Decline In Mobility Research Articles

How Adaptive Ankle Exoskeleton Assistance Affects Stability During Perturbed and Unperturbed Walking in the Elderly.

Slowing the decline in walking mobility in the elderly is critical for maintaining the quality of life. Wearable assistive devices may 1day facilitate mobility in older adults; however, we need to ensure that such devices do not impair stability in this population that is predisposed to fall-related injuries. This study sought to quantify the effects of untethered ankle exoskeleton assistance on measures of stability, whole-body dynamics, and strategies to maintain balance during normal and perturbed walking in older adults. Eight healthy participants (69-84years) completed a treadmill-based walking protocol that included perturbations from unexpected belt accelerations while participants walked with and without ankle exoskeleton assistance. Exoskeleton assistance increased frontal plane range of angular momentum (8-14%, p ≤ 0.007), step width (18-34%, p ≤ 0.006), and ankle co-contraction (21-29%, p ≤ 0.039), and decreased biological ankle moment (16-27%, p ≤ 0.001) during unperturbed and perturbed walking; it did not affect the anteroposterior margin-of-stability, step length, trunk variability, or soleus activity during unperturbed and perturbed walking. Our finding that ankle exoskeleton assistance did not affect the anteroposterior margin-of-stability supports additional investigation of assistive exoskeletons for walking assistance in the elderly.

Organoid Models and Next-Generation Sequencing for Bone Marrow and Related Disorders

Challenges to the musculoskeletal system negatively impact the quality of life of people suffering from them, leading to pain, a decline in mobility, genetic alterations, and potential disorders. The bone marrow (BM) forms an integral part of the musculoskeletal system responsible for erythropoiesis and optimal survival of the various immune and stem cells within the BM. However, due to its dynamic and complex three-dimensional (3D) structure, replicating the BM physiologically in traditional two-dimensional (2D) cell culture settings is often challenging, giving rise to the need for 3D in vitro models to better dissect the BM and its regeneration. Several researchers globally have been investigating various approaches to define an appropriate 3D model for their research. Organoids are novel preclinical models that provide a 3D platform for several tissues and have been analysed using next-generation sequencing (NGS) to identify new molecular pathways at the genetic level. The 3D in vitro models and organoids are increasingly considered important platforms for precision medicine. This review outlines the current knowledge of organoid and 3D in vitro models for the BM. We also discuss different types of 3D models which may be more adaptable for the BM. Finally, we critically review the NGS techniques used for such models and the future combination of these techniques.

OT Needs of Older Adults With Acute Myeloid Leukemia Undergoing Chemotherapy

Abstract Date Presented 04/21/2023 This study identified unique OT needs of older adults with acute myeloid leukemia (AML) receiving oral venetoclax and infusional hypomethalating agent (VEN + HMA) therapy. A battery of tests performed on 19 older adults in the early stages of chemotherapy suggest that grip strength and mobility decline and the need for more nuanced evaluation of cognition. We found careful evaluation was important to understand cognitive and physical impairments in the context of meaningful occupational challenges. Primary Author and Speaker: Farrell Leigh Wiggins Additional Authors and Speakers: Alexis Petteway Contributing Authors: Mackenzi Pergolotti, Todd Schwartz, Zachary Ripberger, Susan Coppola, Ashley Bryant, Ya-Ning Chan

The Impacts of Urban Environment Aspects on The Life Satisfaction of Older Adults

Ageing comes with several discomforts such as a decline in mobility and losses in social networks as well as societal roles. Therefore, improving the life satisfaction of older adults has become a significant policy focus for delivering age-friendliness in national and international movements in the living environment. The hypothesis of the current study is that older people, who live in urban neighbourhoods that provide safe, aesthetic and accessible environments, experience greater life satisfaction. Accessibility, attractiveness and attachment as the three key dimensions of life satisfaction were used to understand the key aspects of the life satisfaction of older people in the neighbourhoods and how the urban environment serves as an indicator. This research consists of two steps. The first step involved in-depth interviews with the older adults aged over 65 in different urban areas, the district of Fatih and Şişli in the city of Istanbul, Turkey, with sampling based on the diversity, heterogeneity and urban functions. Second, these urban areas were analysed using space syntax to understand the street network and connectivity to reveal the urban structure. The qualitative and quantitative findings were analysed comparatively. The study concluded that when attachment to the place is supported by walkability and psychical enticing, the older adults experience a higher level of life satisfaction. Additionally, financial independence serves as a backup solution to access a better environment. This comparative analysis also highlights a mixed method for policymakers to analyse the urban environment and makes room for older adults to raise their voices and participate in the policy and planning process.

