Motor and Nonmotor Complications of Levodopa: Phenomenology, Risk Factors, and Imaging Features

Association between striatal amyloid deposition and motor prognosis in Parkinson's disease

BACKGROUND AND PURPOSE

The co-occurrence of amyloid-β pathology in Parkinson's disease (PD) is common; however, the role of amyloid-β deposition in motor prognosis remains elusive. This study aimed to investigate the association between striatal amyloid deposition, motor complications and motor prognosis in patients with PD.

METHODS

Ninety-six patients with PD who underwent 18F florbetaben (FBB) positron emission tomography were retrospectively assessed. The ratio of the striatum to global (STG) FBB uptake was obtained for each individual, and patients were allotted into low and high STG groups according to the median value. The effect of STG group on regional amyloid deposition, the occurrence of motor complications and longitudinal change in levodopa equivalent dose (LED) requirement were investigated after controlling for age, sex, LED and disease duration at FBB scan.

RESULTS

The high STG group was associated with lower cortical FBB uptake in the parietal, occipital and posterior cingulate cortices and higher striatal FBB uptake compared to the low STG group. Patients in the high STG group had a higher risk of developing wearing off and levodopa-induced dyskinesia than those in the low STG group, whereas the risk for freezing of gait was comparable between the two groups. The high STG group showed a more rapid increase in LED requirements over time than the low STG group.

CONCLUSIONS

These findings suggest that relatively high striatal amyloid deposition is associated with poor motor outcomes in patients with PD.

Subcutaneous Levodopa: A New Engine for the Vintage Molecule

The management of Parkinson's disease (PD) continues to evolve with advancements in non-oral levodopa-based therapies aiming to provide continuous drug delivery (CDD). Such therapies address the challenges posed by the emergence of motor fluctuations, dyskinesias, and non-motor fluctuations (NMF) associated with oral levodopa administration and contributing to define the advanced stage of PD. The key focus of this review is placed on subcutaneous foslevodopa/foscarbidopa (Foslevodopa/foscarbidopa) infusion, showcasing its recent clinical availability and efficacy in providing continuous levodopa delivery. While providing an overview of the other non-oral levodopa-based CDD systems, such as intrajejunal levodopa-carbidopa infusion and levodopa-entacapone-carbidopa infusion, we highlight the current promising evidence for Foslevodopa/foscarbidopa to improve, for example, "on time" without troublesome dyskinesia and reducing "off time" in people with advanced PD. Additionally, Foslevodopa/foscarbidopa demonstrates potential in managing early morning off periods, sleep quality and other motor and non-motor symptoms. Moreover, other non-oral CDD options such as ND0612 and DIZ102/DIZ101 are discussed, with focus on their pharmacokinetics/pharmacodynamics, efficacy, and safety profiles. While these advancements present new therapeutic avenues, long-term observational studies are warranted to elucidate their impact on existing PD therapies. Overall, this review provides insights into the evolving landscape of non-oral CDD therapies and offers a pragmatic approach for their integration into clinical practice.

The effect of dopamine replacement therapy on cortical structure in Parkinson's disease

AIMS

To explore the cortical structural reorganization in Parkinson's disease (PD) patients under chronic dopamine replacement therapy (DRT) in cross-sectional and longitudinal data and determine whether these changes were associated with clinical alterations.

METHODS

A total of 61 DRT-treated, 60 untreated PD patients, and 61 normal controls (NC) were retrospectively included. Structural MRI scans and neuropsychological tests were conducted. Cortical thickness and volume were extracted based on FreeSurfer and were analyzed using general linear model to find statistically significant differences among three groups. Correlation analyses were performed among significant cortical areas, medication treatment (duration and dosage), and neuropsychological tests. Longitudinal cortical structural changes of patients who initiated DRT were analyzed using linear mixed-effect model.

RESULTS

Significant cortical atrophy was primarily observed in the prefrontal cortex in treated patients, including the cortical thickness of right pars opercularis and the volume of bilateral superior frontal cortex (SFC), left rostral anterior cingulate cortex (rACC), right lateral orbital frontal cortex, right pars orbitalis, and right rostral middle frontal cortex. A negative correlation was detected between the left SFC volume and levodopa equivalent dose (LED) (r = -0.316, p = 0.016), as well as the left rACC volume and medication duration (r = -0.329, p = 0.013). In the patient group, the left SFC volume was positively associated with digit span forward score (r = 0.335, p = 0.017). The left SFC volume reduction was longitudinally correlated with increased LED (standardized coefficient = -0.077, p = 0.001).

CONCLUSION

This finding provided insights into the influence of DRT on cortical structure and highlighted the importance of drug dose titration in DRT.

Machine-learning model for the prediction of acute orthostatic hypotension after levodopa administration

BACKGROUND

Levodopa could induce orthostatic hypotension (OH) in Parkinson's disease (PD) patients. Accurate prediction of acute OH post levodopa (AOHPL) is important for rational drug use in PD patients. Here, we develop and validate a prediction model of AOHPL to facilitate physicians in identifying patients at higher probability of developing AOHPL.

METHODS

The study involved 497 PD inpatients who underwent a levodopa challenge test (LCT) and the supine-to-standing test (STS) four times during LCT. Patients were divided into two groups based on whether OH occurred during levodopa effectiveness (AOHPL) or not (non-AOHPL). The dataset was randomly split into training (80%) and independent test data (20%). Several models were trained and compared for discrimination between AOHPL and non-AOHPL. Final model was evaluated on independent test data. Shapley additive explanations (SHAP) values were employed to reveal how variables explain specific predictions for given observations in the independent test data.

RESULTS

We included 180 PD patients without AOHPL and 194 PD patients with AOHPL to develop and validate predictive models. Random Forest was selected as our final model as its leave-one-out cross validation performance [AUC_ROC 0.776, accuracy 73.6%, sensitivity 71.6%, specificity 75.7%] outperformed other models. The most crucial features in this predictive model were the maximal SBP drop and DBP drop of STS before medication (ΔSBP/ΔDBP). We achieved a prediction accuracy of 72% on independent test data. ΔSBP, ΔDBP, and standing mean artery pressure were the top three variables that contributed most to the predictions across all individual observations in the independent test data.

CONCLUSIONS

The validated classifier could serve as a valuable tool for clinicians, offering the probability of a patient developing AOHPL at an early stage. This supports clinical decision-making, potentially enhancing the quality of life for PD patients.

Gastric-filling ultrasonography to evaluate gastric motility in patients with Parkinson's disease

Background

Delayed gastric emptying is a common non-motor symptom of Parkinson's disease (PD). However, there is currently no objective evaluation and diagnostic method for this condition.

Objectives

The purpose of this study was to evaluate the feasibility of gastric-filling ultrasonography for gastric motility in patients with PD and the relationship between gastric dynamics and gastrointestinal symptoms and motor symptoms of PD.

Design setting and patients

We performed a case-control study with 38 patients with PD and 34 healthy controls.

Methods

All patients underwent a 120-min ultrasonography examination using a 500-ml semi-liquid test meal. We determined the antral contraction amplitude (ACA), the antrum contraction frequency (ACF), the motility index (MI), and the gastric antral cross-sectional area (CSA). We acquired the CSA at six time points: fasting for 12 h (T0), immediately after drinking the semi-liquid test meal (T1); and at 30 (T30), 60 (T60), 90 (T90), and 120 (T120) min. We calculated the gastric emptying rate (GER) at different time points by using the CSA. We compared the GER between the groups and evaluated the correlation between the GER and gastrointestinal symptoms and motor symptoms of PD.

Results

The MI and ACF were significantly lower in the PD group compared with the control group (P < 0.05). The GER at T30 and the ACA showed no significant difference between the groups (P > 0.05). At different time points, the GER was significantly different between the PD and control groups (P < 0.001). There was no significant association between the GER and gastrointestinal symptoms; none of them were risk factors for impaired gastric emptying (odds ratio > 1). The GER was negatively correlated with the severity of PD motor symptoms (P < 0.05).

Conclusion

Patients with PD had significantly delayed gastric emptying, which was negatively correlated with the severity of PD motor symptoms. Measuring gastric emptying by gastric-filling ultrasound had good diagnostic value in clinical screening for delayed gastric motility in patients with PD.

Clinical Trial Registration

https://www.chictr.org.cn/showproj.html?proj=126304.

Medical, surgical, and physical treatments for Parkinson's disease

Although dopamine replacement therapy remains a core component of Parkinson's disease treatment, the onset of motor fluctuations and dyskinetic movements might require a range of medical and surgical approaches from a multidisciplinary team, and important new approaches in the delivery of dopamine replacement are becoming available. The more challenging, wide range of non-motor symptoms can also have a major impact on the quality of life of a patient with Parkinson's disease, and requires careful multidisciplinary management using evidence-based knowledge, as well as appropriately tailored strategies according to the individual patient's needs. Disease-modifying therapies are urgently needed to prevent the development of the most disabling refractory symptoms, including gait and balance difficulties, cognitive impairment and dementia, and speech and swallowing impairments. In the third paper in this Series, we present the latest evidence supporting the optimal treatment of Parkinson's disease, and describe an expert approach to many aspects of treatment choice where an evidence base is insufficient.

