Amyloid-ß Deposition Predicts Grocery Shopping Performance in Older Adults Without Cognitive Impairment.

Background: A screening tool sensitive to Alzheimer's disease (AD) risk factors, such as amyloid-ß (Aß) deposition, and subtle cognitive changes, best elicited by complex everyday tasks, is needed. Objective: To determine if grocery shopping performance could differentiate older adults at elevated risk of developing AD (OAer), older adults at low risk of developing AD (OAlr), and young adults (YA), and if amount of Aß deposition could predict grocery shopping performance in older adults (OA). Methods: Twenty-one OAer (78±5 years), 33 OAlr (78±5 years), and 28 YA (31±3 years) performed four grocery shopping trials, with the best and worst performances analyzed. Measures included trial time, number of correct items, number of grocery note fixations, and number of fixations and percentage of time fixating on the correct shelving unit, correct brand, and correct shelf. Linear mixed effects models compared measures by performance rank (best, worst) and group (OAer, OAlr, YA), and estimated the effect of Aß deposition on measures in OA. Results: Relative to their best performance, OAer and OAlr exhibited more correct shelving unit fixations and correct brand fixations during their worst performance, while YA did not. Within OA's worst performance, greater Aß deposition was associated with a smaller percentage of time fixating on the correct shelving unit, correct shelf, and correct brand. Within OA, greater Aß deposition was associated with more grocery note fixations. Conclusions: OA with elevated Aß deposition may exhibit subtle working memory impairments and less efficient visual search strategies while performing a cognitively demanding everyday task.

Age and beta amyloid deposition impact gait speed, stride length, and gait smoothness while transitioning from an even to an uneven walking surface in older adults.

BACKGROUND: Capturing a measure of movement quality during a complex walking task may indicate the earliest signs of detrimental changes to the brain due to beta amyloid (Aß) deposition and be a potential differentiator of older adults at elevated and low risk of developing Alzheimer's disease. This study aimed to determine: 1) age-related differences in gait speed, stride length, and gait smoothness while transitioning from an even to an uneven walking surface, by comparing young adults (YA) and older adults (OA), and 2) if gait speed, stride length, and gait smoothness in OA while transitioning from an even to an uneven walking surface is influenced by the amount of Aß deposition present in an OA's brain. METHODS: Participants included 56 OA (>70 years of age) and 29 YA (25-35 years of age). In OA, Aß deposition in the brain was quantified by PET imaging. All participants completed a series of cognitive assessments, a functional mobility assessment, and self-report questionnaires. Then participants performed two sets of walking trials on a custom-built walkway containing a mixture of even and uneven surface sections, including three trials with a grass uneven surface and three trials with a rocks uneven surface. Gait data were recorded using a wireless inertial measurement unit system. Stride length, gait speed, and gait smoothness (i.e., log dimensionless lumbar jerk) in the anteroposterior (AP), mediolateral (ML), and vertical (VT) directions were calculated for each stride. Outcomes were retained for five stride locations immediately surrounding the surface transition. RESULTS: OA exhibited slower gait (Grass: p < 0.001; Rocks: p = 0.006), shorter strides (Grass: p < 0.001; Rocks: p = 0.008), and smoother gait (Grass AP: p < 0.001; Rocks AP: p = 0.002; Rocks ML: p = 0.02) than YA, but they also exhibited greater reductions in gait speed and stride length than YA while transitioning to the uneven grass and rocks surfaces. Within the OA group, those with greater Aß deposition exhibited decreases in smoothness with age (Grass AP: p = 0.02; Rocks AP: p = 0.03; Grass ML: p = 0.04; Rocks ML: p = 0.03), while those with lower Aß deposition exhibited increasing smoothness with age (Grass AP: p = 0.01; Rocks AP: p = 0.02; Grass ML: p = 0.08; Rocks ML: p = 0.07). Better functional mobility was associated with less smooth gait (Grass ML: p = 0.02; Rocks ML: p = 0.05) and with less variable gait smoothness (Grass and Rocks AP: both p = 0.04) in the OA group. CONCLUSION: These results suggest that, relative to YA, OA may be adopting more cautious, compensatory gait strategies to maintain smoothness when approaching surface transitions. However, OA with greater Aß deposition may have limited ability to adopt compensatory gait strategies to increase the smoothness of their walking as they get older because of neuropathological changes altering the sensory integration process and causing worse dynamic balance (i.e., jerkier gait). Functional mobility, in addition to age and Aß deposition, may be an important factor of whether or not an OA chooses to employ compensatory strategies to prioritize smoothness while walking and what type of compensatory strategy an OA chooses.

