Unveiling Assessment Gaps in Parkinson's Disease Psychosis: A Scoping Review

BACKGROUND

Parkinson's disease psychosis (PDP) is a multidimensional construct that is challenging to measure. Accurate assessment of PDP requires comprehensive and reliable clinical outcome assessment (COA) measures.

OBJECTIVE

To identify PDP measurement gaps in available COAs currently used in clinical and research settings.

METHODS

We conducted a scoping review using Preferred Reporting Items for Systematic Review and Meta-Analysis Extension for Scoping Reviews (PRISMA-ScR) guidelines. We implemented a three-step search strategy in international databases with keywords related to Parkinson's disease (PD), psychosis, and COA. We analyzed studies using COA to assess PDP, classifying their items according to domains and subdomains.

RESULTS

From 5673 identified studies, we included 628 containing 432 PDP core items from 32 COAs. Among the 32 COAs, 19 were PD-specific, containing 266 items, constructed as clinician-reported outcomes (ClinRO) (148 items), patient-reported outcomes (PRO) (112 items), and observer-reported outcomes (ObsRO) (six items). Across all PD-specific COAs, regardless of structure, 89.4% of the items from 27 COAs focused primarily on assessing PDP symptoms' severity, and only 9.7% of items probed the impact of PDP on a person's daily functioning.

CONCLUSIONS

Symptom-based domains are currently prioritized for measuring the severity of PDP, with limited coverage of the functional impact of PDP on patients' lives. Whereas the International Parkinson and Movement Disorder Society has traditionally developed a "Unified" COA that culls items from prior COAs to form a new one, a new COA will largely need newly developed items if the functional impact of PDP is prioritized. © 2024 International Parkinson and Movement Disorder Society.

Transitioning from Subtyping to Precision Medicine in Parkinson's Disease: A Purpose-Driven Approach

The International Parkinson and Movement Disorder Society (MDS) created a task force (TF) to provide a critical overview of the Parkinson's disease (PD) subtyping field and develop a guidance on future research in PD subtypes. Based on a literature review, we previously concluded that PD subtyping requires an ultimate alignment with principles of precision medicine, and consequently novel approaches were needed to describe heterogeneity at the individual patient level. In this manuscript, we present a novel purpose-driven framework for subtype research as a guidance to clinicians and researchers when proposing to develop, evaluate, or use PD subtypes. Using a formal consensus methodology, we determined that the key purposes of PD subtyping are: (1) to predict disease progression, for both the development of therapies (use in clinical trials) and prognosis counseling, (2) to predict response to treatments, and (3) to identify therapeutic targets for disease modification. For each purpose, we describe the desired product and the research required for its development. Given the current state of knowledge and data resources, we see purpose-driven subtyping as a pragmatic and necessary step on the way to precision medicine. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Neuroimaging biomarkers in Huntington's disease: Preparing for a new era of therapeutic development

BACKGROUND

A critical challenge for Huntington's disease (HD) clinical trials in disease modification is the definition of endpoints that can capture change when clinical signs are subtle/non-existent. Reliable biomarkers are therefore urgently needed to facilitate drug development by allowing the enrichment of clinical trial populations and providing measures of benefit that can support the establishment of efficacy.

METHODS

By systematically examining the published literature on HD neuroimaging biomarker studies, we sought to advance knowledge to guide the validation of neuroimaging biomarkers. We started by reviewing both cross-sectional and longitudinal studies and then conducted an in-depth review to make quantitative comparisons between biomarkers using data only from longitudinal studies with samples sizes larger than ten participants in PET studies or 30 participants in MRI studies.

RESULTS

From a total of 2202 publications initially identified, we included 32 studies, 19 of which underwent in-depth comparative review. The majority of included studies used various MRI-based methods (manual to automatic) to longitudinally assess either the volume of the putamen or the caudate, which have been shown to undergo significant structural change during HD natural history.

CONCLUSION

Despite the impressively large number of neuroimaging biomarker studies, only a small number of adequately designed studies met our criteria. Among these various biomarkers, MRI-based volumetric analyses of the caudate and putamen are currently the best validated for use in the disease phase before clinical motor diagnosis. A biomarker that can be used to demonstrate a disease-modifying effect is still missing.

Canadian Healthcare Access in Parkinson's Disease and COVID-19: A Cross-Sectional Survey

BACKGROUND

Parkinson's disease (PD) is a common chronic neurodegenerative condition. As a result of the COVID-19 pandemic, healthcare provision faced challenges worldwide. We aimed to explore how the COVID-19 pandemic changed healthcare experiences for people living with Parkinson's disease (PwP) in Canada.

METHODS

We conducted a national cross-sectional online survey about healthcare access for PwP in 2020. Participants (n = 298) were recruited through Parkinson Canada, the national patient association and its provincial partners, that advertised the study in a monthly newsletter. We used descriptive statistics and multivariate regression modelling to test associations of interest. A P < 0.05 was deemed statistically significant.

RESULTS

During the COVID-19 pandemic, PwP reported greater difficulty obtaining PD-related healthcare services and lesser satisfaction with healthcare provision compared to pre-pandemic experiences. Dissatisfaction with care was associated with the presence of barriers to access services, a lack of confidence in accessing services remotely, pre-pandemic care dissatisfaction, and difficulty in obtaining care during the COVID-19 pandemic. Unmet care needs were associated with a lack of confidence in accessing services remotely, dissatisfaction with pre-pandemic care, difficulty obtaining pre-pandemic care, and communication challenges.

CONCLUSION

Our results suggest that healthcare experiences for PwP significantly changed during the COVID-19 pandemic, with challenges in access to virtual care. Poorer pre-pandemic care experiences were amplified during the pandemic.

The Lessebo Effect in Disease Modification Trials in Parkinson's Disease

BACKGROUND

The impact of expectation of benefit on outcomes is well established in Parkinson's disease (PD). A reduction of a treatment effect due to a perceived placebo allocation (lessebo effect) in randomized controlled trials (RCTs) was documented for symptomatic treatments.

OBJECTIVES

To evaluate the lessebo effect in disease modification RCTs (DMT) in PD.