Application of single wrist-wearable accelerometry for objective motor diary assessment in fluctuating Parkinson's disease

Advanced Parkinson's disease (PD) is characterized by motor fluctuations including unpredictable oscillations remarkably impairing quality of life. Effective management and development of novel therapies for these response fluctuations largely depend on clinical rating instruments such as the widely-used PD home diary, which are associated with biases and errors. Recent advancements in digital health technologies provide user-friendly wearables that can be tailored for continuous monitoring of motor fluctuations. Their criterion validity under real-world conditions using clinical examination as the gold standard remains to be determined. We prospectively examined this validity of a wearable accelerometer-based digital Parkinson's Motor Diary (adPMD) using the Parkinson's Kinetigraph (PKG®) in an alternative application by converting its continuous data into one of the three motor categories of the PD home diary (Off, On and Dyskinetic state). Sixty-three out of 91 eligible participants with fluctuating PD (46% men, average age 66) had predefined sufficient adPMD datasets (>70% of half-hour periods) from 2 consecutive days. 92% of per-protocol assessments were completed. adPMD monitoring of daily times in motor states showed moderate validity for Off and Dyskinetic state (ICC = 0.43-0.51), while inter-rating methods agreements on half-hour-level can be characterized as poor (median Cohen's κ = 0.13-0.21). Individualization of adPMD thresholds for transferring accelerometer data into diary categories improved temporal agreements up to moderate level for Dyskinetic state detection (median Cohen's κ = 0.25-0.41). Here we report that adPMD real-world-monitoring captures daily times in Off and Dyskinetic state in advanced PD with moderate validities, while temporal agreement of adPMD and clinical observer diary data is limited.

Acute effect of levodopa on orthostatic hypotension and its association with motor responsiveness in Parkinson's disease: Results of acute levodopa challenge test

OBJECTIVE

Levodopa administration can induce or worsen orthostatic hypotension (OH) in patients with Parkinson's disease (PD). Understanding of acute OH post levodopa (AOHPL) is important for rational drug use in PD patients. Primary objective of this study was to investigate the incidence of AOHPL in PD patients. The secondary objectives were a) hemodynamic character of AOHPL; b) risk factors of AOHPL; c) relationship between motor responsiveness and blood pressure (BP) change.

METHODS

490 PD inpatients underwent acute levodopa challenge test (LCT). Supine-to-standing test (STS) was done 4 times during LCT, including before levodopa and every hour post levodopa intake within 3 h. Patients were classified into two groups, AOHPL and non-AOHPL. A comprehensive set of clinical features scales was assessed, including both motor (e.g., motor response, wearing-off) and nonmotor symptoms (e.g., autonomic dysfunction, neuropsychology).

RESULTS

33.1% PD patients had OH before drug, 50.8% the same subjects had AOHPL during levodopa effectiveness. PD patients who had better response to levodopa likely to have lower standing mean artery pressure (MAP) and severer systolic BP drop after levodopa intake. BP increased when the motor performance worsened and vice versa. Beneficial response was a risk factors of AOHPL (OR = 1.624, P = 0.017).

CONCLUSIONS

AOHPL was very common in PD patients. We suggested that PD patients with risk factors should monitor hemodynamic change during LCT to avoid AOHPL following the introduction or increase of oral levodopa. The fluctuations of BP were complicated and multifactorial, likely caused by the process of PD and levodopa both.

Validating virtual administration of neuropsychological testing in Parkinson disease: a pilot study

COVID-19 has highlighted the need for remote cognitive testing, but the reliability and validity of virtual cognitive testing in Parkinson disease (PD) is unknown. Therefore, we assessed PD participants enrolled in an observational, cognition-focused study with an extensive cognitive battery completed both in-person and via video conference close in time. Data for 35 PD participants with normal cognition to mild dementia were analyzed. Only one test (semantic verbal fluency) demonstrated a difference in score by administration type, with a significantly better score virtually. Only three tests demonstrated good reliability for in-person versus virtual testing, but reliability values for visit 1 versus visit 2 were similarly low overall. Trail Making Test B was successfully administered virtually to only 18 participants due to technical issues. Virtual and in-person cognitive testing generate similar scores at the group level, but with poor to moderate reliability for most tests. Mode of test administration, learning effects, and technical difficulties explained little of the low test-retest reliability, indicating possible significant short-term variability in cognitive performance in PD in general, which has implications for clinical care and research. In-person cognitive testing with a neuropsychologist remains the gold standard, and it remains to be determined if virtual cognitive testing is feasible in PD.

Importance of time to ON versus wearing OFF in total daily OFF time experienced by patients with Parkinson's disease

Most patients with Parkinson's disease (PD) receiving levodopa (LD)/DOPA decarboxylase inhibitors develop motor fluctuations with an increasing amount of OFF time, negatively impacting patient quality of life. Herein, we review the evidence supporting the substantial, yet underappreciated contribution of delays in time to ON (including delayed ON and no ON) to total daily OFF time. Most clinical studies use patient diaries that do not capture time to ON and wearing OFF separately as related to LD dosing, and consequently, most OFF time has generally been attributed to wearing OFF. Hence, most treatment regimens focus on reducing wearing OFF by changing LD dosing/formulations and/or using "ON-extenders" (eg, catechol-o-methyltransferase inhibitors, monoamine oxidase-B inhibitors, extended-release amantadine, and adenosine A2A receptor antagonists). However, the literature describing approved treatments for PD that has focused on delays in time to ON is sparse and suggests this type of OFF may comprise more than twice the amount of total daily OFF time as wearing OFF. Here, we advocate for the importance of measuring and adequately addressing delays in time to ON and build support for the consistent inclusion of the time to ON measurement in future clinical trials.

Mindfulness or meditation therapy for Parkinson's disease: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide. Mindfulness and meditation therapies have been demonstrated as effective alternative treatments for patients with neurological disorders. However, the effects of mindfulness and meditation therapies on PD remain unclear. This meta-analysis investigated the effects of mindfulness and meditation therapies in PD patients.

METHODS

A literature search was conducted using PubMed, Embase, Cochrane Library, and ClinicalTrials.gov for randomized controlled trials comparing mindfulness and meditation therapies with control treatments in patients with PD.

RESULTS

Nine articles involving eight trials were included, with a total of 337 patients. Our meta-analysis revealed that mindfulness and meditation therapies significantly improved Unified Parkinson's Disease Rating Scale-Part III score (mean difference [MD] = -6.31, 95% confidence interval [95% CI] = -8.57 to -4.05) and cognitive function (standard mean difference [SMD] = 0.62, 95% CI = 0.23 to 1.02). However, no significant differences were discovered between mindfulness therapies and control in gait velocity (MD = 0.05, 95% CI = -0.23 to 0.34), Parkinson's Disease Questionnaire-39 Summary Index (MD = 0.51, 95% CI = -1.12 to 2.14), activities of daily living (SMD = -1.65, 95% CI = -3.74 to 0.45), depression (SMD = -0.43, 95% CI = -0.97 to 0.11), anxiety (SMD = -0.80, 95% CI = -1.78 to 0.19), pain (SMD = 0.79, 95% CI = -1.06 to 2.63), or sleep disturbance (SMD = -0.67, 95% CI = -1.58 to 0.24).

CONCLUSION

Mindfulness and meditation therapies may serve as complementary and alternative treatments for PD patients.

Drugs to the Rescue: Comparison of On-Demand Therapies for OFF Symptoms in Parkinson's Disease

Patients with Parkinson's disease often suffer from OFF symptoms disrupting their daily routines and adding to disabilities. Despite polypharmacy and adjustments to medication schedules, they often do not experience consistent relief from their motor symptoms. As the disease progresses, impaired gastric emptying may evolve, making it even more challenging for dopaminergic drugs to provide consistent results. This review focuses on a group of drugs that have the pharmacokinetic advantage of a much earlier onset of action by virtue of their non-oral routes of absorption. We compare the current marketed options: subcutaneous apomorphine, sublingual apomorphine, and inhaled levodopa. Subcutaneous apomorphine is the speediest to take effect, whereas sublingual apomorphine offers the longest clinical effect. Inhaled levodopa has the most favorable side effect profile among the three options. An inhaled form of apomorphine is currently under development, having passed safety and efficacy studies. Each of these drugs has unique characteristics for the user, including different side effect profiles and onset of action. The best choice for a patient will depend on individual needs and circumstances. In this review, we explore those nuances to allow clinicians to select the best option for their patients.

Levodopa Dose Equivalency in Parkinson's Disease: Updated Systematic Review and Proposals

BACKGROUND

To compare drug regimens across clinical trials in Parkinson's disease (PD) conversion formulae between antiparkinsonian drugs have been developed. These are reported in relation to levodopa as the benchmark drug in PD pharmacotherapy as 'levodopa equivalent dose' (LED). Currently, the LED conversion formulae proposed in 2010 by Tomlinson et al. based on a systematic review are predominantly used. However, new drugs with established and novel mechanisms of action and novel formulations of longstanding drugs have been developed since 2010. Therefore, consensus proposals for updated LED conversion formulae are needed.

OBJECTIVES

To update LED conversion formulae based on a systematic review.

METHODS

The MEDLINE, CENTRAL, and Embase databases were searched from January 2010 to July 2021. Additionally, in a standardized process according to the GRADE grid method, consensus proposals were issued for drugs with scarce data on levodopa dose equivalency.

RESULTS

The systematic database search yielded 3076 articles of which 682 were eligible for inclusion in the systematic review. Based on these data and the standardized consensus process, we present proposals for LED conversion formulae for a wide range of drugs that are currently available for the pharmacotherapy of PD or are expected to be introduced soon.