Systemic vascular basement membrane markers linked to synovial vascular remodeling are biomarkers of hemarthrosis in patients with hemophilia.

INTRODUCTION: Interstitial, cartilage, and bone collagens have been proposed as biomarkers of joint deterioration in hemophilic arthropathy. The role of basement membrane (type IV and VIII) collagens as biomarkers of endothelial turnover in relation to acute joint bleeding is not understood. METHODS: Thirty-one adult patients with hemophilia were studied prospectively for 3 years with musculoskeletal ultrasound/power Doppler (MSKUS/PD) during pain-free intervals and painful events for joint bleed status, synovial vascular flow, and 10 plasma markers of collagen turnover. Joint health was determined using Hemophilia Joint Health Scores and Pettersson scores. In animal studies, bleeding was induced in factor VIII-/- mice by knee joint injury. Synovial vascular remodeling was assessed using MSKUS/PD and histology. Murine plasma samples were analyzed for type IV collagen turnover markers. RESULTS: Ninety-one patient visits were compiled. Twenty-five were due to acute painful episodes, with 16 confirmed hemarthroses. Type IV collagen turnover markers (PRO-C4 and C4M), and a type VIII collagen synthesis marker (PRO-C8), were transiently elevated during acute hemarthrosis. Hemarthrosis was accompanied by increased synovial microvascular flow (MSKUS/PD), and levels of type IV collagen markers correlated with PD signals in the joint. In factor VIII-deficient mice, plasma levels of type IV collagen turnover markers correlated negatively with synovial αSMA staining, indicating that reduced type IV collagen turnover was associated with thicker vessels. CONCLUSIONS: Our findings suggest that basement membrane turnover markers, closely linked to synovial vascular remodeling, may be systemic biomarkers of acute hemarthrosis. Vascular instability during neovascularization may be involved in the dynamics of hemarthrosis.

A Life Course Perspective on Growing Older With Cerebral Palsy.

Despite most children with cerebral palsy (CP) now living within typical life spans, little is known about how the effects of CP unfold across the life course and impact participation in everyday life during adulthood. In this study, we explored the experiences of 38 adults growing older with CP. Data were gathered using semi-structured interviews focused on participants' engagement in activities in their community and analyzed using a life course perspective to deepen our understanding of the experiences of our participants. We found that individual agency, family and social contexts, as well as larger sociocultural contexts all shaped participants' experiences as they grew older. The findings highlight the usefulness of the life course perspective for understanding how the effects of a diagnosis of CP unfold over time. Further use of this perspective can better inform health care services to meet the needs of adults with CP aging with a lifelong disability.

Novel approaches to measuring community integration in adults with cerebral palsy.

