Executive Network Activation is Linked to Walking Speed in Older Adults: Functional MRI and TCD Ultrasound Evidence From the MOBILIZE Boston Study.
Ontology highlight
ABSTRACT: Background
Changes in cerebral blood flow velocity (CBF) in response to a cognitive task (task-related ΔCBF) have been shown by Transcranial Doppler ultrasonography (TCD) to be reduced in slow walkers. However, it is unknown whether reduced task-related ΔCBF is associated with reduced neural activity in specific brain regions, as measured by blood-oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI).Methods
We assessed the regional changes in neural activity associated with reduced middle cerebral artery (MCA) task-related ΔCBF to an executive task and slow walking speed in 67 community-dwelling older adults from the MOBILIZE Boston Study. Participants underwent walking assessments and TCD ultrasonography measures of MCA ΔCBF during the n-back task of executive function. A subset of participants (n = 27) completed the same task during fMRI. Individual BOLD activation maps for the n-back task were correlated with TCD measures and network-level averages were associated with TCD and preferred walking speed.Results
Participants with diminished task-related ΔCBF walked more slowly (β = .39, p = .001). fMRI revealed significant associations between task-related ΔCBF and regional BOLD activation in several brain regions/networks supplied by the MCA. Of these regions and networks, those within the executive network were most strongly associated with walking speed (β = .36, p = .01).Conclusions
Task-related ΔCBF during an executive function task is related to activation in several neural networks and impairment in the ability to recruit the executive network in particular is associated with slow walking speed in older adults.
SUBMITTER: Jor'dan AJ
PROVIDER: S-EPMC5861979 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:ObjectiveTo investigate a proposed cognitively-mediated pathway whereby pain contributes to gait impairments by acting as a distractor in community-living older adults.DesignA cross-sectional study of a population-based cohort of older adults.SettingUrban and suburban communities in a large metropolitan area.ParticipantsCommunity-living participants (N=302) 70 years and older recruited from a previous population-based cohort.InterventionsNot applicable.Main outcome measuresGait parameters including gait speed, stride length, double support and swing characteristics, and variability were assessed under single- and dual-task conditions involving cognitive challenges (eg, counting backward). A joint pain questionnaire assessed pain distribution in the back and major joints. We examined pain-gait relationships using multivariable linear regression and bootstrapping mediation procedures.ResultsForty-three percent of participants had pain in 2 or more musculoskeletal sites. Pain distribution was related to slower gait speed and other gait characteristics for all gait conditions. Associations persisted after adjustment for age, sex, education, body mass index, medication, and vision. Decrements in gait measures related to pain were comparable with decrements in gait related to dual-task conditions. There were no differences in dual-task cost among the pain distribution groups. Adjusted for confounders, pain-gait relationships appear mediated by selective attention.ConclusionsThese findings suggest that chronic pain contributes to decrements in gait, including slower gait speed, and that it operates through a cognitively-mediated pathway. Further research is needed to understand the mechanisms via pain alters mobility and to develop interventions to improve mobility among older adults with chronic pain.
| S-EPMC7050337 | biostudies-literature
Project description:Concerns about polypharmacy and medication side effects contribute to undertreatment of geriatric pain. This study examines use and effects of pharmacologic treatment for persistent pain in older adults.The MOBILIZE Boston Study included 765 adults aged ?70 years, living in the Boston area, recruited from 2005 to 2008. We studied 599 participants who reported chronic pain at baseline. Pain severity, measured using the Brief Pain Inventory (BPI) severity subscale, was grouped as very mild (BPI <2), mild (BPI 2-3.99), and moderate to severe (BPI 4-10). Medications taken in the previous 2 weeks were recorded from medication bottles in the home interview.Half of participants reported using analgesic medications in the previous 2 weeks. Older adults with moderate to severe pain were more likely to use one or more analgesic medications daily than those with very mild pain (49 versus 11%, respectively). The most commonly used analgesic was acetaminophen (28%). Opioid analgesics were used daily by 5% of participants. Adjusted for health and demographic factors, pain severity was strongly associated with daily analgesic use (moderate-severe pain compared to very mild pain, adj. OR?7.19, 95% CI 4.02-12.9). Nearly one third of participants (30%) with moderate to severe pain felt they needed a stronger pain medication while 16% of this group were concerned they were using too much pain medication.Serious gaps persist in pain management particularly for older adults with the most severe chronic pain. Greater efforts are needed to understand barriers to effective pain management and self-management in the older population.
