How Lifetime Evolution of Parkinson's Disease Could Shape Clinical Trial Design: A Shared Patient-Clinician Viewpoint

Parkinson's disease (PD) has a long, heterogeneous, pre-diagnostic phase, during which pathology insidiously accumulates. Increasing evidence suggests that environmental and lifestyle factors in early life contribute to disease risk and progression. Thanks to the extensive study of this pre-diagnostic phase, the first prevention trials of PD are being designed. However, the highly heterogenous evolution of the disease across the life course is not yet sufficiently taken into account. This could hamper clinical trial success in the advent of biological disease definitions. In an interdisciplinary patient-clinician study group, we discussed how an approach that incorporates the lifetime evolution of PD may benefit the design of disease-modifying trials by impacting population, target and outcome selection. We argue that the timepoint of exposure to risk and protective factors plays a critical role in PD subtypes, influencing population selection. In addition, recent developments in differential disease mechanisms, aided by biological disease definitions, could impact optimal treatment targets. Finally, multimodal biomarker panels using this lifetime approach will likely be most sensitive as progression markers for more personalized trials. We believe that the lifetime evolution of PD should be considered in the design of clinical trials, and that such initiatives could benefit from more patient-clinician partnerships.

[Hitting and yelling during sleep: diagnosis and implications of REM sleep behavior disorder]

Rapid eye movement (REM) sleep behavior disorder is characterized by dream enactment during REM sleep. Due to different treatment requirements, it is important to distinguish REM sleep behavior disorder from other causes of nocturnal restlessness, including sleep apnea, non-REM parasomnia and sleep-related hypermotor epilepsy. In addition, a diagnosis of isolated REM sleep behavior disorder is impactful, because it carries a greatly increased risk for the later development of Parkinson's disease and related synucleinopathies. In this clinical lesson we describe three patients with abnormal nocturnal movements and vocalizations. The history can provide important clues towards the diagnosis, but a video-polysomnography is required before REM sleep behavior disorder can be diagnosed.

Age and gender differences in non-motor symptoms in people with Parkinson's disease

Background

Non-motor symptoms of Parkinson's disease (PD) are highly prevalent and heterogenic. Previous studies aimed to gain more insight on this heterogeneity by investigating age and gender differences in non-motor symptom severity, but findings were inconsistent. Furthermore, besides examining the single effects of age and gender, the interaction between them in relation to non-motor functioning has -as far as we know- not been investigated before.

Objectives

To investigate the association of age and gender identity -as well as the interaction between age and gender identity- with non-motor symptoms and their impact on quality of life.

Methods

We combined three large and independent studies. This approach resulted in a total number of unique participants of 1,509. We used linear regression models to assess the association of age and gender identity, and their interaction, with non-motor symptoms and their impact on quality of life.

Results

Older people with PD generally had worse cognitive functioning, worse autonomic functioning and worse quality of life. Women with PD generally experienced more anxiety, worse autonomic functioning and worse quality of life compared to men with PD, whereas men with PD generally had worse cognitive functioning. In interaction analyses by age and gender identity, depressive symptoms and anxiety were disproportionally worse with increasing age in women compared to men.

Conclusion

Our findings indicate that both age and gender -as well as their interaction- are differentially associated with non-motor symptoms of PD. Both research and clinical practice should pay more attention to demographic subgroups differences and possible different treatment approaches with respect to age and gender. We showed how combining datasets is of added value in this kind of analyses and encourage others to use similar approaches.

Towards improved screening of toxins for Parkinson's risk

Parkinson's disease (PD) is a chronic, progressive and disabling neurodegenerative disorder. The prevalence of PD has risen considerably over the past decades. A growing body of evidence suggest that exposure to environmental toxins, including pesticides, solvents and heavy metals (collectively called toxins), is at least in part responsible for this rapid growth. It is worrying that the current screening procedures being applied internationally to test for possible neurotoxicity of specific compounds offer inadequate insights into the risk of developing PD in humans. Improved screening procedures are therefore urgently needed. Our review first substantiates current evidence on the relation between exposure to environmental toxins and the risk of developing PD. We subsequently propose to replace the current standard toxin screening by a well-controlled multi-tier toxin screening involving the following steps: in silico studies (tier 1) followed by in vitro tests (tier 2), aiming to prioritize agents with human relevant routes of exposure. More in depth studies can be undertaken in tier 3, with whole-organism (in)vertebrate models. Tier 4 has a dedicated focus on cell loss in the substantia nigra and on the presumed mechanisms of neurotoxicity in rodent models, which are required to confirm or refute the possible neurotoxicity of any individual compound. This improved screening procedure should not only evaluate new pesticides that seek access to the market, but also critically assess all pesticides that are being used today, acknowledging that none of these has ever been proven to be safe from a perspective of PD. Importantly, the improved screening procedures should not just assess the neurotoxic risk of isolated compounds, but should also specifically look at the cumulative risk conveyed by exposure to commonly used combinations of pesticides (cocktails). The worldwide implementation of such an improved screening procedure, would be an essential step for policy makers and governments to recognize PD-related environmental risk factors.

Exploring the levodopa-paradox of freezing of gait in dopaminergic medication-naïve Parkinson's disease populations

The relationship between dopaminergic treatment and freezing of gait (FOG) in Parkinson's disease (PD) is complex: levodopa is the most effective symptomatic treatment for FOG, but long-term pulsatile levodopa treatment has also been linked to an increase in the occurrence of FOG. This concept, however, continues to be debated. Here, we compared the occurrence of FOG between a levodopa-naive PD cohort and a levodopa-treated cohort. Forty-nine treatment-naive patients and 150 levodopa-treated patients were included. The time since first motor symptoms was at least 5 years. Disease severity was assessed using the MDS-UPDRS part III. Occurrence of FOG was assessed subjectively (new freezing-of-gait-questionnaire) and objectively (rapid turns test and Timed Up-and-Go test). The presence of FOG was compared between the levodopa-treated and levodopa-naive groups using a chi-square test of homogeneity. We also performed a binomial Firth logistic regression with disease duration, disease severity, country of inclusion, location of measurement, and executive function as covariates. Subjective FOG was more common in the levodopa-treated cohort (n = 41, 27%) compared to the levodopa-naive cohort (n = 2, 4%, p < 0.001). The association between FOG and levodopa treatment remained after adjustment for covariates (OR = 6.04, 95%Cl [1.60, 33.44], p = 0.006). Objectively verified FOG was more common in the levodopa-treated cohort (n = 21, 14%) compared to the levodopa-naive cohort (n = 1, 2%, p = 0.02). We found an association between long-term pulsatile levodopa treatment and an increased occurrence of FOG. Future studies should further explore the role of nonphysiological stimulation of dopamine receptors in generating FOG, as a basis for possible prevention studies.

