The Relationship Between Physical Housing Characteristics, Housing Accessibility and Different Aspects of Health Among Community-Dwelling Older People: A Systematic Review.

Objectives: To synthesize the evidence on the relationships between physical housing characteristics or housing accessibility and different aspects of health among community-dwelling people 60 years and older. Methods: A systematic review of recent evidence with a narrative synthesis was conducted. Results: We included 15 studies and found three themes covering physical housing characteristics or housing accessibility that are associated with aspects of health among community-dwelling older adults: (1) interventions by home modifications targeting housing features both at entrances and indoors; (2) non-interventions targeting indoor features; (3) non-interventions targeting entrance features, that is, the presence of an elevator or stairs at the entrance. The overall quality of evidence across studies was assessed as very low. Discussion: The findings highlight the need for studies with a stronger research design and higher methodological quality that address the physical housing environment in relation to health among older adults to strengthen the body of evidence.

Effects of Brain Pathologies on Spatiotemporal Gait Parameters in Patients with Mild Cognitive Impairment.

BACKGROUND: Impaired gait can precede dementia. The associations between gait parameters and brain pathologies are therefore of interest. OBJECTIVE: To explore how different brain pathologies (i.e., vascular and Alzheimer's) are associated with specific gait parameters from various gait components in persons with mild cognitive impairment (MCI), who have an increased risk of developing dementia. METHODS: This cross-sectional study included 96 patients with MCI (mean 72, ±7.5 years; 52% women). Gait was evaluated by using an electronic walkway, GAITRite®. Four gait parameters (step velocity variability; step length; step time; stance time asymmetry) were used as dependent variables in multivariable linear regression analyses. Independent variables included Alzheimer's disease pathologies (amyloid-ß and tau) by using PET imaging and white matter hyperintensities (WMH) by using MRI. Covariates included age, sex, comorbidities (and intracranial volume in analyses that includedWMH). RESULTS: Increased tau-PET (Braak I-IV region of interest [ROI]) was associated with step velocity variability (standardized regression coefficient, ß= 0.383, p < 0.001) and step length (ß= 0.336, p < 0.001), which remained significant when using different Braak ROIs (I-II, III-IV, V-VI). The associations remained significant when adjusting for WMH (p < 0.001). When also controlling for gait speed, tau was no longer significantly (p = 0.168) associated with an increased step length. No significant associations between gait and Aß-PET load or WMH were identified. CONCLUSIONS: The results indicate that one should pay specific attention to assess step velocity variability when targeting single task gait in patients with MCI. Future studies should address additional gait variability measures and dual tasking in larger cohorts.

Cognitive effects of Lewy body pathology in clinically unimpaired individuals.

α-Synuclein aggregates constitute the pathology of Lewy body (LB) disease. Little is known about the effects of LB pathology in preclinical (presymptomatic) individuals, either as isolated pathology or coexisting with Alzheimer's disease (AD) pathology (ß-amyloid (Aß) and tau). We examined the effects of LB pathology using a cerebrospinal fluid α-synuclein-seed amplification assay in 1,182 cognitively and neurologically unimpaired participants from the BioFINDER study: 8% were LB positive, 26% Aß positive (13% of those were LB positive) and 16% tau positive. LB positivity occurred more often in the presence of Aß positivity but not tau positivity. LB pathology had independently negative effects on cross-sectional and longitudinal global cognition and memory and on longitudinal attention/executive function. Tau had cognitive effects of a similar magnitude, but these were less pronounced for Aß. Participants with both LB and AD (Aß and tau) pathology exhibited faster cognitive decline than those with only LB or AD pathology. LB, but not AD, pathology was associated with reduced sense of smell. Only LB-positive participants progressed to clinical LB disease over 10 years. These results are important for individualized prognosis, recruitment and choice of outcome measures in preclinical LB disease trials, but also for the design of early AD trials because >10% of individuals with preclinical AD have coexisting LB pathology.

Time to workforce exit after a Parkinson's disease diagnosis.

