AIDS Dementia Complex

Synonyms

2

Overview

HIV infection weakens the immune system, making it highly susceptible to numerous infections and certain types of cancers. Although it doesn't appear to infect the nerve cells, it can cause neurological symptoms such as confusion, forgetfulness, depression, anxiety and difficulty walking.

In short, HIV-associated neurocognitive disorders (HAND) are neurological disorders associated with HIV infection and AIDS. HAND may include neurological disorders of various severity such as AIDS dementia complex (ADC) also known as HIV dementia and HIV-associated dementia (HAD), HIV encephalopathy, and Mild Neurocognitive Disorder (MND). HIV-associated neurocognitive disorders are associated with a metabolic encephalopathy induced by HIV infection and fueled by immune activation of macrophages and microglia. These cells are actively infected with HIV and secrete neurotoxins of both host and viral origin.

The ADC is one of the most common and clinically important CNS complications of late HIV-1 infection. It is a source of great morbidity and, when severe, is associated with limited survival. The essential features of ADC are disabling cognitive impairment accompanied by motor dysfunction, speech problems and behavioral change. Cognitive impairment is characterised by mental slowness, trouble with memory and poor concentration. Motor symptoms include a loss of fine motor control leading to clumsiness, poor balance and tremors. Behavioral changes may include apathy, lethargy and diminished emotional responses and spontaneity. Histopathologically, it is identified by the infiltration of monocytes and macrophages into the central nervous system (CNS), gliosis, pallor of myelin sheaths, abnormalities of dendritic processes and neuronal loss.

ADC typically occurs after years of HIV infection and is associated with low CD4+ T cell levels and high plasma viral loads. It is sometimes seen as the first sign of the onset of AIDS. Prevalence is between 10-24% in Western countries[3] and has only been seen in 1-2% of India-based infections. With the advent of highly active antiretroviral therapy (HAART), theincidence of ADC has declined in developed countries, although its prevalence is increasing.  HAART may prevent or delay the onset of ADC in people with HIV infection, and may also improve mental function in people who already have ADC.

Dementia only exists when neurocognitive impairment in the patient is severe enough to interfere markedly with day-to-day function. That is, the patient is typically unable to work and may not be able to take care of him or herself. Before this, the patient is said to have a mild neurocognitive disorder.

Symptoms

Stage 1 (Mild):

  • Difficulty concentrating
  • Difficulty remembering details, such as phone numbers, appointments, or tracking daily activities
  • Slowed thinking
  • Longer time needed to complete complicated tasks
  • Irritability
  • Unsteady walking, tremor, or difficulty keeping balance
  • Poor hand function
  • Change in handwriting
  • Depression

Stage 2 (Moderate):

  • Weakness
  • More focus and attention needed
  • Slow responses
  • Frequently dropping objects
  • Feelings of indifference
  • Slowness or difficulty with normal activities, such as eating or writing
  • Walking, balance, and coordination require a great deal of effort at this stage.

Stages 3 and 4 (Severe and End Stage):

  • Loss of bladder or bowel control
  • Abnormal gait, making walking more difficult
  • Muteness
  • Withdrawing from life
  • Severe mental disorders, such as psychosis or mania
  • Unable to leave bed

Causes

It is not clearly understood how HIV infection causes ADC.

Prevention

ADC occurs in people with HIV. Ways to help reduce your chance of getting HIV include:

  • When you have sex, use a male latex condom.
  • Limit your number of sexual partners.
  • Avoid sexual partners who are HIV-infected.
  • Do not share needles for drug injection.
  • If you are a healthcare worker:

Wear appropriate gloves and facial masks during all procedures.
Carefully handle and properly dispose of needles.
Carefully follow universal precautions.

  • If you live in a household with someone who has HIV:

Wear appropriate gloves if handling HIV-infected bodily fluids.
Cover your cuts and sores with bandages. Also cover cuts and sores on the person with HIV.
Do not share any personal hygiene items, such as razors or toothbrushes.
Carefully handle and properly dispose of needles used for medication.

Diagnosis

Marked acquired impairment of at least two ability domains of cognitive function (e.g. memory, attention): typically, the impairment is in multiple domains, especially in learning, information processing and concentration/attention. The cognitive impairment is ascertained by medical history, mental status examination or neuropsychological testing. Cognitive impairments identified in 1. interfere markedly with day-to-day functioning. Cognitive impairments identified in 1. are present for at least one month.

Treatment

Aggressive treatment is required for AIDS dementia complex as it is associated with higher death rates. Treatment with antiretroviral drugs. Ritalin (methylphenidate) a psycho stimulant can be helpful for lethargy and slowed thinking.

Resources

  • NIH