CONCLUSIONS

The LED conversion formulae issued in this Position Paper will serve as a research tool to compare the equivalence of antiparkinsonian medication across PD study cohorts and facilitate research on the clinical efficacy of pharmacological and surgical treatments as well as other non-pharmacological interventions in PD. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Validating virtual administration of neuropsychological testing in Parkinson disease: a pilot study

Background COVID-19 has highlighted the need for remote cognitive testing. Virtual testing may lessen burden and can reach a larger patient population. The reliability and validity of virtual cognitive testing in Parkinson disease (PD) is unknown. Objectives To validate neuropsychological tests for virtual administration in PD. Methods Participants enrolled in an observational, cognition-focused study completed a rater-administered cognitive battery in-person and via video conference 3-7 days apart. Order of administration was counterbalanced. Analyses to compare performance by type of administration (virtual versus in-person) included paired t-test, intraclass correlation (ICC) and linear mixed-effects models. Results Data for 35 (62.9% male) PD participants (62.5% normal cognition, 37.5% cognitive impairment) were analyzed. Only the semantic verbal fluency test demonstrated a difference in score by administration type, with a significantly better score when administered virtually (paired t-test p = 0.011 and linear mixed-effects model p = 0.012). Only the Dementia Rating Scale-2, Trails A test and phonemic verbal fluency demonstrated good reliability (ICC value 0.75-0.90) for virtual versus in-person administration, and values for visit 1 versus visit 2 were similarly low overall. Trail making tests were successfully administered virtually to only 18 (51.4%) participants due to technical issues. Conclusions Virtual cognitive testing overall is feasible in PD, and virtual and in-person cognitive testing generate similar scores at the group level, but reliability is poor or moderate for most tests. Given that mode of test administration, learning effects and technical difficulties explained relatively little of the low test-retest reliability observed, there may be significant short-term variability in cognitive performance in PD in general, which has important implications for clinical care and research.

Effects of Popping For Parkinson’s dance class on the mood of people with Parkinson’s disease

Background/Aims

Depression, low mood and apathy can affect people with Parkinson’s disease, impacting on their quality of life. The aim of this study was to investigate the effects of one Popping For Parkinson’s dance session on the mood of people with Parkinson’s disease.

Methods

A total of 33 people with Parkinson’s disease, with a mean age of 67.5 years (standard deviation 10.3 years), mean Parkinson’s level of 1.8 (standard deviation 1.6), took part in one Popping For Parkinson's dance class at four different locations: London (UK), Hatfield (UK), New York City (USA) and Turin (Italy). Participants’ mood was measured with the Profile of Mood States questionnaire at four time points: immediately before the dance class, immediately after the dance class, 24 hours after the dance class and 1 week after the dance class.

Results

Participants’ total mood score and the subscale score of vigour increased, while the subscales of tension, depression, and confusion decreased on the Profile of Mood States, significantly immediately after the dance intervention. However, at 24 hours and 1 week after the dance class, mood scores did not differ significantly compared with baseline measurements. The improvements in mood immediately after the dance class did not differ depending on sex, age, previous dance experience, the location of the dance class, stage of Parkinson’s disease, presence of tremor and deep brain stimulation treatment.

Conclusions

Participating in a Popping For Parkinson’s dance class boosts mood in the short term, and this improvement lasts less than 24 hours. This finding has implications for the provision of dance classes, suggesting that regular attendance may be necessary for sustained improvements. Further studies are needed to determine whether attending a series of Popping for Parkinson’s classes may have longer-term effects.

Electroacupuncture for motor dysfunction and constipation in patients with Parkinson's disease: a randomised controlled multi-centre trial

BACKGROUND

Motor disturbances and non-motor disturbances such as constipation are the main factors affecting the quality of life in patients with Parkinson's disease (PD). We investigated the efficacy and safety of electroacupuncture combined with conventional pharmacological treatment on motor dysfunction and constipation in PD.

METHODS

In this multi-centre randomised controlled trial, we enrolled 166 eligible participants between September 19, 2018 and September 25, 2019 in four hospitals in China. Participants were randomly assigned (1:1) to the electroacupuncture (EA) group and the waitlist control group. Each participant in both groups received the conventional pharmacological treatment, EA group received 3 sessions of electroacupuncture per week for 12 weeks. The primary outcome was the change in the Unified Parkinson's Disease Rating Scale (UPDRS) score from baseline to week 12. The secondary outcomes included the evaluation of functional disability in motor symptoms and constipation, the adherence and adverse events were also recorded. Registered with Chictr.org.cn, ChiCTR1800019517.

FINDINGS

At week 12, the change in the UPDRS score of the EA group was significantly higher than that of the control group, with a difference of -9.1 points (95% CI, -11.8 to -6.4), and this difference continued into weeks 16 and 24. From baseline to week 12, the 39-item Parkinson Disease Question (PDQ-39) decreased by 10 points (interquartile range, IQR -26.0 to 0.0) in the EA group and 2.5 points (IQR: -11.0 to 4.0) in the control group, the difference was statistically significant. The time and steps for the 20-m walk at week 12, as well as the changes from baseline in the EA group, were comparable with that in the control group. But the EA group had a greater decrease than the control group from baseline in the times for 20-m walks at weeks 16 and 24. From week 4 to week 24, the median values of spontaneous bowel movements (SBMs) per week in the EA group were higher than that in the control group, the differences were all statistically significant. The incidence of EA-related adverse events during treatment was low, and they are mild and transient.

INTERPRETATION

The findings of our study suggested that compared with conventional pharmacological treatment, conventional pharmacological treatment combined with electroacupuncture significantly enhances motor function and increased bowel movements in patients with PD, electroacupuncture is a safe and effective treatment for PD.

FUNDING

Shanghai "Science and Technology Innovation Action Plan" Clinical Medicine Field Project (18401970700), Shanghai Special Project on Aging and Women's and Children's Health Research (020YJZX0134), Shanghai Clinical Research Centre for Acupuncture and Moxibustion (20MC1920500).

Levodopa Carbidopa Intestinal Gel in Advanced Parkinson's Disease: DUOGLOBE Final 3-Year Results

BACKGROUND

Levodopa-carbidopa intestinal gel (LCIG) improves motor and non-motor symptoms in patients with advanced Parkinson's disease (aPD).

OBJECTIVE

To present the final 36-month efficacy and safety results from DUOGLOBE (DUOdopa/Duopa in Patients with Advanced Parkinson's Disease - a GLobal OBservational Study Evaluating Long-Term Effectiveness; NCT02611713).

METHODS

DUOGLOBE was an international, prospective, long-term, real-world, observational study of patients with aPD initiating LCIG in routine clinical care. The primary endpoint was change in patient-reported "Off" time to Month 36. Safety was assessed by monitoring serious adverse events (SAEs).

RESULTS

Significant improvements in "Off" time were maintained over 3 years (mean [SD]: -3.3 hours [3.7]; p < 0.001). There were significant improvements to Month 36 in total scores of the Unified Dyskinesia Rating Scale (-5.9 [23.7]; p = 0.044), Non-Motor Symptoms Scale (-14.3 [40.5]; p = 0.002), Parkinson's Disease Sleep Scale-2 (-5.8 [12.9]; p < 0.001), and Epworth Sleepiness Scale (-1.8 [6.0]; p = 0.008). Health-related quality of life and caregiver burden significantly improved through Months 24 and 30, respectively (Month 24, 8-item Parkinson's Disease Questionnaire Summary Index, -6.0 [22.5]; p = 0.006; Month 30, Modified Caregiver Strain Index, -2.3 [7.6]; p = 0.026). Safety was consistent with the well-established LCIG profile (SAEs: 54.9% of patients; discontinuations: 54.4%; discontinuations due to an adverse event: 27.2%). Of 106 study discontinuations, 32 patients (30.2%) continued LCIG outside the study.

CONCLUSION

DUOGLOBE demonstrates real-world, long-term, reductions in motor and non-motor symptoms in patients with aPD treated with LCIG.

Safety and efficacy of continuous subcutaneous foslevodopa-foscarbidopa in patients with advanced Parkinson's disease: a randomised, double-blind, active-controlled, phase 3 trial

BACKGROUND

Levodopa is the most effective symptomatic therapy for Parkinson's disease, but patients with advanced Parkinson's disease develop motor fluctuations with chronic oral levodopa therapy. Foslevodopa-foscarbidopa is a soluble formulation of levodopa and carbidopa prodrugs that is delivered as a 24-h/day continuous subcutaneous infusion, and we aimed to assess the safety and efficacy of this formulation in patients with advanced Parkinson's disease.

METHODS

A 12-week randomised, double-blind, double-dummy, active-controlled study was done at 65 academic and community study centres in the USA and Australia. Patients with levodopa-responsive advanced Parkinson's disease inadequately controlled on current therapy, including at least 2·5 h of average daily off time, were randomly assigned (1:1) to continuous subcutaneous infusion of foslevodopa-foscarbidopa plus oral placebo or to oral immediate-release levodopa-carbidopa plus continuous subcutaneous infusion of placebo solution. Randomisation was stratified by site by means of a permutated-block schedule with a block size of two. The participants, treating investigators, study site personnel, and sponsor were masked to treatment group allocation. The primary and first key secondary endpoint in the hierarchical testing strategy were change from baseline to week 12 in on time without troublesome dyskinesia and off time, respectively; both endpoints were evaluated by an intention-to-treat analysis applying a mixed model for repeated measures analysis. Safety and tolerability were assessed throughout the study. The study is completed and is listed on ClinicalTrials.gov, NCT04380142.