The impact of Parkinson's disease (PD) on workforce participation has received little attention even though demographic, lifestyle, and political changes together will result in an increased burden of PD on the working-age population. In this study, we investigate workforce survival after a PD diagnosis, as well as what demographic factors that are associated with workforce survival. As an exploratory outcome, we investigate workforce survival in persons with and without device-aided treatment (DAT). This is a nested case-cohort study based on Swedish national data from 2001-2016. Controls were matched on year of birth, sex, and municipality of residence. The used registers contain data on demographics, social insurance, in- and outpatient visits, filled drug prescriptions, and cause of death on the person-level. A total of 4781 persons with PD and 23,905 controls were included. The median survival until all-cause workforce exit was 43 months among persons that were workforce-active at the time of PD diagnosis, compared to 66 months in non-PD controls. Being female, ≥50 years old at diagnosis, or having a lower education were contributing factors to health-related workforce exit. Persons receiving DAT during follow-up exhibited shorter workforce survival than controls. However, this needs further investigation, particularly as patients have generally already left the workforce at the time for start of DAT. It is evident that PD has grave negative effects on workforce participation. Thus, supportive measures need to start at an early stage after diagnosis, and the development of new interventions is urgently needed.

A theoretical framework for addressing fear of falling avoidance behavior in Parkinson's disease.

Postural instability in Parkinson's disease (PD) is associated with several downstream consequences that ultimately lead to a greater risk of falling. Among the prominent downstream consequences is fear of falling (FOF), which is both common and problematic in PD. It can lead to a vicious cycle of FOF avoidance behavior that results in more sedentary behavior, physical deconditioning, and weakening of already impaired balance systems. This, in turn, may make the person with PD more susceptible to a future fall even with benign daily tasks. While FOF activity avoidance can be adaptive (appropriate), it can also be maladaptive (inappropriate or exaggerated). When this adaptive and maladaptive FOF avoidance behavior is contextualized to gait/balance performance, it provides a theoretical framework that can be used by clinicians to match patterns of behavior to a concordant treatment approach. In the theoretical framework proposed in this perspective, four different patterns related to FOF avoidance behavior and gait/balance performance are suggested: appropriate avoiders, appropriate non-avoiders, inappropriate avoiders, and inappropriate non-avoiders. For each of the four FOF avoidance behavior patterns, this paper also provides suggested treatment focuses, approaches and recommendations.

Environmental barriers and housing accessibility problems for people with Parkinson's disease: A three-year perspective.

BACKGROUND: Although housing accessibility is associated with important health outcomes in other populations, few studies have addressed this in a Parkinson's disease population. AIM: To determine the most severe environmental barriers in terms of housing accessibility problems and how these evolved over 3 years among people with Parkinson's disease. MATERIAL AND METHODS: 138 participants were included (men = 67%; mean age = 68 years). The most severe environmental barrier were identified by the Housing Enabler instrument and ranked in descending order. The paired t-test was used to analyse changes in accessibility problems over time. RESULTS: The top 10 barriers remained largely unchanged over 3 years, but with notable changes in order and magnitude. 'No grab bar in hygiene area' and 'Stairs only route' were top-ranked in generating accessibility problems at baseline but decreased significantly (p = 0.041; p = 0.002) at follow-up. 'Difficulties to reach refuse bin' was top-ranked at follow-up, with a significant increase (p < 0.001) of related accessibility problems. CONCLUSIONS AND SIGNIFICANCE: The new knowledge about how accessibility problems evolve over time could be used by occupational therapists to recommend more effective housing adaptations taking the progressive nature of Parkinson's disease into account. On societal level, the results could be used to address accessibility problems systematically.

Enabling Long-term Predictions and Cost-benefit Analysis Related to Housing Adaptation Needs for a Population Aging in Place: Protocol for a Simulation Study.