No human mobility: how is knowledge mobile in a context of internationalisation at a distance? a case study

ABSTRACT The internationalisation of higher education has been challenged by the significant decline in international student mobility caused by the COVID-19 pandemic. The emergence of internationalisation at a distance before COVID-19 paved a new avenue for the internationalisation of higher education, with the distinctive feature of knowledge mobility without human mobility. However, few studies have explored knowledge mobility in an internationalisation at a distance context. The ethnographic case study identifies three knowledge mobility channels – Information and Communication Technology (ICT), curriculum and virtual community of practice – and argues that the knowledge creation model SECI (Socialisation, Externalisation, Combination, and Internalisation) is inapplicable in the internationalisation at a distance context. Additionally, the absence of immersion in face-to-face interaction hinders internationalisation at a distance students’ identity construction, placing them at a disadvantage in acquiring tacit knowledge. The significance of cultural, linguistic and pedagogical contextualisation in the context is also emphasised.

Cross‐sectional and longitudinal associations of plasma makers of amyloid and tau pathology and neurodegeneration with gait speed

AbstractBackgroundHigher brain amyloid PET is associated with slower gait speed and has been hypothesized to play a role in age‐related mobility decline. With the development of blood‐based biomarkers of Alzheimer’s disease pathology, we examined whether plasma levels of amyloid‐beta (Aβ)40, Aβ42, the Aβ42/Aβ40 ratio, phosphorylated tau 181 (p‐tau181) and 217 (p‐tau217), total tau, and neurofilament light chain (NfL) were associated with gait speed.MethodThis study included 779 cognitively unimpaired participants (median age 75, 54.8% male, median follow‐up 6.8 years) in the Mayo Clinic Study of Aging with concurrent measurement of plasma biomarkers and gait speed. Individuals with chronic kidney disease or a history of stroke were excluded. The plasma markers (pg/mL) were measured on the Quanterix Simoa® HD‐1 analyzer (total tau, Aβ42, Aβ40, NfL) and the Meso Scale Discovery platform (p‐tau181, p‐tau217). Gait speed (m/s) was obtained by timing a self‐paced walk across 25 ft using a stopwatch. Linear mixed effects models, with subject‐specific intercepts and slopes for time since baseline, with z‐scored baseline plasma markers were used to predict cross‐sectional and longitudinal gait speed. All models adjusted for baseline age and sex.ResultAt baseline, higher Aβ42 [Beta = ‐0.019; 95%CI = (‐0.035, ‐0.004)], total‐tau [‐0.026; (‐0.041, ‐0.011)], and p‐tau181 [‐0.021; (‐0.036, ‐0.006)] were associated with slower gait speed. Gait speed decreased, on average, by about 0.015 m/s annually for those in this study. Each one standard deviation (SD) increase in baseline level of plasma Aβ40 [‐0.005; (‐0.007, ‐0.002)], NfL [‐0.006; (‐0.009, ‐0.004)], and p‐tau217 [‐0.004; (‐0.007, ‐0.001)] accelerated this decline over time. In contrast, each one SD increase in Aβ42/Aβ40 ratio [0.003; (0.001, 0.006)] mitigated decline. Additional analyses adjusting for Charlson comorbidity index, Beck Depression Inventory, body mass index, and APOE E4 allele status gave similar results.ConclusionBoth cross‐sectional and longitudinal associations of plasma markers of amyloid and tau pathology and neurodegeneration with gait speed among cognitively unimpaired individuals were present. Therefore, not only are these markers of cognitive changes, they are also related to motor changes such as those affecting gait speed.

