The regional pattern of abnormal cerebrovascular reactivity in HIV-infected, virally suppressed women

Abstract

Objective-The purpose of this study was to assess whole brain and regional patterns of cerebrovascular reactivity (CVR) abnormalities in HIV-infected women using quantitative whole brain arterial spin labeling (ASL). We hypothesized that HIV-infected women would demonstrate decreased regional brain CVR despite viral suppression.Design-This cross sectional study recruited subjects from the Bay Area Women's Interagency Health Study (WIHS) -a cohort study designed to investigate the progression of HIV disease in women. In addition to conventional noncontrast cerebral MRI sequences, perfusion imaging was performed before and after the administration of intravenous acetazolamide.Methods-CVR was measured by comparing quantitative ASL brain perfusion before and after administration of intravenous acetazolamide. In order to validate and corroborate ASL-based whole brain and regional perfusion, phase-contrast (PC) imaging was also performed through the major neck vessels. FLAIR and susceptibility weighted sequences were performed to assess for white matter injury and microbleeds, respectively.Results-Ten HIV infected women and seven uninfected, age-matched controls were evaluated. Significant group differences were present in whole brain and regional CVR between HIV infected and uninfected women. These regional differences were significant in the frontal lobe and basal ganglia. CVR measurements were not significantly impacted by the degree of white matter signal abnormality or presence of microbleeds.

Accelerated Brain Aging and Cerebral Blood Flow Reduction in Persons With Human Immunodeficiency Virus

“…A key functional variable is cerebral blood flow (CBF), which governs the rate of oxygen and nutrient delivery to brain parenchyma. CBF is diminished by HIV [13,17] as is cerebrovascular reactivity, indicating uncoupling of neural activity from normal vascular responses [18]. Therefore, we applied structural and perfusion neuroimaging to model brain health across the lifespan in a large group of PWH and HIV-uninfected (HIV -) controls.…”

Initiation of combined antiretroviral therapy confers suboptimal beneficial effects on neurovascular function in people with HIV

“…Two recent studies have also assessed CVR in PWH using alternative approaches to ours. Callen et al ( 55 ) used changes in CBF induced by intravenous acetazolamide and found decreased CVR in the frontal lobe and basal ganglia. Chow et al ( 56 ) used transcranial Doppler ultrasound (TCD) and breath-holding to assess mean flow velocity changes to infer CVR.…”