FINDINGS

Between Oct 19, 2020, and Sept 29, 2021, of 270 participants screened and 174 enrolled, 141 were randomly assigned and received continuous subcutaneous infusion of foslevodopa-foscarbidopa plus oral placebo capsules (n=74) or oral encapsulated immediate-release levodopa-carbidopa plus continuous subcutaneous infusion of placebo solution (n=67). Compared with levodopa-carbidopa, foslevodopa-foscarbidopa showed a significantly greater increase in on time without troublesome dyskinesia (model-based mean [SE] 2·72 [0·52] vs 0·97 [0·50] h; difference 1·75 h, 95% CI 0·46 to 3·05; p=0·0083) and a significantly greater reduction in off time (-2·75 [0·50] vs -0·96 [0·49] h; difference -1·79 h, -3·03 to -0·54; p=0·0054). Hierarchical testing ended after the first secondary endpoint. Adverse events were reported in 63 (85%) of 74 patients in the foslevodopa-foscarbidopa group versus 42 (63%) of 67 in the levodopa-carbidopa group, and incidences of serious adverse events were similar between the groups (six [8%] of 74 vs four [6%] of 67, respectively). The most frequent adverse events in the foslevodopa-foscarbidopa group were infusion site adverse events (erythema 20 [27%]), pain 19 [26%]), cellulitis (14 [19%]), and oedema (nine [12%]), most of which were non-serious and mild-moderate in severity. The only system organ class that had more than one serious adverse event in the foslevodopa-foscarbidopa group was infections and infestations (catheter site cellulitis [one [1%]] and infusion site cellulitis [one [1%]). Adverse events led to premature discontinuation of study drug in 16 (22%) of 74 participants in the foslevodopa-foscarbidopa group versus one (1%) of 67 participants in the oral levodopa-carbidopa group.

INTERPRETATION

Foslevodopa-foscarbidopa improved motor fluctuations, with benefits in both on time without troublesome dyskinesia and off time. Foslevodopa-foscarbidopa has a favourable benefit-risk profile and represents a potential non-surgical alternative for patients with advanced Parkinson's disease.

FUNDING

AbbVie.

Effects of Baduanjin exercise on motor function, balance and gait in Parkinson's disease: a systematic review and meta-analysis

OBJECTIVE

This study aims to systematically evaluate the effects of Baduanjin on motor function, balance and gait in patients with Parkinson's disease (PD).

DESIGN

Systematic review and meta-analysis.

STUDY SELECTION

All eligible randomised controlled trials (RCTs) published in the English and Chinese language were included.

DATA SOURCES

Ten electronic databases were systematically searched, from inception to 17 March 2022: PubMed, Web of Science, Cochrane Library, Embase, EBSCOhost, OVID, SinoMed, China National Knowledge Infrastructure, Wanfang Data and China Science Journal Database (VIP).

REVIEW METHODS

Methodological quality assessment and meta-analysis were performed for the included studies using the Cochrane Review Manager V.5.4 software.

RESULTS

Ten RCTs with 804 participants were included. The results revealed the following: (1) Baduanjin significantly improved the motor function of patients with PD, based on the Unified Parkinson's Disease Rating Scale Part III (mean difference, MD -5.37, 95% CI -8.96 to -1.78, p=0.003) and Fugl-Meyer Assessment of Lower Extremity (MD 5.39, 95% CI 2.71 to 8.07, p<0.0001); (2) Baduanjin significantly improved the ability of balance of patients with PD, based on the Berg Balance Scale (MD 4.40, 95% CI 3.08 to 5.73, p<0.00001); (3) Baduanjin significantly improved the gait of patients with PD, based on the 6 min walk distance (MD 21.62, 95% CI 11.14 to 32.10, p<0.0001). After the further subgroup and sensitivity analyses, the heterogeneity was identified to be potentially due to the different degrees of disease severity in patients with PD and the difference in Baduanjin intervention durations.

CONCLUSIONS

The analysis of this systematic evaluation indicates that Baduanjin might have a positive effect in improving the motor function, balance and gait of patients with PD. However, due to the quantity and clinical heterogeneity limitations of the included studies, this conclusion still warrants more high-quality and multicentre RCTs for further verification.

Why do 'OFF' periods still occur during continuous drug delivery in Parkinson's disease?

Continuous drug delivery (CDD) is used in moderately advanced and late-stage Parkinson’s disease (PD) to control motor and non-motor fluctuations (‘OFF’ periods). Transdermal rotigotine is indicated for early fluctuations, while subcutaneous apomorphine infusion and levodopa-carbidopa intestinal gel are utilised in advanced PD. All three strategies are considered examples of continuous dopaminergic stimulation achieved through CDD. A central premise of the CDD is to achieve stable control of the parkinsonian motor and non-motor states and avoid emergence of ‘OFF’ periods. However, data suggest that despite their efficacy in reducing the number and duration of ‘OFF’ periods, these strategies still do not prevent ‘OFF’ periods in the middle to late stages of PD, thus contradicting the widely held concepts of continuous drug delivery and continuous dopaminergic stimulation. Why these emergent ‘OFF’ periods still occur is unknown. In this review, we analyse the potential reasons for their persistence. The contribution of drug- and device-related involvement, and the problems related to site-specific drug delivery are analysed. We propose that changes in dopaminergic and non-dopaminergic mechanisms in the basal ganglia might render these persistent ‘OFF’ periods unresponsive to dopaminergic therapy delivered via CDD.

Which type of mind-body exercise is most effective in improving functional performance and quality of life in patients with Parkinson's disease? A systematic review with network meta-analysis

BACKGROUND

Several studies have investigated the effect of mind-body exercise (MBE) on functional performance and health-related quality of life (HRQoL) in Parkinson's disease (PD), but it is still very difficult for clinicians to make informed decision on the best mind-body exercise for PD.

PURPOSE

We analyzed the relative efficacy of MBE (yoga, Tai-Chi, Pilates, Qigong, and dance) in improving functional performance and HRQoL in patients with PD.

METHODS

A systematic review of randomized controlled trials (RCTs) was performed using network meta-analysis (NMA), searching the following databases: Cochrane, Web of Science, and PubMed using specific keywords until December 28, 2021, assessing the effects of MBE on functional performance and HRQoL in patients with PD.

RESULTS

This review included 60 RCTs with 2037 participants. A ranking of MBE for modifying various aspects of functional performance and HRQoL was achieved. Pairwise NMA showed Pilates to be the most effective in improving functional mobility (MD: - 3.81; 95% CI (- 1.55, - 6.07) and balance performance (SMD: 2.83; 95% CI (1.87, 3.78). Yoga (MD: - 5.95; 95% CI (- 8.73, - 3.16) and dance (MD: - 5.87; 95% CI (- 8.73, - 3.01) to be the most effective in improving motor function, whereas Qigong (MD: 0.32; 95% CI (0.00, 0.64) was most effective in improving gait speed. Considering HRQoL, dance was found to be the most effective (SMD: - 0.36; 95% CI (- 0.70, -0.01).

CONCLUSION

MBE should be considered an effective strategy for improving functional performance and HRQoL in patients with PD. The most effective MBE intervention varied with the functional performance domain. Dance was an effective exercise for improving HRQoL among people with PD.

PROSPERO REGISTRATION ID

CRD42022301030.

Characterisation of non‐motor fluctuations using the Movement Disorder Society Non‐Motor Rating Scale

Background

Non‐motor fluctuations (NMF) in people with Parkinson's disease (PwP) are clinically important yet understudied.

Objective

To study NMF in PwP using both the Movement Disorder Society Non‐Motor Rating Scale (MDS‐NMS) NMF subscale and wearable sensors.

Methods

We evaluated differences in overall burden of NMF and of specific NMF across disease durations: <2 years (n = 33), 2–5 years (n = 35), 5–10 years (n = 33), and > 10 years (n = 31). In addition, wearable triaxial sensor output was used as an exploratory outcome for early morning “off” periods.

Results

Significant between‐group differences were observed for MDS‐NMS NMF total scores (P < 0.001), and specifically for depression, anxiety, fatigue and cognition, with both NMF prevalence and burden increasing in those with longer disease duration. Whereas only 9.1% with a short disease duration had NMF (none of whom had dyskinesia), in PwP with a disease duration of >10 years this was 71.0% (P < 0.001). From a motor perspective, dyskinesia severity increased evenly with increasing disease duration, while NMF scores in affected individuals showed an initial increase with largest differences between 2–5 years disease duration (P < 0.001), with plateauing afterwards. Finally, we observed that the most common NMF symptoms in patients with sensor‐confirmed early morning “off” periods were fluctuations in cognitive capabilities, restlessness, and excessive sweating.

Conclusions

Non‐motor fluctuations prevalence in PwP increases with disease duration, but in a pattern different from motor fluctuations. Moreover, NMF can occur in PwP without dyskinesia, and in those with NMF the severity of NMF increases most during years 2–5 after diagnosis.

Opicapone versus placebo in the treatment of Parkinson’s disease patients with end-of-dose motor fluctuation-associated pain: rationale and design of the randomised, double-blind OCEAN (OpiCapone Effect on motor fluctuations and pAiN) trial

Background

Optimisation of dopaminergic therapy may alleviate fluctuation-related pain in Parkinson’s disease (PD). Opicapone (OPC) is a third-generation, once-daily catechol-O-methyltransferase inhibitor shown to be generally well tolerated and efficacious in reducing OFF-time in two pivotal trials in patients with PD and end-of-dose motor fluctuations. The OpiCapone Effect on motor fluctuations and pAiN (OCEAN) trial aims to investigate the efficacy of OPC 50 mg in PD patients with end-of-dose motor fluctuations and associated pain, when administered as adjunctive therapy to existing treatment with levodopa/dopa decarboxylase inhibitor (DDCi).

