Proton Chemical Shift Imaging Study of the Combined Antiretroviral Therapy Impact on Neurometabolic Parameters in Chronic HIV Infection.

BACKGROUND AND PURPOSE: The introduction of combination antiretroviral therapy has failed to reduce the high prevalence of mild forms of HIV-associated neurocognitive disorders. The aim of this study was to test the effect of combined antiretroviral therapy on brain metabolite ratios in chronic HIV infection by using proton chemical shift imaging. MATERIALS AND METHODS: We performed 2D chemical shift imaging in 91 subjects (31 HIV+ patients with chronic infection on combination antiretroviral therapy, 19 combination antiretroviral therapy-naïve HIV+ subjects with chronic infection, and 41 healthy controls), covering frontal and parietal subcortical white and cingulate gyrus gray matter, analyzing ratios of NAA/Cr and Cho/Cr on long-TE and mIns/Cr on short-TE MR spectroscopy. We correlated neurometabolic parameters with immunologic, clinical, data and combined antiretroviral therapy efficacy scores. RESULTS: There was a significant decrease in NAA/Cr (P < .05) in HIV-positive patients on and without combined antiretroviral therapy, compared with healthy controls in all locations. There were significant differences in Cho/Cr (P < .05) and mIns/Cr (P < .05) ratios between HIV+ patients on and without therapy, compared with healthy controls, but these differed in distribution. There were no significant differences in brain metabolite ratios between the 2 groups of chronically HIV-infected patients. The CNS penetration efficacy score showed weak positive correlations only with Cho/Cr ratios in some locations. CONCLUSIONS: The impact of combined antiretroviral therapy on the process of neuronal loss and dysfunction in chronic HIV infection appears to be suboptimal in successful peripheral suppression of viral replication. Spectroscopic imaging might be a useful tool for monitoring the effects of different combined antiretroviral therapy regimens on brain metabolite ratios.

Cognitive impairment and functional ability in the acute phase of ischemic stroke.

OBJECTIVE: Acute ischemic stroke significantly affects cognitive efficiency and functional ability, primarily physical ability. Decreased cognitive efficiency is often in correlation with decreased functional ability following an ischemic stroke. The aim of the study was to determine whether there is cognitive impairment in patients with preserved physical ability in acute ischemic stroke, and if so, determine whether there is a significant correlation with the functional, i.e. physical status. PATIENTS AND METHODS: The study included a total of 80 subjects: 40 subjects (26 male and 14 female) in the acute phase of ischemic stroke and 40 healthy subjects (20 male and 20 female) with no history of neurological disease. Both groups were matched with regard to basic sociodemographic characteristics. The cognitive status was evaluated using a comprehensive neuropsychological battery, while physical status was assessed using the modified Rankin scale. Cognitive performance was presented using the following seven cognitive domains: executive function, immediate recall, delayed recall, speech, divergent thinking, attention and concentration, and visual-constructive performance. RESULTS: The two groups differed in all the studied cognitive domains, with acute ischemic stroke subjects achieving poorer results. There was no correlation between the cognitive status and the functional, i.e.physical ability in the acute ischemic stroke group. CONCLUSIONS: The results showed significant impairment in all cognitive domains in the acute phase of ischemic stroke, regardless of the preserved functional, i.e. physical ability of these patients.