BACKGROUND: Policies that promote aging in place are common in Sweden and many other countries. However, the current housing stock cannot sufficiently accommodate a population aging in place considering how functional capacity and housing needs change as people age. To be suitable for all regardless of their functional ability, housing should be designed or adapted to facilitate the performance of activities of daily living. Long-term planning and plausible projections of development 20 to 30 years into the future are needed. OBJECTIVE: The overall aim is to develop simulation models that enable long-term predictions and analysis of potential consequences in terms of societal gains and costs for different large-scale measures and interventions in the ordinary housing stock. METHODS: This study is designed as a simulation study and will broadly apply health impact assessment methods in collaboration with five municipalities in Sweden. Individual interviews and research circles were used to identify current and prioritize potential new policies to improve the accessibility of the housing stock. We will run a series of simulations based on an estimated willingness to pay from discussions with the municipalities. Two to three different prioritized policies will be compared simultaneously using Markov cohort analysis to estimate the potential costs and health impact on the population. Using data from a systematic review and existing population-based data sets with individual-level data on home and health variables, we will calculate parameter estimates for the relations between housing accessibility and health outcomes. The potential impact of selected policy interventions will be estimated in several microsimulations representing people living in the community. Sensitivity analyses will be conducted for each simulation. RESULTS: As of April 2022, open access data was collected, and a systematic review was underway and expected to be completed by November 2022. Collaboration with five municipalities was established in autumn 2020. In spring 2021, the municipalities developed a list of prioritized policy interventions to be tested and used in the simulation models. Inventories of barrier frequencies in ordinary housing started in spring 2022 and are expected to be completed in autumn 2022. Data gathering and analyses for simulation inputs will be completed during 2022 followed by the simulation modeling analyses to be completed in 2023. CONCLUSIONS: Improved accessibility of the ordinary housing stock has the potential to maintain or improve the health of the aging population. This study will generate tools that enable long-term predictions and reliable cost-benefit estimates related to the housing adaptation needs for a population aging in place, thus providing support for the best-informed policy decisions. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/39032.

Spatial Navigation and Its Association With Biomarkers and Future Dementia in Memory Clinic Patients Without Dementia.

BACKGROUND AND OBJECTIVES: Impaired spatial navigation is considered an early sign in many neurodegenerative diseases. We aimed to determine whether spatial navigation was associated with future dementia in patients with subjective cognitive decline (SCD) or mild cognitive impairment (MCI) and to explore associations between spatial navigation and biomarkers of Alzheimer disease (AD) and neurodegeneration. METHODS: This study included memory clinic patients without dementia in the longitudinal BioFINDER cohort. The Floor Maze Test (FMT) was used to assess spatial navigation at baseline. Conversion to dementia was evaluated at 2-year and 4-year follow-ups. At baseline, amyloid-ß 42/40 ratio, phosphorylated-tau (P-tau), and neurofilament light (NfL) were analyzed in CSF. Cortical thickness and volume of regions relevant for navigation and white matter lesion volume were quantified from MRI. The predictive role of the FMT for conversion to all-cause dementia was analyzed using logistic regression analyses in 2 models: (1) controlled for age, sex, and education and (2) adding baseline cognitive status and MMSE. Associations between FMT and biomarkers were adjusted for age, sex, and cognitive status (SCD or MCI). RESULTS: One hundred fifty-six patients with SCD and 176 patients with MCI were included. FMT total time was associated with progression to all-cause dementia in model 2 at 2-year (OR 1.10, 95% CI 1.04-1.16) and at 4-year follow-up (OR 1.10, 95% CI 1.04-1.16), i.e., a 10% increase in odds of developing dementia per every 10 seconds increase in FMT. In the adjusted analyses, P-tau and NfL were associated with FMT total time, as well as hippocampal volume, parahippocampal, and inferior parietal cortical thickness. Amyloid-ß 42/40 ratio was not associated with FMT total time. DISCUSSION: Impaired spatial navigation was associated with conversion to dementia within 2 and 4 years and with key CSF and MRI biomarkers for AD and neurodegeneration in patients with SCD and MCI. This supports its use in early cognitive assessments, but the predictive accuracy should be validated in other cohorts. CLASSIFICATION OF EVIDENCE: This is a Class I prospective cohort study demonstrating association of baseline markers of spatial recognition with development of dementia in patients with SCD or MCI at baseline.