Is Tai Chi beneficial for multisite pain syndrome in older adults?

Chronic musculoskeletal pain is prevalent and undertreated in older adults. In particular, multisite pain is associated with serious functional consequences and falls and appears to be a novel geriatric syndrome. The causes of multisite pain are often multifactorial, and emerging evidence supports a complex pathway whereby multisite pain leads to cognitive problems, mobility decline, fear of falling, falls, and reduced participation in life roles. A few pharmacologic approaches are safe and effective for older adults with chronic multisite pain and evidence for effectiveness of non-pharmacologic treatments for this common condition is very limited. Compared to light physical exercise, mind-body exercise may prove to be more beneficial for older adults living with chronic pain. Tai Chi, as a movement-based mind-body exercise, can relieve pain symptoms, improve cognition and physical function, and lower risk for falls in older adults. However, little is known about the potential benefits of Tai Chi for older adults with multisite pain syndrome. Future large-scale randomized-controlled trials are needed to investigate the effectiveness of Tai Chi in alleviating pain and lowering fall risk in older adults with multisite pain, and the biological mechanisms that underlie its potential benefits to chronic pain, physical and cognitive functions, and falls in this at-risk population.

Can workers still climb the social ladder as middling jobs become scarce? Evidence from two British cohorts

The increase in employment polarization observed in several high-income economies has coincided with a reduction in inter-generational mobility. This paper argues that the disappearance of middling jobs can drive changes in mobility, notably by removing a stepping stone towards high-paying occupations for those from less well-off family backgrounds. Using data from two British cohorts who entered the labour market at two points in time with very different degrees of employment polarization, we examine how parental income affects both entry occupations and occupational upgrading over careers. We find that transitions across occupations are key to mobility and that the impact of parental income has grown over time. At regional level, using a shift-share IV-strategy, we show that the impact of parental income has increased the most in regions experiencing the greatest increase in polarisation. This indicates that the disappearance of middling jobs played a role in the observed decline in mobility.

0722 Sleep disturbances and subsequent mobility disability in chronic disease: Findings from the Nurses’ Health Study

Abstract Introduction Impaired mobility is the leading cause of disability in the U.S. Across chronic neurological, metabolic, and musculoskeletal conditions, mobility reductions are observed beyond expected effects of aging. Poor sleep health may be one common factor that drives accelerated reduction in mobility among people with chronic conditions. This study compared longitudinal associations between self-reported sleep disturbances and mobility disability progression among women with and without multiple sclerosis (MS), diabetes, and osteoarthritis (OA). Methods This prospective cohort study used data from four waves of the Nurses’ Health Study (2008, 2012, 2014, 2016). Logistic regression and the Kaplan-Meier method were used to quantify associations between baseline sleep-related variables and subsequent increase in mobility disability. Results Of 70,303 women (mean age 73), 392 had MS, 7,302 had diabetes, and 24,099 had OA. Between 2008-2016, mobility disability increased in 16.9% of the sample overall, 27.8% in the MS subgroup, 27.0% in the diabetes subgroup, and 23.7% in the OA subgroup. Between 2008-2016, known/suspected OSA was significantly associated with increased mobility disability in the overall sample (OR:1.4, 95%CI:1.2,1.5), and within the diabetes (OR:1.5, 95%CI:1.2,1.9) and OA subgroups (OR:1.2, 95%CI:1.0,1.4), but not the MS subgroup (OR:2.3, 95%CI:0.6,8.9); however, across 2012-2016, this association was significant for MS (OR:4.0, 95%CI:1.0,16.1). Suboptimal sleep duration was significantly associated with increased odds of mobility disability progression in the overall sample, but not within disease subgroups. Conversely, perception of adequate sleep was significantly associated with lower odds of mobility disability progression overall (OR:0.82, 95%CI:0.78,0.87) and for the OA subgroup (OR:0.83, 95%CI:0.76,0.91). Excessive daytime sleepiness was significantly associated with mobility disability progression overall (OR:1.2, 95%CI:1.1,1.4) and for the OA subgroup (OR:1.2, 95%CI:1.0,1.4). Conclusion Prevalent sleep disturbances could increase risk of disability progression among women, particularly in common chronic disease populations. Informed by these data, future research could offer new insight into sleep-based strategies to ameliorate mobility decline. Support (if any) This work was supported in part by a Michigan Institute for Clinical and Health Research Pilot Grant (UL1TR002240). Dr. Shieu was supported by a T32 grant from National Heart, Lung, and Blood Institute (T32HL110952).