Methods

OCEAN is a Phase IV, international, multicentre, randomised, double-blind, placebo-controlled, parallel-group, interventional trial in PD patients with end-of-dose motor fluctuations and associated pain. It consists of a 1-week screening period, 24-week double-blind treatment period and 2-week follow-up period. Eligible patients will be randomised 1:1 to OPC 50 mg or placebo once daily while continuing current treatment with levodopa/DDCi and other chronic, stable anti-PD and/or analgesic treatments. The primary efficacy endpoint is change from baseline in Domain 3 (fluctuation-related pain) of the King’s Parkinson’s disease Pain Scale (KPPS). The key secondary efficacy endpoint is change from baseline in Domain B (anxiety) of the Movement Disorder Society-sponsored Non-Motor rating Scale (MDS-NMS). Additional secondary efficacy assessments include other domains and total scores of the KPPS and MDS-NMS, the Parkinson’s Disease Questionnaire (PDQ-8), the MDS-sponsored Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) Parts III and IV, Clinical and Patient’s Global Impressions of Change, and change in functional status via Hauser’s diary. Safety assessments include the incidence of treatment-emergent adverse events. The study will be conducted in approximately 140 patients from 50 clinical sites in Germany, Italy, Portugal, Spain and the United Kingdom. Recruitment started in February 2021 and the last patient is expected to complete the study by late 2022.

Discussion

The OCEAN trial will help determine whether the use of adjunctive OPC 50 mg treatment can improve fluctuation-associated pain in PD patients with end-of-dose motor fluctuations. The robust design of OCEAN will address the current lack of reliable evidence for dopaminergic-based therapy in the treatment of PD-associated pain.

Trial registration

EudraCT number 2020–001175-32; registered on 2020-08-07.

COMT Inhibitors in the Management of Parkinson's Disease

Levodopa treatment remains the gold standard for Parkinson's disease, but shortcomings related to the pharmacological profile, notably, oral administration and the consequent occurrence of motor complications, have led to the development of several add-on levodopa treatments or to research to improve the method of delivery. Motor fluctuations, and to a lesser extent non-motor fluctuations, concern half of the patients with Parkinson's disease after 5 years of disease and patients identified them as one of their most bothersome symptoms. Catechol-O-methyl transferase inhibitors (COMT-Is) are one of the recommended first-line levodopa add-on therapies for the amelioration of end-of dose motor fluctuations in patient with advanced Parkinson's disease. Currently, two peripheral COMT-Is are considered as first-line choices - entacapone (ENT), which was approved by the US Food and Drug Administration in 1999 and the European Committee in 1998; and opicapone (OPC), which was approved by the European Committee in 2016. A second-line COMT-I that requires regular hepatic monitoring, tolcapone (TOL), was approved by the Food and Drug Administration in 1998 and the European Committee in 1997. Of note, OPC also received Food and Drug Administration approval in 2021, but it is still only marketed in a few countries, including Germany, UK, Spain, Portugal, Italy, Japan, and USA, while ENT and TOL have a wider market. Our narrative review summarizes the pharmacokinetic/pharmacodynamic properties, clinical efficacy in terms of motor fluctuations, motor/non-motor symptoms, quality of life, and safety data of these three COMT-Is, as evidenced by randomized clinical trials, as well as by real-life observational studies. Overall, a phase III non-inferiority trial showed a similar effect between ENT and OPC on off-time (-60.8 min/day and -40.3 min/day, vs placebo, respectively), with a possible additional off-time reduction of 39 min/day, obtained when there is a switch from ENT to OPC. Concomitantly, TOL can reduce off-time by an average of 98 min/day. A significant though discrete concomitant reduction on the Unified Parkinson's Disease Rating Scale motor section (2-3 points) is obtained with all three drugs vs placebo. Data on quality of life are fewer and more heterogeneous, with positive results obtained especially in open-label studies. Effects on non-motor symptoms were investigated as secondary outcome only in a few studies, frequently by means of non-specific scales and a benefit was observed in open-label studies. Dopaminergic adverse effects were the most frequent, dyskinesia being the most common for the three drugs eventually requiring levodopa dose reductions. No urine discoloration and a very low incidence of diarrhea were found with OPC compared with ENT and TOL. Regular hepatic monitoring is needed only for TOL. A combination of COMT-Is with new formulations of levodopa, including the subcutaneous, intrajejunal, or new extended-release formulation, merits further exploration to improve the management of both mild and severe motor fluctuations.

Effect of Pillbox Organizers with Alarms on Adherence to Pharmacotherapy in Parkinson Disease Patients Taking Three and More Daily Doses of Dopaminergic Medications

Improvement of adherence to pharmacotherapy in patients with Parkinson’s disease (PD) is a challenge in routine clinical practice. Our study was aimed at the effect of pillbox organizers with alarms improving adherence to pharmacotherapy and its impact on clinical outcomes. Forty nonadherent patients with PD being treated with ≥ 3 daily doses of levodopa and/or dopamine agonists were pseudorandomized and consecutively ranked to groups A (early-start intervention) and B (delayed-start intervention). We used the following validated diagnostic instruments: MMAS-8 (adherence), PDQ-8 (quality of life, QoL), GDS (depression), NMSS (non-motor symptoms), MDS-UPDRS III (motor involvement), MDS-UPDRS IV, and WOQ-9 (motor and non-motor fluctuations and dyskinesias). We proved a significantly improved rate of adherence with the use of pillbox organizers with alarms. Moreover, after only four weeks of using the pillbox organizer, we detected an improvement in QoL scores, motor involvement, motor-, and non-motor fluctuations. Our study showed that pillbox organizers with alarms are efficient in improving adherence to pharmacotherapy in PD. It also could contribute to better motor states, less severe fluctuations, and improved QoL.

[Relevance of COMT inhibitors in the treatment of motor fluctuations]

Catechol O‑methyltransferase (COMT) inhibitors have been established in the treatment of Parkinson's disease for more than 20 years. They are considered the medication of choice for treating motor fluctuations. The available COMT inhibitors, entacapone, opicapone and tolcapone, differ pharmacokinetically in terms of their half-lives with implications for the dose frequency, in their indication requirements and in their spectrum of side effects, including diarrhea and yellow discoloration of urine. Many patients with motor fluctuations are currently not treated with COMT inhibitors and are, therefore, unlikely to receive individually optimized drug treatment. This manuscript summarizes the results of a working group including several Parkinson's disease experts, in which the value of COMT inhibitors was critically discussed.

Cost-effectiveness analysis of the Parkinson's KinetiGraph and clinical assessment in the management of Parkinson's disease

AIMS

The Parkinson's KinetiGraph (PKG) is a wrist-worn movement recording system that collates continuous, objective, data during daily activities in people with Parkinson's disease (PD) providing a report for clinicians. This study explores the cost-effectiveness of adding the PKG to routine PD assessments.

METHODS

A de novo Markov model of three health states: uncontrolled, controlled and death compared PKG plus routine assessment by a Movement Disease Specialist (MDS) versus routine assessment. Uncontrolled and controlled states were based on the Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) II and III scores. The transition between health states was dependent on improvement in MDS-UPDRS II and III, and transition to death state on all cause-mortality and PD-specific relative mortality risk. Markov cycle length was yearly beyond year 1 and lifetime horizon 22 years.

LIMITATIONS

PKG evidence incorporated in this analysis is based on findings from one clinical trial. Health state utilities were mapped and the probability of patients progressing from uncontrolled to controlled health state at the second visit and beyond was derived from a bootstrap method which assumed a normal distribution for MDS-UPDRS.

RESULTS

The addition of the PKG to usual PD assessments is a cost-effective intervention. PKG plus routine assessment is associated with lower total costs compared to routine assessment (£141,950 versus £159,312) and improved quality-adjusted life years (7.88 versus 7.61), resulting in an incremental cost-effectiveness ratio of -£64,978.99 and a net monetary benefit of £22,706.37 using a £20,000 threshold. Results were robust across sensitivity and scenario analyses.

CONCLUSIONS

Management of PD involves monitoring and evaluation of symptoms to assess disease progression and ensure appropriate treatment choices. Adding the PKG to clinical assessment in routine care allows for improved and objective identification of PD motor symptoms which can be used in clinical decision making to improve patient outcomes.

Deep Brain Stimulation and Treatment Outcomes of Young- and Late-Onset (≤55 Years) Parkinson's Disease: A Population-Based Study

Background: No studies have reported the rate of motor complications (MC) and response to medical and surgical treatment in a population-based cohort of young-onset Parkinson's Disease (YOPD) patients and a cohort of sex-matched late-onset Parkinson's Disease (LOPD).

Objective: To assess the outcomes of dopaminergic treatment in YOPD and LOPD, explore treatment-induced MC, medical adjustment, and rate of deep brain stimulation (DBS).

Methods: We used the expanded Rochester Epidemiology Project (eREP) to investigate a population-based cohort of YOPD between 2010 and 2015 in 7 counties in Minnesota. Cases with onset ≤55 years of age were included as YOPD. An additional sex-matched cohort of LOPD (onset at ≥56 years of age) was included for comparison. All medical records were reviewed to confirm the diagnoses.