[Risk factors for Parkinson's disease: possibilities for prevention and intervention]

Considering age to be the primary risk factor for developing Parkinson's disease and the observation that the Dutch population is rapidly aging, the parkinson prevalence is expected to increase over the coming years, as there is still no cure available for the disease. This has been confirmed by epidemiological data, which show a steady increase of the disease prevalence in the Netherlands for the period 2010-2021. Genetic risk factors only partially explain the disease pathogenesis. Environmental factors, such as exposure to pesticides and trichloroethylene are associated with a higher risk for developing Parkinson's disease. Lifestyle factors such as exercise, caffeine intake and the Mediterranean diet are associated with a lower risk for developing the disease and possibly delay the disease progression. Policy makers and healthcare providers should employ stricter regulations for pesticide use and should stimulate a healthy lifestyle to slow down the increasing prevalence.

Lipopolysaccharide-binding protein and future Parkinson's disease risk: a European prospective cohort

INTRODUCTION

Lipopolysaccharide (LPS) is the outer membrane component of Gram-negative bacteria. LPS-binding protein (LBP) is an acute-phase reactant that mediates immune responses triggered by LPS and has been used as a blood marker for LPS. LBP has recently been indicated to be associated with Parkinson's disease (PD) in small-scale retrospective case-control studies. We aimed to investigate the association between LBP blood levels with PD risk in a nested case-control study within a large European prospective cohort.

METHODS

A total of 352 incident PD cases (55% males) were identified and one control per case was selected, matched by age at recruitment, sex and study center. LBP levels in plasma collected at recruitment, which was on average 7.8 years before diagnosis of the cases, were analyzed by enzyme linked immunosorbent assay. Odds ratios (ORs) were estimated for one unit increase of the natural log of LBP levels and PD incidence by conditional logistic regression.

RESULTS

Plasma LBP levels were higher in prospective PD cases compared to controls (median (interquartile range) 26.9 (18.1-41.0) vs. 24.7 (16.6-38.4) µg/ml). The OR for PD incidence per one unit increase of log LBP was elevated (1.46, 95% CI 0.98-2.19). This association was more pronounced among women (OR 2.68, 95% CI 1.40-5.13) and overweight/obese subjects (OR 1.54, 95% CI 1.09-2.18).

CONCLUSION

The findings suggest that higher plasma LBP levels may be associated with an increased risk of PD and may thus pinpoint to a potential role of endotoxemia in the pathogenesis of PD, particularly in women and overweight/obese individuals.

Exercise knowledge, barriers and motivators among LRRK2 G2019S mutation carriers

INTRODUCTION

People with a Gly2019Ser mutation in the leucine-rich repeat kinase 2 (LRRK2 G2019S) are at increased risk of developing Parkinson's disease (PD). Recent evidence suggests that exercise may delay or prevent the development of clinically overt symptoms of PD in people at risk of PD. We determined whether LRRK2 G2019S mutation carriers with and without manifest PD are aware of the relationship between exercise and PD and how they differ in awareness, barriers and motivators to exercise.

METHODS

We deployed a survey among 4422 LRRK2 G2019S mutation carriers. In total, 505 (11.4%) of them completed the survey, of whom 105 had self-reported manifest PD.

RESULTS

Ninety-two percent of the LRRK2 G2019S mutation carriers with manifest PD and 63% of those with non-manifest PD were aware of the relationship between exercise and PD. Lack of motivation was the top barrier for those without manifest PD, while having an injury/disability was the most common barrier for those with manifest PD. Improvement of body functioning was the top motivator for both.

CONCLUSION

The fact that many at-risk individuals are not aware of the importance of exercise and would exercise more with fewer barriers creates opportunities for trials using exercise as a possible prevention strategy for PD.

Caregiver burden in Parkinson's disease: a mixed-methods study

BACKGROUND

Providing informal care for a person with Parkinson's disease (PD) can be a demanding process affecting several dimensions of a caregiver's life and potentially causing caregiver burden. Despite the emerging literature on caregiver burden in people with PD, little is known about the inter-relationship between quantitative and qualitative findings. Filling this knowledge gap will provide a more holistic approach to develop and design innovations aiming at reducing or even preventing caregiver burden. This study aimed to characterize the determinants of caregiver burden among informal caregivers of persons with PD, in order to facilitate the development of tailored interventions that reduce caregiver burden.

METHODS

We conducted a cross-sectional study in The Netherlands using a sequential mixed methods approach, entailing a quantitative study of 504 persons with PD and their informal caregivers as well as a qualitative study in a representative subsample of 17 informal caregivers. The quantitative study included a standardized questionnaire of caregiver burden (Zarit Burden Inventory) and patient-related (Beck Depression Inventory, State-Trait Anxiety Inventory, Acceptance of Illness Scale, MDS-Unified Parkinson's Disease Rating Scale part II on motor functions in daily life, Self-assessment Parkinson's Disease Disability Score), caregiver-related (Brief Coping Orientation to Problems Experience Inventory, Caregiver Activation Measurement, Multidimensional Scale of Perceived Social Support) and interpersonal determinants (sociodemographic variables including among others gender, age, education, marital status and working status). The qualitative study consisted of semi-structured interviews. Multivariable regression and thematic analysis were used to analyse quantitative and qualitative data, respectively.

RESULTS

A total of 337 caregivers were women (66.9%), and the majority of people with PD were men (N = 321, 63.7%). The mean age of persons with PD was 69.9 (standard deviation [SD] 8.1) years, and the mean disease duration was 7.2 (SD 5.2) years. A total of 366 (72.6%) persons with PD had no active employment. The mean age of informal caregivers was 67.5 (SD 9.2) years. Most informal caregivers were female (66.9%), had no active employment (65.9%) and were the spouse of the person with PD (90.7%). The mean Zarit Burden Inventory score was 15.9 (SD 11.7). The quantitative study showed that a lack of active employment of the person affected by PD was associated with a higher caregiver burden. The qualitative study revealed cognitive decline and psychological or emotional deficits of the person with PD as additional patient-related determinants of higher caregiver burden. The following caregiver-related and interpersonal determinants were associated with higher caregiver burden: low social support (quantitative study), concerns about the future (qualitative study), the caregiving-induced requirement of restrictions in everyday life (qualitative study), changes in the relationship with the person with PD (qualitative study) and a problem-focused or avoidant coping style (both studies). Integration of both data strands revealed that qualitative findings expanded quantitative findings by (1) distinguishing between the impact of the relationship with the person with PD and the relationship with others on perceived social support, (2) revealing the impact of non-motor symptoms next to motor symptoms and (3) revealing the following additional factors impacting caregiver burden: concern about the future, perceived restrictions and limitations in performing daily activities due to the disease, and negative feelings and emotional well-being. Qualitative findings were discordant with the quantitative finding demonstrating that problem-focused was associated with a higher caregiver burden. Factor analyses showed three sub-dimensions of the Zarit Burden Inventory: (i) role intensity and resource strain, (2) social restriction and anger and (3) self-criticism. Quantitative analysis showed that avoidant coping was a determinant for all three subscales, whereas problem-solved coping and perceived social support were significant predictors on two subscales, role intensity and resource strain and self-criticism.

CONCLUSIONS

The burden experienced by informal caregivers of persons with PD is determined by a complex interplay of patient-related, caregiver-related and interpersonal characteristics. Our study highlights the utility of a mixed-methods approach to unravel the multidimensional burden experienced by informal caregivers of persons with chronic disease. We also offer starting points for the development of a tailored supportive approach for caregivers.