METHODS

Subject-level meta-analyses of active treatment arms of DMT (n = 1149 subjects): FS-1, FS-TOO (probability of placebo allocation/P_(placebo)  = 0.33) and DATATOP, PRECEPT, QE2 (P_(placebo)  = 0.25). We tested the association between P_(placebo) and time to dopaminergic treatment initiation using a marginal Cox proportional hazards model.

RESULTS

The adjusted hazard ratio (P_(placebo)  = 0.25 vs. 0.33) for initiation of dopaminergic treatment was 1.15 (95% CI: 0.92-1.43).

CONCLUSIONS

We did not observe the lessebo effect in DMT. The necessary use of a placebo (and no active comparator) is a limitation. The prospective measurement of expectation of benefit could help to evaluate the many impacts of placebo use. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Using Movement Disorder Society Unified Parkinson's Disease Rating Scale Parts 2 and 3 Simultaneously: Combining the Patient Voice with Clinician Ratings

BACKGROUND

Regulatory recommendations favor outcomes combining objective and patient input. The Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), the most commonly used scale in Parkinson's disease (PD), includes patient and investigator ratings in distinct parts, but original clinimetric analyses failed to confirm the validity of combining parts by simple summing.

OBJECTIVES

The aim was to develop clinimetrically valid constructs for combining patient-reported Part 2 and investigator-rated Part 3 MDS-UPDRS scores.

METHODS

Using 7888 MDS-UPDRS scores, we assessed construct validity of combined Part 2 and Part 3 items using exploratory factor analysis (EFA) and graded item response theory (IRT) with threshold criteria: comparative fit index ≥0.9 (EFA) and discrimination parameters ≥0.65 (IRT).

RESULTS

The direct sum of Parts 2 + 3 failed to meet the threshold for a valid outcome of PD severity (comparative fit index, CFI = 0.855). However, a two-domain construct combining item scores for tremor and non-tremor domains from Parts 2 and 3 confirmed validity, meeting both EFA and IRT criteria as distinct but correlated indices of disease severity (CFI = 0.923; discrimination mean 2.197 ± 0.480 [tremor] and 1.737 ± 0.344 [non-tremor] domains).

CONCLUSIONS

The sum of Parts 2 + 3 is not clinimetrically sound. However, considering tremor and non-tremor items of both Parts 2 and 3 as two outcomes results in a valid summary of PD motor severity that leverages simultaneous patient- and investigator-derived measures. This analytic application addresses regulatory prioritizations and retains the well-validated MDS-UPDRS items. In future interventional trials, we suggest that tremor and non-tremor components of PD motor severity from Parts 2 + 3 be monitored and analyzed to accurately detect objective changes that integrate the patient's voice. © 2023 International Parkinson and Movement Disorder Society.

Genetic Testing in Clinical Movement Disorders: A Case-Based Review

Genetics are fundamental to understanding the pathophysiology of neurological disease, including movement disorders. Genetic testing in clinical practice has changed dramatically over the last few decades. While the likelihood of establishing an etiological diagnosis is greater now with increased access to testing and more advanced technologies, clinicians face challenges when deciding whether to test, then selecting the appropriate test, and ultimately interpreting and sharing the results with patients and families. In this review, we use a case-based approach to cover core aspects of genetic testing for the neurologist, namely, genetic testing in Parkinson's disease, interpretation of inconclusive genetic test reports, and genetic testing for repeat expansion disorders using Huntington disease as a prototype.

Motor band sign in a Huntington disease phenocopy

We report a 68-year-old lady who presented with Huntington phenocopy with generalized chorea and was genetically proven to have Spinocerebellar ataxia (SCA)17. MRI Brain demonstrated motor band sign, which is most commonly reported in motor neuron disease. This is the first case of motor band sign with SCA 17 and highlights the widening spectrum of radiological signs in SCA 17.

It Is as It Was: MDS-UPDRS Part III Scores Cannot Be Combined with Other Parts to Give a Valid Sum

BACKGROUND

Original clinimetric analyses by the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) developers did not confirm the validity of summing the scores of its parts. Recent studies used the summed score of Part III and other parts as efficacy outcomes.

OBJECTIVE

The aim of this study was to establish whether summing scores of MDS-UPDRS parts can be recommended.

METHODS

Using 7466 full MDS-UPDRS scores, we applied two-step factor analysis as in the original article to reassess the validity analysis with the threshold criterion set at comparative fit index ≥0.9.

RESULTS

All comparative fit indexes of any combination including Part III were lower than 0.90.

CONCLUSIONS

Summing Part III MDS-UPDRS scores with other parts is not clinimetrically sound. The MDS-UPDRS is a validated four-part scale with corresponding individual part scores and needs to be used within the limits originally presented. © 2022 International Parkinson and Movement Disorder Society.

Impact of the COVID-19 pandemic on perceived access and quality of care in German people with parkinsonism

Due to the heterogeneous clinical presentation, people with Parkinsonism (PwP) develop individual healthcare needs as their disease progresses. However, because of limited health resources during the COVID-19 pandemic, many patients were put at risk of inadequate care. All this occurred in the context of inequitable healthcare provision within societies, especially for such vulnerable populations. This study aimed to investigate factors influencing satisfaction and unmet need for healthcare among PwP during the COVID-19 pandemic in Germany. Analyses relied on an anonymous online survey with a 49-item questionnaire. We aimed at describing access to health services before and during the early stages of the pandemic. To this end, a generalized linear model was used to derive significant predictors and a stepwise regression to subsummarize the main factors of perceived inadequate care. In total, 551 questionnaires showed that satisfaction with Parkinsonism-related care decreased significantly during the pandemic (p < 0.001). In particular, factors such as lower educational level, lower perceived expertise of healthcare providers, less confidence in remote care, difficulties in obtaining healthcare, and restricted access to care before the pandemic but also lower densities of neurologists at residence and less ability to overcome barriers were indicative of higher odds to perceive unmet needs (p < 0.05). The results unveil obstacles contributing to reduced access to healthcare during the COVID-19 pandemic for PwP. These findings enable considerations for improved provision of healthcare services to PwP.

Supporting Trial Participation in People with the Huntington's Gene: A Patient-Centered, Theory-Guided Survey of Barriers and Enablers

BACKGROUND

Under-recruitment regularly impedes clinical trials, leading to wasted resources and opportunity costs. Methods for designing trial participation strategies rarely consider behavior change theory.

