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.

Distinct smell and taste disorder phenotype of post-acute COVID-19 sequelae.

PURPOSE: Olfactory dysfunction (OD) commonly accompanies coronavirus disease 2019 (COVID-19). We investigated the kinetics of OD resolution following SARS-CoV-2 infection (wild-type and alpha variant) and its impact on quality of life, physical and mental health. METHODS: OD prevalence was assessed in an ambulatory COVID-19 survey (n = 906, ≥ 90 days follow-up) and an observational cohort of ambulatory and hospitalized individuals (n = 108, 360 days follow-up). Co-occurrence of OD with other symptoms and effects on quality of life, physical and mental health were analyzed by multi-dimensional scaling, association rule mining and semi-supervised clustering. RESULTS: Both in the ambulatory COVID-19 survey study (72%) and the observational ambulatory and hospitalized cohort (41%) self-reported OD was frequent during acute COVID-19. Recovery from self-reported OD was slow (survey: median 28 days, observational cohort: 90 days). By clustering of the survey data, we identified a predominantly young, female, comorbidity-free group of convalescents with persistent OD and taste disorders (median recovery: 90 days) but low frequency of post-acute fatigue, respiratory or neurocognitive symptoms. This smell and taste disorder cluster was characterized by a high rating of physical performance, mental health, and quality of life as compared with convalescents affected by prolonged fatigue or neurocognitive complaints. CONCLUSION: Our results underline the heterogeneity of post-acute COVID-19 sequelae calling for tailored management strategies. The persistent smell and taste disorder phenotype is characterized by good clinical, physical, and mental recovery and may pose a minor challenge for public health. STUDY REGISTRATION: ClinicalTrials.gov: NCT04661462 (survey study), NCT04416100 (observational cohort).

Factors associated with augmentation in patients with restless legs syndrome.

BACKGROUND AND PURPOSE: Augmentation is a paradoxical reaction mainly to dopaminergic medication in patients with restless legs syndrome (RLS), but the exact pathomechanism remains unclear. The aim of this study was to identify factors associated with augmentation in RLS patients. METHODS: RLS patients with and without current or previous augmentation were recruited. Demographic characteristics, history of smoking, questionnaires for depression, alexithymia, and impulsivity, and RLS severity were obtained. RESULTS: We included 122 patients, of whom half had a history of augmentation. Patients with augmentation had a longer disease duration (p = 0.001), had higher RLS severity scores (p = 0.013), had higher levodopa equivalent doses (p < 0.001), had higher scores for alexithymia (p = 0.028), had higher prevalence of impulse control disorders (p < 0.001), more often had a history of smoking (p = 0.039), were more often currently smoking (p = 0.015), and had more average pack-years (p = 0.016). CONCLUSIONS: Here, we describe several factors commonly associated with augmentation in RLS. These may help clinicians to screen and treat patients carefully to avoid the challenging side effect of augmentation.

Neurological outcomes 1 year after COVID-19 diagnosis: A prospective longitudinal cohort study.

BACKGROUND AND PURPOSE: Neurological sequelae from coronavirus disease 2019 (COVID-19) may persist after recovery from acute infection. Here, the aim was to describe the natural history of neurological manifestations over 1 year after COVID-19. METHODS: A prospective, multicentre, longitudinal cohort study in COVID-19 survivors was performed. At a 3-month and 1-year follow-up, patients were assessed for neurological impairments by a neurological examination and a standardized test battery including the assessment of hyposmia (16-item Sniffin' Sticks test), cognitive deficits (Montreal Cognitive Assessment < 26) and mental health (Hospital Anxiety and Depression Scale and Post-traumatic Stress Disorder Checklist 5). RESULTS: Eighty-one patients were evaluated 1 year after COVID-19, out of which 76 (94%) patients completed a 3-month and 1-year follow-up. Patients were 54 (47-64) years old and 59% were male. New and persistent neurological disorders were found in 15% (3 months) and 12% (10/81; 1 year). Symptoms at 1-year follow-up were reported by 48/81 (59%) patients, including fatigue (38%), concentration difficulties (25%), forgetfulness (25%), sleep disturbances (22%), myalgia (17%), limb weakness (17%), headache (16%), impaired sensation (16%) and hyposmia (15%). Neurological examination revealed findings in 52/81 (64%) patients without improvement over time (3 months, 61%, p = 0.230) including objective hyposmia (Sniffin' Sticks test <13; 51%). Cognitive deficits were apparent in 18%, whereas signs of depression, anxiety and post-traumatic stress disorders were found in 6%, 29% and 10% respectively 1 year after infection. These mental and cognitive disorders had not improved after the 3-month follow-up (all p > 0.05). CONCLUSION: Our data indicate that a significant patient number still suffer from neurological sequelae including neuropsychiatric symptoms 1 year after COVID-19 calling for interdisciplinary management of these patients.

