.
Treatment for HIV-associated dementia
HIV-associated dementia can be fatal without treatment. Fortunately, early and aggressive treatment with ART has been shown to reduce a person’s chances of developing dementia. ART may also help reduce dementia-related symptoms when they arise in a person who is not adequately managed with ART.1,3
Other ways to help support an individual with HIV-associated dementia are to help keep them in a safe, bright, stimulating environment and to utilize regular routines and activities. Limiting changes in surroundings can also be helpful.1-3