Cognitive disorders in HIV-infected patients: are they HIV-related?

Objectives: Large unselected studies on representative samples of HIV-infected patients with a whole battery of neuropsychological tests and cerebral MRI scan are required to assess the frequency of neurocognitive impairment (NCI), the determinants of mild neurocognitive disorders (MNDs), or HIV-associated dementia (HAD) and the relationship between NCI and MRI scan findings.

Methods: Investigation of 400 consecutively enrolled HIV-1-infected adults from the ANRS CO3 Aquitaine Cohort, using standardized neurocognitive tests chosen to achieve consistency with Frascati's criteria. Half of the patients had a cerebral MRI scan allowing gray and white matter volume measurement. Factors associated with NCI were studied by logistic regression models.

Results: Median age of participants was 47 years, 79% were male and 89% received combination antiretroviral treatment (cART), of whom 93% had plasma HIV RNA below 500 copies/ml. Median CD4 cell count was 515 cells/μl. Prevalence of NCI was 59%, including 21% of asymptomatic NCI, 31% of MND, and 7% of HAD. A low level of education, prior neurologic AIDS-defining disorders event, anxiety, depressive symptoms, and prior history of brain damage were independently associated with MND or HAD, but neither HIV nor cART-related variables. The presence of NCI was significantly associated with lower gray matter fraction.

Interpretation: In this large unselected cohort, a high prevalence of symptomatic neurocognitive disorders was mainly related to its traditional determinants and associated with gray matter atrophy at early stages of the disease.