Results: In the seven counties 2010–15, there were 28 YOPD patients, which were matched with a LOPD cohort. Sixteen (57%) YOPD had MC, as compared to 9 (32%) LOPD. In YOPD, 9 had motor fluctuations (MF) and Levodopa-induced dyskinesia (LID) together, whereas 3 had LID only and 4 MF only. In LOPD, 3 had MF and LID, 3 MF only, and 3 LID only. Following medical treatment for MC, 6/16 YOPD (38%) and 3/9 (33%) LOPD had symptoms resolution. In YOPD, 11/16 (69%) were considered for DBS implantation, in LOPD they were 2/9 (22%), but only 7 (6 YOPD and 1 LOPD) underwent the procedure. YOPD had significantly higher rates in both DBS candidacy and DBS surgery (respectively, p = 0.03 and p = 0.04). Among DBS-YOPD, 5/6 (83%) had positive motor response to the surgery; the LOPD case had a poor response. We report the population-based incidence of both YOPD with motor complications and YOPD undergoing DBS, which were 1.17 and 0.44 cases per 100,000 person-years, respectively.

Conclusion: Fifty-seven percent of our YOPD patients and 32% of the LOPD had motor complications. Roughly half of both YOPD and LOPD were treatment resistant. YOPD had higher rates of DBS candidacy and surgery. Six YOPD and 1 LOPD underwent DBS implantation and most of them had a positive motor response after the surgery.

Schwann cells differentiated from skin-derived precursors provide neuroprotection via autophagy inhibition in a cellular model of Parkinson's disease

Autophagy has been shown to play an important role in Parkinson’s disease. We hypothesized that skin-derived precursor cells exhibit neuroprotective effects in Parkinson’s disease through affecting autophagy. In this study, 6-hydroxydopamine-damaged SH-SY5Y cells were pretreated with a culture medium containing skin-derived precursors differentiated into Schwann cells (SKP-SCs). The results showed that the SKP-SC culture medium remarkably enhanced the activity of SH-SY5Y cells damaged by 6-hydroxydopamine, reduced excessive autophagy, increased tyrosine hydroxylase expression, reduced α-synuclein expression, reduced the autophagosome number, and activated the PI3K/AKT/mTOR pathway. Autophagy activator rapamycin inhibited the effects of SKP-SCs, and autophagy inhibitor 3-methyladenine had the opposite effect. These findings confirm that SKP-SCs modulate the PI3K/AKT/mTOR pathway to inhibit autophagy, thereby exhibiting a neuroprotective effect in a cellular model of Parkinson’s disease. This study was approved by the Animal Ethics Committee of Laboratory Animal Center of Nantong University (approval No. S20181009-205) on October 9, 2018.

DUOGLOBE: One-Year Outcomes in a Real-World Study of Levodopa Carbidopa Intestinal Gel for Parkinson's Disease

Background

Levodopa-carbidopa intestinal gel (LCIG) is an established treatment for improving motor and some non-motor symptoms (NMS) in patients with advanced Parkinson's disease (PD). Prospective long-term data in routine clinical practice are limited.

Objective

Assess LCIG effectiveness and safety in patients with advanced PD after 12 months during real-world routine clinical practice.

Methods

Duodopa/Duopa in patients with advanced Parkinson's disease-a global observational study evaluating long-term effectiveness (DUOGLOBE) (NCT02611713) is an ongoing, prospective, multinational, observational study of LCIG-naïve patients treated as part of routine clinical practice; 3 years of follow-up are planned. The primary outcome is the change in patient-reported off time. Other assessments include the Unified Dyskinesia Rating Scale (UDysRS), Non-Motor Symptoms Scale (NMSS), Parkinson's Disease Sleep scale (PDSS-2), Epworth Sleepiness Scale (ESS), health-related quality of life (HR-QoL), caregiver burden, and serious adverse events (SAEs). Outcomes from baseline to month (M) 12 are presented.

Results

In this 12-month follow-up, patients (N = 195) had baseline characteristics similar to other LCIG studies. Significant improvements (mean change to M12) were observed in off time (-3.9 ± 3.6 hr/day, P < 0.001), dyskinesia assessed using the UDysRS (-9.6 ± 22.5, P < 0.001), NMSS (-23.1 ± 41.4, P < 0.001), sleep and sleepiness symptoms on the PDSS-2 (-6.5 ± 12.2, P < 0.001) and ESS (-1.0 ± 5.7, P < 0.05), HR-QoL (-9.0 ± 21.6, P < 0.001), and caregiver burden (-1.9 ± 6.7, P = 0.008). Overall, 40.5% (n = 79) of patients experienced SAEs; fall (n = 6; 3.1%) and urinary tract infection (n = 6; 3.1%) were SAEs reported in ≥3% of patients.

Conclusions

These 12-month outcome data show sustained, long-term improvements and support the real-world effectiveness of LCIG in patients with advanced PD. Safety was consistent with previous studies.

Current Update on Clinically Relevant Sleep Issues in Parkinson's Disease: A Narrative Review

Sleep disturbances are among the common nonmotor symptoms in patients with Parkinson’s disease (PD). Sleep can be disrupted by nocturnal motor and nonmotor symptoms and other comorbid sleep disorders. Rapid eye movement sleep behavior disorder (RBD) causes sleep-related injury, has important clinical implications as a harbinger of PD and predicts a progressive clinical phenotype. Restless legs syndrome (RLS) and its related symptoms can impair sleep initiation. Excessive daytime sleepiness (EDS) is a refractory problem affecting patients’ daytime activities. In particular, during the COVID-19 era, special attention should be paid to monitoring sleep problems, as infection-prevention procedures for COVID-19 can affect patients’ motor symptoms, psychiatric symptoms and sleep. Therefore, screening for and managing sleep problems is important in clinical practice, and the maintenance of good sleep conditions may improve the quality of life of PD patients. This narrative review focused on the literature published in the past 10 years, providing a current update of various sleep disturbances in PD patients and their management, including RBD, RLS, EDS, sleep apnea and circadian abnormalities.

Personalised Advanced Therapies in Parkinson's Disease: The Role of Non-Motor Symptoms Profile

Device-aided therapies, including levodopa-carbidopa intestinal gel infusion, apomorphine subcutaneous infusion, and deep brain stimulation, are available in many countries for the management of the advanced stage of Parkinson’s disease (PD). Currently, selection of device-aided therapies is mainly focused on patients’ motor profile while non-motor symptoms play a role limited to being regarded as possible exclusion criteria in the decision-making process for the delivery and sustenance of a successful treatment. Differential beneficial effects on specific non-motor symptoms of the currently available device-aided therapies for PD are emerging and these could hold relevant clinical implications. In this viewpoint, we suggest that specific non-motor symptoms could be used as an additional anchor to motor symptoms and not merely as exclusion criteria to deliver bespoke and patient-specific personalised therapy for advanced PD.

Implications of dopaminergic medication withdrawal in Parkinson's disease

The trajectory of the use of dopamine replacement therapy (DRT) in Parkinson's disease (PD) is variable and doses may need to be increased, but also tapered. The plan for dose adjustment is usually done as per drug information recommendations from the licensing bodies, but there are no clear guidelines with regards to the best practice regarding the tapering off schedule given sudden dose reductions of drugs such as dopamine agonists may have serious adverse consequences. A systematic literature search was, therefore, performed to derive recommendations and the data show that there are no controlled studies or evidence-based recommendations how to taper or discontinue PD medication in a systematic manner. Most of the data were available on the dopamine agonist withdrawal syndrome (DAWS) and we found only two instructions on how to reduce pramipexole and rotigotine published by the EMA. We suggest that based on the available data, levodopa, dopamine agonists (DA), and amantadine should not be discontinued abruptly. Abrupt or sudden reduction of DA or amantadine in particular can lead to severe life-threatening withdrawal symptoms. Tapering off levodopa, COMT inhibitors, and MAO-B inhibitors may worsen motor and non-motor symptoms. Based on our clinical experience, we have proposed how to reduce PD medication and this work will form the basis of a future Delphi panel to define the recommendations in a consensus.

Parkinson's Disease: Personalized Pathway of Care for Device-Aided Therapies (DAT) and the Role of Continuous Objective Monitoring (COM) Using Wearable Sensors

Parkinson’s disease (PD) is a chronic, progressive neurological disorder and the second most common neurodegenerative condition. Advanced PD is complicated by erratic gastric absorption, delayed gastric emptying in turn causing medication overload, and hence the emergence of motor and non-motor fluctuations and dyskinesia, which is initially predictable and then becomes unpredictable. As the patient progresses to the advanced stage, advanced Parkinson’s disease (APD) is characterized by refractory motor and non motor fluctuations, unpredictable OFF periods, and troublesome dyskinesias. The management of APD is a complex affair. There is growing recognition that GI dysfunction is common in PD, with virtually the entire GI system (the upper and lower GI tracts) causing problems from dribbling to defecation. The management of PD should focus on personalized care addressing both motor and non-motor symptoms, ideally including not only dopamine replacement but also associated non-dopaminergic circuits, particularly focusing on noradrenergic, serotonergic, and cholinergic therapies bypassing the gastrointestinal tract (GIT) by infusion or device-aided therapies (DAT), including levodopa–carbidopa intestinal gel infusion, apomorphine subcutaneous infusion, and deep brain stimulation, which are available in many countries for the management of the advanced stage of Parkinson’s disease (APD). The PKG (KinetiGrap) can be used as a continuous objective monitoring (COM) aid, as a screening tool to help to identify advanced PD (APD) patients suitable for DAT, and can thus improve clinical outcomes.