Determinants of coping styles of people with Parkinson's Disease

Little is known about how people with Parkinson's disease (PD) cope with stressful life events. We examined the determinants of specific coping strategies and whether specific choices have any impact on quality of life (QoL). We recruited patients with PD who had been seen at a neurology outpatient clinic at least once during the past year as part of the PRIME-NL cohort study. Coping was measured using the Ways of Coping Questionnaire (WCQ) and QoL was measured using the Parkinson's Disease Questionnaire (PDQ-39). 977 out of 988 participants completed the questionnaires and 935 participants were diagnosed with PD. Factor analysis was undertaken to test if ways of coping were similar or different to previous findings in a PD population. We used linear regression analyses to examine predictors of coping styles. We then used multivariable linear regression to test how coping style was associated with the domains of QoL conditional on potential confounders. The five coping styles identified by the factor analysis were: "taking action and emphasizing the positive", "distancing and fantasizing", "goal oriented and planful problem solving", "seeking social support" and "avoidance and acceptance". Age, gender, education and anxiety were associated with the type of coping strategy. For example, higher education was associated with more active coping strategies (e.g. β = 4.39, p < 0.001 for goal oriented). Conditional on other confounders, most coping strategies had little effect on QoL domains. These findings demonstrate that coping behavior of people with PD is influenced by psychological status and personal traits. However, there was only a modest effect of coping behavior on QoL. Future research needs to test whether the enhancement or discouragement of certain coping strategies is feasible and can enhance QoL.

The salience of gender in the illness experiences and care preferences of people with Parkinson's disease

RATIONALE

In recent years, interest in sex characteristics and gender dimensions of Parkinson's disease (PD) has increased. Yet, much remains to be understood about how gender-related aspects specifically impact the illness and experiences of care in persons living with PD.

OBJECTIVE

The purpose of this study was to explore the salience of gender-related aspects in the illness experiences and care provision preferences of people with PD.

METHODS

A descriptive qualitative study including semi-structured life story interviews was conducted with men and women living with PD in the Netherlands. Between September 2020 and February 2021, forty people with PD (20 men and 20 women) participated in digital interviews of which thirty-one (18 men and 13 women) were included in the thematic analyses for this specific study.

RESULTS

Overall, most participants did not consider gender-related aspects salient towards their illness experiences. However, when prompted, a number of participants described several stereotypical views about gender as related to the visibility of PD, emotional experiences, help seeking, role patterns and physical appearance. While most men and women with PD did not express specific gender-related preferences for their healthcare providers, those that did, all preferred women as healthcare providers. These preferences were generally related to attributed feminine traits which are considered relevant in routine, particularly sensitive, physical examinations of people with PD.

CONCLUSION

This study demonstrates that although every person has a gender identity, the salience attributed to gender varies with illness experiences and in care provision preferences between people with PD. These findings highlight the need for precise and personalized methodologies to capture more nuanced insights into the impact of gender dimensions on PD. Furthermore, drivers behind gender-related preferences in care provision are multifactorial and warrant further investigation among people with PD.

Proactive and Integrated Management and Empowerment in Parkinson's Disease protocol for a randomised controlled trial (PRIME-UK) to evaluate a new model of care

BACKGROUND

People living with Parkinson's disease experience progressive motor and non-motor symptoms, which negatively impact on health-related quality of life and can lead to an increased risk of hospitalisation. It is increasingly recognised that the current care models are not suitable for the needs of people with parkinsonism whose care needs evolve and change as the disease progresses. This trial aims to evaluate whether a complex and innovative model of integrated care will increase an individual's ability to achieve their personal goals, have a positive impact on health and symptom burden and be more cost-effective when compared with usual care.

METHODS

This is a single-centre, randomised controlled trial where people with parkinsonism and their informal caregivers are randomised into one of two groups: either PRIME Parkinson multi-component model of care or usual care. Adults ≥18 years with a diagnosis of parkinsonism, able to provide informed consent or the availability of a close friend or relative to act as a personal consultee if capacity to do so is absent and living in the trial geographical area are eligible. Up to three caregivers per patient can also take part, must be ≥18 years, provide informal, unpaid care and able to give informed consent. The primary outcome measure is goal attainment, as measured using the Bangor Goal Setting Interview. The duration of enrolment is 24 months. The total recruitment target is n=214, and the main analyses will be intention to treat.

DISCUSSION

This trial tests whether a novel model of care improves health and disease-related metrics including goal attainment and decreases hospitalisations whilst being more cost-effective than the current usual care. Subject to successful implementation of this intervention within one centre, the PRIME Parkinson model of care could then be evaluated within a cluster-randomised trial at multiple centres.

Cerebral Small Vessel Disease Progression Increases Risk of Incident Parkinsonism

OBJECTIVE

Cerebral small vessel disease (SVD) is associated with motor impairments and parkinsonian signs cross-sectionally, however, there are little longitudinal data on whether SVD increases risk of incident parkinsonism itself. We investigated the relation between baseline SVD severity as well as SVD progression, and incident parkinsonism over a follow-up of 14 years.

METHODS

This study included 503 participants with SVD, and without parkinsonism at baseline, from the RUN DMC prospective cohort study. Baseline inclusion was performed in 2006 and follow-up took place in 2011, 2015, and 2020, including magnetic resonance imaging (MRI) and motor assessments. Parkinsonism was diagnosed according to the UK Brain Bank criteria, and stratified into vascular parkinsonism (VaP) and idiopathic Parkinson's disease (IPD). Linear mixed-effect models were constructed to estimate individual rate changes of MRI-characteristics.

RESULTS

Follow-up for incident parkinsonism was near-complete (99%). In total, 51 (10.2%) participants developed parkinsonism (33 VaP, 17 IPD, and 1 progressive supranuclear palsy). Patients with incident VaP had higher SVD burden compared with patients with IPD. Higher baseline white matter hyperintensities (hazard ratio [HR] = 1.46 per 1-SD increase, 95% confidence interval [CI] = 1.21-1.78), peak width of skeletonized mean diffusivity (HR = 1.66 per 1-SD increase, 95% CI = 1.34-2.05), and presence of lacunes (HR = 1.84, 95% CI = 0.99-3.42) were associated with increased risk of all-cause parkinsonism. Incident lacunes were associated with incident VaP (HR = 4.64, 95% CI = 1.32-16.32).

INTERPRETATION

Both baseline SVD severity and SVD progression are independently associated with long-term parkinsonism. Our findings indicate a causal role of SVD in parkinsonism. Future studies are needed to examine the underlying pathophysiology of this relation. ANN NEUROL 2023.

Specialized Versus Generic Allied Health Therapy and the Risk of Parkinson's Disease Complications

BACKGROUND

Specialized versus generic physiotherapy (PT) reduces Parkinson's disease (PD)-related complications. It is unclear (1) whether other specialized allied heath disciplines, including occupational therapy (OT) and speech and language therapy (S&LT), also reduce complications; (2) whether there is a synergistic effect among multiple specialized disciplines; and (3) whether each allied health discipline prevents specific complications.

OBJECTIVES

To longitudinally assessed whether the level of expertise (specialized vs. generic training) of PT, OT, and S&LT was associated with the incidence rate of PD-related complications.

