With the decline in morbidity and mortality from opportunistic infections and cancers in the combination antiretroviral therapy era, one of the most frightening possible complications of HIV infection is neurological decline. Previous research has shown that asymptomatic neurocognitive impairment (ANI; impairment in ≥2 domains on formal neuropsychological testing, without apparent functional impairment in everyday life) affects a sizable number of HIV-infected individuals.
In a recent investigation involving 347 CNS HIV Anti-Retroviral Therapy Effects Research (CHARTER) study participants, investigators assessed whether the presence of ANI increases the risk for future neurological decline. Neurocognitive assessments were conducted approximately every 6 months (median follow-up duration, 45.2 months).
At baseline, 121 individuals had ANI and 226 were neurocognitively normal; those with ANI had a higher educational level, a lower estimated verbal IQ, a lower nadir CD4 count (162 vs. 201 cells/mm3), and a higher incidence of comorbid conditions (44.6% vs. 22.6%), and a higher likelihood of an undetectable cerebrospinal fluid viral load (75.9% vs. 59.6%). A higher proportion of participants with ANI went on to develop symptomatic neurological decline (50.4% vs. 21.7%), as determined by self-report or performance-based assessment, and the neurological decline was noted earlier in those with ANI than in those who were neurocognitively normal at baseline. Risk factors for neurological decline, in addition to ANI, included older age, lower educational level, female sex, substance abuse, and lower nadir CD4-cell count.