Conditions for uptake of evidence-based knowledge in municipal care for older people in Sweden: a developmental evaluation.

OBJECTIVE: The objective of this paper is to describe the initial phase of a long-term collaboration initiative between a municipality and the Faculty of Medicine at a university in Sweden. The overall ambition of the collaboration is to strengthen the quality of care for older people. The concrete goal is to equip academically trained registered health care professionals (HCP) with tools for transferring evidence-based knowledge into practice. As municipal healthcare for older people is mainly carried out by staff lacking academic education, reg. HCP are key actors to bring in and consolidate an evidence-based approach in this setting. Developmental evaluation (DE) has been used to evaluate four separate activities in the initial phase. The activities where sequenced in a cumulative design to provide knowledge for further development of adequate tools. RESULTS: The cumulative design originally planned did not fit the internal logic of the municipality. Therefore, workflow and pace adjustments were made to proceed towards the joint ambition; the creation of fruitful conditions for the uptake of evidence-based knowledge. Long-term collaboration between academia and organizations outside academia demands a sensitive and flexible research approach, recognizing that collaboration implies mutuality and restricts the sovereignty of academia in designing research.

Objective Observer vs. Patient Motor State Assessments Using the PD Home Diary in Advanced Parkinson's Disease.

Background: The Parkinson Disease (PD) Home Diary (HD) is a commonly used clinical outcome measure, but it has not been extensively compared to direct assessments by experienced observers. Objective: Validation of patient-reported HD by investigating the agreement between motor state assessments by patients and observers. Methods: This observational study included patients with PD and motor fluctuations. Observers were physicians or research nurses. Patients completed a screening visit, one day of diary ratings at home, and then two days of ratings on-site during which patients and observers simultaneously judged the participants' motor state. Results: Observers and 40 patients completed 1,288 pairs of half-hourly blinded motor state assessments. There were significant differences between observer and patient ratings (P < 0.001) and the temporal agreement was poor (Cohen's κ = 0.358). The agreement between patient and observer ratings was 71.1% for observed "On without dyskinesia", 57.3% for observed "Off", and 49.4% for observed "On with dyskinesia". Daily times spent in the three motor states as aggregated diary data showed fair to excellent reliability with intraclass coefficient values ranging from 0.45 to 0.52 for "On" and 0.77 for "Off". Conclusion: There were significant differences between observer and patient ratings. Patients and observers generally agreed on when the patients was in the "On" state (with or without dyskinesia). Patient ratings on the hour level seem to be influenced by other aspects of the patients' experience than the observed motor state, but assessment of daily time spent in the different motor state provides reasonable reliability.

Components of gait in people with and without mild cognitive impairment.

BACKGROUND: Several objective gait parameters are associated with cognitive impairment, but there is limited knowledge of gait models in people with mild cognitive impairment (MCI). RESEARCH QUESTION: How can 18 objective gait characteristics be used to define different components of gait in people with MCI (with suspected incipient neurocognitive disorder) and cognitively unimpaired people (CU), respectively? METHODS: Spatiotemporal gait data were collected by using an electronic walkway (GAITRite®), i.e. assessments in comfortable gait speed. Using cross-sectional gait data, two principal component analyses (PCA) were performed (varimax rotation) to define different components of gait in people with MCI (n = 114) and CU (n = 219), respectively, from the BioFINDER-2 study. RESULTS: Both PCAs produced four components, here called Variability, Pace/Stability, Rhythm and Asymmetry. Total variance explained was 81.0% (MCI) versus 80.3% (CU). The Variability component explained the largest amount of variance (about 25%) in both groups. The highest loading gait parameter was the same for both groups in three out of four components, i.e. step velocity variability (Variability), mean step length (Pace/Stability) and mean step time (Rhythm). In the asymmetry component, stance time asymmetry (MCI) and swing time asymmetry (CU) loaded the highest. SIGNIFICANCE: The gait components seem similar in people with and without MCI, although there were some differences. This study may aid the identification of gait variables that represent different components of gait. Gait parameters such as step velocity variability, mean step length, mean step time as well as swing and stance time asymmetry could serve as interesting core variables of different gait components in future research in people with MCI (with suspected incipient neurocognitive disorder) and CU. However, the selection of gait variables depends on the purpose. It needs to be noted that assessment of variability measures requires more advanced technology than is usually used in the clinic.