Factors associated with impaired quality of life three months after being diagnosed with COVID-19.

PURPOSE: To assess patient characteristics associated with health-related quality of life (HR-QoL) and its mental and physical subcategories 3 months after diagnosis with COVID-19. METHODS: In this prospective multicentre cohort study, HR-QoL was assessed in 90 patients using the SF-36 questionnaire (36-item Short Form Health Survey), which consists of 8 health domains that can be divided into a mental and physical health component. Mental health symptoms including anxiety, depression, and post-traumatic stress disorders were evaluated using the Hospital Anxiety and Depression Scale (HADS) and Post-traumatic Stress Disorder Checklist-5 (PCL-5) 3 months after COVID-19. Using descriptive statistics and multivariable regression analysis, we identified factors associated with impaired HR-QoL 3 months after COVID-19 diagnosis. RESULTS: Patients were 55 years of age (IQR, 49-63; 39% women) and were classified as severe (23%), moderate (57%), or mild (20%) according to acute disease severity. HR-QoL was impaired in 28/90 patients (31%). Younger age [per year, adjOR (95%CI) 0.94 (0.88-1.00), p = 0.049], longer hospitalization [per day, adjOR (95%CI) 1.07 (1.01-1.13), p = 0.015], impaired sleep [adjOR (95%CI) 5.54 (1.2-25.61), p = 0.028], and anxiety [adjOR (95%CI) 15.67 (3.03-80.99), p = 0.001) were independently associated with impaired HR-QoL. Twenty-nine percent (n = 26) scored below the normal range on the mental health component of the SF-36 and independent associations emerged for anxiety, depression, and self-reported numbness. Impairments in the physical health component of the SF-36 were reported by 12 (13%) patients and linked to hypogeusia and fatigue. CONCLUSION: Every third patient reported a reduction in HR-QoL 3 months after COVID-19 diagnosis and impairments were more prominent in mental than physical well-being.

Cardiac sympathetic innervation in Parkinson's disease versus multiple system atrophy.

PURPOSE: The aims of this study were to evaluate the diagnostic accuracy of the dual imaging method combining cardiac iodine-123-metaiodobenzylguanidine single-photon emission computed tomography combined with low-dose chest computed tomography compared to routine cardiac scintigraphy, and assess regional differences in tracer distribution and the relationships between imaging and autonomic function in Parkinson's disease and multiple system atrophy. METHODS: A prospective study including 19 Parkinson's disease and 12 multiple system atrophy patients was performed. Patients underwent clinical evaluation, iodine-123-metaiodobenzylguanidine single-photon emission computed tomography combined with chest computed tomography, planar scintigraphy, and cardiovascular autonomic function tests. RESULTS: Co-registration of single-photon emission computed tomography and chest computed tomography resulted in three groups with distinct patterns of tracer uptake: homogeneous, non-homogeneously reduced and absent. There was a significant difference in group allocation among patients with multiple system atrophy and Parkinson's disease (p = 0.001). Most multiple system atrophy patients showed homogeneous uptake, and the majority of Parkinson's disease patients showed absent cardiac tracer uptake. We identified a pattern of heterogeneous cardiac tracer uptake in both diseases with reductions in the apex and the lateral myocardial wall. Sympathetic dysfunction reflected by a missing blood pressure overshoot during Valsalva manoeuvre correlated with cardiac tracer distribution in Parkinson's disease patients (p < 0.001). CONCLUSIONS: The diagnostic accuracy of the dual imaging method and routine cardiac scintigraphy were similar. Anatomical tracer allocation provided by the dual imaging method of cardiac iodine-123-metaiodobenzylguanidine single-photon emission computed tomography and chest computed tomography identified a heterogeneous subgroup of Parkinson's disease and multiple system atrophy patients with reduced cardiac tracer uptake in the apex and the lateral wall. Sympathetic dysfunction correlated with cardiac imaging in Parkinson's disease patients.

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.

Impaired Inhibitory Control of Saccadic Eye Movements in Cervical Dystonia: An Eye-Tracking Study.

