In 1991, the AIDS Task Force of the American Academy of Neurology published nomenclature and research case definitions to guide the diagnosis of neurologic manifestations of HIV-1 infection. Now, 16 years later, the National Institute of Mental Health and the National Institute of Neurological Diseases and Stroke have charged a working group to critically review the adequacy and utility of these definitional criteria and to identify aspects that require updating. This report represents a majority view, and unanimity was not reached on all points. It reviews our collective experience with HIV-associated neurocognitive disorders (HAND), particularly since the advent of highly active antiretroviral treatment, and their definitional criteria; discusses the impact of comorbidities; and suggests inclusion of the term asymptomatic neurocognitive impairment to categorize individuals with subclinical impairment. An algorithm is proposed to assist in standardized diagnostic classification of HAND.

GLOSSARY: AAN = American Academy of Neurology; ADLs = activities of daily living; ANI = asymptomatic neurocognitive impairment; HAART = highly active antiretroviral treatment; HAD = HIV-associated dementia; HAND = HIV-associated neurocognitive disorders; HNRC = HIV Neurobehavioral Research Center; IADLs = instrumental ADLs; MCMD = minor cognitive motor disorder; MND = HIV-associated mild neurocognitive disorder; MSE = mental status examination.