OBJECTIVE

Informed by the Theoretical Domains Framework, we identified factors important to participating in Huntington's disease research and provide examples of how such a theory-informed approach can make specific suggestions about how to design targeted recruitment strategies.

METHODS

We identified a range of trial participation barriers and enablers based on interviews of key informants and implemented an online survey of members of the Huntington's disease community, asking them to rate the extent to which different factors would affect likelihood to participate in a generic Huntington's disease trial.

RESULTS

From 4,195 members, we received 323 responses and 243 completed surveys (323/4,195 or 8% participation, 243/323 or 75% completion). Respondents endorsed 9 barriers and 23 enablers relevant to trial participation. Most frequently endorsed barriers were travel to the study site (69%), worry about unknown side effects (65%), trial documents being difficult to understand (64%), and participation affecting other activities (49%). Enablers included optimism about likelihood of trial participation leading to a cure (98%), helping others (98%), contributing to science (97%), and having helpful people available to help with the participation decision (89%).

CONCLUSION

Our theory-informed survey to identify barriers to and enablers of Huntington's disease trial participation identified 32 factors, from 13 theoretical domains relevant to trial participation, and suggests effective approaches for improving trial participation and patient experience.

The Unified Multiple System Atrophy Rating Scale: Status, Critique, and Recommendations

The Unified Multiple System Atrophy (MSA) Rating Scale was developed to provide a surrogate marker of disease severity and clinical progression in patients with MSA. It is comprised of four subscales: UMSARS-I (12 items) rates patient-reported functional disability; UMSARS-II (14 items) assesses motor impairment based on a clinical examination; UMSARS-III records blood pressure and heart rate in the supine and standing positions; and UMSARS-IV (1 item) rates chore-based disability. Strengths of the UMSARS include its wide acceptance in the field, the comprehensive coverage of motor symptoms and its clinimetric properties (including reliability and validity). However, with its increasing use, potential areas of improvement in the UMSARS have become apparent. To address these limitations, a task force, involving clinicians, researchers, patient groups, and industry representatives, has recently been endorsed by the International Parkinson’s Disease and Movement Disorders Society. The present viewpoint summarizes strengths and weaknesses of the UMSARS and suggests a roadmap to develop an improved MSA clinical outcome assessment.

Evaluation of the PREDIGT score’s performance in identifying newly diagnosed Parkinson’s patients without motor examination

Several recent publications described algorithms to identify subjects with Parkinson’s disease (PD). In creating the “PREDIGT Score”, we previously developed a hypothesis-driven, simple-to-use formula to potentially calculate the incidence of PD. Here, we tested its performance in the ‘De Novo Parkinson Study’ (DeNoPa) and ‘Parkinson’s Progression Marker Initiative’ (PPMI); the latter included participants from the ‘FOllow Up persons with Neurologic Disease’ (FOUND) cohort. Baseline data from 563 newly diagnosed PD patients and 306 healthy control subjects were evaluated. Based on 13 variables, the original PREDIGT Score identified recently diagnosed PD patients in the DeNoPa, PPMI + FOUND and the pooled cohorts with area-under-the-curve (AUC) values of 0.88 (95% CI 0.83–0.92), 0.79 (95% CI 0.72–0.85), and 0.84 (95% CI 0.8–0.88), respectively. A simplified version (8 variables) generated AUC values of 0.92 (95% CI 0.89–0.95), 0.84 (95% CI 0.81–0.87), and 0.87 (0.84–0.89) in the DeNoPa, PPMI, and the pooled cohorts, respectively. In a two-step, screening-type approach, self-reported answers to a questionnaire (step 1) distinguished PD patients from controls with an AUC of 0.81 (95% CI 0.75–0.86). Adding a single, objective test (Step 2) further improved classification. Among seven biological markers explored, hyposmia was the most informative. The composite AUC value measured 0.9 (95% CI 0.88–0.91) in DeNoPa and 0.89 (95% CI 0.84–0.94) in PPMI. These results reveal a robust performance of the original PREDIGT Score to distinguish newly diagnosed PD patients from controls in two established cohorts. We also demonstrate the formula’s potential applicability to enriching for PD subjects in a population screening-type approach.

The Role of Parkinson Nurses for Personalizing Care in Parkinson’s Disease: A Systematic Review and Meta-Analysis

Background: Quality of life (QoL) of persons with Parkinson’s disease (PD) is diminished by (non-)motor symptoms, that require personalized care. Parkinson Nurses (PN) may be pivotal promoting tailored care offerings. This systematic review and meta-analysis investigates PD care models and aims at furnishing current concepts of PN to offer personalized care. Objective: The purpose of this study is to identify the various roles and functions that PN may hold for personalized PD care. Methods: We performed a systematic literature review, utilizing: PubMed, Web of Science, The Cochrane Library, and PsycINFO. The review qualitatively evaluated articles, which described personalized care models involving PNs and was guided by the personalized care management model. A meta-analysis compared patient-reported QoL (quantified using the 39-item Parkinson’s Disease Questionnaire) between personalized care interventions involving PN versus standard care with. Results: Twenty-seven publications were identified, including six randomized, controlled trials ascertaining with health related QoL (n = 1830 PwPs). The qualitative evaluation revealed that PN contribute to all aspects of personalized care. The meta-analysis showed no improved QoL in personalized care models compared to standard care, thought a great heterogeneity among study design and interventions was outlined (Standardized Mean Difference = –0.8935; 95% Confidence Interval, –2.1177 to 0.3307; z = –1.43, p = 0.1526). Conclusion: PN fulfil important functions in personalized PD care. For the future, a clear role definition will be necessary to adjust training for PN across healthcare systems and care settings but especially to realize their full potential for PD care.