| S-EPMC5565717 | biostudies-literature
Project description:BackgroundExposure to ambient air pollution, particularly from traffic, has been associated with adverse cognitive outcomes, but the association with depressive symptoms remains unclear.ObjectivesWe investigated the association between exposure to ambient air and traffic pollution and the presence of depressive symptoms among 732 Boston-area adults ? 65 years of age (78.1 ± 5.5 years, mean ± SD).MethodsWe assessed depressive symptoms during home interviews using the Revised Center for Epidemiological Studies Depression Scale (CESD-R). We estimated residential distance to the nearest major roadway as a marker of long-term exposure to traffic pollution and assessed short-term exposure to ambient fine particulate matter (PM2.5), sulfates, black carbon (BC), ultrafine particles, and gaseous pollutants, averaged over the 2 weeks preceding each assessment. We used generalized estimating equations to estimate the odds ratio (OR) of a CESD-R score ? 16 associated with exposure, adjusting for potential confounders. In sensitivity analyses, we considered CESD-R score as a continuous outcome and mean annual residential BC as an alternate marker of long-term exposure to traffic pollution.ResultsWe found no evidence of a positive association between depressive symptoms and long-term exposure to traffic pollution or short-term changes in pollutant levels. For example, we found an OR of CESD-R score ? 16 of 0.67 (95% CI: 0.46, 0.98) per interquartile range (3.4 ?g/m(3)) increase in PM2.5 over the 2 weeks preceding assessment.ConclusionsWe found no evidence suggesting that ambient air pollution is associated with depressive symptoms among older adults living in a metropolitan area in attainment of current U.S. regulatory standards.
| S-EPMC4050499 | biostudies-literature
Project description:In older people, less diurnal variability in cortisol levels has been consistently related to worse physical performance, especially to slower walking speed (WS). The cortisol awakening response (CAR) is a discrete component of the hypothalamic-pituitary-adrenal axis that has been related to several health problems, such as cardiovascular disease and/or worse performance on executive function and memory. The relationship between the CAR and physical performance in older people is poorly understood. In this study, in 86 older people (mean age = 64.42, SD = 3.93), we investigated the relationship between the CAR and WS, a commonly used measure of physical performance in the older population that has also been related to health problems, such as cardiovascular disease and executive function performance in older people. Additionally, we studied whether the relationship between the CAR and WS was independent from cortisol levels on awakening and several possible confounders. Results showed that a CAR of reduced magnitude (measured with 3 samples each day, for two consecutive days, and calculated as the area under the curve with respect to the increase), but not cortisol levels on awakening, was related to slower WS. In addition, this relationship was independent from cortisol levels on awakening. It is possible that a CAR of reduced magnitude would contribute to less diurnal cortisol variability, affecting physical performance. Additionally, it is possible that a CAR of reduced magnitude affects WS through a possible negative effect on executive function, or that the association between the CAR and WS is due to the fact that both are related to similar health problems and to changes in cognitive performance in older people.
