Vascular health risks and fMRI activation during a memory task in older adults

Abstract

Vascular problems increase Alzheimer's disease (AD) risk, but the nature of this relationship remains unclear. Older adults having genetic risk for AD show regionally increased functional magnetic resonance imaging (fMRI) activity during memory, possibly representing compensation for a genetically induced neural deficit. We investigated whether vascular health risks, which similarly could lead to neuropsychological deficits, also showed increased fMRI activity during a memory task performed by 30 cognitively intact, primarily normotensive older adults (mean age = 61). Vascular risk measures included systolic blood pressure (sBP), body mass index (BMI), and total cholesterol. Higher sBP and BMI (but not total cholesterol) were significantly correlated with increased activation in posterior cingulate cortex and frontal, temporal, and parietal regions. In posterior cingulate and parietal cortices, these relationships were evident even within sBP and BMI ranges considered normal, and were independent of hippocampal volume. Our results are similar to those in prior AD risk research, and suggest that fMRI reveals an abnormal response to cognitive processes in cognitively intact older adults with increased vascular risk.

Cardiovascular risks and brain function: a functional magnetic resonance imaging study of executive function in older adults

“…Furthermore, the increased or decreased activation between a resting state positron emission tomography scan and a task-related fMRI scan require different interpretations. Another recent study by Braskie et al (2010) using fMRI found that during a memory task, participants with higher systolic blood pressure and body mass index had increased activation in the posterior cingulate cortex and parietal cortex. Our results are somewhat consistent with this finding since both found that increased CV risk was associated with higher activation in task-related brain regions.…”

Relationships between default-mode network connectivity, medial temporal lobe structure, and age-related memory deficits

“…Additionally, memory function is well described as a distributed process (Mesulam, 1990), and the brain substrates and modifiers of this process are highly variable, particularly in a cognitive aging context (Braskie, et al, 2010, Head, et al, 2008, Raz and Rodrigue, 2006, Verhaeghen, et al, 1993). Vascular risk factors, diabetes, and level of physical activity, sleep duration, and sleep quality have all been linked to brain structure and function necessary for supporting memory processes (den Heijer, et al, 2003, Goel, et al, 2009, Guzman, et al, 2013, Harrison and Horne, 2000, Honea, et al, 2009, Mander, et al, 2013, Raz and Rodrigue, 2006, Voss, et al, 2010, Zlokovic, 2011).…”

The Effects of Aerobic Exercise on Cognitive and Neural Decline in Aging and Cardiovascular Disease

“…CVD has also been associated with structural and functional alterations in the fronto-parietal and medial temporal lobe regions, including reduced brain volume [40–42], decreased white matter integrity [43, 44], reductions in cerebral blood flow [45, 46] and altered fMRI activity in the hippocampus, cingulate gyrus and fronto-parietal regions during memory [47, 48] and executive function tasks [49–52]. Structural and functional brain alterations associated with aging and CVD induce predictable cognitive impairments such as deficits in episodic memory and executive dysfunction [53–55].…”