METHODS

We used claims data of all insured persons with PD in the Netherlands between January 1, 2010, and December 31, 2018. ParkinsonNet-trained therapists were classified as specialized, and other therapists as generic. We used mixed-effects Poisson regression models to estimate rate ratios adjusting for sociodemographic and clinical characteristics.

RESULTS

The population of 51,464 persons with PD (mean age, 72.4 years; standard deviation 9.8) sustained 10,525 PD-related complications during follow-up (median 3.3 years). Specialized PT was associated with fewer complications (incidence rate ratio [IRR] of specialized versus generic = 0.79; 95% confidence interval, [0.74-0.83]; P < 0.0001), as was specialized OT (IRR = 0.88 [0.77-0.99]; P = 0.03). We found a trend of an association between specialized S&LT and a lower rate of PD-related complications (IRR = 0.88 [0.74-1.04]; P = 0.18). The inverse association of specialized OT persisted in the stratum, which also received specialized PT (IRR = 0.62 [0.42-0.90]; P = 0.001). The strongest inverse association of PT was seen with orthopedic injuries (IRR = 0.78 [0.73-0.82]; P < 0.0001) and of S&LT with pneumonia (IRR = 0.70 [0.53-0.93]; P = 0.03).

CONCLUSIONS

These findings support a wider introduction of specialized allied health therapy expertise in PD care and conceivably for other medical conditions. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Case management interventions in chronic disease reduce anxiety and depressive symptoms: A systematic review and meta-analysis

BACKGROUND

There is no systematic insight into the effect of case management on common complications of chronic diseases, including depressive symptoms and symptoms of anxiety. This is a significant knowledge gap, given that people with a chronic disease such as Parkinson Disease or Alzheimer's Disease have identified care coordination as one of their highest priorities. Furthermore, it remains unclear whether the putative beneficial effects of case management would vary by crucial patient characteristics, such as their age, gender, or disease characteristics. Such insights would shift from "one size fits all" healthcare resource allocation to personalized medicine.

OBJECTIVE

We systematically examined the effectiveness of case management interventions on two common complications associated PD and other chronic health conditions: Depressive symptoms and symptoms of anxiety.

METHODS

We identified studies published until November 2022 from PubMed and Embase databases using predefined inclusion criteria. For each study, data were extracted independently by two researchers. First, descriptive and qualitative analyses of all included studies were performed, followed by random-effects meta-analyses to assess the impact of case management interventions on anxiety and depressive symptoms. Second, meta-regression was performed to analyze potential modifying effects of demographic characteristics, disease characteristics and case management components.

RESULTS

23 randomized controlled trials and four non-randomized studies reported data on the effect of case management on symptoms of anxiety (8 studies) or depressive symptoms (26 studies). Across meta-analyses, we observed a statistically significant effect of case management on reducing symptoms of anxiety (Standardized Mean Difference [SMD] = - 0.47; 95% confidence interval [CI]: -0.69, -0.32) and depressive symptoms (SMD = - 0.48; CI: -0.71, -0.25). We found large heterogeneity in effect estimates across studies, but this was not explained by patient population or intervention characteristics.

CONCLUSIONS

Among people with chronic health conditions, case management has beneficial effects on symptoms of depressive symptoms and symptoms of anxiety. Currently, research on case management interventions are rare. Future studies should assess the utility of case management for potentially preventative and common complications, focusing on the optimal content, frequency, and intensity of case management.

Lifestyle Interventions for the Prevention of Parkinson Disease: A Recipe for Action

The prevalence of Parkinson disease (PD) is growing fast, amplifying the quest for disease-modifying therapies in early disease phases where pathology is still limited. Lifestyle interventions offer a promising avenue for preventing progression from prodromal to manifest PD. We illustrate this primarily for 1 specific lifestyle intervention, namely aerobic exercise because the case for the other main lifestyle factor (dietary interventions) to modify the course of prodromal PD is currently less persuasive. Various observations have hinted at the disease-modifying potential of exercise. First, studies in rodents with experimental parkinsonism showed that exercise elicits adaptive neuroplasticity in basal ganglia circuitries. Second, exercise is associated with a reduced risk of developing PD, suggesting a disease-modifying potential. Third, 2 large trials in persons with manifest PD indicate that exercise can help to stabilize motor parkinsonism, although this could also reflect a symptomatic effect. In addition, exercise seems to be a feasible intervention, given its minimal risk of side effects. Theoretical risks include an increase in fall incidents and cardiovascular complications, but these concerns seem to be acceptably low. Innovative approaches using gamification elements indicate that adequate long-term compliance with regular exercise programs can be achieved, although more work remains necessary to demonstrate enduring adherence for multiple years. Advances in digital technology can be used to deliver the exercise intervention in the participant's own living environment and also to measure the outcomes remotely, which will help to further boost long-term compliance. When delivering exercise to prodromal participants, outcome measures should focus not just on phenoconversion to manifest PD (which may well take many years to occur) but also on measurable intermediate outcomes, such as physical fitness or prodromal nonmotor symptoms. Taken together, there seems to be sufficient evidence to advocate the first judicious attempt of investigating exercise as a disease-modifying treatment in prodromal PD.

Risk factors, neuroimaging correlates and prognosis of the motoric cognitive risk syndrome: a population-based comparison with mild cognitive impairment

Background and purpose

This study was undertaken to compare risk factors, neuroimaging characteristics and prognosis between two clinical prodromes of dementia, namely, the motoric cognitive risk syndrome (MCRS) and mild cognitive impairment (MCI).

Methods

Between 2009 and 2015, dementia‐free participants of the population‐based Rotterdam Study were classified with a dementia prodrome if they had subjective cognitive complaints and scored >1 SD below the population mean of gait speed (MCRS) or >1.5 SD below the population mean of cognitive test scores (MCI). Using multinomial logistic regression models, we determined cross‐sectional associations of risk factors and structural neuroimaging markers with MCRS and MCI, followed by subdistribution hazard models, to determine risk of incident dementia until 2016.

Results

Of 3025 included participants (mean age = 70.4 years, 54.7% women), 231 had MCRS (7.6%), 132 had MCI (4.4%), and 62 (2.0%) fulfilled criteria for both. Although many risk factors were shared, a higher body mass index predisposed to MCRS, whereas male sex and hypercholesterolemia were associated with MCI only. Gray matter volumes, hippocampal volumes, white matter hyperintensities, and structural white matter integrity were worse in both MCRS and MCI. During a mean follow‐up of 3.9 years, 71 individuals developed dementia and 200 died. Five‐year cumulative risk of dementia was 7.0% (2.5%–11.5%) for individuals with MCRS, versus 13.3% (5.8%–20.8%) with MCI and only 2.3% (1.5%–3.1%) in unaffected individuals.

Conclusions

MCRS is associated with imaging markers of neurodegeneration and risk of dementia, even in the absence of MCI, highlighting the potential of motor function assessment in early risk stratification for dementia.

Mental health in people with Parkinson's disease during the COVID-19 pandemic: potential for targeted interventions?

