Rasinio S. Graves

Feasibility of a Memory Clinic-Based Physical Activity Prescription Program

BACKGROUND Effective programs for promoting physical activity are needed for those with cognitive impairment. OBJECTIVE To test the feasibility of mobile Health (mHealth) technology-supported physical activity prescription from a tertiary care memory clinic. METHODS This feasibility study was designed as a 16-week randomized, crossover trial of a physical activity prescription: 8 weeks of intervention, 8 weeks of baseline or maintenance phase data collection. We recruited 2 cohorts: 21 individuals with Alzheimer-related cognitive impairment (mean age 72.3 (5.2), 9 females), and 9 individuals with normal cognition (mean age 69.6 (5.8), 8 females). We gave each cohort an mHealth accelerometer-based physical activity prescription to double number of steps taken. Our primary outcomes were feasibility and safety. Our secondary outcomes were change in weekly steps taken, Dementia Quality of Life Scale, Self-efficacy Scale, 6-minute Walk, and mini-Physical Performance Test. RESULTS Set-up and use of the device was not a barrier to participation. However, only 62% of participants with cognitive impairment completed the intervention. The cohort with cognitive impairment did not change their weekly step count above Week 1. All participants in the cohort with normal cognition were able to set up and use their device and increased their weekly step count above Week 1. There were no differences between Week 1 and Week 8 for any secondary measures in either cohort. CONCLUSIONS Setup and daily use of mHealth technology appears to be feasible for a person with cognitive impairment with the help of a partner, but increasing daily step counts over 8 weeks was not achieved. Future work needs to assess alternative activity prescription goals or additional support for patients and their partners.

Cardiorespiratory fitness and white matter integrity in Alzheimer’s disease

The objective of this study was to investigate the relationship between cardiorespiratory (CR) fitness and the brain’s white matter tract integrity using diffusion tensor imaging (DTI) in the Alzheimer’s disease (AD) population. We recruited older adults in the early stages of AD (n = 37; CDR = 0.5 and 1) and collected cross-sectional fitness and diffusion imaging data. We examined the association between CR fitness (peak oxygen consumption [VO2peak]) and fractional anisotropy (FA) in AD-related white matter tracts using two processing methodologies: a tract-of-interest approach and tract-based spatial statistic (TBSS). Subsequent diffusivity metrics (radial diffusivity [RD], mean diffusivity [MD], and axial diffusivity [A × D]) were also correlated with VO2peak. The tract-of-interest approach showed that higher VO2peak was associated with preserved white matter integrity as measured by increased FA in the right inferior fronto-occipital fasciculus (p = 0.035, r = 0.36). We did not find a significant correlation using TBSS, though there was a trend for a positive association between white matter integrity and higher VO2peak measures (p < 0.01 uncorrected). Our findings indicate that higher CR fitness levels in early AD participants may be related to preserved white matter integrity. However to draw stronger conclusions, further study on the relationship between fitness and white matter deterioration in AD is necessary.

Cardiopulmonary exercise testing is well tolerated in people with Alzheimer-related cognitive impairment.

OBJECTIVE To retrospectively assess whether cardiopulmonary exercise testing would be well tolerated in individuals with Alzheimer disease (AD) compared with a nondemented peer group. DESIGN We retrospectively reviewed 575 cardiopulmonary exercise tests (CPETs) in individuals with and without cognitive impairment caused by AD. SETTING University medical center. PARTICIPANTS Exercise tests (N=575) were reviewed for nondemented individuals (n=340) and those with AD-related cognitive impairment (n=235). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES The main outcome measure for this study was reporting the reason for CPET termination. The hypothesis reported was formulated after data collection. RESULTS We found that in cognitively impaired individuals, CPETs were terminated because of fall risk more often, but that overall test termination was infrequent-5.5% versus 2.1% (P=.04) in peers without cognitive impairment. We recorded 6 cardiovascular and 7 fall risk events in those with AD, compared with 7 cardiovascular and 0 fall risk events in those without cognitive impairment. CONCLUSIONS Our findings support using CPETs to assess peak oxygen consumption in older adults with cognitive impairment caused by AD.

AEROBIC EXERCISE REDUCES HIPPOCAMPAL ATROPHY IN INDIVIDUALS WITH EARLY ALZHEIMER'S DISEASE

Owen Thomas Carmichael, Tom Meade, Dementia Research Centre, London, England, United Kingdom; London School of Hygiene and Tropical Medicine, London, United Kingdom; UCL, London, United Kingdom; London School of Hygiene and Tropical Medicine, London; University College London, London, United Kingdom; UCL Institute of Neurology, London, United Kingdom; University of California, Davis, Davis, California, United States. Contact e-mail: jennifer.nicholas@lshtm. ac.uk

Augmenting amyloid PET interpretations with quantitative information improves consistency of cerebral amyloid detection

James B. Leverenz, Osama Sabri, Ana M. Catafau, Henryk Barthel, John Seibyl, Bernardino Ghetti, James W. Ironside, Santiago Bullich, Walter J. Schulz-Schaeffer, Anja Hoffman, Cleveland Clinic Neurological Institute, Cleveland, OH, USA; University of Leipzig, Leipzig, Germany; Piramal Imaging GmbH, Berlin, Germany; Molecular NeuroImaging, New Haven, CT, USA; Indiana University School of Medicine, Indianapolis, IN, USA; University of Edinburgh, Edinburgh, Scotland; Georg-August University G€ottingen, G€ottingen, Germany; Bayer Pharma AG, Berlin, Germany. Contact e-mail: leverej@ccf.org

Insulin resistance and cerebral amyloid deposition in cognitively healthy and preclinical ad subjects

(VAN), default mode network, and dorsal attention network) was assessed using template based rotation, an approach designed for use with existing network parcellations. A linear regression model with backward elimination (p<0.1 cut-off) was utilized with the FAQ as the dependent variable and the 4 networks as the predictors of interest. Covariates included age, sex, American National Adult Reading Test intelligence quotient (AMNART IQ, a proxy of premorbid IQ), processing speed, episodic memory, and fMRI confounders (signal-to-noise ratio, movement, and bad volumes). Results:There was a significant association between greater IADL impairment and reduced FPCN connectivity (b1⁄4-29.76, partial r(pr)1⁄4-0.36, p1⁄40.03) and increased VAN connectivity (b1⁄437.44, pr1⁄40.40, p1⁄40.02). Covariates retained in the model included premorbid IQ (b1⁄40.26, pr1⁄40.42, p1⁄40.01), processing speed (b1⁄40.12, pr1⁄4-0.37, p1⁄40.03), episodic memory (b1⁄4-0.11, pr1⁄4-0.29, p1⁄40.09), and movement (b1⁄427.61, pr1⁄40.33, p1⁄40.05). The overall model was significant (p1⁄40.005) and accounted for 41% of the variance. There was no significant association with the other networks. Conclusions:These results suggest that IADL impairment inMCI relates to a complex pattern of both reduced and increased connectivity in networks spanning frontal and parietal regions. Similar findings have been reported in a study using a global functioning measure, which consists of both IADL and cognition. Furthermore, reduced FPCNconnectivity has been associatedwith greater apathy, which has been associated with IADL impairment, and increased VAN connectivity has been associated with greater executive dysfunction, which has been associated with IADL impairment.