BACKGROUND: The pathophysiology of cervical dystonia is still unclear. Recent evidence points toward a network disorder affecting several brain areas. The objective of this study was to assess the saccadic inhibition as a marker of corticostriatal function in cervical dystonia. METHODS: We recruited 31 cervical dystonia patients and 17 matched healthy controls. Subjects performed an overlap prosaccade, an antisaccade, and a countermanding task on an eye tracker to assess automatic visual response and response inhibition. RESULTS: Cervical dystonia patients made more premature saccades (P = 0.041) in the overlap prosaccade task and more directional errors in the antisaccade task (P = 0.011) and had a higher rate of failed inhibition in the countermanding task (P = 0.001). CONCLUSIONS: The results suggest altered saccadic inhibition in cervical dystonia, possibly as a consequence of dysfunctional corticostriatal networks. Further studies are warranted to confirm whether these abnormalities are affected by the available therapies and whether this type of impairment is found in other focal dystonias. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Decision making and framing effects in multiple sclerosis.

BACKGROUND: Previous studies reported reduced decision-making abilities for patients with multiple sclerosis (MS) relative to healthy controls (HC). This study aimed to evaluate whether these problems arise when sampling information or when pondering about the evidence collected. METHODS: In a cross-sectional, controlled study, 43 relapsing-remitting MS patients (RRMS; Expanded Disability Status Scale 1.5, range 0-4) and 53 HC performed an information sampling task ('beads task'), a health-related framing task, and neuropsychological background tests. RESULTS: In the beads task, patients collected as much information as HC prior to a decision. However, there were twice as many patients as HC making irrational decisions, that is, decisions against the evidence collected (RRMS: 26/43, 60%; HC: 16/53, 30%; p = 0.003). Compared to HC, patients also showed a stronger framing effect, that is, they were more strongly biased by the way health-related information was presented (p < 0.05, Cohen's d = 0.5). Overall, the framing effect predicted whether a participant would make irrational decisions (OR 2.12, 95% CI 1.29-3.49, p < 0.001). CONCLUSIONS: Predecisional information sampling is intact in RRMS. However, compared to HC, patients are more likely to make irrational decisions and to be biased by the way health-related information is framed. This warrants caution in communication, especially in the medical context, with patients.

Neurological outcome and quality of life 3 months after COVID-19: A prospective observational cohort study.

BACKGROUND AND PURPOSE: To assess neurological manifestations and health-related quality of life (QoL) 3 months after COVID-19. METHODS: In this prospective, multicenter, observational cohort study we systematically evaluated neurological signs and diseases by detailed neurological examination and a predefined test battery assessing smelling disorders (16-item Sniffin Sticks test), cognitive deficits (Montreal Cognitive Assessment), QoL (36-item Short Form), and mental health (Hospital Anxiety and Depression Scale, Posttraumatic Stress Disorder Checklist-5) 3 months after disease onset. RESULTS: Of 135 consecutive COVID-19 patients, 31 (23%) required intensive care unit (ICU) care (severe), 72 (53%) were admitted to the regular ward (moderate), and 32 (24%) underwent outpatient care (mild) during acute disease. At the 3-month follow-up, 20 patients (15%) presented with one or more neurological syndromes that were not evident before COVID-19. These included polyneuro/myopathy (n = 17, 13%) with one patient presenting with Guillain-Barré syndrome, mild encephalopathy (n = 2, 2%), parkinsonism (n = 1, 1%), orthostatic hypotension (n = 1, 1%), and ischemic stroke (n = 1, 1%). Objective testing revealed hyposmia/anosmia in 57/127 (45%) patients at the 3-month follow-up. Self-reported hyposmia/anosmia was lower (17%) at 3 months, however, improved when compared to the acute disease phase (44%; p < 0.001). At follow-up, cognitive deficits were apparent in 23%, and QoL was impaired in 31%. Assessment of mental health revealed symptoms of depression, anxiety, and posttraumatic stress disorders in 11%, 25%, and 11%, respectively. CONCLUSIONS: Despite recovery from the acute infection, neurological symptoms were prevalent at the 3-month follow-up. Above all, smelling disorders were persistent in a large proportion of patients.

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.

Lower nucleus accumbens α-synuclein load and D3 receptor levels in Parkinson's disease with impulsive compulsive behaviours.