The COVID-19 pandemic has introduced a myriad of challenges to the social life and care of people with Parkinson’s disease (PD), which could potentially worsen mental health problems. We used baseline data of the PRIME-NL study (N = 844) to examine whether the association between COVID-19 stressors and mental health is disproportionately large in specific subgroups of people with PD and to explore effects of hypothetical reductions in COVID-19 stressors on mental health and quality of life. The mean (SD) age of the study population was 70.3 (7.8) years and 321 (38.0%) were women. The linear regression effect estimate of the association of COVID-19 stressors with mental health was most pronounced in women, highly educated people, people with advanced PD and people prone to distancing or seeking social support. Smaller effect estimates were found in people scoring high on confrontive coping or planful problem solving. The parametric G-formula method was used to calculate the effects of hypothetical interventions on COVID-19 stressors. An intervention reducing stressors with 50% in people with above median MDS-UPDRS-II decreased the Beck Depression Inventory in this group from 14.7 to 10.6, the State-Trait Anxiety Inventory from 81.6 to 73.1 and the Parkinson’s Disease Quality of Life Questionnaire from 35.0 to 24.3. Insights from this cross-sectional study help to inform tailored care interventions to subgroups of people with PD most vulnerable to the impact of COVID-19 on mental health and quality of life.

Personalized Care Management for Persons with Parkinson's Disease

There is a growing awareness that delivery of integrated and personalized care is necessary to meet the needs of persons living with Parkinson's disease. In other chronic diseases than Parkinson's disease, care management models have been deployed to deliver integrated and personalized care, yielding positive effects on patients' health outcomes, quality of life and health care utilization. However, care management models have been highly heterogeneous, as there is currently no clear operationalization of its core elements. In addition, most care management models are disease-specific and not tailored to the individual needs and preferences of a patient. In this viewpoint we present an integrated and personalized care management model for persons with Parkinson's disease costing of five core elements: (1) care coordination, (2) patient navigation, (3) information provision, (4) early detection of signs and symptoms through proactive monitoring and (5) process monitoring. Following the description of each core element, implications for implementing the model into practice are discussed. Finally, we provide clinical and methodological considerations on the evaluation of care management models.

Rationale and design to evaluate the PRIME Parkinson care model: a prospective observational evaluation of proactive, integrated and patient-centred Parkinson care in The Netherlands (PRIME-NL)

BACKGROUND

Culminating evidence shows that current care does not optimally meet the needs of persons with parkinsonism, their carers and healthcare professionals. Recently, a new model of care was developed to address the limitations of usual care: Proactive and Integrated Management and Empowerment in Parkinson's Disease (PRIME Parkinson). From 2021 onwards, PRIME Parkinson care will replace usual care in a well-defined region in The Netherlands. The utility of PRIME Parkinson care will be evaluated on a single primary endpoint (parkinsonism-related complications), which reflects the health of people with parkinsonism. Furthermore, several secondary endpoints will be measured for four dimensions: health, patient and carer experience, healthcare professional experience, and cost of healthcare. The reference will be usual care, which will be continued in other regions in The Netherlands.

METHODS

This is a prospective observational study which will run from January 1, 2020 until December 31, 2023. Before the new model of care will replace the usual care in the PRIME Parkinson care region all baseline assessments will take place. Outcomes will be informed by two data sources. We will use healthcare claims-based data to evaluate the primary endpoint, and costs of healthcare, in all persons with parkinsonism receiving PRIME Parkinson care (estimated number: 2,000) and all persons with parkinsonism receiving usual care in the other parts of The Netherlands (estimated number: 48,000). We will also evaluate secondary endpoints by performing annual questionnaire-based assessments. These assessments will be administered to a subsample across both regions (estimated numbers: 1,200 persons with parkinsonism, 600 carers and 250 healthcare professionals).

DISCUSSION

This prospective cohort study will evaluate the utility of a novel integrated model of care for persons with parkinsonism in The Netherlands. We anticipate that the results of this study will also provide insight for the delivery of care to persons with parkinsonism in other regions and may inform the design of a similar model for other chronic health conditions.

Trajectories of Cognitive and Motor Function Between Ages 45 and 90 Years: A Population-Based Study

Background

To establish trajectories of cognitive and motor function, and to determine the sequence of change across individual tests in community-dwelling individuals aged 45–90 years.

Method

Between 1997 and 2016, we repeatedly assessed cognitive function with 5 tests in 9514 participants aged 45–90 years from the population-based Rotterdam Study. Between 1999 and 2016, we measured motor function with 3 tests in 8297 participants. All participants were free from dementia, stroke, and parkinsonism. We assessed overall and education-specific cognitive and motor trajectories using linear mixed models with age as time scale. Next, we determined the sequence of change across individual tests.

Results

The number of assessments per participant ranged between 1 and 6 (mean interval, years [SD]: 5.1 [1.4]) for cognitive function, and 1 and 4 (5.4 [1.4]) for motor function. Cognitive and motor trajectories declined linearly between ages 45 and 65 years, followed by steeper declines after ages 65–70 years. Lower educated participants had lower cognitive function at age 45 years (baseline), and declined faster on most cognitive, but not on motor tests than higher educated participants. Up to a 25-year age difference between the fastest and slowest declining test scores was observed.

Conclusions

On a population-level, cognitive and motor function decline similarly. Compared to higher educated individuals, lower educated individuals had lower cognitive function at baseline, and a faster rate of decline thereafter. These educational-effects were not seen for motor function. These findings benefit the understanding of the natural course of cognitive and motor function during aging, and highlight the role of education in the preservation of cognitive but not motor function.

Unraveling the Association Between Gait and Mortality-One Step at a Time

BACKGROUND

Slowness of walking is one of the very first signs of aging and is considered a marker for overall health that is strongly associated with mortality risk. In this study, we sought to disentangle the clinical drivers of the association between gait and mortality.

METHODS

We included 4,490 participants of the Rotterdam Study who underwent a gait assessment between 2009 and 2015 and were followed-up for mortality until 2018. Gait was assessed with an electronic walkway and summarized into the domains Rhythm, Phases, Variability, Pace, Tandem, Turning, and Base of Support. Cox models adjusted for age, sex, and height were built and consecutively adjusted for six categories of health indicators (lifestyle, musculoskeletal, cardiovascular, pulmonary, metabolic, and neurological). Analyses were repeated in comorbidity-free individuals.

RESULTS

Multiple gait domains were associated with an increased risk of mortality, including Pace (hazard ratio (HR) per SD worse gait, adjusted for other domains: 1.34 [1.19-1.50]), Rhythm (HR: 1.12 [1.02-1.23]) and Phases (HR: 1.12 [1.03-1.21]). Similarly, a 0.1 m/s decrease in gait speed was associated with a 1.21 (1.15-1.27) times higher hazard of mortality (HR fully adjusted: 1.14 [1.08-1.20]). In a comorbidity-free subsample, the HR per 0.1 m/s decrease in gait speed was 1.25 (1.09-1.44). Cause-specific mortality analyses revealed an association between gait speed and multiple causes of death.

CONCLUSIONS

Several gait domains were associated with mortality risk, including Pace which primarily represents gait speed. The association between gait speed and mortality persisted after an extensive adjustment for covariates, suggesting that gait is a marker for overall health.

