| 1. |
- Cedervall, Ylva, et al.
(författare)
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Timed Up-and-Go Dual-Task Testing in the Assessment of Cognitive Function : A Mixed Methods Observational Study for Development of the UDDGait Protocol
- 2020
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 17:5
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Tidskriftsartikel (refereegranskat)abstract
- New methods to screen for and identify early-stage dementia disorders are highly sought after. The purpose of this pilot study is to develop a study protocol for a dual-task test aimed at aiding the early detection of dementia disorders. We used the Timed Up-and-Go (TUG) test, which is a mobility task involving starting in a sitting position, standing up, walking three meters to cross a line on the floor, turning around, walking back and sitting down again. We combined TUG with the verbal task of naming different animals. Pilot study participants were 43 individuals with and without established dementia diagnoses who attended a clinic for memory assessment. Video-recorded test performances were systematically analysed. Deviant test performances concerning the interplay between test administration and participants' responses to the assessment instructions were revealed and led to refinements being made to the final study protocol. Exploration of the dual-task test outcome measures in a sub-sample of 22 persons, ten with and twelve without dementia, indicated that step-length and number of named animals after the turning point of the dual-task test might constitute appropriate measures for examining this kind of sample. We concluded that the refined study protocol is feasible for testing individuals undergoing initial memory assessments and healthy controls. Follow-up studies with larger samples are being carried out and will bring new knowledge to this area of research. It may also provide an opportunity for further studies exploring possibilities for broad clinical implementation.
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| 2. |
- Olivo, G., et al.
(författare)
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Immediate effects of a single session of physical exercise on cognition and cerebral blood flow: A randomized controlled study of older adults
- 2021
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Ingår i: Neuroimage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 225
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Tidskriftsartikel (refereegranskat)abstract
- Background: Regular physical activity is beneficial for cognitive performance in older age. A single bout of aerobic physical exercise can transiently improve cognitive performance. Researchers have advanced improvements in cerebral circulation as a mediator of long-term effects of aerobic physical exercise on cognition, but the immediate effects of exercise on cognition and cerebral perfusion are not well characterized and the effects in older adults are largely unknown. Methods: Forty-nine older adults were randomized to a 30-min aerobic exercise at moderate intensity or relaxation. Groups were matched on age and cardiovascular fitness (VO2 max). Average Grey Matter Blood Flow (GMBF), measured by a pulsed arterial-spin labeling (pASL) magnetic resonance imaging (MRI) acquisition, and working memory performance, measured by figurative n-back tasks with increasing loads were assessed before and 7 min after exercising/resting. Results: Accuracy on the n-back task increased from before to after exercising/resting regardless of the type of activity. GMBF decreased after exercise, relative to the control (resting) group. In the exercise group, higher n-back performance after exercise was associated with lower GMBF in the right hippocampus, left medial frontal cortex and right orbitofrontal cortex, and higher cardiovascular fitness was associated with lower GMBF. Conclusion: The decrease of GMBF reported in younger adults shortly after exercise also occurs in older adults and relates to cardiovascular fitness, potentially supporting the link between cardiovascular fitness and cerebrovascular reactivity in older age.
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| 3. |
- Heiland, Emerald G, et al.
(författare)
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Cerebral small vessel disease, cardiovascular risk factors, and future walking speed in old age : a population-based cohort study.
- 2021
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Ingår i: BMC Neurology. - : BioMed Central. - 1471-2377. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The purpose of this study was to examine the associations between combined and individual cerebral small vessel disease (cSVD) markers on future walking speed over 9 years; and to explore whether these associations varied by the presence of cardiovascular risk factors (CRFs).METHODS: This population-based cohort study included 331 adults, aged ≥60 years, without limitation in walking speed (≥0.8 m/s). At baseline, cSVD markers, including white matter hyperintensities (WMH), lacunes, and perivascular spaces (PVS), were assessed on magnetic resonance imaging. The modifiable CRFs (physical inactivity, heavy alcohol consumption, smoking, hypertension, high total cholesterol, diabetes, and overweight/obese) were combined into a score. The association between baseline cSVD markers and the decline in walking speed was examined using linear mixed-effects models, whereas Cox proportional hazards models were used to estimate the association with walking speed limitation (defined as < 0.8 m/s) over the follow-up.RESULTS: Over the follow-up period, 76 (23.0%) persons developed walking speed limitation. Participants in the highest tertile of the combined cSVD marker score had a hazard ratio (HR) of 3.78 (95% confidence interval [CI] 1.70-8.45) for walking speed limitation compared with people in the lowest score tertile, even after adjusting for socio-demographics, CRFs, cognitive function, and chronic conditions. When investigating the cSVD markers individually, having the highest burden of WMH was associated with a significantly faster decline in walking speed (β coefficient - 0.020; 95% CI -0.035-0.004) and a greater HR of walking speed limitation (HR 2.78; 95% CI 1.31-5.89) compared with having the lowest WMH burden. Similar results were obtained for the highest tertile of PVS (HR 2.13; 95% CI 1.04-4.36). Lacunes were associated with walking speed limitation, but only in men. Having ≥4 CRFs and high WMH volume simultaneously, showed a greater risk of walking speed limitation compared with having ≥4 CRFs and low WMH burden. CRFs did not modify the associations between lacunes or PVS and walking speed.CONCLUSIONS: Combined cSVD markers strongly predict walking speed limitation in healthy older adults, independent of cognitive function, with WMH and PVS being the strongest contributors. Improving cardiovascular health may help to mitigate the negative effects of WMH on future walking speed.