A biological classification of Huntington's disease: the Integrated Staging System

The current research paradigm for Huntington's disease is based on participants with overt clinical phenotypes and does not address its pathophysiology nor the biomarker changes that can precede by decades the functional decline. We have generated a new research framework to standardise clinical research and enable interventional studies earlier in the disease course. The Huntington's Disease Integrated Staging System (HD-ISS) comprises a biological research definition and evidence-based staging centred on biological, clinical, and functional assessments. We used a formal consensus method that involved representatives from academia, industry, and non-profit organisations. The HD-ISS characterises individuals for research purposes from birth, starting at Stage 0 (ie, individuals with the Huntington's disease genetic mutation without any detectable pathological change) by using a genetic definition of Huntington's disease. Huntington's disease progression is then marked by measurable indicators of underlying pathophysiology (Stage 1), a detectable clinical phenotype (Stage 2), and then decline in function (Stage 3). Individuals can be precisely classified into stages based on thresholds of stage-specific landmark assessments. We also demonstrated the internal validity of this system. The adoption of the HD-ISS could facilitate the design of clinical trials targeting populations before clinical motor diagnosis and enable data standardisation across ongoing and future studies.

Telemedicine as an Untapped Opportunity for Parkinson’s Nurses Training in Personalized Care Approaches

(1) Background: Parkinson nurses (PN) take over important functions in the telemedical care of person’s with Parkinson’s disease (PwPs). This requires special competencies that have so far been largely unexplored. The aim of the article is to identify competencies of PN operating in a personalized care model. (2) Methods: This study employed a qualitative approach. Based on the competency framework for telenursing, PN were asked about their competencies using a qualitative online survey. (3) Results: The results show that PN need competencies on a personal and organizational level, as well as in the relationship with PwPs. PN have developed these skills through professional exchange, training, and personal experience. In addition, both hindering and beneficial factors for the development of competencies could be identified. (4) Conclusions: Competency development for telemedical care is complex and must be designed and promoted in a targeted manner.

Resolving Missing Data from the Movement Disorder Society Unified Parkinson's Disease Rating Scale: Implications for Telemedicine

BACKGROUND

Telemedicine has become standard in clinical care and research during the coronavirus disease 2019 pandemic. Remote administration of Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III (Motor Examination) precludes ratings of all items, because Rigidity and Postural Stability (six scores) require in-person rating.

OBJECTIVE

The objective of this study was to determine imputation accuracy for total-sum and item-specific MDS-UPDRS Motor Examination scores in remote administration.

METHODS

We applied multivariate imputation by chained equations techniques in a cross-sectional dataset where patients had one MDS-UPDRS rating (International Translational Program, n = 8,588) and in a longitudinal dataset where patients had multiple ratings (Rush Program, n = 396). Successful imputation was stringently defined as (1) generalized Lin's concordance correlation coefficient >0.95, reflecting near-perfect agreement between total-sum score with complete data and surrogate score, calculated without patients' actual Rigidity and Postural Stability scores; and (2) perfect agreement for item-level scores for Rigidity and Postural Stability items.

RESULTS

For total-sum score when Rigidity and Postural Stability scores were withdrawn, using one or multiple visits, multivariate imputation by chained equations imputation reached near-perfect agreement with the original total-sum score. However, at the item level, the degree of perfect agreement between the surrogate and actual Rigidity items and Postural Stability scores always fell below threshold.

CONCLUSIONS

The MDS-UPDRS Part III total-sum score, a key clinical outcome in research and in clinical practice, can be accurately imputed without the Rigidity and Postural Stability items that cannot be rated by telemedicine. No formula, however, allows for specific item-level imputation. When Rigidity and Postural Stability item scores are of key clinical or research interest, patients with PD must be scored in person. © 2022 International Parkinson and Movement Disorder Society.

Disease Burden of Huntington's Disease (HD) on People Living with HD and Care Partners in Canada

Background:

Huntington’s disease (HD) has been shown to reduce health-related quality of life (HRQoL) and affect healthcare resource utilization (HRU) among patients and care partners internationally but has not been studied specifically in the Canadian context.

Objective:

To characterize the burden of HD on individuals with HD and care partners of individuals with HD in Canada.

Methods:

An online survey was distributed (September 14–November 23, 2020) through patient organizations to collect data on demographic and clinical characteristics, as well as: HRQoL, measured using the 36-Item Short-Form Health Survey (SF-36v1); HRU, measured using the Client Service Receipt Inventory (CSRI); and care partner burden, measured using the Caregiver Strain Index (CSI) and Huntington’s Disease Quality of Life Battery for Carers (HDQoL-C). Descriptive statistics were used to report data and compare subgroups.

Results:

A total of 62 adult individuals with HD (or their proxies) and 48 care partners met defined eligibility criteria. The mean [standard deviation] age was 51.2 [13.8] and 58.1 [13.9] years for individuals with HD and care partner respondents, respectively. For individuals with HD, the greatest HRQoL burden (i.e., lowest score) was for the SF-36v1 Role –Physical scale (46.8 [42.9]). HRU was higher for some services (e.g., general practitioner visits) for respondents who had experienced motor onset transition. Among care partners, 55.3% experienced high strain, as indicated by the CSI. The HDQoL-C showed the greatest HRQoL burden in feelings about life (45.1 [17.9]).

Conclusion:

This study quantified the substantial burden on individuals with HD and care partners in Canada, addressing a critical knowledge gap that can affect the availability of and access to healthcare services.

Evaluation of the Impact of Integrated Care and Self-Management After Deep Brain Stimulation in Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) is a progressive neurodegenerative disorder with a myriad of motor and non-motor symptoms. Although deep brain stimulation (DBS) has a dramatic impact in the lives of people with PD, care delivery remains complex. There is a lack of evidence on the implementation and role of integrated care and self-management support in people with PD with chronic DBS.

OBJECTIVE

To evaluate care needs, implementation and impact of a pragmatic network for PD care, the Integrated Parkinson Care Network (IPCN).

METHODS

This is a subgroup analyses of a 6-month, pre-post design, single-centre, phase 2 study to assess a patient-centred care model based on integrated care, self-management support (IPCN) in PD, focusing on those participants with chronic DBS.

RESULTS

We included 22 people with PD and chronic DBS (median time since DBS - 30 months). The mean age was 63.9 (7.6) years and mean disease duration was 15.2 (6.9) years. The top three care priorities were speech (54.5%), mobility (40.9%) and mood (31.8%). After the IPCN program, there was a positive change in the perception of support for chronic care (Patient Assessment of Chronic Illness Case: 0.85; 95% CI: 1.2 to -0.4) and self-management (5As: 0.77; 95% CI: 0.39 -1.15), along with quality of life (PDQ8 : 7.1, 95% CI:1.8 -12.4).