Towards subgroup-specific risk estimates: A meta-analysis of longitudinal studies on olfactory dysfunction and risk of Parkinson's disease

BACKGROUND

Interest has risen in identifying individuals at high risk of incident Parkinson's disease (PD) to facilitate inclusion in neuroprotective treatment trials. Current risk estimates of prodromal markers are based on aggregated data of an entire population, but this approach disregards differences in risk estimates by subgroups of a population. In this proof of concept, we determine subgroup-specific risk estimates of olfactory dysfunction for incident PD.

METHODS

PubMed, EMBASE and Cochrane were searched for prospective studies investigating the association between olfactory dysfunction and incident PD. Random-effects meta-analysis, subgroup analyses and meta-regression were performed to investigate general and subgroup risk estimates.

RESULTS

Individuals with odor identification dysfunction seemed to be at greater risk of incident PD compared to controls without olfactory dysfunction (OR = 4.18; 95%CI [2.47-7.07]). Risk estimates were higher in studies that included higher percentages of women (regression slope β = 0.053 increase in log odds ratio per 1% increase 1%, p = 0.0006), increased with mean study age (β = 0.21 per one year increase; p = 0.005) and in REM-sleep behavior disorder cohorts (β = 1.95; p = 0.03). Furthermore, the association between olfactory dysfunction and incident PD was most distinct in studies with shorter follow-up duration (ß = -0.56; p = 0.0047).

CONCLUSION

The presence of olfactory dysfunction conveys a considerably elevated risk of incident PD, likely more in studies with a higher proportion of women, older individuals or short follow-up duration. Individual patient data are warranted to confirm these findings and to yield subgroup-specific risk estimates of other common markers to refine prodromal PD criteria.

From trials to clinical practice: Temporal trends in the coverage of specialized allied health services for Parkinson's disease

BACKGROUND AND PURPOSE

To determine how the coverage of specialized allied health services for patients with Parkinson's disease (PD) has developed in the Netherlands since the publication of trials that demonstrated cost-effectiveness.

METHODS

We used healthcare expenditure-based data on all insured individuals in the Netherlands to determine the annual proportion of patients with PD who received either specialized or generic allied health services (physiotherapy, occupational therapy, speech-language therapy) in 2 calendar years separated by a 5-year interval (2012 and 2017). Specialized allied health services were delivered through the ParkinsonNet approach, which encompassed professional training and concentration of care among specifically trained professionals.

RESULTS

Between 2012 and 2017, there was an increase in the number of patients with any physiotherapy (from 17,843 [62% of all patients with PD that year] to 22,282 [68%]), speech-language therapy (from 2171 [8%] to 3378 [10%]), and occupational therapy (from 2813 [10%] to 5939 [18%]). Among therapy-requiring patients, the percentage who were treated by a specialized therapist rose substantially for physiotherapy (from 36% in 2012 to 62% in 2017; χ²  = 2460.2; p < 0.001), speech-language therapy (from 59% to 85%; χ²  = 445.4; p < 0.001), and occupational therapy (from 61% to 77%; χ²  = 231.6; p < 0.001). By contrast, the number of patients with generic therapists did not change meaningfully. By 2017, specialized care delivery had extended to regions that had been poorly covered in 2012, essentially achieving nationwide coverage.

CONCLUSIONS

Following the publication of positive trials, specialized allied healthcare delivery was successfully scaled for patients with PD in the Netherlands, potentially serving as a template for other healthcare innovations for patients with PD elsewhere.

The Impact of Sex and Gender on the Multidisciplinary Management of Care for Persons With Parkinson's Disease

The impact of sex and gender on disease incidence, progression, and provision of care has gained increasing attention in many areas of medicine. Biological factors–sex–and sociocultural and behavioral factors–gender–greatly impact on health and disease. While sex can modulate disease progression and response to therapy, gender can influence patient-provider communication, non-pharmacological disease management, and need for assistance. Sex and gender issues are especially relevant in chronic progressive diseases, such as Parkinson's disease (PD), because affected patients require multidisciplinary care for prolonged periods of time. In this perspective paper, we draw from evidence in the field of PD and various other areas of medicine to address how sex and gender could impact PD care provision. We highlight examples for which differences have been reported and formulate research topics and considerations on how to optimize the multidisciplinary care of persons with PD.

Ethical Considerations in Screening for Rapid Eye Movement Sleep Behavior Disorder in the General Population

Clinical studies have shown that up to 90% of patients with idiopathic rapid eye movement sleep behavior disorder (RBD) will eventually be diagnosed with a clinical α-synucleinopathy. Because of this high conversion rate, screening for RBD is often performed to identify eligible participants for studies aimed at elucidating the prodromal phase of α-synucleinopathies. However, screening for RBD, especially in the general population, raises many ethical dilemmas. In light of the existing ethical literature and our experience in establishing a screening approach for RBD in the Rotterdam Study, we discuss ethical dilemmas when screening for RBD in population-based studies. We conclude that informing study participants about the reason for invitation and the possible trajectory that lies ahead when participating is essential. However, participants should not be troubled unnecessarily by giving them detailed information about possible diagnoses or associated disease risks. © 2020 International Parkinson and Movement Disorder Society.

Personalized care management for persons with Parkinson's disease: A telenursing solution

Poor recognition and inadequate treatment of motor and non-motor symptoms negatively impact on the quality of life of persons with Parkinson's Disease (PD). Furthermore, failure to incorporate timely detection and management of symptoms increases the risk of partially avoidable complications. A promising approach to overcome these pitfalls is telenursing, which entails proactive care delivery by a PD Nurse Specialist (PDNS) through telephone contacts. We hypothesized that adding telenursing to usual care could fill a gap in currently available services, including offering patients easy accessibility to a nurse with specific expertise in PD. We explored this hypothesis by prospectively assessing the effects of a telenursing intervention on motor and non-motor symptoms in a patient with PD. During a threemonth intervention period which comprised 13 telephone contacts, the patient reported a remarkable reduction in number of falls, from 99 falls per three months to 3 falls per three months; and a reduction in non-motor symptoms. The main working mechanism was presumably rather indirect and mediated via alleviation of anxiety, achieved by the individually tailored information and problem-solving strategies provided by the PDNS. Our observations should encourage large-scale evaluations to assess the long-term effectiveness and cost-effectiveness of telenursing interventions in persons with PD.

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Proactive care delivery through telenursing has potential to improve motor and non-motor symptoms in Parkinson's Disease.

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Observation of a marked reduction in falls and lower impact of hallucinations on quality of life.

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Main working mechanisms presumably indirect and mediated via alleviation of anxiety.