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| 4. |
- Gallo, Federico, et al.
(författare)
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Cognitive Trajectories and Dementia Risk : A Comparison of Two Cognitive Reserve Measures.
- 2021
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives: Cognitive reserve (CR) is meant to account for the mismatch between brain damage and cognitive decline or dementia. Generally, CR has been operationalized using proxy variables indicating exposure to enriching activities (activity-based CR). An alternative approach defines CR as residual variance in cognition, not explained by the brain status (residual-based CR). The aim of this study is to compare activity-based and residual-based CR measures in their association with cognitive trajectories and dementia. Furthermore, we seek to examine if the two measures modify the impact of brain integrity on cognitive trajectories and if they predict dementia incidence independent of brain status.Methods: We used data on 430 older adults aged 60+ from the Swedish National Study on Aging and Care in Kungsholmen, followed for 12 years. Residual-based reserve was computed from a regression predicting episodic memory with a brain-integrity index incorporating six structural neuroimaging markers (white-matter hyperintensities volume, whole-brain gray matter volume, hippocampal volume, lateral ventricular volume, lacunes, and perivascular spaces), age, and sex. Activity-based reserve incorporated education, work complexity, social network, and leisure activities. Cognition was assessed with a composite of perceptual speed, semantic memory, letter-, and category fluency. Dementia was clinically diagnosed in accordance with DSM-IV criteria. Linear mixed models were used for cognitive change analyses. Interactions tested if reserve measures modified the association between brain-integrity and cognitive change. Cox proportional hazard models, adjusted for brain-integrity index, assessed dementia risk.Results: Both reserve measures were associated with cognitive trajectories [β × time (top tertile, ref.: bottom tertile) = 0.013; 95% CI: -0.126, -0.004 (residual-based) and 0.011; 95% CI: -0.001, 0.024, (activity-based)]. Residual-based, but not activity-based reserve mitigated the impact of brain integrity on cognitive decline [β (top tertile × time × brain integrity) = -0.021; 95% CI: -0.043, 0.001] and predicted 12-year dementia incidence, after accounting for the brain-integrity status [HR (top tertile) = 0.23; 95% CI: 0.09, 0.58].Interpretation: The operationalization of reserve based on residual cognitive performance may represent a more direct measure of CR than an activity-based approach. Ultimately, the two models of CR serve largely different aims. Accounting for brain integrity is essential in any model of reserve.
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| 5. |
- Speh, Andreja, et al.
(författare)
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The Relationship Between Cardiovascular Health and Rate of Cognitive Decline in Young-Old and Old-Old Adults : A Population-Based Study
- 2021
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 84:4, s. 1523-1537
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Tidskriftsartikel (refereegranskat)abstract
- Background: Modifiable vascular risk factors have been associated with late-life cognitive impairment. The Life Simple 7 (LS7) score comprises seven cardiovascular health metrics: smoking, diet, physical activity, body mass index, plasma glucose, total serum cholesterol, and blood pressure. Objective: To investigate the association between individual and composite LS7 metrics and rate of cognitive decline, and potential differences in these associations between young-old and old-old individuals. Methods: This cohort study included 1,950 participants aged >= 60 years (M= 70.7 years) from the Swedish National Study on Aging and Care-Kungsholmen (SNAC-K), who underwent repeated neuropsychological testing (episodic and semantic memory, verbal fluency, processing speed, global cognition) across 12 years. The LS7 score was assessed at baseline and categorized as poor, intermediate, or optimal. Level and change in cognitive performance as a function of LS7 categories were estimated using linear mixed-effects models. Results: Having an optimal LS7 total score was associated with better performance (expressed in standard deviation units) at baseline for perceptual speed (beta=0.21, 95% CI 0.12-0.29), verbal fluency (beta=0.08, 0.00-0.16), and global cognition (beta = 0.06, 0.00-0.12) compared to the poor group. Age-stratified analyses revealed associations for cognitive level and change only in the young-old (< 78 years) group. For the specific metrics, diverging patterns were observed for young-old and old-old individuals. Conclusion: Meeting the LS7 criteria for ideal cardiovascular health in younger old age is associated with slower rate of cognitive decline. However, the LS7 criteria may have a different meaning for cognitive function in very old adults.
