Interactive effects of vascular risk burden and advanced age on cerebral blood flow.

Vascular risk factors and cerebral blood flow (CBF) reduction have been linked to increased risk of cognitive impairment and Alzheimer's disease (AD); however the possible moderating effects of age and vascular risk burden on CBF in late life remain understudied. We examined the relationships among elevated vascular risk burden, age, CBF, and cognition. Seventy-one non-demented older adults completed an arterial spin labeling MR scan, neuropsychological assessment, and medical history interview. Relationships among vascular risk burden, age, and CBF were examined in a priori regions of interest (ROIs) previously implicated in aging and AD. Interaction effects indicated that, among older adults with elevated vascular risk burden (i.e., multiple vascular risk factors), advancing age was significantly associated with reduced cortical CBF whereas there was no such relationship for those with low vascular risk burden (i.e., no or one vascular risk factor). This pattern was observed in cortical ROIs including medial temporal (hippocampus, parahippocampal gyrus, uncus), inferior parietal (supramarginal gyrus, inferior parietal lobule, angular gyrus), and frontal (anterior cingulate, middle frontal gyrus, medial frontal gyrus) cortices. Furthermore, among those with elevated vascular risk, reduced CBF was associated with poorer cognitive performance. Such findings suggest that older adults with elevated vascular risk burden may be particularly vulnerable to cognitive change as a function of CBF reductions. Findings support the use of CBF as a potential biomarker in preclinical AD and suggest that vascular risk burden and regionally-specific CBF changes may contribute to differential age-related cognitive declines

Bipolar Patients with Vascular Risk Display a Steeper Age-Related Negative Slope in Inhibitory Performance but Not Processing Speed: A Preliminary Study

ObjectiveBipolar disorder (BD) is associated with cognitive deficits, yet little is known about associations between cognition, vascular risk (VR), and age in this population. This study investigated whether BD patients with VR demonstrate stronger apparent age-related decline in inhibitory performance and processing speed (PS).MethodsA full medical history was obtained for 34 euthymic BD and 41 healthy comparison (HC) individuals. The Delis-Kaplan Executive Functions Color Word Interference Subtests were administered to all participants to assess for inhibitory performance (condition 3) and PS (conditions 1 and 2). VR positive (VRPos) and VR negative (VRNeg) groups were created based on the presence of one or more VR factors.ResultsVRPos-BD participants demonstrated significantly worse inhibitory performance with older age, whereas age and inhibition were not significantly related in the VRPos-HC group or in those who were VRNeg. The same was not true for PS.ConclusionBD patients with VR may also be at risk for greater decline in inhibitory performance, but not PS, with age. Longitudinal studies are needed to further investigate the contributions of VR to cognitive decline among older BD patients

Disruptions in resting state functional connectivity in euthymic bipolar patients with insomnia symptoms

Insomnia is prevalent in bipolar disorder (BD) even during periods of euthymic mood. We compared resting state brain activity and cognitive function between euthymic BD with and without insomnia, and secondarily to healthy individuals. BD patients with insomnia symptoms showed a significantly lower functional connectivity within the task-positive network, compared to those without insomnia. They also showed significantly slower cognitive processing speed. These two features of BD with insomnia appeared relatively independent of each other. Preliminary findings suggest that exploration of the mechanisms of sleep disturbance in BD could lead to improved understanding and treatment of inattention in BD

Distinct neural correlates of emotional and cognitive empathy in older adults.

Empathy is thought to be a mechanism underlying prosocial behavior across the lifespan, yet little is known about how levels of empathy relate to individual differences in brain functioning among older adults. In this exploratory study, we examined the neural correlates of affective and cognitive empathy in older adults. Thirty older adults (M=79 years) underwent fMRI scanning and neuropsychological testing and completed a test of affective and cognitive empathy. Brain response during processing of cognitive and emotional stimuli was measured by fMRI in a priori and task-related regions and was correlated with levels of empathy. Older adults with higher levels of affective empathy showed more deactivation in the amygdala and insula during a working memory task, whereas those with higher cognitive empathy showed greater insula activation during a response inhibition task. Our preliminary findings suggest that brain systems linked to emotional and social processing respond differently among older adults with more or less affective and cognitive empathy. That these relationships can be seen both during affective and non-emotional tasks of "cold" cognitive abilities suggests that empathy may impact social behavior through both emotional and cognitive mechanisms

Bipolar Patients with Vascular Risk Display a Steeper Age-Related Negative Slope in Inhibitory Performance but Not Processing Speed: A Preliminary Study

OBJECTIVE: Bipolar disorder (BD) is associated with cognitive deficits, yet little is known about associations between cognition, vascular risk (VR) and age in this population. This study investigated whether BD patients with VR demonstrate stronger apparent age-related decline in inhibitory performance and processing speed (PS). METHODS: A full medical history was obtained for 34 euthymic BD and 41 healthy comparison (HC) individuals. The Delis-Kaplan Executive Functions Color Word Interference Subtests was administered to all participants to assess for inhibitory performance (condition 3) and PS (condition 1 and 2). VR positive (VRPos) and VR negative (VRNeg) groups were created based on the presence of one or more VR factors. RESULTS: VRPos-BD participants demonstrated significantly worse inhibitory performance with older age, while age and inhibition were not significantly related in the VRPOS-HC group or in those who were VRNeg. The same was not true for PS. CONCLUSION: BD patients with VR may also be at risk for greater decline in inhibitory performance, but not PS, with age. Longitudinal studies are needed to further investigate the contributions of VR to cognitive decline among older BD patients

Dynamic Functional Connectivity in Bipolar Disorder Is Associated With Executive Function and Processing Speed: A Preliminary Study

ObjectiveDisturbances in functional connectivity have been suggested to contribute to cognitive and emotion processing deficits observed in bipolar disorder (BD). Functional connectivity between medial prefrontal cortex (mPFC) and other brain regions may be particularly abnormal. The goal of the present study was to characterize the temporal dynamics of the default mode network (DMN) connectivity in BD and examine its association with cognition.MethodIn a preliminary study, euthymic BD (n = 15) and healthy comparison (HC, n = 19) participants underwent resting-state functional MRI, using high-resolution sequences adapted from the Human Connectome Project, and completed neuropsychological measures of processing speed and executive function. A seed-based approach was used to measure DMN correlations in each participant, with regions of interest in the mPFC, posterior cingulate cortex (PCC), and lateral parietal cortex. Subsequently, to characterize temporal dynamics, correlational analyses between the mPFC and other DMN nodes were repeated using a sliding-window correlational analysis with subsets of the time series.ResultsWhen averaged across the entire scan, there were no group differences in overall connectivity strength between the mPFC and other regions of the DMN. However, dynamic connectivity between the mPFC and PCC was altered in BD, such that connectivity was less variable (i.e., more rigid) over time. Decreased connectivity variability was associated with slower processing speed and reduced cognitive set-shifting in BD patients.ConclusionsVariability in resting-state functional connectivity may be an index of internetwork flexibility that is reduced in BD and a correlate of ongoing cognitive impairment during periods of euthymia. (PsycINFO Database Recor