People with Parkinson's disease and housing issues: A scoping review.

BACKGROUND AND AIMS: There is evidence that housing issues are associated with health outcomes as people age, but little is known in this respect regarding the specific population of people with Parkinson's disease (PD). The objective of this literature review was to identify and analyze the knowledge gap concerning people with PD and housing issues. METHODS: Applying established guidelines for scoping reviews, a systematic literature search was done in relevant databases applying the following inclusion criteria: empirical studies including human participants with PD, addressing housing in the objective, hypothesis or research questions, and published in English in peer-reviewed journals. Data were analyzed using a framework of domains, factors, and variables influencing housing decisions among older people. RESULTS: Twelve publications were identified, originating from a few researchers and with very different scopes. While the social dimension was scarcely attended to, the publications addressed all six domains of the analytical framework and 30% of the variables specified therein, but many were only used for descriptive purposes. CONCLUSION: This scoping review reveals that there is a substantial knowledge gap regarding people with PD and housing issues. The knowledge gap is most evident in the social dimension, while the studies identified provide more information relating to the health dimension than what is the case in research on housing targeting the general aging population. Because society urgently needs evidence to support the development of housing policies and provide suitable housing for this vulnerable population, more research targeting people with PD and housing issues is warranted.

Strategic alterations of posture are delayed in Parkinson's disease patients during deep brain stimulation.

Parkinson's disease (PD) is characterized by rigidity, akinesia, postural instability and tremor. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) reduces tremor but the effects on postural instability are inconsistent. Another component of postural control is the postural strategy, traditionally referred to as the ankle or hip strategy, which is determined by the coupling between the joint motions of the body. We aimed to determine whether DBS STN and vision (eyes open vs. eyes closed) affect the postural strategy in PD in quiet stance or during balance perturbations. Linear motion was recorded from the knee, hip, shoulder and head in 10 patients with idiopathic PD with DBS STN (after withdrawal of other anti-PD medication), 25 younger adult controls and 17 older adult controls. Correlation analyses were performed on anterior-posterior linear motion data to determine the coupling between the four positions measured. All participants were asked to stand for a 30 s period of quiet stance and a 200 s period of calf vibration. The 200 s vibration period was subdivided into four 50 s periods to study adaptation between the first vibration period (30-80 s) and the last vibration period (180-230 s). Movement was recorded in patients with PD with DBS ON and DBS OFF, and all participants were investigated with eyes closed and eyes open. DBS settings were randomized and double-blindly programmed. Patients with PD had greater coupling of the body compared to old and young controls during balance perturbations (p ≤ 0.046). Controls adopted a strategy with greater flexibility, particularly using the knee as a point of pivot, whereas patients with PD adopted an ankle strategy, i.e., they used the ankle as the point of pivot. There was higher flexibility in patients with PD with DBS ON and eyes open compared to DBS OFF and eyes closed (p ≤ 0.011). During balance perturbations, controls quickly adopted a new strategy that they retained throughout the test, but patients with PD were slower to adapt. Patients with PD further increased the coupling between segmental movement during balance perturbations with DBS ON but retained a high level of coupling with DBS OFF throughout balance perturbations. The ankle strategy during balance perturbations in patients with PD was most evident with DBS OFF and eyes closed. The increased coupling with balance perturbations implies a mechanism to reduce complexity at a cost of exerting more energy. Strategic alterations of posture were altered by DBS in patients with PD and were delayed. Our findings therefore show that DBS does not fully compensate for disease-related effects on posture.

Deep brain stimulation in the subthalamic nuclei alters postural alignment and adaptation in Parkinson's disease.

