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How Does Hiv Cause Dementia

Neurodevelopmental Disorders Associated With Infection

Researchers Say HIV Attacks the Brain and Causes Dementia

Mother-to-child transmission during pregnancy is the dominant mode of acquisition of HIV infection in children and has been associated with an increased risk of mortality and developmental delay. Children with AIDS appear to have neurological diseases as a consequence of HIV-1 infection. In HIV-1 infected newborn and children, central nervous system is infected with HIV-1 weeks after primary infection, causing neuronal damage and cell death. Although neurological dysfunctions have been associated to HIV infection of the CNS, it is unclear how the pathogenesis of neurological disorders has been established.

In addition to the production of cytokines, HIV-1 infected mononuclear cells and astrocytes can produce a number of soluble mediators, including viral proteins such as gp120 and Tat, that can exert damaging effects on both developing and mature neural tissues. Moreover, molecules such as the platelet activating factor and prostaglandins, which are produced upon microglia/macrophages and astrocytes functional interactions, have been reported to mediate cell damage in primary neural cell cultures and neural cell lines with immaturephenotype.

Who Is At Risk

The risk of cognitive problems increases as you get older. Because of genetic factors, you are at greater risk if a close family member has had cognitive impairment or dementia. Women are at greater risk.

Having any of these health conditions puts you at increased risk: raised cholesterol, diabetes, high blood pressure, atherosclerosis , stroke or transient ischaemic attack . Having previously had depression increases the risk of cognitive impairment later in life.

The lifestyle factors mentioned in the previous section are also important.

What Are Some Of The Neurological Complications That Are Associated With Hiv Infection

AIDS-related disorders of the nervous system may be caused directly by the HIV virus, by certain cancers and opportunistic infections , or by toxic effects of the drugs used to treat symptoms. Other neuro-AIDS disorders of unknown origin may be influenced by but are not caused directly by the virus.

AIDS dementia complex , or HIV-associated dementia , occurs primarily in persons with more advanced HIV infection. Symptoms include encephalitis , behavioral changes, and a gradual decline in cognitive function, including trouble with concentration, memory, and attention. Persons with ADC also show progressive slowing of motor function and loss of dexterity and coordination. When left untreated, ADC can be fatal. It is rare when anti-retroviral therapy is used. Milder cognitive complaints are common and are termed HIV-associated neurocognitive disorder . Neuropsychologic testing can reveal subtle deficits even in the absence of symptoms.

Central nervous system lymphomas are cancerous tumors that either begin in the brain or result from a cancer that has spread from another site in the body. CNS lymphomas are almost always associated with the Epstein-Barr virus . Symptoms include headache, seizures, vision problems, dizziness, speech disturbance, paralysis, and mental deterioration. Individuals may develop one or more CNS lymphomas. Prognosis is poor due to advanced and increasing immunodeficiency, but is better with successful HIV therapy.

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What Is Hiv Encephalopathy

HIV encephalopathy is a serious complication of HIV. HIV affects many body systems, including the immune system and the central nervous system. When the virus reaches the brain, a variety of mental and intellectual problems can happen.

When an HIV infection causes the brain to swell, its called HIV encephalopathy. Other names for this are HIV-associated dementia and AIDS dementia complex. This condition can affect motor functions and cognitive abilities, and lead to dementia.

Even though the virus can enter the brain fairly soon after infection, HIV encephalopathy tends to occur in advanced HIV, making it an AIDS-defining condition.

HIV encephalopathy cant be cured, but it can be slowed or managed with treatment such as antiretroviral therapy.

Aids Dementia Exams And Tests


In a person who’s known to have HIV infection, cognitive, behavioral, or motor symptoms suggests that the person might have ADC. It’s important to consider, however, other possible causes of these symptoms, such as metabolic disorders, infections, degenerative brain diseases, stroke, tumor, and many others. Your healthcare provider will carry out an evaluation to determine the cause of your symptoms. This will likely include a medical interview, physical and mental status exams, CT or MRI scans, neuropsychological testing, and, possibly, a spinal tap.