CONCLUSION

The IPCN is a care delivery model that addresses specific care needs of people with PD and chronic DBS. The current study showed its feasibility and warrants further evaluation.

The Disease Modification Conundrum in Parkinson’s Disease: Failures and Hopes

In the last half-century, Parkinson’s disease (PD) has played a historical role in demonstrating our ability to translate preclinical scientific advances in pathology and pharmacology into highly effective clinical therapies. Yet, as highly efficacious symptomatic treatments were successfully developed and adopted in clinical practice, PD remained a progressive disease without a cure. In contrast with the success story of symptomatic therapies, the lack of translation of disease-modifying interventions effective in preclinical models into clinical success has continued to accumulate failures in the past two decades. The ability to stop, prevent or mitigate progression in PD remains the “holy grail” in PD science at the present time. The large number of high-quality disease modification clinical trials in the past two decades with its lessons learned, as well as the growing knowledge of PD molecular pathology should enable us to have a deeper understanding of the reasons for past failures and what we need to do to reach better outcomes. Periodic reviews and mini-reviews of the unsolved disease modification conundrum in PD are important, considering how this field is rapidly evolving along with our views and understanding of the possible explanations.

Remote Evaluation of Parkinson's Disease Using a Conventional Webcam and Artificial Intelligence

Objective: This study aimed to prove the concept of a new optical video-based system to measure Parkinson's disease (PD) remotely using an accessible standard webcam.

Methods: We consecutively enrolled a cohort of 42 patients with PD and healthy subjects (HSs). The participants were recorded performing MDS-UPDRS III bradykinesia upper limb tasks with a computer webcam. The video frames were processed using the artificial intelligence algorithms tracking the movements of the hands. The video extracted features were correlated with clinical rating using the Movement Disorder Society revision of the Unified Parkinson's Disease Rating Scale and inertial measurement units (IMUs). The developed classifiers were validated on an independent dataset.

Results: We found significant differences in the motor performance of the patients with PD and HSs in all the bradykinesia upper limb motor tasks. The best performing classifiers were unilateral finger tapping and hand movement speed. The model correlated both with the IMUs for quantitative assessment of motor function and the clinical scales, hence demonstrating concurrent validity with the existing methods.

Conclusions: We present here the proof-of-concept of a novel webcam-based technology to remotely detect the parkinsonian features using artificial intelligence. This method has preliminarily achieved a very high diagnostic accuracy and could be easily expanded to other disease manifestations to support PD management.

Epidemiology and economic burden of Huntington's disease: a Canadian provincial public health system perspective

AIMS

To evaluate the epidemiology, healthcare resource utilization, and direct healthcare costs associated with Huntington's disease in a Canadian setting with a universal healthcare system.

MATERIALS AND METHODS

Using Albertan administrative health data, a retrospective cohort was identified applying an algorithm requiring two HD diagnostic codes within two years, using the first record as the index date (i.e. proxy for diagnosis date), from 1 April 2010 to 31 March 2019 for patients ≥21 years old. Incidence/prevalence measures were evaluated from 1 April 2010 to 31 March 2019, while healthcare resource utilization and healthcare costs per person-year (inflated to 2020 Canadian dollars) were evaluated from index to the end of follow-up (death, moved out of province, or 31 March 2020).

RESULTS

Mean [standard deviation] age at index (n = 395) was 53.9 [13.8] years and 53.7% were female. From 2010 to 2019, annual HD incidence varied between 0.47 and 1.21/100,000 person-years and HD prevalence increased from 7.25 to 9.33/100,000 persons. The mean number of visits per person-year for general and specialist practitioners was 19.2 [18.8] and 12.2 [25.5], respectively. The mean total all-cause direct healthcare costs were $23,211 [$38,599] per person-year, with hospitalizations accounting for 57.8% of all-cause costs. Costs were higher among individuals with a long-term care stay, a proxy for disease severity.

LIMITATIONS AND CONCLUSIONS

This study utilizes administrative health data to describe the epidemiology of HD and utilization of publicly funded care by individuals with HD. While administrative data presents limitations since it is not collected for research purposes, it provides a population-level examination of the burden of HD. There was a substantial economic burden associated with HD in a Canadian setting.

Validation of biomarkers in Huntington disease to support the development of disease-modifying therapies: A systematic review and critical appraisal scheme

BACKGROUND

There are promising novel genetic-based therapies under development intended to modify the disease trajectory in Huntington disease (HD). Valid biomarkers that can facilitate the development of such disease-modifying therapies are urgently needed. There are currently no studies that appraise the quality of research for validation of biomarkers in HD.

OBJECTIVE

To review studies for disease progression biomarkers in HD and evaluate their methodological quality.

METHODS

A systematic review of all HD biomarker studies up to June 2020 was conducted. Each study was assessed for methodological quality using a 24-item standardized checklist. We completed a subgroup analyses based on year of publication and biomarker type.

RESULTS

We included 218 HD biomarker studies, 76 (34.9%) were longitudinal and 161 (74%) included premanifest HD. On average, 10 ± 3 items (out of 24) were rated as good quality. The items more commonly rated as poor quality were: reporting of validity and reliability of assessments, sampling method, report of adverse events associated with the biomarker test, power calculation and appropriateness of study enrolment. Publications from 2016 to 2020 (mean score = 11.2 ± 2.3) had a better methodological quality than publications prior to 2016 (mean score = 9.8 ± 3.1; p = 0.018).

CONCLUSION

Overall, the reported methodological quality of the existing research on biomarkers for disease progression is low, which undermines the confidence of biomarkers use in drug development studies. It will be important to invest in better designed studies to support the use of biomarkers as valid drug development tools.

A MDS Evidence-Based Review on Treatments for Huntington's Disease

BACKGROUND

Huntington's disease (HD) is a rare neurodegenerative disorder with protean clinical manifestations. Its management is challenging, consisting mainly of off-label treatments.

OBJECTIVES

The International Parkinson and Movement Disorder Society commissioned a task force to review and evaluate the evidence of available therapies for HD gene expansion carriers.

METHODS

We followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Eligible randomized controlled trials were identified via an electronic search of the CENTRAL, MEDLINE, and EMBASE databases. All eligible trials that evaluated one or more of 33 predetermined clinical questions were included. Risk of bias was evaluated using the Cochrane Risk of Bias tool. A framework was adapted to allow for efficacy and safety conclusions to be drawn from the balance between the GRADE level of evidence and the importance of the benefit/harm of the intervention.

