Cognitive Performance and Neuro-Metabolites in HIV using 3T Magnetic Resonance Spectroscopy: A Cross-Sectional Study from India.

BACKGROUND Cognitive impairment in patients with human immunodeficiency virus (HIV) is associated with higher morbidity. The prevalence of and the metabolite changes in the brain associated with cognitive impairment in anti-retroviral therapy naive patients with HIV is unknown. OBJECTIVE To estimate the prevalence of, and the neurometabolites associated with cognitive impairment in antiretroviral therapy (ART) naive patients with HIV. METHODS We conducted a cross-sectional study among ART naive patients with HIV aged 18-50 years in a tertiary care center in India. Cognition was tested using the Post Graduate Institute battery of brain dysfunction across five domains; memory, attentioninformation processing, abstraction executive, complex perceptual, and simple motor skills. We assessed the total N-acetyl aspartyl (tNAA), creatine (tCr) and glutamate + glutamine (Glx) using 3T magnetic resonance spectroscopy. Cognitive impairment was defined as an impairment in ≥2 domains. RESULTS Among 43 patients eligible for this study, the median age was 32 years (IQR 29, 40) and 30% were women. Median CD4 count and viral load were 317 cells/µL (IQR 157, 456) and 9.3 copies/ µL (IQR 1.4, 38), respectively. Impairment in at least one cognitive domain was present in 32 patients (74.4%). Impairment in simple motor skills and memory was present in 46.5% and 44% of patients, respectively. Cognitive impairment, defined by impairment in ≥2 domains, was found in 22 (51.2%) patients. There was a trend towards higher concentration of tNAA (7.3 vs. 7.0 mmol/kg), tGlx (9.1 vs. 8.2 mmol/kg), and tCr (5.5 vs. 5.2 mmol/kg) in the frontal lobe of patients with cognitive impairment vs. without cognitive impairment but it did not reach statistical significance (p>0.05 for all). There was no difference in the concentration of these metabolites in the two groups in the basal ganglia. CONCLUSIONS There is a high prevalence of cognitive impairment in ART naive patients with HIV. There is no difference in metabolites in patients with or without cognitive impairment. Further studies, with longitudinal follow-up, are required to understand the underlying pathophysiological mechanisms.