Cognitive reserve moderates the association between cerebral blood flow and language performance in older adults with mild cognitive impairment

• Published in: Neurobiology of aging 2023-05, Vol.125, p.83-89
• Main Authors: Brenner, Einat K., Thomas, Kelsey R., Weigand, Alexandra J., Edwards, Lauren, Edmonds, Emily C., Bondi, Mark W., Bangen, Katherine J.
• Format: Article
• Language: English
• Subjects: Aged; Alzheimer's disease; Category fluency; Cerebral blood flow; Cerebrovascular Circulation - physiology; Cognition - physiology; Cognitive Dysfunction - psychology; Cognitive Reserve; Humans; Language; Magnetic Resonance Imaging; Mild cognitive impairment
• ISSN: 0197-4580; 1558-1497; 1558-1497
• DOI: 10.1016/j.neurobiolaging.2023.01.012

•Verbal intelligence quotient (VIQ), perfusion, and group interact on fluency.•In mild cognitive impairment (MCI), VIQ and perfusion interact on category fluency.•Among the cognitively unimpaired, VIQ and perfusion did not interact on cognition.•As VIQ increased, the strength of the perfusion-fluency association increased.•In MCI, higher VIQ strengthens associations between perfusion and category fluency. Higher cognitive reserve (CR) may offer protection from cognitive changes associated with reduced cerebral blood flow (CBF). We investigated CR as a moderator of the effect of CBF on cognition in older adults with mild cognitive impairment (MCI; N = 46) and those who are cognitively unimpaired (CU; N = 101). Participants underwent arterial spin labeling MRI, which was used to quantify CBF in 4 a priori regions. Estimated verbal intelligence quotient (VIQ) served as a proxy for CR. Multiple linear regressions examined whether VIQ moderated associations between CBF and cognition and whether this differed by cognitive status. Outcomes included memory and language performance. There were 3-way interactions (CBF*VIQ*cognitive status) on category fluency when examining hippocampal, superior frontal, and inferior frontal CBF. Follow-up analyses revealed that, within the MCI but not CU group, there were CBF*VIQ interactions on fluency in all a priori regions examined, where there were stronger, positive associations between CBF and fluency at higher VIQ. Conclusion: In MCI, higher CR plays a role in strengthening CBF-fluency associations.