The Emergence and Progression of Motor Dysfunction in Individuals at Risk of Parkinson's Disease.

BACKGROUND: PREDICT-PD is a United Kingdom population-based study aiming to stratify individuals for future Parkinson's disease (PD) using a risk algorithm. METHODS: A randomly selected, representative sample of participants in PREDICT-PD were examined using several motor assessments, including the motor section of the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS)-III, at baseline (2012) and after an average of 6 years of follow-up. We checked for new PD diagnoses in participants seen at baseline and examined the association between risk scores and incident sub-threshold parkinsonism, motor decline (increasing ≥5 points in MDS-UPDRS-III) and single motor domains in the MDS-UPDRS-III. We replicated analyses in two independent datasets (Bruneck and Parkinson's Progression Markers Initiative [PPMI]). RESULTS: After 6 years of follow-up, the PREDICT-PD higher-risk group (n = 33) had a greater motor decline compared with the lower-risk group (n = 95) (30% vs. 12.5%, P = 0.031). Two participants (both considered higher risk at baseline) were given a diagnosis of PD during follow-up, with motor signs emerging between 2 and 5 years before diagnosis. A meta-analysis of data from PREDICT-PD, Bruneck, and PPMI showed an association between PD risk estimates and incident sub-threshold parkinsonism (odds ratio [OR], 2.01 [95% confidence interval (CI), 1.55-2.61]), as well as new onset bradykinesia (OR, 1.69 [95% CI, 1.33-2.16]) and action tremor (OR, 1.61 [95% CI, 1.30-1.98]). CONCLUSIONS: Risk estimates using the PREDICT-PD algorithm were associated with the occurrence of sub-threshold parkinsonism, including bradykinesia and action tremor. The algorithm could also identify individuals whose motor examination experience a decline over time. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Comparison of different risk scores for Parkinson disease in a population-based 10-year study.

BACKGROUND AND PURPOSE: Different algorithms aiming to identify individuals at risk of Parkinson disease (PD) have been proposed. Comparative studies of these scores and their recent updates in the general elder population are needed. METHODS: We have previously applied the "basic" PREDICT-PD algorithm, designed for remote screening, and the original and updated Movement Disorder Society (MDS) criteria for prodromal PD to the longitudinal population-based Bruneck study cohort. We have now additionally employed the "enhanced" PREDICT-PD algorithm (which includes motor assessment, olfaction, probable rapid eye movement sleep behaviour disorder status, pesticide exposure, and diabetes as additional factors). Risk scores were calculated based on comprehensive baseline assessments (2005) in 574 subjects aged 55-94 years (290 females), and cases of incident PD were identified at 5-year (n = 11) and 10-year follow-up (n = 9). We analysed the association of the different log-transformed risk scores with incident PD at follow-up (calculated per 1-SD unit change). RESULTS: The enhanced PREDICT-PD algorithm was associated with incident PD over 10-years of follow-up, yielding higher odds for incident PD (odds ratio [OR] = 4.61, 95% confidence interval [CI] = 2.68-7.93, p < 0.001) compared with the basic PREDICT-PD score (OR = 2.38, 95% CI = 1.49-3.79, p < 0.001). The updated MDS prodromal criteria yielded a numerically higher OR of 7.13 (95% CI = 3.49-14.54, p < 0.001) in comparison with the original criteria as well as the enhanced PREDICT-PD algorithm, with overlapping 95% CIs. CONCLUSIONS: The enhanced PREDICT-PD algorithm was significantly associated with incident PD. The consistent performance of both the enhanced PREDICT-PD algorithm and the updated MDS prodromal criteria compared to their original versions supports their use in PD risk screening.

Associations of Gait Disorders and Recurrent Falls in Older People: A Prospective Population-Based Study.

BACKGROUND: Recurrent falls represent a major source of serious adverse health outcomes in the general older population. Gait impairment has been linked to recurrent falls, but there are only limited long-term data on this association. OBJECTIVES: The objective of the study was to investigate the association of gait disorders (GDs) and gait tests with future falls in an existing longitudinal population-based cohort. METHOD: The study was performed in participants of the Bruneck Study cohort 2010 aged 60-97 years, with prospective 5-year follow-up. At baseline, participants underwent a clinical gait assessment (to determine neurological and non-neurological GDs according to an established classification) and were also evaluated by quantitative and semiquantitative gait tests (Hauser Index, Tinetti balance and gait test, and gait speed). Logistic regression analysis adjusted for age and sex was used to determine the relationship of baseline variables with incident recurrent falls at 5-year follow-up. RESULTS: Of 328 included participants, 22 (6.7%) reported recurrent falls at follow-up. Baseline presence of GDs was associated with recurrent falls at follow-up (odds ratio [OR] 4.2; 95% confidence interval [CI] 1.6-11.1; p = 0.004), and this effect was largely driven by neurological GDs (OR 5.5; 95% CI 1.7-17.4; p = 0.004). All 3 simple gait tests were predictive for incident falls (Hauser Index, p = 0.002; Tinetti test, p = 0.006; and gait speed, p < 0.001). CONCLUSIONS: Clinical assessment of GDs and gait tests both had independent significant predictive value for recurrent falls over a 5-year follow-up period. This highlights the potential of such assessments for early fall risk screening and timely implementation of fall-preventive measures.