Impulsive compulsive behaviours in Parkinson's disease have been linked to increased dopaminergic release in the ventral striatum and excessive stimulation of dopamine D3 receptors. Thirty-one patients with impulsive compulsive behaviours and Parkinson's disease who donated their brains to the Queen Square Brain Bank for Neurological Disorders were assessed for α-synuclein neuropathological load and tyrosine hydroxylase levels in the nucleus accumbens, dorsal putamen and caudate using immunohistochemistry. Dopamine D2 and dopamine D3 receptors protein levels in the nucleus accumbens, frontal cortex and putamen were determined using western blotting. Results were compared to 29 Parkinson's disease cases without impulsive compulsive behaviours matched by age, sex, disease duration, age at Parkinson's disease onset and disease duration. The majority of patients with impulsive compulsive behaviours had dopamine dysregulation syndrome. Patients with Parkinson's disease and impulsive compulsive behaviours had lower α-synuclein load and dopamine D3 receptor levels in the nucleus accumbens. No differences were seen between groups in the other brain areas and in the analysis of tyrosine hydroxylase and dopamine D2 receptor levels. Lower α-synuclein load in the nucleus accumbens of individuals with Parkinson's disease and impulsive compulsive behaviours was confirmed on western blotting. Downregulation of the dopamine D3 receptor levels may have occurred either as a consequence of the degenerative process or of a pre-morbid trait. The lower levels of α-synuclein may have contributed to an excessive stimulation of the ventral striatum resulting in impulsive compulsive behaviours.

Nabilone for non-motor symptoms of Parkinson's disease: a randomized placebo-controlled, double-blind, parallel-group, enriched enrolment randomized withdrawal study (The NMS-Nab Study).

Although open-label observations report a positive effect of cannabinoids on non-motor symptoms (NMS) in Parkinson's disease (PD) patients, these effects remain to be investigated in a controlled trial for a broader use in NMS in PD patients. Therefore, we decided to design a proof-of-concept study to assess the synthetic cannabinoid nabilone for the treatment of NMS. We hypothesize that nabilone will improve NMS in patients with PD and have a favorable safety profile. The NMS-Nab Study is as a mono-centric phase II, randomized, placebo-controlled, double-blind, parallel-group, enriched enrollment withdrawal study. The primary efficacy criterion will be the change in Movement Disorders Society-Unified Parkinson's Disease-Rating Scale Part I score between baseline (i.e. randomization) and week 4. A total of 38 patients will have 80% power to detect a probability of 0.231 that an observation in the treatment group is less than an observation in the placebo group using a Wilcoxon rank-sum test with a 0.050 two-sided significance level assuming a true difference of 2.5 points between nabilone and placebo in the primary outcome measure and a standard deviation of the change of 2.4 points. The reduction of harm through an ineffective treatment, the possibility of individualized dosing, the reduction of sample size, and the possible evaluation of the influence of the placebo effect on efficacy outcomes justify this design for a single-centered placebo-controlled investigator-initiated trial of nabilone. This study should be the basis for further evaluations of long-term efficacy and safety of the use of cannabinoids in PD patients.

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.

Performance of the Movement Disorders Society criteria for prodromal Parkinson's disease: A population-based 10-year study.

OBJECTIVE: We aimed to identify prodromal Parkinson's disease (PD) and its predictive accuracy for incident PD in an unselected elderly population and to estimate the relevance of this approach for future neuroprotection trials. METHODS: We applied the recently published Movement Disorders Society (MDS) research criteria for prodromal PD to participants of the prospective population-based Bruneck Study of the 2005 assessment (n = 574, ages 55-94 years). Cases of incident PD were identified at 3-year, 5-year, and 10-year follow-up visits. We calculated predictive accuracies of baseline prodromal PD status for incident cases, and, based on them, estimated sample sizes for neuroprotection trials with conversion to PD as the primary outcome. RESULTS: Baseline status of probable prodromal PD (n = 12) had a specificity in predicting incident PD of 98.8% (95% confidence interval, 97.3%-99.5%), a sensitivity of 66.7% (29.6%-90.8%), and a positive predictive value of 40.0% (16.7%-68.8%) over 3 years. Specificity remained stable with increasing follow-up time, sensitivity decreased to 54.6% (28.0%-78.8%) over 5 years and to 35.0% (18.0%-56.8%) over 10 years, whereas positive predictive value rose to 60.0% (31.2%-83.3%) and 77.8% (44.3%-94.7%), respectively. Sample size estimates at 80% power in an intention-to-treat approach ranged from 108 to 540 patients with probable prodromal PD depending on trial duration (3-5 years) and effect size of the agent (30%-50%). CONCLUSIONS: Our findings show that the MDS criteria for prodromal PD yield moderate to high predictive power for incident PD in a community-based setting and may thus be helpful to define target populations of future neuroprotection trials. © 2018 International Parkinson and Movement Disorder Society.

Verbal adynamia in parkinsonian syndromes: behavioral correlates and neuroanatomical substrate.

