What is HIV Encephalitis (HIV-associated neurological disorder (HAND)?
HIV encephalitis, sometimes referred to as HIV-associated neurological disorder (HAND), involves a range of brain-related problems that can occur after an HIV infection. The way this condition shows itself can vary greatly: there may be no symptoms at all, mild mental impairment, or at its worst, severe dementia. An extreme form of this disorder is called HIV encephalopathy or AIDS-dementia complex. To diagnose HIV encephalitis, doctors examine the patient’s mental health and carry out imaging studies of the brain. The best treatment involves timely and effective use of antiretroviral therapy (ART), which is medication to manage HIV.
What Causes HIV Encephalitis (HIV-associated neurological disorder (HAND)?
The exact process of how HIV infection leads to HIV encephalitis, which is a brain inflammation, is not completely understood. There is some research suggesting that genetics may play a role. For example, having a specific variant of the apoE gene, known as the E4 allele, might increase the risk of brain cognitive damage related to HIV.
However, not all studies agree on this. Some have found no solid link between the presence of this gene variation and a higher occurrence of HIV encephalitis. Factors like a low CD4 count and a high amount of the virus in the blood are solid indicators of who might be at risk of developing HIV encephalitis. CD4 is a type of protein on the surface of cells that HIV targets and infects.
Another thing to consider is the age when the person first contracted the virus. Older individuals tend to have a higher prevalence of cognitive deficits compared to younger populations. Other health conditions that are prevalent in older people, like resistance to insulin (which leads to high blood sugar levels) and obesity, may also contribute to the risk.
Risk Factors and Frequency for HIV Encephalitis (HIV-associated neurological disorder (HAND)
People with HIV can experience a range of neurological issues, caused by different factors like infections in the brain, nerve damage, spinal cord problems, and a condition called HIV encephalitis. In the United States, where treatments for HIV are widely available, HIV encephalitis is often the main cause of these neurological symptoms. In contrast, in developing countries, where access to HIV treatments is more limited, these symptoms are often due to infections in the brain like toxoplasmosis and cryptococcosis. HIV encephalitis does not affect one gender more than the other.
The severity of HIV encephalitis has significantly decreased thanks to the widespread use of antiretroviral therapy (ART). However, even with this treatment, nearly half of those with HIV might experience some level of brain function problems. It’s hard to tell exactly how much of this is due to HIV encephalitis alone because other factors like drug abuse, diabetes, high blood pressure, and aging can also affect brain function.
Signs and Symptoms of HIV Encephalitis (HIV-associated neurological disorder (HAND)
HIV encephalitis is a condition linked with HIV that mainly impacts your brain. Its symptoms come and go rather than steadily worsening, unlike diseases like Alzheimer’s. It usually occurs in the later stages of HIV, but it can also affect people with higher levels of certain immune cells (CD4 counts above 350 cells/μL).
Symptoms usually involve a noticeable decline in mental abilities compared to previous levels. These may include slow thinking, trouble concentrating, reduced attention, becoming more forgetful, and having issues with complex tasks. In the later stages, people might experience problems controlling their bowel movements or bladder.
During a physical exam, doctors might notice issues like shaking, difficulty walking or maintaining balance, exaggerated reflexes, and increased muscle tone. They may also use a Mini-Mental Status Examination (MMSE) to objectively measure and compare cognitive functions over time. The absence of certain mental function issues, such as problems recognizing objects, difficulties with movement, and language impairment, can rule out cortical dementia like Alzheimer’s and support the diagnosis of HIV encephalitis.
Doctors classify HIV encephalitis based on the severity of cognitive issues and how much they interfere with daily life. The stages are as follows:
- Asymptomatic: Mental abilities are slightly below average in two cognitive areas, but daily life isn’t affected.
- Mild: Mental abilities are slightly below average in two cognitive areas, and daily life is somewhat affected.
- HIV-associated dementia: Mental abilities are significantly below average in two cognitive areas, and daily life is noticeably affected.
Testing for HIV Encephalitis (HIV-associated neurological disorder (HAND)
If you are experiencing new or worsening neurological issues and are known to have HIV, a spinal tap/ lumbar puncture to analyze your spinal fluid may be used as a part of your evaluation. This can show an increase in protein, cell count, and HIV RNA in the spinal fluid – signs that can often be associated with HIV-related brain issues. The spinal tap also helps to ensure other infections, that can take advantage of the weak immune system in people with HIV (known as “opportunistic infections”), are not causing your symptoms.
Culturing (growing in a lab) HIV from samples taken from the nerves, spinal fluid, and brain has yielded positive results. However, this positive result can be seen in all stages of HIV infection and so cannot be linked to the presence or absence of neurological symptoms. For this reason, testing for HIV viral levels and drug resistance in the spinal fluid is not typically done.
Tests will also be done to check for other conditions that could be causing your symptoms. These include thyroid disease, folate deficiency, vitamin B12 deficiency, syphilis, and liver disease.
Imaging of the brain with CT or MRI scans can show changes related to HIV infection in the brain. This usually appears as brain shrinkage or “atrophy.” In the later stages of the disease, multiple bright, un-enhanced lesions can be seen in certain parts of the brain when the images are created with specific settings (T2-weighted sequences).