RESULTS

Twenty-two eligible studies involving 17 interventions were included, providing data to address 8 clinical questions. These data supported a likely effect of deutetrabenazine on motor impairment, chorea, and dystonia and of tetrabenazine on chorea. The data did not support a disease-modifying effect for premanifest and manifest HD. There was no eligible evidence to support the use of specific treatments for depression, psychosis, irritability, apathy, or suicidality. Similarly, no evidence was eligible to support the use of physiotherapy, occupational therapy, exercise, dietary, or surgical treatments.

CONCLUSIONS

Data for therapeutic interventions in HD are limited and support only the use of VMAT2 inhibitors for specific motor symptoms. © 2021 International Parkinson and Movement Disorder Society.

Expectations of Benefit in a Trial of a Candidate Disease-Modifying Treatment for Parkinson Disease

BACKGROUND

Expectations of benefit have an important therapeutic impact. How well study participants understand the concept of slowing disease progression and how their expectations of benefit are shaped in related clinical trials is not well known.

OBJECTIVE

We aimed to assess expectancy and treatment arm preference of participants in a disease-modification trial in Parkinson disease (PD).

METHODS

Participant expectations and treatment preference were assessed before treatment randomization in the SURE-PD3 trial (NCT02642393).

RESULTS

We included 297 PD patients (0.71 ± 0.67 years after diagnosis). Pre-randomization, 90% of participants expressed a preference for inosine (active treatment) allocation (n = 266/297), and 53% (n = 158) expected to be "somewhat" or "a lot better" in their symptoms over 2 years of treatment with inosine.

CONCLUSIONS

Participants of a disease-modification trial in PD had likely unrealistic expectations of benefit (ie, improvement in symptoms over years), which may affect clinical trial interpretation and calls for improved education in future disease-modification trials in PD. © 2021 International Parkinson and Movement Disorder Society.

Moving towards Integrated and Personalized Care in Parkinson's Disease: A Framework Proposal for Training Parkinson Nurses

Delivering healthcare to people living with Parkinson's disease (PD) may be challenging in face of differentiated care needs during a PD journey and a growing complexity. In this regard, integrative care models may foster flexible solutions on patients' care needs whereas Parkinson Nurses (PN) may be pivotal facilitators. However, at present hardly any training opportunities tailored to the care priorities of PD-patients are to be found for nurses. Following a conceptual approach, this article aims at setting a framework for training PN by reviewing existing literature on care priorities for PD. As a result, six prerequisites were formulated concerning a framework for training PN. The proposed training framework consist of three modules covering topics of PD: (i) comprehensive care, (ii) self-management support and (iii) health coaching. A fourth module on telemedicine may be added if applicable. The framework streamlines important theoretical concepts of professional PD management and may enable the development of novel, personalized care approaches.

Uptake of telehealth in Parkinson's disease clinical care and research during the COVID-19 pandemic

INTRODUCTION

Traditionally, medical care and research in Parkinson's disease (PD) have been conducted with in-person encounters. The recent COVID-19 pandemic has profoundly impacted the delivery of in-person clinical care and clinical research. We conducted an online survey of active clinician members of the Parkinson Study Group (PSG) to evaluate the adoption of various non-face-to-face methods in clinical practice and research in PD during the COVID-19 pandemic.

METHODS

We conducted a survey using the open-access online SurveyMonkey tool (http://www.surveymonkey.com). The survey had 27 items and was designed to elucidate clinical/research care before and during the COVID-19 pandemic. The survey was sent to 414 active PSG members with weekly reminders and it remained accessible for 30 days from May 2020.

RESULTS

We received 142 responses, of which 133 (93.7%) provided demographic data. The clinical use of virtual visits via synchronous video conferencing increased from 39.5% pre-COVID-19 to 94.6% during the COVID-19 pandemic. Lack of access for patients (68.2%) and patient resistance (51.4%) were the top barriers for its use. Approximately 70% respondents stated that 75-100% of their research activities were suspended during the COVID-19 pandemic. Many sites had to fill out protocol deviations (38.2%), protocol exceptions (25.5%) or change their research profile due to layoffs (16.8%). The overall use of video conferencing increased from 30.3% to 64.1%.

CONCLUSION

The current results suggest a need for flexibility in conducting office visits and clinical trials in PD patients. Technology has the potential to enhance patient care and convenience, when in-person visits can be challenging.

Parkinson's Disease Subtypes: Critical Appraisal and Recommendations

BACKGROUND

In Parkinson's disease (PD), there is heterogeneity in the clinical presentation and underlying biology. Research on PD subtypes aims to understand this heterogeneity with potential contribution for the knowledge of disease pathophysiology, natural history and therapeutic development. There have been many studies of PD subtypes but their impact remains unclear with limited application in research or clinical practice.

OBJECTIVE

To critically evaluate PD subtyping systems.

METHODS

We conducted a systematic review of PD subtypes, assessing the characteristics of the studies reporting a subtyping system for the first time. We completed a critical appraisal of their methodologic quality and clinical applicability using standardized checklists.

RESULTS

We included 38 studies. The majority were cross-sectional (n = 26, 68.4%), used a data-driven approach (n = 25, 65.8%), and non-clinical biomarkers were rarely used (n = 5, 13.1%). Motor characteristics were the domain most commonly reported to differentiate PD subtypes. Most of the studies did not achieve the top rating across items of a Methodologic Quality checklist. In a Clinical Applicability Checklist, the clinical importance of differences between subtypes, potential treatment implications and applicability to the general population were rated poorly, and subtype stability over time and prognostic value were largely unknown.

CONCLUSION

Subtyping studies undertaken to date have significant methodologic shortcomings and most have questionable clinical applicability and unknown biological relevance. The clinical and biological signature of PD may be unique to the individual, rendering PD resistant to meaningful cluster solutions. New approaches that acknowledge the individual-level heterogeneity and that are more aligned with personalized medicine are needed.

