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 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.