Treatment Options for HIV Encephalitis (HIV-associated neurological disorder (HAND)
Highly Active Antiretroviral Therapy (HART), a type of treatment for HIV, has been shown to be effective in managing a condition known as HIV encephalitis, a brain disease that can be caused by HIV. This treatment has led to significant improvements in mental health and cognitive abilities in affected patients. HART can lessen and even undo some of the damage to the brain caused by HIV. It can also delay or prevent the onset of cognitive impairment in people with HIV.
The success of HART in treating patients has led to a decrease in the severity and prevalence of HIV encephalopathy. This is a brain disease associated with HIV, which can also appear as a kind of dementia (decline in mental ability) known as AIDS-dementia complex. The shifting landscape has seen a decrease in cases of AIDS-dementia complex and more cases of milder forms of brain disease related to HIV. It is important to note that while HART has proved beneficial for patients with HIV-related dementia, patients with milder cognitive conditions have not shown any significant improvement.
Medication that can effectively penetrate the central nervous system (CNS) has been found to be more effective in managing patients with HIV encephalitis. Each patient is unique and tailoring treatment to consider both the ability of medication to penetrate the CNS, and each individual patient’s needs can result in the best patient outcomes. It is worth noting that a drug called Efavirenz is often not the first choice in treating neurocognitive disorders due to its potential negative effects on mental health.
For patients diagnosed with HIV-associated dementia, if the plan is to start HART, favoured regimens often include drugs such as tenofovir, dolutegravir plus emtricitabine, or a combination of lamivudine, abacavir plus dolutegravir. It’s also important to note that certain drugs, including lithium, memantine, and minocycline, have not shown any benefit in patients with HIV encephalitis.
What else can HIV Encephalitis (HIV-associated neurological disorder (HAND) be?
When doctors want to diagnose HIV-related encephalitis (inflammation of the brain), they have to consider other similar conditions. These might include:
- Primary CNS lymphoma: This may also lead to issues like cognitive decline, memory loss, and motor symptoms like hemiparesis (partial weakness on one side of the body). But it often comes with other symptoms like night sweats and fever. Medical imagery can help differentiate between this and HIV encephalitis, as it tends to show mass lesions mainly in the periventricular regions, around the brain’s ventricles.
- Progressive multifocal leukoencephalopathy (PML): An aggressive disorder that causes destruction of the brain’s white matter, PML affects people with weakened immune systems. It can cause symptoms like hemiparesis, unstable movement (ataxia), and memory loss. It’s caused by a virus called JC virus, and an MRI can identify it due to bilateral, asymmetric areas of demyelination without mass effect in the periventricular and subcortical regions of the brain.
- Opportunistic infections like cryptococcosis and toxoplasmosis: Doctors can tell these apart from HIV encephalitis by looking for specific clinical features, like seizures. Imagery would show focussed tissue indentations (mass effect) with a contrast (enhancement). Cryptococcus can also cause meningitis and toxoplasmosis can lead to brain abscesses.
- Nutritional deficiencies: It’s essential to exclude any disorders linked to deficiencies in vitamin B12 and folate.
What to expect with HIV Encephalitis (HIV-associated neurological disorder (HAND)
Without proper medication, severe complications of AIDS, including dementia, could lead to death within a year. However, antiretroviral therapy (ART), a medical treatment for HIV/AIDS, can significantly slow this progression and increase a patient’s lifespan. Two factors typically tied to worse outcomes are older age and not following the ART medication regimen closely.
The type of ART given also has a significant impact on the severity of mental and behavioral symptoms associated with the disease. Some studies have even shown that using a combination of different ART drugs, rather than a single one, led to improvements in spatial awareness and attention, although learning efficiency may decrease.
Even if a patient does not exhibit severe signs of mental impairment at first, the mere presence of such impairment, no matter how minor, can signal a potential decline in neurological health in the future. Some studies have shown that even in the era of advanced ART treatment, the existence of cognitive impairments in a patient with HIV could signal a high risk of mortality.
Possible Complications When Diagnosed with HIV Encephalitis (HIV-associated neurological disorder (HAND)
The use of antiretroviral therapy (ART) largely influences the disease progression and complications in patients with HIV-related brain inflammation. There’s a rare condition known as CNS viral escape syndrome that has been seen in patients undergoing ART. This condition surfaces as new neurological and cognitive problems. Lab tests show increased viral activity in the cerebrospinal fluid (the fluid around the brain and spinal cord) even when the virus levels in the blood are low.
- The use of antiretroviral therapy affects the course of illness in patients with HIV-related brain inflammation.
- CNS viral escape syndrome is a rare condition seen in patients using ART.
- This condition shows itself as new neurological and cognitive issues.
- Lab tests indicate high viral activity in the cerebrospinal fluid, despite low virus levels in the blood.
Preventing HIV Encephalitis (HIV-associated neurological disorder (HAND)
Starting treatment for HIV disease, known as ART (Antiretroviral Therapy), should be considered as soon as the diagnosis is made. This is because the treatment has a positive impact on the disease. It’s very important for patients to take their ART medication regularly and correctly, as this can lead to significantly improved health results.
