What is the epidemiology of HIV associated neurocognitive disorder (HAND) and how has antiretroviral therapy (ART) affected this epidemiology?
The advent of ART has markedly decreased the prevalence of moderate to severe HIV-associated dementia.
However, milder forms of impairment remain very common, with some studies showing rates as high as 45%.
It is believed that this may be related to low levels of viral replication causing chronic inflammation.
What are the diagnostic criteria of HIV associated neurocognitive disorder?
HIV associated neurocognitive disorder (HAND) is divided into three categories.
Asymptomatic neurocognitive impairment (ANI) is characterized by poor performance (more than one standard deviation below the mean) in two or more domains of neuropsychiatric testing without note of symptoms by either patients or families.
Patients are categorized as having mild neurocognitive disorder once performance falls more than one standard deviation below the mean in at least two domains and experience mild impairment in daily function.
Patients have HIV-associated dementia (HAD) when performance falls at least two standard deviations below the mean in two or more domains and daily function is markedly impaired.
What is the pathogenesis of HAND?
Development of HAND is directly associated with CD4 nadir. Thus, early diagnosis and initiation of ART remains the mainstay of management.
What is the treatment of HAND?
While some ART regimens have been shown to have better CNS penetration, there is no consensus as to whether ART drugs with higher CNS penetration lead to improved cognitive outcomes.