| S-EPMC4871454 | biostudies-other
Project description:BackgroundWalking speed is reduced with aging. However, it is not certain whether the reduced walking speed is associated with physical and coordination fitness. This study explores the physical and coordination determinants of the walking speed decline in older women.MethodsOne-hundred-eighty-seven active older women (72.2 ± 6.8 years) were asked to perform a 10-m walk test (self-selected and maximal walking speed) and a battery of the Senior fitness test: lower body strength, lower body flexibility, agility/dynamic balance, and aerobic endurance. Two parameters characterized the walking performance: closeness to the modeled speed minimizing the energetic cost per unit distance (locomotor rehabilitation index, LRI), and the ratio of step length to step cadence (walk ratio, WR). For dependent variables (self-selected and maximal walking speeds), a recursive partitioning algorithm (classification and regression tree) was adopted, highlighting interactions across all the independent variables.ResultsParticipants were aged from 60 to 88 years, and their self-selected and maximal speeds declined by 22% and 26% (p < 0.05), respectively. Similarly, all physical fitness variables worsened with aging (muscle strength: 33%; flexibility: 0 to -8 cm; balance: 22%; aerobic endurance: 12%; all p < 0.050). The predictors of maximal walking speed were only WR and balance. No meaningful predictions could be made using LRI and WR as dependent variables.DiscussionThe results suggest that at self-selected speed, the decrease in speed itself is sufficient to compensate for the age-related decline in the motor functions tested; by contrast, lowering the WR is required at maximal speed, presumably to prevent imbalance. Therefore, any excessive lowering of LRI and WR indicates loss of homeostasis of walking mechanics and invites diagnostic investigation.
| S-EPMC10007973 | biostudies-literature
Project description:Background and purposeOur objective was to investigate the associations between polymorphisms in representative genes of the renin angiotensin system with measures of cerebral blood flow regulation in older adults.MethodsParticipants in this analysis were white subjects (n=335) in the MOBILIZE Boston study (Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly of Boston), an observational study of community-dwelling elders who underwent transcranial Doppler while sitting and standing and during hypercapnea and hypocapnea. Autoregulation phenotype was the change in cerebrovascular resistance from sit to stand. Vasoreactivity phenotype was the slope of the change in cerebrovascular conductance versus change in end-tidal CO2. A total of 33 tagged single nucleotide polymorphisms were selected in the angiotensinogen gene, the angiotensin converting enzyme gene, and the angiotensin receptor gene. Regression analyses adjusted for age, gender, body mass index, mean arterial blood pressure, stroke, and use of antihypertensives were conducted for each single nucleotide polymorphism and outcome. Bonferroni corrections were used to adjust P values for multiple testing.ResultsIn the angiotensinogen gene, only the rs699 single nucleotide polymorphism was associated with vasoreactivity after Bonferroni correction (P=0.00028). Homozygous carriers of the CC genotype of this single nucleotide polymorphism had lower vasoreactivity compared with the CT or TT genotypes. There were no significant associations with autoregulation measures. None of the single nucleotide polymorphisms in the other genes were associated with our phenotypes.ConclusionThis analysis suggests that the angiotensinogen gene may be involved in vasoreactivity independent of blood pressure. Larger studies are needed to confirm the role of this gene in cerebrovascular health and aging.
| S-EPMC3563282 | biostudies-literature
Project description:The literature increasingly demonstrates the importance of gait speed (GS) in the frailty assessment of patients aged 60 years and older. Conventional GS measurement, however, maybe contraindicated in settings such as trauma where the patient is temporarily immobilized. We devised a Walking Speed Questionnaire (WSQ) to allow assessment of preinjury baseline GS, in meters per second, in a self-reported manner, to overcome the inability to directly test the patients' walking speed.Four questions comprise the WSQ, and were derived using previously published questionnaires and expert opinion of 6 physician-researchers.Four ambulatory clinics.Ambulating individuals aged 60-95 (mean age, 73.2 ± 8.1 years, 86.1% female, n = 101).Participants completed the WSQ and underwent GS measurement for comparison.WSQ score correlation to true GS, receiver operating characteristics, and validation statistics were performed.All 4 questions of the WSQ independently predicted true GS significantly (P < 0.001). The WSQ sufficiently predicted true GS with r = 0.696 and ? = 0.717.The WSQ is an effective tool for assessing baseline walking speed in patients aged 60 years and older in a self-reported manner. It permits gait screening in health care environments where conventional GS testing is contraindicated due to temporary immobilization and maybe used to provide baseline targets for goal-oriented post-trauma care. Given its ability to capture GS in patients who are unable to ambulate, it may open doors for frailty research in previously unattainable populations.Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.