Cognitive and physical declines and falls in older people with and without mild cognitive impairment: a 7-year longitudinal study.

We examined longitudinal changes in cognitive and physical function and associations between change in function and falls in people with and without mild cognitive impairment (MCI). Prospective cohort study with assessments every 2 years (for up to 6 years). Community, Sydney, Australia. Four hundred and eighty one people were classified into three groups: those with MCI at baseline and MCI or dementia at follow-up assessments (n = 92); those who fluctuated between cognitively normal and MCI throughout follow-up (cognitively fluctuating) (n = 157), and those who were cognitively normal at baseline and all reassessments (n = 232). Cognitive and physical function measured over 2-6 years follow-up. Falls in the year following participants' final assessment. In summary, 27.4%, 38.5%, and 34.1% of participants completed 2, 4, and 6 years follow-up of cognitive and physical performance, respectively. The MCI and cognitive fluctuating groups demonstrated cognitive decline, whereas the cognitively normal group did not. The MCI group had worse physical function than the cognitively normal group at baseline but decline over time in physical performance was similar across all groups. Decline in global cognitive function and sensorimotor performance were associated with multiple falls in the cognitively normal group and decline in mobility (timed-up-and-go test) was associated with multiple falls across the whole sample. Cognitive declines were not associated with falls in people with MCI and fluctuating cognition. Declines in physical function were similar between groups and decline in mobility was associated with falls in the whole sample. As exercise has multiple health benefits including maintaining physical function, it should be recommended for all older people. Programs aimed at mitigating cognitive decline should be encouraged in people with MCI.

Energizing Mitochondria to Prevent Mobility Loss in Aging: Rationale and Hypotheses.

Based on recent studies from our group and others, we hypothesize that mitochondrial dysfunction during aging may be the root cause of mobility decline through deficits in the musculoskeletal and central nervous systems. Mitochondrial dysfunction could be a therapeutic target to prevent mobility decline in aging.

Optoelectronic properties of sprayed MnxZn1−xO optical waveguide thin films: Refractive index and birefringence tailoring

This study investigated the properties of MnxZn1−xO thin films with varying Mn concentrations (x = 0, 0.03, 0.05, 0.07, and 0.09) fabricated via spray pyrolysis on glass substrates. The films exhibited a wurtzite structure with (002) orientation and decreasing crystal size. By utilizing the first derivative technique, it was found that the optical gap energy increased linearly by 0.06 eV, starting at 3.24 eV. Photoluminescence spectra deconvolution revealed the presence of multiple point defects, particularly VO, which correlated with the increase in optical gap energy. The Hall effect-based electric measurements indicated a decline in charge carriers and mobility accompanied by an increase in magnetoresistance and resistivity. The SEM observations revealed a morphological transition from flaky to dome-shaped grains with a reduction in size. The waveguiding properties of the films were studied using the m-lines technique, which showed that all films were dual-mode waveguides. The ordinary and extraordinary refractive indices increased to 2.0019 and 2.0005, respectively with Mn doping, while the birefringence inversion began at Mn0.05Zn0.95O and remained constant at Mn content of 7 and 9 at.%. Overall, these findings provide valuable insights into the structural, optical, electrical, and waveguiding properties of MnxZn1−xO thin films, which could be useful for the development of new optoelectronic devices.