Parkinson's disease (PD) can produce postural abnormalities of the standing body position such as kyphosis. We investigated the effects of PD, deep brain stimulation (DBS) in the subthalamic nucleus (STN), vision and adaptation on body position in a well-defined group of patients with PD in quiet standing and during balance perturbations. Ten patients with PD and 25 young and 17 old control participants were recruited. Body position was measured with 3D motion tracking of the ankle, knee, hip, shoulder and head. By taking the ankle as reference, we mapped the position of the joints during quiet standing and balance perturbations through repeated calf muscle vibration. We did this to explore the effect of PD, DBS in the STN, and vision on the motor learning process of adaptation in response to the repeated stimulus. We found that patients with PD adopt a different body position with DBS ON vs. DBS OFF, to young and old controls, and with eyes open vs. eyes closed. There was an altered body position in PD with greater flexion of the head, shoulder and knee (p≤0.042) and a posterior position of the hip with DBS OFF (p≤0.014). With DBS ON, body position was brought more in line with the position taken by control participants but there was still evidence of greater flexion at the head, shoulder and knee. The amplitude of movement during the vibration period decreased in controls at all measured sites with eyes open and closed (except at the head in old controls with eyes open) showing adaptation which contrasted the weaker adaptive responses in patients with PD. Our findings suggest that alterations of posture and greater forward leaning with repeated calf vibration, are independent from reduced movement amplitude changes. DBS in the STN can significantly improve body position in PD although the effects are not completely reversed. Patients with PD maintain adaptive capabilities by leaning further forward and reducing movement amplitude despite their kyphotic posture.

Test-retest reliability of physical activity questionnaires in Parkinson's disease.

BACKGROUND: People with Parkinson's disease are less physically active than controls. It is important to promote physical activity, which can be assessed using different methods. Subjective measures include physical activity questionnaires, which are easy and cheap to administer in clinical practice. Knowledge of the psychometric properties of physical activity questionnaires for people with Parkinson's disease is limited. The aim of this study was to evaluate the test-retest reliability of physical activity questionnaires in individuals with Parkinson's disease without cognitive impairment. METHODS: Forty-nine individuals with Parkinson's disease without cognitive impairment participated in a test-retest reliability study. At two outpatient visits 8 days apart, the participants completed comprehensive questionnaires and single-item questions: International Physical Activity Questionnaire-Short Form (IPAQ-SF), Physical Activity Scale for the Elderly (PASE), Saltin-Grimby Physical Activity Level Scale (SGPALS) and Health on Equal Terms (HOET). Test-retest reliability was evaluated using the intraclass correlation coefficient (ICC), standard error of measurement (SEM), limits of agreement, weighted kappa or the Svensson method. RESULTS: Several of the physical activity questionnaires had relatively low test-retest reliability, including the comprehensive questionnaires (IPAQ-SF and PASE). Total physical activity according to IPAQ-SF had an ICC value of 0.46 (95% confidence interval [CI], 0.21-0.66) and SEM was 2891 MET-min/week. The PASE total score had an ICC value of 0.66 (95% CI, 0.46-0.79), whereas the SEM was 30 points. The single-item scales of SGPALS-past six months (SGPALS-6 m) and HOET question 1 (HOET-q1) with longer time frames (6 or 12 months, respectively) showed better results. Weighted kappa values were 0.64 (95% CI, 0.45-0.83) for SGPALS-6 m and 0.60 (95% CI, 0.39-0.80) for HOET-q1, whereas the single-item questions with a shorter recall period had kappa values < 0.40. CONCLUSIONS: Single-item questions with a longer time frame (6 or 12 months) for physical activity were shown to be more reliable than multi-item questionnaires such as the IPAQ-SF and PASE in individuals with Parkinson's disease without cognitive impairments. There is a need to develop a core outcome set to measure physical activity in people with Parkinson's disease, and there might be a need to develop new physical activity questionnaires.

Perceived walking difficulties in Parkinson's disease - predictors and changes over time.