Verbal adynamia (impaired language generation, as during conversation) has not been assessed systematically in parkinsonian disorders. We addressed this in patients with Parkinson's dementia, progressive supranuclear palsy and corticobasal degeneration. All disease groups showed impaired verbal fluency and sentence generation versus healthy age-matched controls, after adjusting for general linguistic and executive factors. Dopaminergic stimulation in the Parkinson's group selectively improved verbal generation versus other cognitive functions. Voxel-based morphometry identified left inferior frontal and posterior superior temporal cortical correlates of verbal generation performance. Verbal adynamia warrants further evaluation as an index of language network dysfunction and dopaminergic state in parkinsonian disorders.

Optimizing odor identification testing as quick and accurate diagnostic tool for Parkinson's disease.

INTRODUCTION: The aim of this study was to evaluate odor identification testing as a quick, cheap, and reliable tool to identify PD. METHODS: Odor identification with the 16-item Sniffin' Sticks test (SS-16) was assessed in a total of 646 PD patients and 606 controls from three European centers (A, B, and C), as well as 75 patients with atypical parkinsonism or essential tremor and in a prospective cohort of 24 patients with idiopathic rapid eye movement sleep behavior disorder (center A). Reduced odor sets most discriminative for PD were determined in a discovery cohort derived from a random split of PD patients and controls from center A using L1-regularized logistic regression. Diagnostic accuracy was assessed in the rest of the patients/controls as validation cohorts. RESULTS: Olfactory performance was lower in PD patients compared with controls and non-PD patients in all cohorts (each P < 0.001). Both the full SS-16 and a subscore of the top eight discriminating odors (SS-8) were associated with an excellent discrimination of PD from controls (areas under the curve ≥0.90; sensitivities ≥83.3%; specificities ≥82.0%) and from non-PD patients (areas under the curve ≥0.91; sensitivities ≥84.1%; specificities ≥84.0%) in all cohorts. This remained unchanged when patients with >3 years of disease duration were excluded from analysis. All 8 incident PD cases among patients with idiopathic rapid eye movement sleep behavior disorder were predicted with the SS-16 and the SS-8 (sensitivity, 100%; positive predictive value, 61.5%). CONCLUSIONS: Odor identification testing provides excellent diagnostic accuracy in the distinction of PD patients from controls and diagnostic mimics. A reduced set of eight odors could be used as a quick tool in the workup of patients presenting with parkinsonism and for PD risk indication. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Nonmotor symptoms in subjects without evidence of dopaminergic deficits.

BACKGROUND: A subgroup of patients initially diagnosed with Parkinson's disease (PD) turn out to have normal dopamine transporter single-photon emission computed tomography imaging and have been labeled as subjects without evidence of dopaminergic deficit (SWEDDs). In this study, we sought to further characterize these patients and have analyzed the frequency of nonmotor symptoms (NMS) in SWEDDs, PD patients, and healthy controls. METHODS: We analyzed the baseline clinical data of 412 PD patients, 184 controls, and 62 SWEDDs included in the Parkinson's Progression Marker Initiative study on a variety of different NMS questionnaires. RESULTS: Both PD patients and SWEDDs had greater frequency of NMS than healthy controls. Furthermore, some NMS, such as orthostatic hypotension as well as cardiovascular and thermoregulatory dysfunction were even more commonly reported in SWEDDs than in PD patients, whereas hyposmia was more common in PD, compared to SWEDDs. CONCLUSION: NMS are more frequent in SWEDDs than in controls, and autonomic dysfunction and orthostatic hypotension were even more common than in PD patients. These findings support the notion that SWEDDS represent a group of patients with still poorly understood pathophysiology. © 2015 International Parkinson and Movement Disorder Society.

Probable RBD and association with neurodegenerative disease markers: A population-based study.

BACKGROUND: The prevalence of rapid eye movement sleep behavior disorder (RBD) and its association with markers of neurodegeneration in the general population are poorly defined. METHODS: We assessed the prevalence of probable RBD defined by two validated questionnaires, the RBD Screening Questionnaire (RBDSQ) and the Innsbruck RBD-Inventory (RBD-I), and studied its associations with clinical and imaging markers for neurodegeneration in the Bruneck Study cohort aged 60 y or older. RESULTS: Of the 456 participants without Parkinson's disease, 4.6% (RBDSQ; 95%CI, 3.0%-7.0%) and 7.7% (RBD-I; 95%CI, 5.6%-10.5%) had probable RBD. Probable RBD diagnosed with either of the questionnaires was associated with hyposmia (trend; P < 0.1), anxiety (P < 0.05), depression (P < 0.05), antidepressant use (P < 0.05), and self-reported non-motor symptoms (P < 0.01), specifically, dribbling saliva, memory problems, apathy, concentration problems, and anxiety. CONCLUSIONS: Our findings may provide a basis for future studies intending to identify cohorts at risk for Lewy body diseases through screening of the general elderly population for RBD.