Imaging Studies

CT scan and MRI may detect changes in the brain that support the diagnosis of AIDS dementia complex. Brain changes in ADC worsen over time, so these studies may be repeated periodically. Importantly, these scans help rule out other potentially treatable conditions such as infection, stroke, and brain tumor.

A CT scan or an MRI gives a detailed, 3-dimensional picture of the brain. These scans can show brain atrophy that is consistent with ADC as well as changes in the appearance of different parts of the brain.

Lab Tests

No lab test confirms the diagnosis of AIDS dementia complex. If you have lab tests, they serve to rule out conditions that might cause similar symptoms. You may have blood drawn for multiple tests.


Neuropsychological Testing

Testing assesses cognitive abilities such as:

  • Memory
  • Abilities to carry out various tasks and follow instructions

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Does Hiv Cause Cognitive Impairment

HIV-associated neurocognitive disorder is more common in people who started treatment with a low CD4 count. This is less common now that guidelines recommend that people start treatment right away.

If someone has started treatment with a very low CD4 count, theyre more likely to have some HIV-induced damage to the brain or an opportunistic infection that affects the brain.

People living with HIV can experience cognitive impairment caused by HIV itself, or by factors like:

  • depression, anxiety or other mental health problems
  • conditions that reduce blood flow to the brain
  • excessive use of alcohol or recreational drugs
  • Alzheimers disease
  • an opportunistic infection such as toxoplasmosis
  • lymphoma a type of tumour which often affects the brain
  • side effects from antiretroviral drugs, particularly efavirenz
  • neurosyphilis untreated syphilis can cause damage to the nervous system.

There are also more subtle forms of impairment which dont cause noticeable problems but which can be picked up by tests.

According to the Alzheimers Society, only around 2% of people living with HIV now experience dementia, whereas this figure was 20-30% before antiretrovirals were available.

Common Mechanisms Between Hiv Neuroinfection And Ad

Because AIDS became a chronic disease with the advent of cART, an important proportion of HIV+ patient population is now over 50 years of age and also facing age-related disorders . In addition, accelerated ageing, including immunosenescence, is a constitutive part of the natural history of HIV infection. In particular, HAND is weakening an already age-targeted organ and could favor the occurrence of neurodegenerative diseases. Regarding AD, questions have risen about potential links with HIV CNS infection from observations and studies demonstrating modulation of common pathways/mechanism . In this context, several symptoms associated with AD physiopathology were reported in HIV+ patients and murine in vivo and in vitro models of neuroAIDS .

Table 1. Common neurotoxicity pathways between Alzheimers disease and human immunodeficiency virus .

HIV+ patients presenting HAND show CSF features very similar to early and late stages of AD . For instance, biomarkers such as A142 are found to be dysregulated in the CSF of HAND patients . When comparing CSF from age-matched controls, HAND and late-stage AD patients, a similar trend for decreased A142 levels was found in HIV+ individuals suffering from neuronal disorders . Notably, HIV+ patients without neurological symptoms had levels of A142 in the same range as non-dementia controls . Consequently, plaques caused by extracellular amyloid peptide accumulation can be seen in patients, particularly before the cART era .

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How Likely Are You To Develop Memory Problems

The risk of developing brain impairment is higher if you received a late HIV diagnosis. It also depends on your lowest ever CD4 count.

Most people are diagnosed and start treatment in good time to prevent memory impairment and in those who are experiencing it, antiretroviral treatments can sometimes reverse the problem.

Hiv Neuroinfection And Alzheimers Disease: Similarities And Potential Links

HIV-associated Dementia : Causes, Diagnosis, Symptoms, Treatment
  • 1Molecular Mechanisms in Neurodegenerative Dementia, INSERM, University of Montpellier/EPHE, Montpellier, France
  • 2Pathogenesis and Control of Chronic Infections, INSERM, University of Montpellier, Etablissement français du Sang, Montpellier, France
  • 3Memory Research and Resources Center, CHU Montpellier, University of Montpellier, Montpellier, France
  • 4Laboratoire de la Barrière Hémato-Encéphalique, Université dArtois, Lens, France
  • 5Cerebrovascular Mechanisms of Brain Disorders, Department of Neuroscience, Institute of Functional Genomics, CNRS, INSERM, University of Montpellier, Montpellier, France
  • 6Department of Infectious Diseases CHU Montpellier, INSERM, IRD, University of Montpellier, Montpellier, France
  • 7Pathogenesis and Control of Chronic Infections, INSERM, University of Montpellier, Etablissement français du Sang, CHU Montpellier, Montpellier, France