| S-EPMC4801662 | biostudies-literature
Project description:BackgroundWalking speed is an important measure associated with health outcomes in older individuals, such as dependency and death. This study aimed to examine whether the walking speed of community-dwelling older adults varies between time periods within a day, as measured outdoors in daily life. We aimed to determine the types of walking speed variations and examine the factors associated with them.MethodsDaily life outdoor walking speed was measured in 92 participants (average age 71.9 years±5.64) using a GPS smartphone app for 1 month. Average walking speeds for five time periods were analyzed with a linear mixed model. Intra-day walking speed variation patterns were classified by latent class analysis. Factors associated with the class were identified by logistic regression analysis.ResultsA statistically significant difference in average walking speed was found between early morning (1.33 m/s), and afternoon (1.27 m/s) and evening (1.26 m/s) (p < 0.01). The intra-day variation in walking speed was attributed to variation in cadence. Two classes were identified: (1) fast walking speed with large variation and (2) slow walking speed with little variation; hypertension and frailty level were associated with the class.ConclusionThe results suggest that there is intra-day variation in walking speed in daily life, wherein the speed is the fastest early in the morning and slower in the afternoon and evening. A larger variation in the walking speed was related to the health status without hypertension or frailty. These results suggest that if a person shows less intra-day variation in walking speed, this could be a sign that they are susceptible to hypertension and an increased frailty level.
| S-EPMC8268528 | biostudies-literature
Project description:BACKGROUND:Although walking speed is associated with important clinical outcomes and designated as the sixth vital sign of the elderly, few walking-speed estimation algorithms using an inertial measurement unit (IMU) have been derived and tested in the older adults, especially in the elderly with slow speed. We aimed to develop a walking-speed estimation algorithm for older adults based on an IMU. METHODS:We used data from 659 of 785 elderly enrolled from the cohort study. We measured gait using an IMU attached on the lower back while participants walked around a 28 m long round walkway thrice at comfortable paces. Best-fit linear regression models were developed using selected demographic, anthropometric, and IMU features to estimate the walking speed. The accuracy of the algorithm was verified using mean absolute error (MAE) and root mean square error (RMSE) in an independent validation set. Additionally, we verified concurrent validity with GAITRite using intraclass correlation coefficients (ICCs). RESULTS:The proposed algorithm incorporates the age, sex, foot length, vertical displacement, cadence, and step-time variability obtained from an IMU sensor. It exhibited high estimation accuracy for the walking speed of the elderly and remarkable concurrent validity compared to the GAITRite (MAE = 4.70%, RMSE = 6.81 𝑐𝑚/𝑠, concurrent validity (ICC (3,1)) = 0.937). Moreover, it achieved high estimation accuracy even for slow walking by applying a slow-speed-specific regression model sequentially after estimation by a general regression model. The accuracy was higher than those obtained with models based on the human gait model with or without calibration to fit the population. CONCLUSIONS:The developed inertial-sensor-based walking-speed estimation algorithm can accurately estimate the walking speed of older adults.
| S-EPMC6932800 | biostudies-literature
Project description:Cortical activity and walking speed are known to decline with age and can lead to an increased risk of falls in the elderly. Despite age being a known contributor to this decline, individuals age at different rates. This study aimed to analyse left and right cortical activity changes in elderly adults regarding their walking speed. Cortical activation and gait data were obtained from 50 healthy older individuals. Participants were then grouped into a cluster based on their preferred walking speed (slow or fast). Analyses on the differences of cortical activation and gait parameters between groups were carried out. Within-subject analyses on left and right-hemispheric activation were also performed. Results showed that individuals with a slower preferred walking speed required a higher increase in cortical activity. Individuals in the fast cluster presented greater changes in cortical activation in the right hemisphere. This work demonstrates that categorizing older adults by age is not necessarily the most relevant method, and that cortical activity can be a good indicator of performance with respect to walking speed (linked to fall risk and frailty in the elderly). Future work may wish to explore how physical activity training influences cortical activation over time in the elderly.
| S-EPMC10141493 | biostudies-literature