Non-Motor Symptoms in Parkinson's Disease are Reduced by Nabilone.

OBJECTIVE: The objective of this study was to assess the efficacy and safety of nabilone, a synthetic tetrahydrocannabinol analogue, as a treatment for non-motor symptoms (NMS) in Parkinson's disease (PD). METHODS: This was a phase II placebo-controlled, double-blind, parallel-group, enriched enrollment randomized withdrawal trial conducted at the Medical University Innsbruck. A random sample of 47 patients with PD with stable motor disease and disturbing NMS defined by a score of ≥4 points on the Movement Disorder Society - Unified PD Rating Scale-I (MDS-UPDRS-I) underwent open-label nabilone titration (0.25 mg once daily to 1 mg twice daily, phase I). Responders were randomized 1:1 to continue with nabilone or switch to placebo for 4 weeks (phase II). The primary efficacy criterion was the change of the MDS-UPDRS-I between randomization and week 4. Safety was analyzed in all patients who received at least one nabilone dose. RESULTS: Between October 2017 and July 2019, 19 patients received either nabilone (median dose = 0.75 mg) or placebo. At week 4, mean change of the MDS-UPDRS-I was 2.63 (95% confidence interval [CI] 1.53 to 3.74, p = 0.002, effect size = 1.15) in the placebo versus 1.00 (95% CI -0.16 to 2.16, p = 0.280, effect size = 0.42) in the nabilone-group (difference: 1.63, 95% CI 0.09 to 3.18, p = 0.030, effect size = 0.66). Seventy-seven percent of patients had adverse events (AEs) during open-label titration, most of them were transient. In the double-blind phase, similar proportions of patients in each group had AEs (42% in the placebo group and 32% in the nabilone group). There were no serious AEs. INTERPRETATION: Our results highlight the potential efficacy of nabilone for patients with PD with disturbing NMS, which appears to be driven by positive effects on anxious mood and night-time sleep problems. TRIAL REGISTRY: ClinicalTrials.gov (NCT03769896) and EudraCT (2017-000192-86). ANN NEUROL 2020;88:712-722.

Application of a Simple Parkinson's Disease Risk Score in a Longitudinal Population-Based Cohort.

BACKGROUND: Identifying individuals at risk of developing Parkinson's disease (PD) is critical to define target populations for future neuroprotective trials. OBJECTIVE: The objective of this study was to apply the PREDICT-PD algorithm of risk indicators for PD in a prospective community-based study (the Bruneck study), representative of the general elderly population. METHODS: PREDICT-PD risk scores were calculated based on risk factor assessments obtained at baseline (2005, n = 574 participants). Cases of incident PD were identified at 5-year and 10-year follow-ups. Participants with PD or secondary parkinsonism at baseline were excluded (n = 35). We analyzed the association of log-transformed risk scores with the presence of well-established markers as surrogates for PD risk at baseline and with incident PD at follow-up. RESULTS: A total of 20 participants with incident PD were identified during follow-up (11 after 5 years and 9 after 10 years). Baseline PREDICT-PD risk scores were associated with incident PD with odds ratios of 2.09 (95% confidence interval, 1.35-3.25; P = 0.001) after 5 years and of 1.95 (1.36-2.79; P < 0.001) after 10 years of follow-up per doubling of risk scores. In addition, higher PREDICT-PD scores were significantly correlated with established PD risk markers (olfactory dysfunction, signs of rapid eye movement sleep behavior disorder and motor deficits) and significantly associated with higher probability for prodromal PD according to the Movement Disorder Society research criteria at baseline. CONCLUSIONS: The PREDICT-PD score was associated with an increased risk for incident PD in our sample and may represent a useful first screening step in future algorithms aiming to identify cases of prodromal PD. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Prevalence and Associated Factors of Sarcopenia and Frailty in Parkinson's Disease: A Cross-Sectional Study.