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How Long Can You Live With Hiv Encephalopathy

It is impossible to cure HIV encephalopathy. A person with HIV-associated dementia can die within 3 to 6 months if they do not receive treatment. Eventually, you will need more help to manage your daily life as the condition progresses. Mental and physical problems gradually reduce your quality of life.

Immune Reconstitution Inflammatory Syndrome

Clinical worsening may be observed in patients with HIV soon after initiation of HAART therapy, due to mounting of a significant inflammatory response. This is seen even while a patients CD4+ count improves and viral load dramatically decreases. Immune reconstitution inflammatory syndrome may actually worsen AIDS dementia complex and progressive multifocal leukoencephalopathy.

ADC can be distinguished from IRIS by the speed of onset. ADC is subacute to chronic, whereas IRIS can be more acute to subacute. ADC occurs in the setting of untreated, progressive AIDS, whereas IRIS begins with the start of treatment. Distinguishing between the 2 is important, because the treatment is different. ADC requires HAART with high penetration into the CNS. IRIS should be treated with steroids, depending on its severity.

An entity termed encephalitis with CD8 cell infiltration has been identified in patients with latent or inactive HIV infection of the brain due to restoration of T-cell function with HAART, leading to an intense inflammatory reaction with an influx of CD8+ lymphocytes. The influx of the CD8 cells may cause macrophage activation and control of infection but can also present with a subacute or acute encephalopathy. The imbalance between CD8+/CD4+ cells may cause worsening of the HIV encephalopathy and can also produce an acute demyelinating process similar to multiple sclerosis or acute demyelinating encephalomyelitis.

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Neurologic Examination In Pediatric Patients

In neonates, the physical examination findings are often normal. Although the age of onset is usually in the first year of life, manifestations may not be noticeable until age 23 years. At this time, children may present with cognitive impairment, masklike facies, acquired microcephaly, and pseudobulbar and corticospinal tract signs.

Common findings in older children and adolescents are impaired attention, decreased linguistic and scholastic performance, psychomotor slowing, emotional lability, and social withdrawal. Examination findings are similar to those in adults with AIDS dementia complex .

Direct Effects Of Hiv


HIV enters the brain early on in the infection. It is thought that HIV uses a “Trojan horse” mechanism to enter the brain. Normally, the bloodâbrain barrier serves as a protective mechanism by preventing entry of foreign substances disruption of the BBB by HIV contributes to the progression of infection. The virus is able to enter the brain through infected cells that pass through the BBB to replace the immune cells surrounding the blood supply in the brain. When infected, immune cells are able to better migrate into tissues compared to uninfected cells. Infected microglia add to the production of the virus. This activation of the microglia may contribute to the process of neuropathogenesis that spreads the infection to nearby cells. Other cells that can get infected include the astrocytes, which can trigger bystander cellular dysfunction and apoptosis, further compromising the bloodâbrain barrier. The toxicity spreads through a gap junction-dependent mechanism.

Brain regions affected

Changes in the brain may be ongoing but asymptomatic, that is with minimal interference in functioning, making it difficult to diagnose HIV-associated neurocognitive disorders in the early stages.

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Causes Of Aids Dementia

AIDS dementia complex is caused by the HIV virus itself, not by the opportunistic infections that occur commonly in advanced HIV. We do not know exactly how the virus damages brain cells.

HIV may affect the brain through several mechanisms. Viral proteins may damage nerve cells directly or by infecting inflammatory cells in the brain and spinal cord. HIV may then induce these cells to damage and disable nerve cells. HIV causes generalized inflammation, which can cause memory issues, as well ass other aging processes, including heart disease.

Facts On Dementia Due To Hiv Infection

Decline in mental processes is a common complication of HIV infection .