Technology-Enabled Care: Integrating Multidisciplinary Care in Parkinson's Disease Through Digital Technology

Parkinson's disease (PD) management requires the involvement of movement disorders experts, other medical specialists, and allied health professionals. Traditionally, multispecialty care has been implemented in the form of a multidisciplinary center, with an inconsistent clinical benefit and health economic impact. With the current capabilities of digital technologies, multispecialty care can be reshaped to reach a broader community of people with PD in their home and community. Digital technologies have the potential to connect patients with the care team beyond the traditional sparse clinical visit, fostering care continuity and accessibility. For example, video conferencing systems can enable the remote delivery of multispecialty care. With big data analyses, wearable and non-wearable technologies using artificial intelligence can enable the remote assessment of patients' conditions in their natural home environment, promoting a more comprehensive clinical evaluation and empowering patients to monitor their disease. These advances have been defined as technology-enabled care (TEC). We present examples of TEC under development and describe the potential challenges to achieve a full integration of technology to address complex care needs in PD.

Pilot Evaluation of a Pragmatic Network for Integrated Care and Self-Management in Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) is a chronic neurodegenerative disorder that challenges care provision. A multidisciplinary care model needs to be impactful, feasible, and viable economically for widespread utilization. Supportive evidence is lacking.

OBJECTIVE

The objective of this study was to evaluate the implementation and impact of a pragmatic network for PD care, the Integrated Parkinson Care Network (IPCN).

METHODS

A 6-month, pre-post design, single-center, phase 2 study for complex interventions for patients with newly diagnosed (<1 year) and advanced (diagnosis >8 years) PD was used to assess a patient-centered care model based on integrated care, self-management support, and technology-enabled care. We comprehensively assessed the implementation of care paths, change in selected health and care quality outcomes after the Integrated Parkinson Care Network program, and costs analyses.

RESULTS

We recruited 100 participants in 6 months. Overall, the top care priorities were speech and communication (33.7%), anxiety and depression (31.6%), and mobility, balance, and falls (29.6%), and the most commonly (>45%) used resources were speech-language pathology, community seniors services, and physiotherapy. Care priorities were met successfully in 90.6% of the cases, and there was a positive change in the Parkinson's Disease Questionnaire-8 (2.7; 95% confidence interval, 0.4-5.0; statistically significant in the advanced group), the perception of support for chronic care (Patient Assessment of Chronic Illness Case score, 1.1; 95% confidence interval, 0.9-1.4), and self-management (5As score, 1.2; 95% confidence interval, 1.0-1.4). The total cost of the Integrated Parkinson Care Network was C$1367 per patient.

CONCLUSIONS

A pragmatic development of a care delivery network based on integrated care and self-management support is promising for its feasibility, impact, and a sustainable cost. © 2020 International Parkinson and Movement Disorder Society.

Therapeutic Update on Huntington's Disease: Symptomatic Treatments and Emerging Disease-Modifying Therapies

Huntington's disease (HD) is a monogenic neurodegenerative disorder that presents with progressive motor, behavior, and cognitive symptoms leading to early disability and mortality. HD is caused by an expanded CAG repeats in exon 1 of the huntingtin (HTT) gene. The corresponding genetic test allows a clinical, definite diagnosis in life and the identification of a fully penetrant mutation carrier in a premanifest stage. In addition to the development of symptomatic treatments that attempt to address unmet care needs such as apathy, irritability, and cognition, novel therapies that target pathways specific to HD biology are being developed with the intent of slowing disease progression. Among these approaches, HTT protein lowering therapies hold great promise. There are currently active programs using antisense oligonucleotides (ASOs), RNA interference, small-molecule splicing modulators, and zinc-finger protein transcription factor. Except for ASOs and RNA interference approaches, the remaining therapeutic strategies are at a preclinical stage of development. While the current therapeutic landscape in HD may bring an unparalleled change in the lives of people with HD and their families with the first-ever disease-modifying therapy, the evaluation of these therapies requires novel tools that enable a more efficient and expedited discovery and evaluative process. Examples are biomarkers targeting the HTT protein to measure target engagement or disease progression and rating scales more sensitive to the earliest clinical changes. These tools will be instrumental in the next phase of disease-modifying clinical trials in HD likely to target the phenoconversion period of the disease, including the prodromal HD stage.

Therapy of Parkinson's Disease Subtypes

Early descriptions of subtypes of Parkinson's disease (PD) are dominated by the approach of predetermined groups. Experts defined, from clinical observation, groups based on clinical or demographic features that appeared to divide PD into clinically distinct subsets. Common bases on which to define subtypes have been motor phenotype (tremor dominant vs akinetic-rigid or postural instability gait disorder types), age, nonmotor dominant symptoms, and genetic forms. Recently, data-driven approaches have been used to define PD subtypes, taking an unbiased statistical approach to the identification of PD subgroups. The vast majority of data-driven subtyping has been done based on clinical features. Biomarker-based subtyping is an emerging but still quite undeveloped field. Not all of the subtyping methods have established therapeutic implications. This may not be surprising given that they were born largely from clinical observations of phenotype and not in observations regarding treatment response or biological hypotheses. The next frontier for subtypes research as it applies to personalized medicine in PD is the development of genotype-specific therapies. Therapies for GBA-PD and LRRK2-PD are already under development. This review discusses each of the major subtyping systems/methods in terms of its applicability to therapy in PD, and the opportunities and challenges designing clinical trials to develop the evidence base for personalized medicine based on subtypes.

The Role of Architecture and Design in the Management of Parkinson's Disease: A Systematic Review

Background:

Parkinson’s disease (PD) is a neurological condition characterized by the development of daily disabling symptoms. Although the architecture and design of a PD patient’s environment can hinder or facilitate full participation in daily activities, their putative role in the management of these patients has received little attention to date.

Objective:

We conducted a systematic review to evaluate the evidence of architectural and design features in the management of people with PD.

Methods:

An electronic database search of observational and experimental studies was conducted in MEDLINE and Embase from inception to May 2020, with two independent reviewers identifying the studies. Falls, fear of falling, postural instability, gait impairment/disability, and functional mobility were our outcomes of interest.

Results:

Thirty-six studies were included, among which nineteen were observational and seventeen were experimental studies (overall participants = 2,965). Pavement characteristics, notably unstable surfaces and level differences, were found to be a major cause of falling. Ground-based obstacles and confined/narrowed spaces were found to disturb gait, increase postural instability, and decrease functional mobility. Housing type did not appear to increase risk of falling, nor to significantly explain concerns about falling.

