HAND comprises all types of neurocognitive impairment that can be seen in individuals with HIV. HAND can be categorized: into 3 categories based on severity: asymptomatic neurocognitive impairment (where there is no problem with daily functioning and there is impairment on two or more neurocognitive domains), mild neurocognitive disorder (where there is mild to moderate interference in daily functioning and there is impairment two or more neurocognitive domains), and HIV-associated dementia (where there is marked interference with daily functioning and there is marked impairment in two or more neurocognitive domains). It was widely assumed that CART would end HIV-related neurocognitive disorders, but this did not turn out to be true. Antiretrovirals have variable penetration in the CNS which can allow for ongoing replication of the virus within the CNS. Antiretrovirals also can cause direct toxicity and immune activation which can contribute to neurocognitive decline. Despite similar rates of incidence and prevalence of HAND with the advent of CART, there has been a significant decline in HIV-associated dementia, suggesting that CART has been effective in slowing both the progression and severity of HAND. Asymptomatic neurocognitive impairment and mild neurocognitive disorder have increased in incidence and prevalence since the advent of CART, which may be a reflection of the increased survival time in individuals living with HIV that are compliant with CART.

Publication reference : Sacktor, N., Skolasky, R. L., Seaberg, E., Munro, C., Becker, J. T., Martin, E., ... & Miller, E. (2016). Prevalence of HIV-associated neurocognitive disorders in the Multicenter AIDS Cohort Study. Neurology, 86(4), 334-340.
Reference URL: https://www.ncbi.nlm.nih.gov/pubmed/26718568