The Effects of Yoga on Patients with Parkinson's Disease: A Meta-Analysis of Randomized Controlled Trials

Methods

A meta-analysis was conducted by systematically searching PubMed, Embase, and Cochrane Library databases till August 2020 for studies published in English. The reference lists of eligible studies were also searched. The motor symptoms (UPDRS-Part III), balance function (BBS and BESTest), functional mobility (TUG), anxiety (HADS and BAI), depression (HADS and BDI), and the quality of life (PDQ-39 and PDQ-8) were the primary evaluation indexes.

Results

Ten studies including 359 participants were included in this meta-analysis. The pooled results showed significant difference between the yoga training group and the control group. Patients in the yoga training group had better functional outcomes in terms of motor status (MD = −5.64; 95% CI, -8.57 to -2.7), balance function (SMD = 0.42; 95% CI, 0.08 to 0.77), functional mobility (MD = −1.71; 95% CI, -2.58 to -0.84), anxiety scale scores (SMD = −0.72; 95% CI, -1.01 to -0.43), depression scale scores (SMD = −0.92; 95% CI, -1.22 to -0.62), and QoL (SMD = −0.54; 95% CI, -0.97 to -0.11).

Conclusion

Our pooled results showed the benefits of yoga in improving motor function, balance, functional mobility, reducing anxiety and depression, and increasing QoL in PD patients.

Frequency of Non-motor Symptoms in Parkinson's Patients With Motor Fluctuations

Background: Non-motor symptoms (NMS), including neuropsychiatric, sleep, autonomic, and sensory domains, are an integral aspect of the clinical presentation of Parkinson disease (PD) and affect neurocognitive functioning as well as patients' and caregivers' well-being.

Objective: To describe the occurrence of NMS in PD patients with motor fluctuations in real-life condition.

Methods: The present study is a secondary analysis of a previous multinational, multicenter, retrospective-prospective cohort observational study (SYNAPSES). Patients with PD diagnosis and motor fluctuations aged ≥18 years were included. Data collected at the baseline visit were used for this study, and descriptive analyzes were conducted to describe the distribution of NMS in motor-fluctuating PD patients distributed according to different clinical characteristics.

Results: Of the 1,610 patients enrolled, 1,589 were included for the analysis (978 males and 611 females), with a mean age of 68.4 (SD = 9.6). Most patients had at least one NMS (88.5%). Sleep problems and psychiatric symptoms were the most prevalent NMS in motor fluctuating PD patients in all H and Y stages. Psychiatric disorders were more frequent in older patients and in patients with a larger number of years of PD diagnosis, while sleep problems were more preeminent in younger patients and with inferior disease duration.

Conclusions: The present findings further support the high prevalence of NMS in PD patients with motor fluctuations, thus reinforcing the need for assessing them for diagnostic accuracy and for delivering holistic care.

Recent advances in the pathology of prodromal non-motor symptoms olfactory deficit and depression in Parkinson's disease: clues to early diagnosis and effective treatment

Parkinson’s disease (PD) is a progressive neurodegenerative disease characterized by movement dysfunction due to selective degeneration of dopaminergic neurons in the substantia nigra pars compacta. Non-motor symptoms of PD (e.g., sensory dysfunction, sleep disturbance, constipation, neuropsychiatric symptoms) precede motor symptoms, appear at all stages, and impact the quality of life, but they frequently go unrecognized and remain untreated. Even when identified, traditional dopamine replacement therapies have little effect. We discuss here the pathology of two PD-associated non-motor symptoms: olfactory dysfunction and depression. Olfactory dysfunction is one of the earliest non-motor symptoms in PD and predates the onset of motor symptoms. It is accompanied by early deposition of Lewy pathology and neurotransmitter alterations. Because of the correlation between olfactory dysfunction and an increased risk of progression to PD, olfactory testing can potentially be a specific diagnostic marker of PD in the prodromal stage. Depression is a prevalent PD-associated symptom and is often associated with reduced quality of life. Although the pathophysiology of depression in PD is unclear, studies suggest a causal relationship with abnormal neurotransmission and abnormal adult neurogenesis. Here, we summarize recent progress in the pathology of the non-motor symptoms of PD, aiming to provide better guidance for its effective management.

Switch from rasagiline to safinamide in fluctuating Parkinson's disease patients: a retrospective, pilot study

Besides the inhibition of monoamine-oxidase-B, high-dose safinamide (100 mg) also blocks voltage-gated Na⁺ and Ca⁺⁺ channels and inhibits glutamate release at overactive synapses. This latter mechanism may provide further benefit to fluctuating Parkinson's disease (PD) patients compared to rasagiline. Here, we retrospectively investigated the consequences of shifting from rasagiline to high-dose safinamide in PD patients reporting symptoms of wearing-off, defined by the Wearing-Off-Questionnaire-19 (WOQ-19) score ≥3 at baseline. Seventeen PD patients were switched from rasagiline 1 mg to safinamide 100 mg because of the report of symptoms of fluctuations while under therapy with either levodopa+rasagiline or levodopa+rasagiline+dopamine agonists, or re-occurrence of fluctuations previously corrected by add-on with rasagiline. Patients were re-evaluated 4-6 months after switch. Switch to safinamide 100 mg produced benefit in 9/17 (52.9%) subjects, together with significant reduction of subjective symptoms of wearing-off. There was no report of adverse events. Findings from this retrospective, exploratory study suggest that safinamide 100 mg may produce more powerful benefit that rasagiline 1 mg as add-on to levodopa in fluctuating PD patients, possibly because of the bimodal mechanism of action of the former drug.

Helicobacter pylori eradication improves motor fluctuations in advanced Parkinson's disease patients: A prospective cohort study (HP-PD trial)

BACKGROUND

Helicobacter pylori (HP) is a bacterium associated with many gastrointestinal (GI) diseases and has shown a high prevalence in Parkinson's disease (PD). As HP-associated GI dysfunction could affect L-dopa (levodopa) absorption, HP eradication might improve the clinical response and decrease motor fluctuations.

METHODS

A prospective cohort study was conducted on the clinical symptoms of PD patients with motor fluctuations. The 13C-urea breath test was used to diagnose a current HP infection. All patients with HP infection received a 2-week regimen of triple therapy. The changes in the Unified Parkinson's Disease Rating Scale (UPDRS) motor score, L-dopa onset time, wearing-off symptoms, mean daily on-off time, GI symptom scores, and quality of life score were measured at baseline and at a 6-week follow-up.

RESULTS

A total of 163 PD patients were assessed, of whom 40 were enrolled. Fifty-five percent of the enrolled patients (22/40) had a current HP infection, whereas HP eradication was identified in 17 of 22 (77.3%) patients who received eradication therapy. Patients with HP eradication showed a significant decrease in daily 'off' time (4.0 vs. 4.7 h, p = 0.040) and an increase in daily 'on' time (11.8 vs. 10.9 h, p = 0.009). Total wearing-off score (4.4 vs. 6.0, p = 0.001) and the GI symptom score (8.1 vs. 12.8, p = 0.007) were significantly improved. There was no significant improvement in L-dopa onset time, UPDRS motor score, or quality of life score.

CONCLUSIONS

HP eradication leads to significant clinical improvement in the symptoms of PD. Eradication of HP not only increases the total daily 'on' time but also decreases wearing-off symptoms and improves GI symptoms.

Evidence-Based Guidelines and Secondary Meta-Analysis for the Use of Transcranial Direct Current Stimulation in Neurological and Psychiatric Disorders

BACKGROUND

Transcranial direct current stimulation has shown promising clinical results, leading to increased demand for an evidence-based review on its clinical effects.

OBJECTIVE

We convened a team of transcranial direct current stimulation experts to conduct a systematic review of clinical trials with more than 1 session of stimulation testing: pain, Parkinson's disease motor function and cognition, stroke motor function and language, epilepsy, major depressive disorder, obsessive compulsive disorder, Tourette syndrome, schizophrenia, and drug addiction.

METHODS

Experts were asked to conduct this systematic review according to the search methodology from PRISMA guidelines. Recommendations on efficacy were categorized into Levels A (definitely effective), B (probably effective), C (possibly effective), or no recommendation. We assessed risk of bias for all included studies to confirm whether results were driven by potentially biased studies.

RESULTS

Although most of the clinical trials have been designed as proof-of-concept trials, some of the indications analyzed in this review can be considered as definitely effective (Level A), such as depression, and probably effective (Level B), such as neuropathic pain, fibromyalgia, migraine, post-operative patient-controlled analgesia and pain, Parkinson's disease (motor and cognition), stroke (motor), epilepsy, schizophrenia, and alcohol addiction. Assessment of bias showed that most of the studies had low risk of biases, and sensitivity analysis for bias did not change these results. Effect sizes vary from 0.01 to 0.70 and were significant in about 8 conditions, with the largest effect size being in postoperative acute pain and smaller in stroke motor recovery (nonsignificant when combined with robotic therapy).

CONCLUSION

All recommendations listed here are based on current published PubMed-indexed data. Despite high levels of evidence in some conditions, it must be underscored that effect sizes and duration of effects are often limited; thus, real clinical impact needs to be further determined with different study designs.