BACKGROUND: Sarcopenia and frailty are found in up to one-third of the general elderly population. Both are associated with major adverse health outcomes such as nursing home placement, disability, decreased quality of life, and death. Data on the frequency of both syndromes in Parkinson's disease (PD), however, are very limited. OBJECTIVE: We aimed to screen for sarcopenia and frailty in PD patients and to assess potential associations of both geriatric syndromes with demographic and clinical parameters as well as quality of life. METHODS: In this observational, cross-sectional study, we included 104 PD patients from a tertiary center and 330 non-PD controls from a population-based cohort aged > 65 years. All groups were screened for sarcopenia using the SARC-F score and for frailty using the Clinical Frailty Scale of the Canadian Study of Health and Aging (CSHA CFS). Prevalence rates of sarcopenia and frailty were also assessed in 18 PD patients from a population-based cohort aged > 65 years. Moreover, PD patients from the tertiary center were evaluated for motor and non-motor symptoms, quality of life, and dependency. RESULTS: The prevalence of sarcopenia was 55.8% (95% CI: 46.2-64.9%) in PD patients from the tertiary center and 8.2% (5.7-11.7%; p < 0.001) in non-PD controls. Frailty was detected in 35.6% (27.0-45.2%) and 5.2% (3.2-8.1%; p < 0.001). Prevalence rates for sarcopenia and frailty were 33.3% (16.1-56.4%; p = 0.004) and 22.2% (8.5-45.8%; p = 0.017) in the community-based PD sample. Both sarcopenia and frailty were significantly associated with longer disease duration, higher motor impairment, higher Hoehn and Yahr stages, decreased quality of life, higher frequency of falls, a higher non-motor symptom burden, institutionalization, and higher care levels in PD patients from a tertiary center compared to not affected PD patients (all p < 0.05). CONCLUSIONS: Both frailty and sarcopenia are more common in PD patients than in the general community and are associated with a more adverse course of the disease. Future studies should look into underlying risk factors for the occurrence of sarcopenia and frailty in PD patients and into adequate management to prevent and mitigate them.

Long-term safety and efficacy of open-label nabilone on sleep and pain in Parkinson´s Disease.

The synthetic tetrahydrocannabinol-analog nabilone improved non-motor symptoms (NMS) in Parkinson's disease (PD) patients in a placebo-controlled, double-blind, parallel-group, randomized withdrawal trial with enriched enrollment (NMS-Nab-study). This was a single-center open-label extension study to assess the long-term safety and efficacy of nabilone for NMS in PD. To be eligible for this study, patients had to be treatment responders during the previous NMS-Nab-trial and complete its double-blind phase without experiencing a drug-related serious/severe/moderate adverse event (AE). Patients were re-introduced to nabilone during an up-titration phase until their overall NMS burden improved. Nabilone was continued for six months with clinic visits every 3 months. Evaluation of AEs was based on self-report and clinical assessment. Twenty-two patients participated in the NMS-Nab2-study (age-median 68.33 y, 52% females, disease duration-median 7.42 y). Nabilone was well tolerated with concentration difficulties as the most common treatment-related AE (possibly/not related n = 1 each). One in two drop-outs discontinued because of an AE for which a prohibited concomitant medication needed to be introduced (night-time sleep problems). Efficacy evaluation showed a significant and lasting improvement in NMS burden according to the CGI-I (79% at V3). Nabilone improved overall sleep (NMSS Domain-2: -8.26 points; 95%CI -13.82 to -2.71; p = 0.004; ES = -0.72), night-time sleep problems (MDS-UPDRS-1.7: -1.42 points; 95 CI -2.16 to -0.68; p = 0.002; ES = -0.92), and overall pain (KPPS Total Score: -8.00 points; 95%CI -15.05 to -0.95; p = 0.046; ES -0.55 and MDS-UPDRS-1.9: -0.74 points; 95%CI -1.21 to -0.26; p = 0.008; ES = -0.74). This study demonstrates continuous long-term safety and efficacy in PD patients responding early to nabilone without intolerable side effects.

Temporal Muscle Thickness Correlates with Sarcopenia in Parkinson's Disease.

