EMPIRICALLY IDENTIFIED NEUROPSYCHOLOGICAL SUBTYPES IN HIV INFECTION: IMPLICATIONS FOR ETIOLOGY AND PROGNOSIS

Abstract

Heterogeneity in the profile of HIV-associated neuropsychological disorder (HAND) may obscure understanding of its etiology and prognosis. Despite longstanding acknowledgement of this heterogeneity, HAND diagnostic approaches such as the Frascati criteria characterize neuropsychological function based on the level of impairment, without regard to the pattern of strengths and weaknesses. Attention to these patterns may enhance etiologic and prognostic specificity. We used latent class analysis (LCA) to identify relatively homogeneous subtypes of neurocognitive function in adults with well-treated HIV infection. We compared the diagnostic agreement of latent classes and Frascati categories, as well as their associations with demographics, HIV markers and antiretroviral factors, comorbid medical and psychiatric conditions, and everyday functioning. LCA identified four classes, whose cognitive profiles are depicted in Figure 1: cognitively intact, mild-to-moderate motor/speed impairment, mild-to-moderate memory/visuoconstruction impairment, and moderate mixed impairment. Latent classes and Frascati categories demonstrated good agreement in the overall classification of impaired cognition but more disagreement regarding subtypes of impairment. Both latent classes and Frascati categories demonstrated unique associations with etiologic factors and significant associations with functional outcomes. However, only latent classes, not Frascati categories, were associated with HIV variables. Additionally, functional difficulties were significantly elevated in the motor impairment class but not the memory impairment class despite similar levels of cognitive impairment in the two groups. Findings support the utility of a diagnostic approach that accounts for both the level and pattern of neurocognitive impairment. Future research should examine the neuropathological mechanisms, longitudinal trajectories, and treatments of empirically identified HAND subtypes.