The role of gut dysbiosis in Parkinson's disease: mechanistic insights andtherapeutic options

Parkinson's disease is a common neurodegenerative disease in which gastrointestinal symptoms may appear prior to motor symptoms. The gut microbiota of patients with Parkinson's disease shows unique changes, which may be used as early biomarkers of disease. Alteration in gut microbiota composition may be related to the cause or effect of motor or non-motor symptoms, but the specific pathogenic mechanisms are unclear. The gut microbiota and its metabolites have been suggested to be involved in the pathogenesis of Parkinson's disease by regulating neuroinflammation, barrier function and neurotransmitter activity. There is bidirectional communication between the enteric nervous system and the central nervous system, and the microbiota-gut-brain axis may provide a pathway for the transmission of α-synuclein. We highlight recent discoveries and alterations of the gut microbiota in Parkinson's disease, and highlight current mechanistic insights on the microbiota-gut-brain axis in disease pathophysiology. We discuss the interactions between production and transmission of α-synuclein and gut inflammation and neuroinflammation. In addition, we also draw attention to diet modification, use of probiotics and prebiotics and fecal microbiota transplantation as potential therapeutic approaches that may lead to a new treatment paradigm for Parkinson's disease.

Coadministration With Carbidopa Enhances the Antimyopic Effects of Levodopa in Chickens

Purpose

Topical application of levodopa inhibits the development of form-deprivation myopia (FDM) and lens-induced myopia (LIM) in chicks. Here we examine whether coadministration with carbidopa enhances this protection and compare the effectiveness of topical versus systemic administration. We also investigate the degree to which topical and systemic administration of these compounds alters retinal dopamine release and examine whether this is the mechanism by which they inhibit experimental myopia.

Methods

Levodopa and levodopa:carbidopa (at a 4:1 ratio) were administered as twice-daily eye drops or once-daily intraperitoneal injections to chicks developing FDM or LIM over an ascending dose range. Axial length and refraction were measured following 4 days of treatment. Dopamine levels in the vitreous and blood were analyzed using liquid chromatography-mass spectrometry following topical or systemic administration of levodopa or levodopa:carbidopa. Finally, chicks receiving topical or systemic levodopa or levodopa:carbidopa were cotreated with the dopamine antagonist spiperone.

Results

Levodopa:carbidopa inhibited the development of FDM and LIM to a greater extent than levodopa alone (P < 0.05). Topical application was more effective than systemic administration (P < 0.001). Vitreal dopamine levels were increased to the greatest extent by topical application of levodopa:carbidopa (P < 0.001). Systemic but not topical administration significantly increased dopamine levels within the blood (P < 0.01). Cotreatment with spiperone inhibited the antimyopic effects (P < 0.05) of levodopa and levodopa:carbidopa.

Conclusions

The presence of carbidopa increases the bioavailability of levodopa within the eye, enhancing its antimyopic effects, with topical application showing the greatest efficacy. Thus levodopa:carbidopa may be a promising treatment for controlling the progression of human myopia.

Non-motor symptoms in essential tremor, akinetic rigid and tremor-dominant subtypes of Parkinson's disease

Objectives

To compare non-motor symptoms (NMSs) among patients with essential tremor (ET), Parkinson’s disease (PD) subtypes (akinetic-rigid type (ART) and tremor-dominant type (TDT)), and healthy controls.

Patients and methods

This retrospective study included 129 participants, 72 PD (33 PD-ART, 33 PD-TDT, and 6 Mixed), 29 ET patients, and 28 controls. PD patients were assessed by the unified Parkinson’s disease rating scale (UPDRS), Hoehn, and Yahr scale (H&Y), while ET patients were evaluated by the Fahn Tolosa Marin Tremor Rating Scale. All subjects were evaluated by non-motor symptoms scale (NMSS) for NMSs and Beck depression inventory (BDI) for depression.

Results

PD subtypes groups, ET, and controls were age and gender-matched. Compared to controls, all PD, PD subtypes, and ET showed significantly worse most of NMSs (p<0.001) and depression. Compared to ET, all PD and PD-ART had significantly worse gastrointestinal (p = 0.002), urinary symptoms (p = 0.001, p = 0.003) and depression (p = 0.002) and PD-TDT worse depression, while ET patients showed worse memory/attention than PD subtypes. Total NMSS of ET is highly correlated to depression and moderately to tremor severity and age of onset, while total of NMSS is highly correlated to depression, disease severity, and disability.

Conclusion

The current study demonstrated several comparable domains of NMSs of PD subtypes and ET, except worse gastrointestinal and urinary symptoms among PD-ART. Identifying different NMSs profiles is important for predicting, better assessing, and tailoring management of ET and PD subtypes.

[Deep brain stimulation for Parkinson's disease]

Deep brain stimulation is an established and evidence-based therapeutic option for the treatment of advanced Parkinson's disease. Main indication and inclusion criteria are the presence of idiopathic Parkinsonism with motor fluctuations and / or dyskinesias and / or with medication refractory tremor, a significant improvement of akinesia / rigidity in response to dopaminergic medication, the absence of relevant cognitive deficits and other significant comorbidities. DBS neurosurgery has a low risk of complications. The clinical programming should follow an established monopolar review algorithm. Regular follow-up visits are required for stimulation monitoring.

Glial Nrf2 signaling mediates the neuroprotection exerted by Gastrodia elata Blume in Lrrk2-G2019S Parkinson's disease

The most frequent missense mutations in familial Parkinson's disease (PD) occur in the highly conserved LRRK2/PARK8 gene with G2019S mutation. We previously established a fly model of PD carrying the LRRK2-G2019S mutation that exhibited the parkinsonism-like phenotypes. An herbal medicine, Gastrodia elata Blume (GE), has been reported to have neuroprotective effects in toxin-induced PD models. However, the underpinning molecular mechanisms of GE beneficiary to G2019S-induced PD remain unclear. Here, we show that these G2019S flies treated with water extracts of GE (WGE) and its bioactive compounds, gastrodin and 4-HBA, displayed locomotion improvement and dopaminergic neuron protection. WGE suppressed the accumulation and hyperactivation of G2019S proteins in dopaminergic neurons and activated the antioxidation and detoxification factor Nrf2 mostly in the astrocyte-like and ensheathing glia. Glial activation of Nrf2 antagonizes G2019S-induced Mad/Smad signaling. Moreover, we treated LRRK2-G2019S transgenic mice with WGE and found that the locomotion declines, the loss of dopaminergic neurons, and the number of hyperactive microglia were restored. WGE also suppressed the hyperactivation of G2019S proteins and regulated the Smad2/3 pathways in the mice brains. We conclude that WGE prevents locomotion defects and the neuronal loss induced by G2019S mutation via glial Nrf2/Mad signaling, unveiling a potential therapeutic avenue for PD.

Therapeutic Strategies to Treat or Prevent Off Episodes in Adults with Parkinson's Disease

Parkinson's disease is a chronic, neurodegenerative disease, which manifests with a mixture of motor, cognitive and behavioural symptoms. Levodopa is the most effective antiparkinsonian treatment to date, although chronic use engenders a mixture of complications in a substantial proportion of patients. Amongst these is the occurrence of episodes of worsening symptoms-'off' phenomena. These episodes can manifest with either motor or non-motor symptoms or a combination of these features and have been found to have profound impacts on patients' quality of life. Although preventative measures are poorly evidenced, avoiding excessive total daily levodopa intake in selected populations that are deemed to be of a higher risk for developing these episodes warrants further exploration. Methods to improve levodopa bioavailability and delivery to the brain are currently available and are of value in addressing these episodes once they have become established. These include modifications to levodopa formulations as well as the use of complimentary agents that improve levodopa bioavailability. The deployment of device-assisted approaches is a further dimension that can be considered in addressing these debilitating episodes. This review summarises the clinical manifestations of 'off' phenomena and the current approaches to treat them. Although we briefly discuss clinical advances on the horizon, the predominant focus is on existing, established treatments.

Pharmacogenetic profile and the development of the dyskinesia induced by levodopa-therapy in Parkinson's disease patients: a population-based cohort study

Levodopa-induced dyskinesia (LID) is an adverse effect that negatively impacts the quality of life of patients with Parkinson's disease (PD). Studies report that genetic variations in the genes of the pharmacogenetic pathway of the levodopa (L-DOPA) might be associated with LID development. The goal of the present study was to investigate a possible influence of functional genetic variants in the DRD1 (rs4532), DRD2 (rs1800497), DAT1 (rs28363170), and COMT (rs4680) genes with LID development. A total of 220 patients with idiopathic PD were enrolled. The genotyping for DRD1 (rs4532), DRD2 (rs1800497), DAT1 (rs28363170), and COMT (rs4680) polymorphisms were performed using Restriction Fragment Length Polymorphism (PCR-RFLP). Univariate and multivariate analyses were performed to assess the association of these polymorphisms and risk factors with LID development. Multivariate Cox regression analysis showed increased risk to LID development for both Levodopa Dose Equivalency (LED) (Hazard ratios (HR) = 1.001; 95% CI 1.00-1.01; p = 0.009) and individuals carrying the COMT L/L genotype (HR = 2.974; 95% CI 1.12-7.83; p = 0.010). Furthermore, when performed a Cox regression analysis adjusted for a total LED, we observed that the genotype COMT L/L had a 3.84-fold increased risk for LID development (HR = 3.841; 95% CI 1.29-11.37; p = 0.012). Our results suggest that before treating LID in PD patients, it is important to take into consideration genetic variant in the COMT gene, since COMT LL genotype may increase the risk for LID development.