BACKGROUND: Sarcopenia is characterized by a progressive loss of muscle mass, strength, and function resulting in adverse health outcomes. Current assessment strategies are bothersome and means to simplify the diagnosis are an unmet medical need in Parkinson's disease (PD). OBJECTIVE: To evaluate temporal muscle thickness (TMT) obtained on routine cranial MRI as a surrogate marker of sarcopenia in PD patients. METHODS: We correlated TMT from axial non-contrast-enhanced T1-weighted sequences of MRI close (±12 months) to an outpatient visit including sarcopenia (EWGSOP1, EWGSOP2, SARC-F), frailty (Fried's criteria, clinical frailty scale), and disease characteristics of Parkinson's patients (Hoehn and Yahr-scale, Movement Disorder Society-Unified Parkinson's Disease Rating Scale, quality of life with the Parkinson's Disease Questionnaire-8) assessments. RESULTS: Cranial MRI was available in 32 patients with a mean age of 73.56±5.14 years, mean disease duration of 11.46±5.66 years, and median Hoehn and Yahr stage of 2.5. The mean TMT was 7.49±2.76 (7.15) mm. Mean TMT was significantly associated with sarcopenia (EWGSOP2, p = 0.018; EWGSOP1, p = 0.023) and frailty status (physical phenotype; p = 0.045). Moreover, there were significant moderate to strong correlations between TMT measurement and appendicular skeletal muscle mass index (r: 0.437, p = 0.012), as well as handgrip strength (r: 0.561, p < 0.001). CONCLUSION: Reduced TMT seems to be a promising surrogate marker for sarcopenia (EWGSOP2) and muscle strength in this pilot study in PD patients.

Prodromal Parkinson's disease: hype or hope for disease-modification trials?

The ultimate goal in Parkinson's disease (PD) research remains the identification of treatments that are capable of slowing or even halting the progression of the disease. The failure of numerous past disease-modification trials in PD has been attributed to a variety of factors related not only to choosing wrong interventions, but also to using inadequate trial designs and target populations. In patients with clinically established PD, neuronal pathology may already have advanced too far to be modified by any intervention. Based on such reasoning, individuals in yet prediagnostic or prodromal disease stages, may provide a window of opportunity to test disease-modifying strategies. There is now sufficient evidence from prospective studies to define diagnostic criteria for prodromal PD and several approaches have been studied in observational cohorts. These include the use of PD-risk algorithms derived from multiple established risk factors for disease as well as follow-up of cohorts with single defined prodromal markers like hyposmia, rapid eye movement sleep behavior disorders, or PD gene carriers. In this review, we discuss recruitment strategies for disease-modification trials in various prodromal PD cohorts, as well as potential trial designs, required trial durations, and estimated sample sizes. We offer a concluding outlook on how the goal of implementing disease-modification trials in prodromal cohorts might be achieved in the future.

Eye Tracking in Patients with Parkinson's Disease Treated with Nabilone-Results of a Phase II, Placebo-Controlled, Double-Blind, Parallel-Group Pilot Study.

The topic of the therapeutic use of cannabinoids in Parkinson's disease (PD) is broadly discussed and frequently comes up in the outpatient clinic. So far, there are only a few randomized clinical trials assessing the effects of cannabinoids in PD. We are able to demonstrate a reduction in non-motor symptom (NMS) burden after the administration of nabilone. As impairment of attention and working memory have been described earlier as possible side effects, we assess cognitive performance using saccadic paradigms measured by an eye tracker. We do not observe a significant difference in any of the saccadic paradigms between PD patients on placebo versus those treated with nabilone. We, therefore, conclude that top-down inhibitory control is not affected by the tetrahydrocannabinol analogue. Nabilone did not significantly worsen cognitive performance and appears to be safe to use in selected PD patients who suffer from disabling NMS.

Characterization of gait variability in multiple system atrophy and Parkinson's disease.

BACKGROUND: Gait impairment is a pivotal feature of parkinsonian syndromes and increased gait variability is associated with postural instability and a higher risk of falls. OBJECTIVES: We compared gait variability at different walking velocities between and within groups of patients with Parkinson-variant multiple system atrophy, idiopathic Parkinson's disease, and a control group of older adults. METHODS: Gait metrics were recorded in 11 multiple system atrophy, 12 Parkinson's disease patients, and 18 controls using sensor-based gait analysis. Gait variability was analyzed for stride, swing and stance time, stride length and gait velocity. Values were compared between and within the groups at self-paced comfortable, fast and slow walking speed. RESULTS: Multiple system atrophy patients displayed higher gait variability except for stride time at all velocities compared with controls, while Parkinson's patients did not. Compared with Parkinson's disease, multiple system atrophy patients displayed higher variability of swing time, stride length and gait velocity at comfortable speed and at slow speed for swing and stance time, stride length and gait velocity (all P < 0.05). Stride time variability was significantly higher in slow compared to comfortable walking in patients with multiple system atrophy (P = 0.014). Variability parameters significantly correlated with the postural instability/gait difficulty subscore in both disease groups. Conversely, significant correlations between variability parameters and MDS-UPDRS III score was observed only for multiple system atrophy patients. CONCLUSION: This analysis suggests that gait variability parameters reflect the major axial impairment and postural instability displayed by multiple system atrophy patients compared with Parkinson's disease patients and controls.

