Asymptomatic neurocognitive impairment is common among HIV-infected patients. Can it be used to predict future cognitive decline? New research answers the question.
HIV infection is associated with a spectrum of neurocognitive disorders that range from severe HIV-associated dementia (HAD) on one end to the more subtle forms-mild neurocognitive disorder [MND] and asymptomatic neurocognitive impairment [ANI] on the other end. Although antiretroviral therapy (ART) has rendered HAD relatively rare, MND and ANI remain prevalent.
ANI is the most common HIV-associated neurocognitive disorder, yet its clinical relevance is still unclear.1 Cognitive impairment among patients with ANI is detectable on formal neuropsychologic tests but does not noticeably impair daily function. Better understanding of ANI prevalence and, more importantly, of whether this milder form predicts more severe forms of neurocognitive decline would be invaluable to clinical practice. A new study published in the journal Neurology examines this question.
Investigators studied 347 subjects from the CNS HIV Anti-Retroviral Therapy Effects Research (CHARTER) cohort. At baseline, 262 patients were neurocognitively normal (NCN) and 121 had ANI as assessed by the Frascati criteria,2 which are based on comprehensive neuromedical, neurocognitive, psychiatric, and functional evaluations. Study participants were assessed approximately every 6 months, with a median follow-up of 45.2 (28.7 to 63.7) months. The study assessed risk ratios for progression to symptomatic HIV-associated neurocognitive disorders after adjusting for baseline and time-dependent covariates, including CD4+ cell count, virologic suppression, antiretroviral therapy, and mood.1
The study found that the time to symptomatic HIV-associated neurocognitive disorders was shorter in the ANI group than in the NCN group after adjusting for other baseline predictive factors. According to the method used to assess cognitive dysfunction (self-report or objective performance-based problems in daily function), there was a 2- to 6-fold increased risk for earlier development of symptomatic HIV-associated neurocognitive disorders in the ANI group. The findings strongly suggest that early ANI can be a harbinger of more severe forms of cognitive dysfunction later in life.1
All physicians caring for HIV-infected patients should be aware of the prognostic value of early ANI. This may enable early identification of those at highest risk for symptomatic decline and thus may offer an opportunity to adjust treatment to delay progression.1