Towards early disease modification of Parkinson's disease: a review of lessons learned in the Alzheimer field

Parkinson’s disease (PD) research is beginning to focus on early disease modification and prevention. The therapeutic pipeline includes a growing range of pharmacological interventions that could theoretically intervene with the underlying disease process. It is hoped that applying such interventions in a very early stage of the disease pathology, before the onset of motor symptoms or during its early stages, may prevent or delay further disease progression. To identify people in this early disease stage, criteria for ‘prodromal PD’ have been proposed—describing people with one or more specific features that jointly constitute a variably increased risk of developing clinically manifest PD. Here, we aim to draw lessons from the field of Alzheimer’s research, which has followed a similar strategy over the last decade, including the expansion of the disease label to ‘prodromal’ stages. Importantly, none of the large and costly randomized-controlled trials aiming to slow down or prevent Alzheimer’s dementia by targeting the alleged disease pathology, i.e., amyloid-β aggregation, resulted in detectable clinical effects. Lack of sufficiently robust phase 2 trial results before moving to phase 3 studies, suboptimal participant selection, insensitive outcomes, a too narrow target focus, and trial design flaws contributed to this disappointing outcome. We discuss the various similarities between these Alzheimer’s and PD approaches, and review the design of prevention or early disease modification trials for both diseases including the potential for immunotherapy. Finally, we offer considerations to optimize the design of such trials in PD, benefiting from the lessons learned in Alzheimer’s prevention research.

Twenty-seven-year time trends in dementia incidence in Europe and the United States: The Alzheimer Cohorts Consortium

OBJECTIVE

To determine changes in the incidence of dementia between 1988 and 2015.

METHODS

This analysis was performed in aggregated data from individuals >65 years of age in 7 population-based cohort studies in the United States and Europe from the Alzheimer Cohort Consortium. First, we calculated age- and sex-specific incidence rates for all-cause dementia, and then defined nonoverlapping 5-year epochs within each study to determine trends in incidence. Estimates of change per 10-year interval were pooled and results are presented combined and stratified by sex.

RESULTS

Of 49,202 individuals, 4,253 (8.6%) developed dementia. The incidence rate of dementia increased with age, similarly for women and men, ranging from about 4 per 1,000 person-years in individuals aged 65-69 years to 65 per 1,000 person-years for those aged 85-89 years. The incidence rate of dementia declined by 13% per calendar decade (95% confidence interval [CI], 7%-19%), consistently across studies, and somewhat more pronouncedly in men than in women (24% [95% CI 14%-32%] vs 8% [0%-15%]).

CONCLUSION

The incidence rate of dementia in Europe and North America has declined by 13% per decade over the past 25 years, consistently across studies. Incidence is similar for men and women, although declines were somewhat more profound in men. These observations call for sustained efforts to finding the causes for this decline, as well as determining their validity in geographically and ethnically diverse populations.

Quantitative Gait Impairments in Patients With Stroke or Transient Ischemic Attack: A Population-Based Approach

BACKGROUND AND PURPOSE

Gait is a complex process involving various cortical and subcortical brain regions. An acute stroke or transient ischemic attack (TIA) may disrupt white and gray matter integrity and, therefore, affect gait in patients without evident neurological signs. We determined whether patients with stroke and TIA experience subtle changes in global gait and several independent gait domains.

METHODS

In the population-based Rotterdam Study, 4456 participants (median age, 65 years; 55% women) underwent detailed quantitative gait assessment (GAITRite) between 2009 and 2016. We summarized 30 gait parameters into a global gait score and 7 mutually independent gait domains. First, we assessed the association between prior stroke or TIA and global and domain-specific gait using linear regression models adjusted for age, sex, vascular risk factors, and cognition. Subsequently, we repeated the analysis stratified by the presence of different neurological symptoms in a subgroup of participants with ischemic stroke after study entry.

RESULTS

Compared with participants without prior stroke, patients with stroke had a worse global gait (SD, -0.49 [95% CI, -0.64 to -0.34]), especially in the gait domains Pace, Phases, and Turning. The detrimental effect of stroke on gait was amplified in participants with worse cognition. No gait differences were found between participants with and without prior TIA. Ischemic stroke patients without lower limb weakness, loss of coordination, or visuospatial problems still had a worse gait compared with participants without stroke. Stratification by different stroke symptoms showed that different gait domains were affected in each group.

CONCLUSIONS

Prior stroke without neurological signs that affect gait is still associated with gait difficulties compared with individuals without stroke. Our study suggests that stroke not only has a direct impact on gait through neurological impairments but also includes an indirect effect possibly through disruption of gray and white matter integrity and accelerated neurodegeneration.

Parkinson Matters

Recent epidemiological observations have drawn attention to the rapid rise in the burden caused by Parkinson's disease over the past years, emphasizing that Parkinson's disease is a matter of serious concern for our future generations. A recent report by Public Health England corroborates this message, by providing new insight on trends in deaths associated with neurological diseases in England between 2001 to 2014. The report indicates that mortality associated with Parkinson's disease and related disorders increased substantially between 2001 and 2014. This trend is partially explained by increased longevity in the population. However, it is possible that changes in exposure to risk factors, recent improvements in multidisciplinary care (leading to prolonged survival), and improved diagnostic awareness or improved registration also influenced the observed trend. Furthermore, patients with Parkinson's disease and related disorders were found to die at an advanced age, and the majority die in a care home or hospital, despite a preponderant preference for many patients and their families to spend their last days at home. To combat these concerning observations, future efforts should be focused on providing resources for vulnerable elderly Parkinson patients, avoiding unplanned hospital admissions and out-of-home deaths as much as possible. Possible solutions include a community-based network of specifically trained allied health therapists, personal case managers for Parkinson patients, dedicated Parkinson nursing homes, and improved centralised support services from university clinics to regional community hospitals aimed at facilitating optimal wide-scale care delivery.

Home-based monitoring of falls using wearable sensors in Parkinson's disease

INTRODUCTION

Falling is among the most serious clinical problems in Parkinson's disease (PD). We used body-worn sensors (falls detector worn as a necklace) to quantify the hazard ratio of falls in PD patients in real life.

METHODS

We matched all 2063 elderly individuals with self-reported PD to 2063 elderly individuals without PD based on age, gender, comorbidity, and living conditions. We analyzed fall events collected at home via a wearable sensor. Fall events were collected either automatically using the wearable falls detector or were registered by a button push on the same device. We extracted fall events from a 2.5-year window, with an average follow-up of 1.1 years. All falls included were confirmed immediately by a subsequent telephone call. The outcomes evaluated were (1) incidence rate of any fall, (2) incidence rate of a new fall after enrollment (ie, hazard ratio), and (3) 1-year cumulative incidence of falling.

RESULTS

The incidence rate of any fall was higher among self-reported PD patients than controls (2.1 vs. 0.7 falls/person, respectively; P < .0001). The incidence rate of a new fall after enrollment (ie, hazard ratio) was 1.8 times higher for self-reported PD patients than controls (95% confidence interval, 1.6-2.0).