Rapid eye movement sleep behavior disorder and rapid eye movement sleep without atonia are more frequent in advanced versus early Parkinson's disease.

STUDY OBJECTIVES: To evaluate macro sleep architecture and characterize rapid eye movement (REM) sleep without atonia (RWA) by using the SINBAR excessive electromyographic (EMG) montage including mentalis and upper extremity muscles in early and advanced Parkinson's disease (PD). METHODS: We recruited 30 patients with early- and advanced-stage of PD according to Movement Disorder Society (MDS) Clinical Diagnostic Criteria. Participants were classified as early-stage PD if they were treatment-naïve or had no motor complications and had been diagnosed with PD within the previous 6 years. Advanced PD was defined as a disease duration equal to or >6 years with or without motor complications. RESULTS: There was significantly shorter REM sleep latency in early as compared to the advanced stage of PD. We found that the sleep Innsbruck Barcelona (SINBAR) EMG index and tonic EMG activity of the mentalis muscle in advanced-stage PD were significantly higher than in early-stage PD with a trend in phasic EMG activity of the flexor digitorum superficialis muscles. The SINBAR EMG index, tonic and any EMG activity of the mentalis muscle, and phasic EMG activity of flexor digitorum superficialis muscles significantly correlated with disease duration. CONCLUSIONS: This study analyzed RWA using the SINBAR EMG montage in early- and advanced-stage of PD and showed higher RWA in mentalis and flexor digitorum superficialis muscles and SINBAR EMG index in advanced-PD patients compared to patients in the early stage. Also, polysomnography-confirmed REM sleep behavior disorder was more common in advanced versus early-stage patients. Our findings suggest that RWA worsens or is more intense or more frequent with disease progression.

New hopes for disease modification in Parkinson's Disease.

To date, despite numerous clinical trials, no intervention has been demonstrated to modify the progression of Parkinson's disease (PD). However, over the past decades encouraging progress has been made towards a better understanding of molecular pathways relevant for the neurodegenerative process in PD. This is also based on new insights into the genetic architecture of the disease, revealing multiple novel targets for potentially disease-modifying interventions. Important achievements have also been made in the field of risk markers and combinations thereof, in the form of risk algorithms, will hopefully soon provide the possibility to identify affected individuals at yet prediagnostic or prodromal stages of the illness. Such phases of the disease would provide an ideal window for neuroprotection trials. Taken together, these developments offer hope that a breakthrough towards modifying the course of PD might be reached. In this article we summarize various approaches currently pursued in this quest. This article is part of the special issue entitled 'The Quest for Disease-Modifying Therapies for Neurodegenerative Disorders'.

Midbrain hyperechogenicity, hyposmia, mild parkinsonian signs and risk for incident Parkinson's disease over 10 years: A prospective population-based study.

INTRODUCTION: Associations of substantia nigra (SN) hyperechogenicity on transcranial sonography, olfactory dysfunction, and mild parkinsonian signs (MPS) with incident Parkinson's disease (PD) have only been studied over limited periods of follow-up and their long-term predictive properties are unclear. We aimed to prospectively assess the risk for incident PD over 10 years in community-dwelling elderly individuals with these risk markers. METHODS: SN-hyperechogenicity, olfactory function, and MPS were assessed in the prospective population-based Bruneck Study (2005 in-person assessment; n = 574, aged 55-94 years). Cases of incident PD were identified at 5-year and 10-year follow-up visits. We estimated relative risks of baseline markers for incident cases. RESULTS: After excluding 35 cases with PD or secondary parkinsonism at baseline, a total of 20 cases of incident PD were identified from the remaining 539 participants (11 at 5 years and 9 at 10 years). Relative risks for incident PD over the 10-year follow-up period were 7.43 (2.71-20.39), 3.60 (1.48-8.78), and 5.52 (2.43-12.57) for baseline SN-hyperechogenicity, hyposmia, and mild parkinsonian signs, respectively. While risk of hyposmia for incident PD was similar for the two sequential 5-year periods studied, relative risks of SN-hyperechogenicity and MPS were higher for the first five years as compared to later. CONCLUSION: Our findings extend the established risk relationship of SN-hyperechogenicity, hyposmia, and MPS with incident PD beyond 5 years of follow-up.