Purpose: Rehabilitation goals often focus on increasing community integration for adults with disabilities and are measured by objective assessments. Research methods have lagged behind in capturing current conceptualizations of community integration as a multidimensional construct that incorporates participation, social supports, and feelings of belonging in the community. This paper addresses this challenge by describing a multi-method approach to assessing community integration for adults with cerebral palsy.Methods: Measures include standardized questionnaires, qualitative methods, measures of function and physical activity, and geospatial measures using Geographic Information System mapping and Global Positioning System tracking. These objective and subjective data are used to determine where adults spend time and are most active, and which activities and social connections are associated with feeling integrated into the community.Results: Two case examples highlight the importance of using a multi-method approach to assess community integration for adults with cerebral palsy. Results of objective clinical measures were comparable among case examples; however, actual experiences of feeling connected to the community were vastly different.Conclusions: Multiple measures are required to capture the complexity of community integration. Relying solely on objective measures may not provide a complete picture of community integration.IMPLICATIONS FOR REHABILITATIONCommunity integration is a complex construct that incorporates participation, socialization, and feelings of belonging in the community.New methods and measures are needed to assess the many aspects of community integration in adults with disabilities.A multi-method approach is recommended to provide a richer characterization of community integration in individuals with disabilities.A combination of quantitative and qualitative measures addressing the physical, social and psychological aspects of community integration should be used.

Test-retest reliability and minimal detectable change for measures of balance and gait in adults with cerebral palsy.

BACKGROUND: Walking and balance often begin to deteriorate in ambulant adults with cerebral palsy (CP) in early adulthood. The decline in walking and balance imposes a more sedentary lifestyle, increases falls risk, negatively affects health, participation, and quality of life, and ultimately results in increased disability. Available research is not sufficient to guide interventions to improve walking and balance in this population. To advance research in this area, there is a need for measures of gait and balance with proven psychometrics for adults with CP. RESEARCH QUESTION: The goal of this study was to determine test-retest reliability and minimal detectable change (MDC) values and to assess score distribution for the Balance Evaluation Systems Test (BESTest) and the Four Square Step Test (FSST) as measures of balance, for the Activities-specific Balance Confidence (ABC) Scale and the Modified Fall Efficacy Scale (MFES) as measures of balance confidence, and for over-ground spatiotemporal gait parameters at comfortable gait speed (CGS) and fast gait speed (FGS). METHODS: Twenty ambulant adults with CP (mean age 32.7 years), GMFCS-E&R Levels I and II, were tested twice within an average of 10 days. Test-retest reliability was evaluated using intra-class correlation coefficients (ICC2,1), and MDC95 values were calculated using standard error of measurement values. RESULTS: The test-retest reliability of most outcome measures was good to excellent. ICC values were: BESTest = 0.99, BESTest sections 0.88 to 0.98, FSST = 0.91, ABC=0.86, MFES = 0.9, CGS = 0.88, and FGS = 0.98. MDC values were: BESTest total = 4.9%, BESTest sections 8.7%-21.2%, FSST = 3.7 s, ABC = 18%, MFES = 1 point, CGS = 0.26 m/s, and FGS = 0.14 m/s. Most outcome scores were broadly distributed over scales ranges. SIGNIFICANCE: Adults with CP demonstrated stable test-retest performance on the selected measures. These measures could be useful to assess balance and gait of adults with CP. The MDC values can help evaluate whether observed changes exceed the expected random test-retest variations.

Gait Training With Visual Feedback and Proprioceptive Input to Reduce Gait Asymmetry in Adults With Cerebral Palsy: A Case Series.

PURPOSE: The purpose of this case series was to investigate the feasibility of using visual feedback on gait asymmetry during gait retraining and whether this leads to reduced asymmetry, improvement in gait speed, cost of walking, and dynamic balance in ambulant adults with cerebral palsy (CP). METHODS: Five adults with CP, who were ambulatory and had step length or stance time asymmetry, trained for 18 sessions on a split-belt treadmill with concurrent visual feedback from a virtual environment. Training also included overground gait training to encourage transfer of learning. RESULTS: All participants reduced gait asymmetry and improved on outcomes at posttest and follow-up. CONCLUSIONS: Outcome measures and training protocols were feasible in this sample of convenience of adults with CP who were ambulatory and who did not have visual impairment. The adults with CP in this study demonstrated individual improvements in gait and balance following training.