Conclusion:

Findings suggest a need to adjust architectural features of the surrounding space to ensure appropriate care and provide a safe environment to PD patients. More evidence about the impact of such modifications on PD outcomes is needed.

Glycopyrrolate Improves Disability From Sialorrhea in Parkinson's Disease: A 12-Week Controlled Trial

OBJECTIVE

The objective of this study was to assess the 12-week efficacy and safety of oral glycopyrrolate for moderate-to-severe sialorrhea in Parkinson's disease (PD).

BACKGROUND

Chronic moderate-to-severe sialorrhea has a negative impact on quality of life in PD. There is no robust evidence for oral treatments for sialorrhea longer than 1 week.

METHODS

This was a 12-week, double-blinded, placebo-controlled, parallel phase II study in patients with PD and Movement Disorder Society-Unified Parkinson's Disease Rating Scale item 2.2 > 2. The intervention was glycopyrrolate up to 4.5 mg/d; the primary outcome was sialorrhea related-disability (Radboud Oral Motor Inventory for Parkinson's Disease-Saliva). We used an intention-to-treat analysis. A P < 0.05 was deemed significant.

RESULTS

We recruited 28 patients (age, 71.1 ± 6.9 years; PD duration, 11.4 ± 7.2 years; Radboud Oral Motor Inventory for Parkinson's Disease-Saliva, 22.4 ± 5.7). Glycopyrrolate was superior to placebo at 12 weeks in the Radboud Oral Motor Inventory for Parkinson's Disease-Saliva (between-group difference, 5.3; 95% confidence interval, 1.0-9.6). Dry mouth was the most common adverse event (glycopyrrolate, n = 6; placebo, n = 2).

CONCLUSIONS

The results support the efficacy of glycopyrrolate to treat sialorrhea-related disability up to 12 weeks and contribute to addressing unmet nonmotor care needs in PD. © 2020 International Parkinson and Movement Disorder Society.

Moving towards home-based community-centred integrated care in Parkinson's disease

People living with Parkinson's disease (PwP) experience a wide range of motor and non-motor symptoms associated with increasing complexity of care delivery. A multispecialty approach has been presented as an intuitive solution for tailored and comprehensive care delivery. Nevertheless, past trials of both multidisciplinary or interdisciplinary care models in PD suggested no measurable change to a small benefit in quality of life (QoL) and failed to show economic sustainability. We propose a home-based community-centred integrated care (iCARE-PD) for PwP as a pragmatic solution to harness the potential of existing care resources using an integrated care strategy, enable self-management support and implement technology-enabled care. The iCARE-PD model is based on Freeman's concept of continuity of care and the expanded Chronic Care Model for organization of care strategies. A home-based community-centred integrated care has immediate implications for clinical practice, with potential benefits in rural areas or lower-income countries, by enhancing access to care with optimized costs. There is a need to establish which and how interventions may be used as an instrument of care in each local deployment of the iCARE-PD model. We put forward a multidisciplinary framework to generate the evidence supportive of its implementation as the standard of care in the future and delineate the core strategies to secure the implementation of this care approach across different health care systems to ensure feasibility and economic sustainability. We envision this model becoming a paradigm of personalized care transferable to people with atypical forms of neurodegenerative parkinsonism.

Nocebo and lessebo effects

The power of placebos is commonly associated with the placebo effect. In contrast, detrimental effects related to the use of a placebo are little studied and less well recognized. This chapter covers the nocebo and lessebo effects defined, respectively, as expectation of harm in the form of adverse events in a placebo arm and reduction of therapeutic benefit due to the uncertainty of being allocated to placebo. The lessebo effect is a more recent concept and has been described only in depression, schizophrenia and Parkinson's disease. The nocebo response was evaluated in many neurological diseases, including epilepsy, multiple sclerosis, Parkinson's disease, Alzheimer's disease, restless leg syndrome, among others. Meta-analyses of randomized controlled trials in these conditions reveal a significant variability of the magnitude of the nocebo response and that factors related to study design, study participants or neurological disease can be associated with a nocebo response, although with the opposing findings across conditions. The knowledge about neurobiological mechanisms of the nocebo effect is poor for neurological diseases, and most of the information has been generated in pain. Functional neuroimaging suggests the existence of a distinct network for the anticipation and the experience of a hyperalgesia nocebo response. Different types of neurotransmitters have been involved, including cholecystokinin, dopamine and opioids. Recognizing the potential impact of nocebo and lessebo effects, mitigating strategies are in development with application to clinical research and clinical practice, such as a contextualized informed consent process, alternative study designs and enhancement of patient-physician communication.

Synuclein Meeting 2019: where we are and where we need to go

The Synuclein Meetings are a series that has been taking place every 2 years for about 12 years. The Synuclein Meetings bring together leading experts in the field of synuclein and related human conditions with the goal of discussing and advancing the research. In 2019, the Synuclein Meeting is taking place in Ofir, a city in the outskirts of Porto, Portugal. The meeting is entitled 'Synuclein Meeting 2019: Where we are and where we need to go'. It has now been 22 years since the initial report of the genetic and pathological association between alpha-synuclein and Parkinson's disease (PD). The field has grown and matured, and major advances have been made. We are witnessing exciting times, with the first clinical trials being conducted that target synuclein, and bring the hope of novel therapies for patients with PD and their families. However, we still face many challenges and need to address fundamental questions for the field to progress to where we need to go: having biomarkers and effective therapies for PD and other synucleinopathies. In this context, we have designed the Synuclein Meeting 2019 with a different format. The program will include sessions in the format of a round-table discussion, to break away from the more rigid format of regular scientific meetings based on oral presentations. Our goal was to create opportunities for discussing the major questions in the field of synuclein and related human disorders, and challenge dogmatic ideas that require a critical revision in light of the most recent knowledge. In this issue, we assembled a series of comprehensive overviews of major topics, questions, and challenges in the field, that will be discussed in the meeting. We are confident that this special issue will be an instrumental reference for inspiring novel paths for future discoveries in the synuclein field and generate other discussions in the scientific community. This is the Preface for the Special Issue "Synuclein". Cover Image for this issue: doi: 10.1111/jnc.14520.