DCE-MRI of Brain Fluid Barriers: In Vivo Water Cycling at the Human Choroid Plexus.

Metabolic deficits at brain-fluid barriers are an increasingly recognized feature of cognitive decline in older adults. At the blood-cerebrospinal fluid barrier, water is transported across the choroid plexus (CP) epithelium against large osmotic gradients via processes tightly coupled to activity of the sodium/potassium pump. Here, we quantify CP homeostatic water exchange using dynamic contrast-enhanced MRI and investigate the association of the water efflux rate constant (kco) with cognitive dysfunction in older individuals. Temporal changes in the longitudinal relaxation rate constant (R1) after contrast agent bolus injection were measured in a CP region of interest in 11 participants with mild cognitive dysfunction [CI; 73 ± 6 years] and 28 healthy controls [CN; 72 ± 7 years]. kco was determined from a modified two-site pharmacokinetic exchange analysis of the R1 time-course. Ktrans, a measure of contrast agent extravasation to the interstitial space was also determined. Cognitive function was assessed by neuropsychological test performance. kco averages 5.8 ± 2.7 s-1 in CN individuals and is reduced by 2.4 s-1 [ca. 40%] in CI subjects. Significant associations of kco with global cognition and multiple cognitive domains are observed. Ktrans averages 0.13 ± 0.07 min-1 and declines with age [-0.006 ± 0.002 min-1 yr-1], but shows no difference between CI and CN individuals or association with cognitive performance. Our findings suggest that the CP water efflux rate constant is associated with cognitive dysfunction and shows an age-related decline in later life, consistent with the metabolic disturbances that characterize brain aging.

Differentiating among stages of cognitive impairment in aging: Version 3 of the Uniform Data Set (UDS) neuropsychological test battery and MoCA index scores.

INTRODUCTION: Federally funded Alzheimer's Disease Centers in the United States have been using a standardized neuropsychological test battery as part of the National Alzheimer's Coordinating Center Uniform Data Set (UDS) since 2005. Version 3 (V3) of the UDS replaced the previous version (V2) in 2015. We compared V2 and V3 neuropsychological tests with respect to their ability to distinguish among the Clinical Dementia Rating (CDR) global scores of 0, 0.5, and 1. METHODS: First, we matched participants receiving V2 tests (V2 cohort) and V3 tests (V3 cohort) in their cognitive functions using tests common to both versions. Then, we compared receiver-operating characteristic (ROC) area under the curve in differentiating CDRs for the remaining tests. RESULTS: Some V3 tests performed better than V2 tests in differentiating between CDR 0.5 and 0, but the improvement was limited to Caucasian participants. DISCUSSION: Further efforts to improve the ability for early identification of cognitive decline among diverse racial groups are required.

"Are You Sure?": Lapses in Self-Reported Activities Among Healthy Older Adults Reporting Online.

Accurate retrospective reporting of activities and symptoms has been shown to be problematic for older adults, yet standard clinical care relies on self-reports to aid in assessment and management. Our aim was to examine the relationship between self-report and sensor-based measures of activity. We administered an online activity survey to participants in our ongoing longitudinal study of in-home ubiquitous monitoring. We found a wide range of accuracies when comparing self-report with time-stamped sensor-based data. Of the 95 participants who completed the 2-hr activity log, nearly one quarter did not complete the task in a way that could potentially be compared with sensor data. Where comparisons were possible, agreement between self-reported and sensor-based activity was achieved by a minority of participants. The findings suggest that capture of real-time events with unobtrusive activity monitoring may be a more reliable approach to describing behavioral patterns and meaningful changes in older adults.

Computer-related self-efficacy and anxiety in older adults with and without mild cognitive impairment.

BACKGROUND: This study examines differences in computer-related self-efficacy and anxiety in subgroups of older adults, and changes in those measures after exposure to a systematic training program and subsequent computer use. METHODS: Participants were volunteers in the Intelligent Systems for Assessment of Aging Changes study (ISAAC) carried out by the Oregon Center for Aging and Technology. Participants were administered two questionnaires before training and again 1 year later, which were related to computer self-efficacy and anxiety. Continuous recording of computer use was also assessed for a subset of participants. RESULTS: Baseline comparisons by sex, age, education, living arrangement, and computer proficiency, but not cognitive status, yielded significant differences in confidence and anxiety related to specific aspects of computer use. At 1-year follow-up, participants reported less anxiety and greater confidence. However, the benefits of training and exposure varied by group and task. Comparisons based on cognitive status showed that the cognitively intact participants benefited more from training and/or experience with computers than did participants with mild cognitive impairment (MCI), who after 1 year continued to report less confidence and more anxiety regarding certain aspects of computer use. CONCLUSION: After 1 year of consistent computer use, cognitively intact participants in this study reported reduced levels of anxiety and increased self-confidence in their ability to perform specific computer tasks. Participants with MCI at baseline were less likely to demonstrate increased efficacy or confidence than their cognitively intact counterparts.

Reactions to a remote-controlled video-communication robot in seniors' homes: a pilot study of feasibility and acceptance.

OBJECTIVE: Remote telepresence provided by tele-operated robotics represents a new means for obtaining important health information, improving older adults' social and daily functioning and providing peace of mind to family members and caregivers who live remotely. In this study we tested the feasibility of use and acceptance of a remotely controlled robot with video-communication capability in independently living, cognitively intact older adults. MATERIALS AND METHODS: A mobile remotely controlled robot with video-communication ability was placed in the homes of eight seniors. The attitudes and preferences of these volunteers and those of family or friends who communicated with them remotely via the device were assessed through survey instruments. RESULTS: Overall experiences were consistently positive, with the exception of one user who subsequently progressed to a diagnosis of mild cognitive impairment. Responses from our participants indicated that in general they appreciated the potential of this technology to enhance their physical health and well-being, social connectedness, and ability to live independently at home. Remote users, who were friends or adult children of the participants, were more likely to test the mobility features and had several suggestions for additional useful applications. CONCLUSIONS: Results from the present study showed that a small sample of independently living, cognitively intact older adults and their remote collaterals responded positively to a remote controlled robot with video-communication capabilities. Research is needed to further explore the feasibility and acceptance of this type of technology with a variety of patients and their care contacts.

Wechsler Memory Scale-III Faces test performance in patients with mild cognitive impairment and mild Alzheimer's disease.

Little is known about the sensitivity of the Wechsler Memory Scale-Third Edition (WMS-III) Faces subtest to memory impairment associated with mild cognitive impairment (MCI). In this study, Faces performance was examined in 24 MCI patients, 46 mild Alzheimer's disease (AD) patients, and 98 elderly controls. We hypothesized that participants with diagnoses of MCI or AD would be impaired relative to controls on Faces. Analyses showed that AD participants performed significantly worse than MCI and intact participants, although there were no significant differences between MCI and intact participants. Data suggest that brain areas specialized for face recognition memory may be less affected by MCI and mild AD than regions specialized for verbal memory.