BACKGROUND: People with Parkinson's disease (PD) have described their walking difficulties as linked to activity avoidance, social isolation, reduced independence and quality of life. There is a knowledge gap regarding predictive factors of perceived walking difficulties in people with PD. Such knowledge could be useful when designing intervention studies. This study aimed to investigate how perceived walking difficulties evolve over a 3-year period in people with PD. A specific aim was to identify predictive factors of perceived walking difficulties. METHODS: One hundred forty-eight people with PD (mean age 67.9 years) completed the Generic Walk-12 (Walk-12G) questionnaire (which assesses perceived walking difficulties) at both baseline and the 3-year follow-up. Paired samples t-test was used for comparing baseline and follow-up mean scores. Multivariable linear regression analyses were used to identify predictive factors of perceived walking difficulties. RESULTS: Perceived walking difficulties increased after 3 years: mean Walk-12G score 14.8 versus 18.7, p < 0.001. Concerns about falling was the strongest predictor (ß = 0.445) of perceived walking difficulties, followed by perceived balance problems while dual tasking (ß = 0.268) and pain (ß = 0.153). Perceived balance problems while dual tasking was the strongest predictor (ß = 0.180) of a change in perceived walking difficulties, followed by global cognitive functioning (ß = - 0.107). CONCLUSIONS: Perceived walking difficulties increase over time in people with PD. Both personal factors (i.e. concerns about falling) and motor aspects (i.e. balance problems while dual tasking) seem to have a predictive role. Importantly, our study indicates that also non-motor symptoms (e.g. pain and cognitive functioning) seem to be of importance for future perceived walking difficulties. Future intervention studies that address these factors need to confirm their preventative effect on perceived walking difficulties.

Spectral analysis of body movement during deep brain stimulation in Parkinson's disease.

BACKGROUND: The characteristics of Parkinson's disease (PD) include postural instability and resting tremor. However, reductions of tremor amplitude do not always improve postural stability. RESEARCH QUESTION: What is the effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) on spectral analysis of body movement in patients with PD when tested without anti-PD medication? The effect of visual cues was also studied. METHODS: Ten patients with PD (mean age 64.3 years, range 59-69 years) and 17 control participants (mean age 71.2 years, range 65-79 years) were recruited. Spectral power following a period of quiet stance (35 s) was analysed in three different spectral power bands (0-4 Hz, 4-7 Hz and 7-25 Hz). Motion markers were secured to the head, shoulder, hip, and knee, which recorded movements in two directions, the anteroposterior and lateral. RESULTS: DBS STN significantly changed the spectral distribution pattern across the body in the anteroposterior (p = 0.029) and lateral directions (p ≤ 0.003). DBS predominantly reduced spectral power at the head (p ≤ 0.037) and shoulder (p ≤ 0.031) in the lateral direction. The spectral power of the lower and upper body in patients with PD, with DBS ON, were more similar to the control group, than to DBS OFF. Visual cues mainly reduced spectral power in the anteroposterior direction at the shoulder (p ≤ 0.041) in controls and in patients with PD with DBS ON. SIGNIFICANCE: There is an altered postural strategy in patients with PD with DBS ON as shown by an altered spectral power distribution pattern across body segments and a reduction of spectral power in the lateral direction at the head and shoulder. A reduction of spectral power in controls and in patients with PD with DBS ON suggests that visual cues are able to reduce spectral power to some extent, but not with DBS OFF where postural sway and power are larger.

The Effects of Tau, Amyloid, and White Matter Lesions on Mobility, Dual Tasking, and Balance in Older People.