Synthetic polymers as bone engineering scaffold

AbstractDamage or loss of the bone tissue leads to mobility decline contributing to one of the major issues of human well‐being. Tissue engineering is used to recover fractures and damaged parts of the bone tissue. Various biomaterials and scaffolds have been evaluated for regeneration of hard tissues, however, polymers are the most frequently required biomaterials for the improvement of synthetic bone scaffolds due to their suitable mechanical properties and similar degradation rates to the proteins in hard and soft tissues. Synthetic polymeric materials in bone replacement have several advantages because their physical characteristics can be designed according to their application and their composition can be changed easily. On the other hand, the high adaptability, tenability, and biocompatibility of synthetic materials have received considerable acceptance in the field of tissue engineering. This article presents an update on materials for the fabrication of scaffolds in bone tissue engineering; in addition, we provide information of different kinds of scaffolds and their application usage for hard tissue regeneration.

Classical Ballet for Women Aged Over 50 Years: Investigating Balance, Strength, and Range of Motion

ABSTRACT Background: Regular exercise can mitigate the loss of strength, balance, and flexibility that contribute to age-related decline in physical function and mobility. However, traditional exercise interventions often report poor adherence rates. There is growing interest in classical ballet as an enjoyable exercise modality for adults in middle to late age. Classical ballet requires muscular strength, coordination, and flexibility. The current study investigated a classical ballet intervention on the balance, physical function, and range of motion of women aged over 50 years. Methods: Twenty-two healthy female participants (aged 56.2 (4.5) years (mean (SD)) completed a 10-week ballet intervention. Results: This single-arm study showed significant improvements (p<.05) in lower limb strength (measured by 5 times sit-to-stand and forward leap) and high adherence rates (95% adherence for participants who completed the intervention). No adverse events were reported. Improvements in balance were reported in the left leg only (as measured by center of pressure ellipse area in the parallel retiré condition). Conclusions: These results allude to the positive effects of ballet training on strength and balance in adults aged 50 years and over. High adherence rates suggest that ballet training was enjoyed and may thus be a long-term exercise modality for this population. Although this study was a single-arm design, it suggests promising results for future research wishing to evaluate the effectiveness of classical ballet training using randomized controlled trial designs.

A Risk Prediction Model for Physical Restraints Among Older Chinese Adults in Long-term Care Facilities: Machine Learning Study.

Numerous studies have identified risk factors for physical restraint (PR) use in older adults in long-term care facilities. Nevertheless, there is a lack of predictive tools to identify high-risk individuals. We aimed to develop machine learning (ML)-based models to predict the risk of PR in older adults. This study conducted a cross-sectional secondary data analysis based on 1026 older adults from 6 long-term care facilities in Chongqing, China, from July 2019 to November 2019. The primary outcome was the use of PR (yes or no), identified by 2 collectors' direct observation. A total of 15 candidate predictors (older adults' demographic and clinical factors) that could be commonly and easily collected from clinical practice were used to build 9 independent ML models: Gaussian Naïve Bayesian (GNB), k-nearest neighbor (KNN), decision tree (DT), logistic regression (LR), support vector machine (SVM), random forest (RF), multilayer perceptron (MLP), extreme gradient boosting (XGBoost), and light gradient boosting machine (Lightgbm), as well as stacking ensemble ML. Performance was evaluated using accuracy, precision, recall, an F score, a comprehensive evaluation indicator (CEI) weighed by the above indicators, and the area under the receiver operating characteristic curve (AUC). A net benefit approach using the decision curve analysis (DCA) was performed to evaluate the clinical utility of the best model. Models were tested via 10-fold cross-validation. Feature importance was interpreted using Shapley Additive Explanations (SHAP). A total of 1026 older adults (mean 83.5, SD 7.6 years; n=586, 57.1% male older adults) and 265 restrained older adults were included in the study. All ML models performed well, with an AUC above 0.905 and an F score above 0.900. The 2 best independent models are RF (AUC 0.938, 95% CI 0.914-0.947) and SVM (AUC 0.949, 95% CI 0.911-0.953). The DCA demonstrated that the RF model displayed better clinical utility than other models. The stacking model combined with SVM, RF, and MLP performed best with AUC (0.950) and CEI (0.943) values, as well as the DCA curve indicated the best clinical utility. The SHAP plots demonstrated that the significant contributors to model performance were related to cognitive impairment, care dependency, mobility decline, physical agitation, and an indwelling tube. The RF and stacking models had high performance and clinical utility. ML prediction models for predicting the probability of PR in older adults could offer clinical screening and decision support, which could help medical staff in the early identification and PR management of older adults.