CONCLUSION

Having PD nearly doubles the incidence of falling in real life. These findings highlight PD as a prime "falling disease." The results also point to the feasibility of using body-worn sensors to monitor falls in daily life. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Sleep and risk of parkinsonism and Parkinson's disease: a population-based study

Sleep disturbances may signal presence of prodromal parkinsonism, including Parkinson's disease. Whether general sleep quality or duration in otherwise healthy subjects is related to the risk of parkinsonism remains unclear. We hypothesized that both worse self-reported sleep quality and duration, as well as a longitudinal deterioration in these measures, are associated with the risk of parkinsonism, including Parkinson's disease. In the prospective population-based Rotterdam Study, we assessed sleep quality and duration with the Pittsburgh Sleep Quality Index in 7726 subjects (mean age 65 years, 57% female) between 2002 and 2008, and again in 5450 subjects between 2009 and 2014. Participants were followed until 2015 for a diagnosis of parkinsonism and Parkinson's disease. Outcomes were assessed using multiple modalities: interviews, physical examination, and continuous monitoring of pharmacy records and medical records of general practitioners. We used Cox regression to associate sleep, and changes in sleep over time, with incident parkinsonism and Parkinson's disease, adjusting for age, sex, education and smoking status. Over 64 855 person-years in 13 years of follow-up (mean: 8.4 years), 75 participants developed parkinsonism, of whom 47 developed Parkinson's disease. We showed that within the first 2 years of follow-up, worse sleep quality {hazard ratio (HR) 2.38 per standard deviation increase [95% confidence interval (CI 0.91-6.23)]} and shorter sleep duration [HR 0.61 per standard deviation increase (95% CI 0.31-1.21)] related to a higher risk of parkinsonism. Associations of worse sleep quality [HR 3.86 (95% CI 1.19-12.47)] and shorter sleep duration [HR 0.48 (95% CI 0.23-0.99)] with Parkinson's disease were more pronounced, and statistically significant, compared to parkinsonism. This increased risk disappeared with longer follow-up duration. Worsening of sleep quality [HR 1.76 per standard deviation increase (95% CI 1.12-2.78)], as well as shortening of sleep duration [HR 1.72 per standard deviation decrease (95% CI 1.08-2.72)], were related to Parkinson's disease risk in the subsequent 6 years. Therefore, we argue that in the general population, deterioration of sleep quality and duration are markers of the prodromal phase of parkinsonism, including Parkinson's disease.

Lifetime risk of common neurological diseases in the elderly population

OBJECTIVE

To quantify the burden of common neurological disease in older adults in terms of lifetime risks, including their co-occurrence and preventive potential, within a competing risk framework.

METHODS

Within the prospective population-based Rotterdam Study, we studied lifetime risk of dementia, stroke and parkinsonism between 1990 and 2016. Among 12 102 individuals (57.7% women) aged ≥45 years free from these diseases at baseline, we studied co-occurrence, and quantified the combined, and disease-specific remaining lifetime risk of these diseases at various ages for men and women separately. We also projected effects on lifetime risk of hypothetical preventive strategies that delay disease onset by 1, 2 and 3 years, respectively.

RESULTS

During follow-up of up to 26 years (156 088 person-years of follow-up), 1489 individuals were diagnosed with dementia, 1285 with stroke and 263 with parkinsonism. Of these individuals, 438 (14.6%) were diagnosed with multiple diseases. Women were almost twice as likely as men to be diagnosed with both stroke and dementia during their lifetime. The lifetime risk for any of these diseases at age 45 was 48.2% (95% CI 47.1% to 51.5%) in women and 36.2% (35.1% to 39.3%) in men. This difference was driven by a higher risk of dementia as the first manifesting disease in women than in men (25.9% vs 13.7%; p<0.001), while this was similar for stroke (19.0%vs18.9% in men) and parkinsonism (3.3% vs 3.6% in men). Preventive strategies that delay disease onset with 1 to 3 years could theoretically reduce lifetime risk for developing any of these diseases by 20%-50%.

CONCLUSION

One in two women and one in three men will develop dementia, stroke or parkinsonism during their life. These findings strengthen the call for prioritising the focus on preventive interventions at population level which could substantially reduce the burden of common neurological diseases in the ageing population.

Kidney function, gait pattern and fall in the general population: a cohort study

Background

Gait disturbance is proposed as a mechanism for higher risk of fall in kidney disease patients. We investigated the association of kidney function with gait pattern in the general population and tested whether the association between impaired kidney function and fall is more pronounced in subjects with lower gait function.

Methods

We included 1430 participants (mean age: 60 years) from the Rotterdam Study. Kidney function was assessed using estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR). We assessed global gait, gait velocity and seven independent gait domains: Rhythm, Phases, Variability, Pace, Tandem, Turning and Base of Support. Regression models adjusted for cardiometabolic and neurological factors were used. We evaluated whether participants with impaired kidney function and impaired gait fell more in the previous year.

Results

The study population had a median (interquartile range) ACR of 3.6 (2.5-6.2) mg/g and mean ± SD eGFR of 87.6 ± 15 mL/min/1.73 m2. Higher ACR and lower eGFR were associated with lower global gait score [per doubling of ACR: -0.10, 95% confidence interval (CI): -0.14 to -0.06, and per SD eGFR:-0.09, 95% CI: -0.14 to -0.03] and slower gait speed (ACR: -1.44 cm/s, CI: -2.12 to -0.76; eGFR: -1.55 cm/s, CI: -2.43 to -0.67). Worse kidney function was associated with lower scores in Variability domain. The association between impaired kidney function and history of fall was present only in participants with lower gait scores [odds ratio (95% CI): ACR: 1.34 (1.09-1.65); eGFR: 1.58 (1.07-2.33)].

Conclusions

We observed a graded association between lower kidney function and impaired gait suggesting that individuals with decreased kidney function, even at an early stage, need to be evaluated for gait abnormalities and might benefit from fall prevention programmes.

Professional occupation and the risk of Parkinson's disease

BACKGROUND AND PURPOSE

Creativity in Parkinson's disease (PD) is strongly related to dopaminergic activity and medication. We hypothesized that patients with PD, including those who are in the pre-diagnostic phase of PD, are prone to choose highly structured 'conventional' professional occupations and avoid highly creative 'artistic' occupations.

METHODS

At baseline of the population-based Rotterdam Study, we asked 12 147 individuals aged ≥45 years about their latest occupation and categorized occupations according to the RIASEC model. Participants underwent baseline and follow-up (median 11 years) examinations for PD. We determined associations of artistic (versus any other occupation) and conventional (versus any other occupation) occupations with PD. Additionally, we pooled our results with a recently published case-control study (Radboud Study).

RESULTS

At baseline, conventional occupations were common [n = 4356 (36%)], whereas artistic occupations were rare [n = 137 (1%)]. There were 217 patients with PD, including 91 with prevalent PD and 126 with incident PD. The risk of PD varied substantially across occupational categories (chi-square, 14.61; P = 0.01). The penalized odds ratio (OR) of artistic occupations for PD was 0.19 [95% confidence interval (CI), 0.00-1.31; P = 0.11], whereas the OR of conventional occupations for PD was 1.23 (95% CI, 0.95-1.66; P = 0.10). The direction and magnitude of ORs were similar in cross-sectional and longitudinal subsamples. Pooled ORs across the Rotterdam and Radboud Studies were 0.20 (95% CI, 0.08-0.52; P < 0.001) for artistic and 1.23 (95% CI, 0.92-1.67; P = 0.08) for conventional occupations.

CONCLUSIONS

The risk of PD varies substantially by choice of professional occupation. Our findings suggest that dopaminergic degeneration affects choice of occupation, which may start in the pre-diagnostic phase of PD.