An exploratory analysis of the relationship between cerebral flood flow, mood, and fluid cognition in older adults

Abstract

AbstractBackgroundASL, a common MRI measure of cerebral blood flow (CBF), is thought to be a potential tool in the detection of preclinical Alzheimer’s disease. This exploratory analysis examined the relationship between CBF, mood, and fluid cognitive performance on the NIH Toolbox Cognition Battery (NIHTB‐CB) as part of an ongoing triglyceride intervention study.Method20 female older adults (age 65.6 ± 7.6) underwent ASL MRI when fasting and two hours after a triglyceride intervention. 3D pCASL MRI with background suppression was used to measure CBF in ml/100g/min using label duration = 1.8 s, post‐labeling delay = 2 s, labeling offset = 25‐30 mm, slices = 30, resolution = 2×2×4 mm3, SENSE‐factor = 2, TR/TE = 5000/18 ms. We also performed a reference scan (M0, 1 minute) identical to the one above but with no labeling or background suppression and TR = 10,000 ms. CBF was measured globally and in four regions of interest: angular gyrus (AG), posterior cingulate (PC), temporal lobe, and the hippocampus. Subjects completed the Generalized Anxiety Disorder Scale (GAD‐7) and MoCA at screening. The NIHTB‐CB was completed following the second MRI, and age‐adjusted scores were used in all analyses.ResultBaseline global CBF, AG CBF, and hippocampal CBF negatively correlated with GAD‐7 scores (r = ‐.797, p<.0001; r = ‐.635, p = .0026; r = ‐.620, p = .0036, respectively). In contrast, global CBF and hippocampal CBF positively correlated with performance on the MoCA (r = .501, p = .0243; r = .546, p = .0126, respectively). Post‐intervention CBF in 3 of the 4 areas of interest positively correlated with fluid measures on the NIHTB‐CB, including the Flanker (AG: r = .528, p = .0166), Picture Sequence Memory Test (AG: r = .501, p = .0245; temporal lobe: r = .578, p = .0077), List Sorting Test (PC: r = .508, p = .0241), and fluid composite scores (AG: r = .610, p = .0043).ConclusionGreater anxiety correlated with lower baseline CBF overall and in the AG and hippocampus. Post‐lipid CBF correlated with better performance in working memory, executive function, and episodic memory. These results align with our predictions based on each of these regions’ functions. Further research exploring the relationship between mood and CBF is warranted, as well as investigating the effects of APOE4 status on these associations.