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| 6. |
- Hoy, Sara, et al.
(författare)
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Effects of yoga-based interventions on cognitive function in healthy older adults : A systematic review of randomized controlled trials.
- 2021
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Ingår i: Complementary Therapies in Medicine. - : Elsevier. - 0965-2299 .- 1873-6963. ; 58
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The world's elderly population is growing. Physical activity has positive effects on health and cognition, but is decreasing among the elderly. Interest in yoga-based exercises has increased in this population, especially as an intervention targeting balance, flexibility, strength, and well-being. Recent interest has arisen regarding yoga's potential benefits for cognition.OBJECTIVE: To systematically review evidence from randomized controlled trials (RCTs) examining the effects of yoga-based interventions on cognitive functioning in healthy adults aged ≥60. A secondary aim was to describe intervention characteristics and, where possible, the extent to which these influenced study outcomes.METHOD: The review was conducted in accordance with PRISMA guidelines. Searches were performed from inception to June 2020 using the following electronic databases: (1) PubMed (NLM); (2) Embase (Elsevier); (3) Cochrane Central (Wiley); (4) PsycINFO (EBSCOhost); and (5) Cinahl (EbscoHost).INCLUSION CRITERIA: RCTs of yoga-based interventions assessing cognition in healthy adults ≥60 years. Risk of bias was assessed using the revised Cochrane risk of bias tool.RESULTS: A total of 1466 records were initially identified; six studies (5 unique trials) were included in the review. Four of the six articles reported significant positive effects of yoga-based interventions on cognition, including gross memory functioning and executive functions. Intervention characteristics and assessment methods varied between studies, with a high overall risk of bias in all studies.CONCLUSION: Yoga-based interventions are associated with improvements in cognition in healthy older adults. Adequately powered RCTs with robust study designs and long-term follow-ups are required. Future studies should explicitly report the intervention characteristics associated with changes in cognitive function.
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| 7. |
- Nilsson, Jonna, et al.
(författare)
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Acute increases in brain-derived neurotrophic factor in plasma following physical exercise relates to subsequent learning in older adults.
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Multidomain lifestyle interventions represents a promising strategy to counteract cognitive decline in older age. Brain-derived neurotrophic factor (BDNF) is essential for experience-dependent plasticity and increases following physical exercise, suggesting that physical exercise may facilitate subsequent learning. In a randomized-controlled trial, healthy older adults (65-75 years) completed a 12-week behavioral intervention that involved either physical exercise immediately before cognitive training (n = 25; 13 females), physical exercise immediately after cognitive training (n = 24; 11 females), physical exercise only (n = 27; 15 females), or cognitive training only (n = 21; 12 females). We hypothesized that cognition would benefit more from cognitive training when preceded as opposed to followed by physical exercise and that the relationship between exercise-induced increases in peripheral BDNF and cognitive training outcome would be greater when cognitive training is preceded by physical exercise. Greater increases of plasma BDNF were associated with greater cognitive training gains on trained task paradigms, but only when such increases preceded cognitive training (ß = 0.14, 95% CI [0.04, 0.25]). Average cognitive training outcome did not differ depending on intervention order (ß = 0.05, 95% CI [-0.10, 0.20]). The study provides the first empirical support for a time-critical but advantageous role for post-exercise increases in peripheral BDNF for learning at an interindividual level in older adults, with implications for future multidomain lifestyle interventions.
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| 8. |
- Shang, Ying, et al.
(författare)
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Association of diabetes with stroke and post-stroke dementia : A population-based cohort study
- 2020
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 16:7, s. 1003-1012
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The impact of prediabetes and diabetes on stroke and the development of dementia after a stroke remain unclear.Methods: A total of 2655 dementia-free participants (including a stroke-free cohort and a prevalent stroke cohort) were followed-up for 12 years. Dementia and post-stroke dementia were determined by clinical examinations and national registry data. Diabetes was ascertained via medical examination, medication use, medical records, or glycated hemoglobin (HbA1c) >= 6.5%. Prediabetes was defined as H bA1c >= 5.7% in diabetes-free participants.Results: In the stroke-free cohort, 236 participants developed ischemic stroke, and 47 developed post-stroke dementia. Diabetes was associated with ischemic stroke (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1.16 to 2.67) and post-stroke dementia (HR 2.56, 95% CI 1.04 to 6.25). In the prevalent stroke cohort, diabetes was also related to dementia risk. Prediabetes was not significantly related to stroke or post-stroke dementia.Discussion: Diabetes, but not prediabetes, is associated with an increased risk of ischemic stroke and post-stroke dementia.
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