  • Although the specific symptoms vary from person to person, they may be part of a single disorder known as AIDSdementia complex, or ADC. Other names for ADC are HIV-associated dementia and HIV/AIDSencephalopathy.
  • Common symptoms include decline in thinking, or cognitive, functions such as memory, reasoning, judgment, concentration, and problem solving.
  • Other common symptoms are changes in personality and behavior, speech problems, and motor problems, such as clumsiness and poor balance.
  • When these symptoms are severe enough to interfere with everyday activity, a diagnosis of dementia may be warranted.

AIDS dementia complex typically occurs as CD4+ count falls to less than 200 cells/microliter. It may be the first sign of AIDS. With the advent of highly active antiretroviral therapy , the frequency of ADC has declined from 30-60% of people infected with HIV to less than 20%. HAART may not only prevent or delay the onset of AIDS dementia complex in people with HIV infection, it can also improve mental function in people who already have ADC.

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How Long Can You Live With Hiv Before Dying

Infections usually last between eight and ten years before they become fatal. A person with HIV can live for a long period of time without being diagnosed with HIV. However, if an untreated HIV infection is present, the overall mortality rate is more than 90%. Infections usually last between eight and ten years before they become fatal.

Symptoms Of Aids Dementia

M. Christine Zink | Finding Treatments for HIV Dementia

AIDS dementia complex can affect behavior, memory, thinking, and movement. At first, symptoms are subtle and may be overlooked, but they gradually become troublesome. The symptoms vary widely from person to person.

Symptoms of early dementia include:

  • Reduced productivity at work

Without ART, these symptoms gradually worsen. They can lead to a vegetative state, in which the person has minimal awareness of his or her surroundings and is incapable of interacting.

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Patient Competence And Decision Making

Patients should be encouraged to prepare a living will or assign power of attorney early in their disease process. Issues of competence to make medical decisions must be addressed.

Patients may reject proposed treatments. A persons right to autonomy cannot be challenged, provided that they have the competence to understand the risks and benefits of the treatment offered.

Competence to consent to medical treatment is defined as the mental capacity necessary to comprehend the risks and benefits of a proposed medical treatment and its alternatives. The only exception to this situation would be a medical emergency in which the hospital or physician may obtain consent from a surrogate, a close family member, or a spouse. Bioethics consultations may be helpful.

Only a mental health professional psychiatric crisis team, state-designated mental health professional, or peace officer can authorize involuntary hospitalization. Within 72 hours, the patient must be evaluated for mental capacity and grave disability. Grave disability is determined by the ability of the person to provide basic food, clothing, and shelter for himself or herself. If the patient is determined to be gravely disabled, the hold can be extended for 14 days, and the superior court can be petitioned for appointment of a conservator.

Does Hiv Affect Your Memory

There are several key points to be aware of. Alzheimers disease is caused by the spread of HIV to the brain. Memory loss, difficulty thinking, concentration, and or speaking clearly, lack of interest in activities, and gradual loss of motor skills are some of the symptoms of HIV-associated dementia.

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When Should I Call My Health Care Provider

If you notice changes in your ability to speak, focus, or concentrate, talk with your health care provider. These symptoms are common to other conditions, including other infections, depression, and nutritional deficiencies. Unusual shifts in mood or emotions and changes in social behavior also require a conversation with a health care provider. Best results are achieved with early diagnosis and treatment.

What Happens In Hiv

AIDS dementia complex. Causes, symptoms, treatment AIDS ...

People with HAD can have changes in behavior, mood, movement, and/or thinking skills. A person with HAD can have symptoms that vary, and they might be better one day and worse the next. Some people have more trouble with thinking changes such as attention, memory, and concentration. For example, a person with HAD may have trouble following a conversation, remembering phone numbers and appointments, or difficulty understanding questions they are being asked. These problems are often the first to become apparent to the individual and their family members.

In later stages of HIV, movement and behavior symptoms may develop or become worse. People with HAD may begin to have weakness in their legs or difficulty balancing. Mood and behavior problems may also develop later. For example, people with HAD may become depressed, irritable, or uninterested.

A person with HAD can live many years with the disease, although this can vary from person to person. cART may prevent or delay the onset of HAD.

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