Differential Associations of Mobility With Fronto-Striatal Integrity and Lesion Load in Older Adults With and Without Multiple Sclerosis

Background Mobility impairment is common in older persons with multiple sclerosis (MS), and further compounded by general age-related mobility decline but its underlying brain substrates are poorly understood. Objective Examine fronto-striatal white matter (WM) integrity and lesion load as imaging correlates of mobility outcomes in older persons with and without MS. Methods Fifty-one older MS patients (age 64.9 ± 3.7 years, 29 women) and 50 healthy, matched controls (66.2 ± 3.2 years, 24 women), participated in the study, which included physical and cognitive test batteries and 3T MRI imaging session. Primary imaging measures were fractional anisotropy (FA) and WM lesion load. The relationship between mobility impairment, defined using a validated short physical performance battery cutoff score, and neuroimaging measures was assessed with stratified logistic regression models. FA was extracted from six fronto-striatal circuits (left/right): dorsal striatum (dStr)-to-anterior dorsolateral prefrontal cortex (aDLPFC), dStr-to-posterior DLPFC, and ventral striatum (vStr)-to-ventromedial prefrontal cortex (VMPFC). Results Mobility impairment was significantly associated with lower FA in two circuits, left dStr-aDLPFC (P = .003) and left vStr-VMPFC (P = .004), in healthy controls but not in MS patients (P > .20), for fully adjusted regression models. Conversely, in MS patients but not in healthy controls, mobility impairment was significantly associated with greater lesion volume (P < .02). Conclusions Comparing older persons with and without MS, we provide compelling evidence of a double dissociation between the presence of mobility impairment and two neuroimaging markers of white matter integrity, fronto-striatal fractional anisotropy, and whole brain lesion load.

Visual-somatosensory integration (VSI) as a novel marker of Alzheimer's disease: A comprehensive overview of the VSI study.

Identification of novel, non-invasive, non-cognitive based markers of Alzheimer's disease (AD) and related dementias are a global priority. Growing evidence suggests that Alzheimer's pathology manifests in sensory association areas well before appearing in neural regions involved in higher-order cognitive functions, such as memory. Previous investigations have not comprehensively examined the interplay of sensory, cognitive, and motor dysfunction with relation to AD progression. The ability to successfully integrate multisensory information across multiple sensory modalities is a vital aspect of everyday functioning and mobility. Our research suggests that multisensory integration, specifically visual-somatosensory integration (VSI), could be used as a novel marker for preclinical AD given previously reported associations with important motor (balance, gait, and falls) and cognitive (attention) outcomes in aging. While the adverse effect of dementia and cognitive impairment on the relationship between multisensory functioning and motor outcomes has been highlighted, the underlying functional and neuroanatomical networks are still unknown. In what follows we detail the protocol for our study, named The VSI Study, which is strategically designed to determine whether preclinical AD is associated with neural disruptions in subcortical and cortical areas that concurrently modulate multisensory, cognitive, and motor functions resulting in mobility decline. In this longitudinal observational study, a total of 208 community-dwelling older adults with and without preclinical AD will be recruited and monitored yearly. Our experimental design affords assessment of multisensory integration as a new behavioral marker for preclinical AD; identification of functional neural networks involved in the intersection of sensory, motor, and cognitive functioning; and determination of the impact of early AD on future mobility declines, including incident falls. Results of The VSI Study will guide future development of innovative multisensory-based interventions aimed at preventing disability and optimizing independence in pathological aging.

