HIV-1 Encephalopathy and Aids Dementia Complex

Excerpt

Neurocognitive deficits are the presenting complaint in 4% to 15% of patients diagnosed with human immunodeficiency virus (HIV). Patients may present with nonspecific complaints such as deficits in memory, concentration, attention, and motor skills. These symptoms are common in many disorders, and accurate diagnosis is critical for appropriate treatment. The acquired immunodeficiency syndrome (AIDS) dementia complex (ADC) was first defined in 1986. This was a frequent feature of HIV disease before antiretroviral therapy (ART) and highly active antiretroviral therapy came into common use in the mid-1990s. In addition to medical comorbidities, patients also frequently have various mental or psychosocial issues that can affect cognitive function, including mood disorders, post-traumatic stress disorder, and substance abuse or dependence. Increased risk of opportunistic infections, tumors, and side effects of ART drugs may also contribute to neurologic effects. Patients can experience delirium as part of the acute HIV syndrome or develop dementia during the later stages of their disease.

The spectrum of progressively more severe neurologic and cognitive symptoms (previously known as ADC) are now referred to as HIV-associated neurocognitive disorders (HAND) and were categorized in 2007 by the United States National Institutes of Health to include 3 classifications. These range in severity from asymptomatic neurocognitive impairment to minor neurocognitive disorder and HIV-associated dementia (HAD). The distinction between these levels is made by the use of neuropsychological testing in addition to observation of symptomatic functional impairment. Any other condition, including infection, cerebrovascular disease, or toxic encephalopathy, must not explain the observed impairment. In practice, distinguishing between the less severe categories of disease in the acute care setting is difficult due to the necessity of neuropsychological testing. Due to the profound symptomology and functional deficits associated with HAD, this diagnosis may be presumed, especially in patients with untreated or advanced stages of AIDS disease.