BACKGROUND: This study aimed to investigate whether white matter lesions (WML), ß-amyloid-, and tau pathologies are independently associated with mobility, dual tasking, and dynamic balance performance in older nondemented individuals. METHODS: We included 299 older people (mean, SD, age: 71.8, 5.6 years) from the Swedish BioFINDER study, whereof 175 were cognitively unimpaired and 124 had mild cognitive impairment (MCI). In multivariable regression analyses, dependent variables included mobility (Timed Up & Go [TUG]), dual tasking (TUG with a simultaneous subtraction task, that is, TUG-Cog, as well as dual task cost), and balance (Figure-of-eight). The analyses were controlled for age, sex, education, diagnosis (ie, MCI), and comorbidity (stroke, diabetes, and ischemic heart disease). Independent variables included WML volume, and measures of ß-amyloid (abnormal cerebrospinal fluid [CSF] Aß42/40 ratio) and tau pathology (CSF phosphorylated tau [p-tau]). RESULTS: Multivariable regression analyses showed that an increased WML volume was independently associated with decreased mobility, that is, TUG (standardized ß = 0.247; p < .001). Tau pathology was independently associated with dual tasking both when using the raw data of TUG-Cog (ß = 0.224; p = .003) and the dual-task cost (ß= -0.246; p = .001). Amyloid pathology was associated with decreased balance, that is, Figure-of-eight (ß = 0.172; p = .028). The independent effects of WML and tau pathology were mainly observed in those with MCI, which was not the case for the effects of amyloid pathology on balance. CONCLUSIONS: Common brain pathologies have different effects where WML are independently associated with mobility, tau pathology has the strongest effect on dual tasking, and amyloid pathology seems to be independently associated with balance. Although these novel findings need to be confirmed in longitudinal studies, they suggest that different brain pathologies have different effects on mobility, balance, and dual-tasking in older nondemented individuals.

Coping Styles among People with Parkinson's Disease: A Three-Year Follow-Up Study.

People with Parkinson's disease (PD) experience a gradual loss of functional abilities that affects all facets of their daily life. There is a lack of longitudinal studies on coping styles in relation to the disease progression among people with PD. The aim of this study was to explore how coping styles in PD evolve over a 3-year period. Data from the longitudinal project "Home and Health in People Ageing with PD" was utilized (N = 158), including baseline and 3-year follow-up assessments. Coping was captured by ratings of 13 different coping styles. A factor analysis was conducted to analyse patterns of coping styles. Stability and change were analysed for each of the 13 styles with respect to the course of the disease. The factor analysis revealed four coping patterns: pessimistic, optimistic, persistent and support-seeking. The stability of each coping style over time ranged from 75.3% to 90.5%. Those who experienced a worsening of the disease were most inclined to change their coping style (p = 0.006). The results suggest that even when facing severe challenges due to PD in daily life, coping styles remain relatively stable over time. However, a worsening in PD severity appeared to trigger a certain re-evaluation of coping styles.

The meaning of home questionnaire revisited: Psychometric analyses among people with Parkinson's disease reveals new dimensions.

BACKGROUND: Research addressing perceptions of housing in people with Parkinson's disease (PD) is rare, and existing instruments capturing perceived aspects of housing are rarely used. Perceived housing comprises of several domains and is associated with health in general older populations. One such domain is meaning of home, captured by the Meaning of Home Questionnaire (MOH). The aim of this study was to evaluate psychometric properties of the MOH among people with PD. MATERIALS AND METHODS: The MOH was administrated to 245 participants with PD (mean age = 69.9 years; mean PD duration = 9.7 years). The instrument consisted of four sub-scales with 28 items, each with 11 response options (strongly disagree = 0; strongly agree = 10). We evaluated data quality, structural validity (factor analysis), construct validity (i.e., testing correlations with relevant constructs according to pre-defined hypotheses), corrected item total correlations, floor and ceiling effects and internal consistency. RESULTS: The data quality was high (0-1.2% missing data). The exploratory factor analysis suggested removal of five items and revealed three new factors; "My home is my castle", "My home is my prison" and "My home is my social hub". The 23-item MOH showed statistically significant correlations with life satisfaction, usability and ADL dependence, while not correlated with number of environmental barriers. These findings were largely as hypothesised, thus supporting construct validity (both convergent and discriminant). The corrected item total correlations were >0.3 for all items and the internal consistency was >0.70 for all sub-scales. No floor or ceiling effects were reported except for the sub-scale "My home is my castle" (ceiling effect = 15.6%). CONCLUSIONS: The 23-item MOH version with three new sub-scales is sufficiently reliable and valid for use in PD populations. This paves the way for further research of meaning of home among people with PD, using the 23-item MOH version.