Tourism De-Metropolisation but Not De-Concentration: COVID-19 and World Destinations

The current COVID-19 pandemic has caused a significant decline in human mobility during the past three years. This may lead to reconfiguring future tourism flows and resulting transformations in the geographic patterns of economic activities and transportation needs. This study empirically addresses the changes in tourism mobility caused by the pandemic. It focuses on the yet unexplored effects of the destination type on tourism volume change. To investigate this, 1426 metropolitan, urban/resort and dispersed destinations were delimited based on Airbnb offers. Airbnb reviews were used as the proxy for the changes in tourist visits in 2019–2022. Linear mixed-effects models were employed to verify two hypotheses on the differences between the effects of the pandemic on three kinds of tourism destinations. The results confirm the tourism de-metropolisation hypothesis: metropolitan destinations have experienced between −12.4% and −7.5% additional decreases in tourism visits compared to secondary cities and resorts. The second de-concentration hypothesis that urban/resort destinations are more affected than dispersed tourism destinations is not supported. The results also confirm that stricter restrictions and destination dependence on international tourism have negatively affected their visitation. The study sheds light on post-pandemic scenarios on tourism mobility transformations in various geographic locations.

Cortical atrophy and leukoaraiosis, imaging markers of cerebrovascular small vessel disease, are associated with driving behavior changes among cognitively normal older adults

BackgroundCerebral small vessel disease (CSVD) as measured by cortical atrophy and white matter hyperintensities [leukoaraiosis], captured via magnetic resonance imaging (MRI) are increasing in prevalence due to the growth of the aging population and an increase in cardiovascular risk factors in the population. CSVD impacts cognitive function and mobility, but it is unclear if it affects complex, functional activities like driving. MethodsIn a cohort of 163 cognitively normal, community-dwelling older adults (age ≥ 65), we compared naturalistic driving behavior with mild/moderate leukoaraiosis, cortical atrophy, or their combined rating in a clinical composite termed, aging-related changes to those without any, over a two-and-a-half-year period. ResultsOlder drivers with mild or moderate cortical atrophy and aging-related changes (composite) experienced a greater decrease in the number of monthly trips which was due to a decrease in the number of trips made within a one-to-five-mile diameter from their residence. Older drivers with CSVD experience a larger reduction in daily driving behaviors than drivers without CSVD, which may serve as an early neurobehavioral marker for functional decline. ConclusionsAs CSVD markers, leukoaraiosis and cortical atrophy are standard MRI metrics that are widely available and can be used for screening individuals at higher risk for driving safety risk and decline in community mobility.

Neural correlates of gait adaptation in younger and older adults

Mobility decline is a major concern for older adults. A key component of maintaining mobility with advancing age is the ability to learn and adapt to the environment. The split-belt treadmill paradigm is an experimental protocol that tests the ability to adapt to a dynamic environment. Here we examined the magnetic resonance imaging (MRI) derived structural neural correlates of individual differences in adaptation to split-belt walking for younger and older adults. We have previously shown that younger adults adopt an asymmetric walking pattern during split-belt walking, particularly in the medial-lateral (ML) direction, but older adults do not. We collected T_1-weighted and diffusion-weighted MRI scans to quantify brain morphological characteristics (i.e. in the gray matter and white matter) on these same participants. We investigated two distinct questions: (1) Are there structural brain metrics that are associated with the ability to adopt asymmetry during split-belt walking; and (2) Are there different brain-behavior relationships for younger and older adults? Given the growing evidence that indicates the brain has a critical role in the maintenance of gait and balance, we hypothesized that brain areas commonly associated with locomotion (i.e. basal ganglia, sensorimotor cortex, cerebellum) would be associated with ML asymmetry and that older adults would show more associations between split-belt walking and prefrontal brain areas. We identified multiple brain-behavior associations. More gray matter volume in the superior frontal gyrus and cerebellar lobules VIIB and VIII, more sulcal depth in the insula, more gyrification in the pre/post central gyri, and more fractional anisotropy in the corticospinal tract and inferior longitudinal fasciculus corresponded to more gait asymmetry. These associations did not differ between younger and older adults. This work progresses our understanding of how brain structure is associated with balance during walking, particularly during adaptation.