Spontaneous cerebrovascular reactivity at rest in older adults with and without mild cognitive impairment and memory deficits

Abstract

BackgroundOlder adults with mild cognitive impairment (MCI) exhibit deficits in cerebrovascular reactivity (CVR), suggesting CVR is a biomarker for vascular contributions to MCI. This study examined if spontaneous CVR is associated with MCI and memory impairment.Methods161 older adults free of dementia or major neurological/psychiatric disorders were recruited. Participants underwent clinical interviews, cognitive testing, venipuncture for Alzheimer’s biomarkers, and brain MRI. Spontaneous CVR was quantified during 5 minutes of rest.ResultsWhole brain CVR was negatively associated with age, but not MCI. Lower CVR in the parahippocampal gyrus (PHG) was found in participants with MCI and was linked to worse memory performance on memory tests. Results remained significant after adjusting for Alzheimer’s biomarkers and vascular risk factors.ConclusionSpontaneous CVR deficits in the PHG are observed in older adults with MCI and memory impairment, indicating medial temporal microvascular dysfunction’s role in cognitive decline.