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Introduction Parkinson's disease (PD) is characterized by a wide spectrum of non-motor symptoms that may impact negatively on the activities of the patient's daily life and reduce Health-related quality of life (HRQoL). The present study explored the impact of specific non-motor symptoms on the HRQoL in PD. Methods Eighty-four outpatients underwent the Montreal Cognitive Assessment (MoCA) assessing global functioning and several questionnaires to assess depression, apathy, impulse control disorders (ICD), anxiety, anhedonia and functional impact of cognitive impairment. The perceived QoL was assessed by Parkinson's Disease Questionnaire (PDQ-8). The PD sample was divided into patients with high and low HRQoL around the median of PDQ-8 and compared on clinical features, cognitive and neuropsychiatric variables. A linear regression analysis, in which the global functioning, apathy, depression, anxiety, anhedonia, ICD and the functional autonomy scores were entered as independent variables and PDQ-8 score as dependent variable, was applied. Results Patients with lower HRQoL were more depressed, apathetic, anxious and showed more severe reduction of functional autonomy and global functioning than patients with high HRQoL. The regression analysis revealed that higher level of anxiety, executive apathy and more reduced functional autonomy were significantly associated with higher score on PDQ-8. Conclusions The finding indicated that anxiety, apathy associated with impaired planning, attention and organization (i.e., executive apathy evaluated by the Dimensional Apathy Scale) and reduced functional autonomy contribute significantly to reduce the HRQoL in PD. Therefore, early identification and management of these neuropsychiatric symptoms should be relevant to preserve HRQoL in PD.

Low serum uric acid (UA) has been consistently shown to be associated with increased risk of Parkinson's disease (PD), and to predict faster motor and cognitive decline in established PD. The aim of the present study is to evaluate the relationship between serum UA and non-motor symptoms (NMS) in de novo PD. Methods: Serum UA was measured in consecutively recruited, early drug-naïve PD patients. Exclusion criteria were: treatment with UA modifying drugs; current smoking status; metabolic or cardiac morbidity. All patients completed the NMS Questionnaire (NMSQuest). The relationship between UA levels and NMSQuest domains was explored by logistic regression, subsequently adjusted for age, gender, disease duration (months since reported motor onset) UPDRS part III, H&Y scale, and MMSE. Regression analysis studied the overall relationship between UA levels and total NMS score, and was subsequently adjusted for age, gender, disease duration UPDRS part III, H&Y scale and MMSE. Results: Eighty PD patients were recruited. At logistic regression, higher UA levels were related to lower involvement of Attention/Memory (p=0.004), Cardiovascular (0.009) and Sleep (p=0.028) domains of NMSQuest. UA levels showed a significant negative correlation with total NMSQuest score at regression analysis (p=0.001; Adjusted R-squared=0.319). Discussion: The present study investigated, for the first time, the relationship between NMSQuest and UA in de novo PD. Lower UA was related to higher NMSQuest total score and in particular to Attention/Memory, Cardiovascular and Sleep domains. Thus, UA seems to be a major candidate to be a valuable biomarker of such early features of PD as NMS. © 2014 Elsevier Ltd.

About 90% of cases of Parkinson’s disease (PD) are idiopathic and attempts to understand pathogenesis typically assume a multifactorial origin. Multifactorial diseases can be studied using metabolomics, since the cellular metabolome reflects the interplay between genes and environment. The aim of our case–control study is to compare metabolomic profiles of whole blood obtained from treated PD patients, de-novo PD patients and controls, and to study the perturbations correlated with disease duration, disease stage and motor impairment. We collected blood samples from 16 drug naive parkinsonian patients, 84 treated parkinsonian patients, and 42 age matched healthy controls. Metabolomic profiles have been obtained using gas chromatography coupled to mass spectrometry. Multivariate statistical analysis has been performed using supervised models; partial least square discriminant analysis and partial least square regression. This approach allowed separation between discrete classes and stratification of treated patients according to continuous variables (disease duration, disease stage, motor score). Analysis of single metabolites and their related metabolic pathways revealed unexpected possible perturbations related to PD and underscored existing mechanisms that correlated with disease onset, stage, duration, motor score and pharmacological treatment. Metabolomics can be useful in pathogenetic studies and biomarker discovery. The latter needs large-scale validation and comparison with other neurodegenerative conditions.

Background Non-motor symptoms in Parkinson's disease (PD), such as cognitive, emotional, autonomic and somatosensory alterations, are not ubiquitous but vary between the tremor dominant (TD) and postural instability/gait difficulty (PIGD) subtypes of the syndrome. Non-motor phenomena (e.g., anxiety, depression and apathy) have been related to representation of autonomic and somatosensory sensations (interoception), and recent findings suggest interoceptive deficits in PD. Objectives To test whether interoceptive processing is differently affected in TD and PIGD phenotypes, by assessing both interoceptive accuracy and sensibility in PD patients with TD and PIGD subtypes, and in healthy controls. Methods Interoceptive accuracy was measured by the heartbeat perception task requiring participants to count their own heartbeats in a given time interval. A time-estimation, control task was also administered asking participants to count the seconds in a set period of time. Interoceptive sensibility was assessed by a questionnaire of subjective interoception. Finally, the patients underwent measures of anxiety, depression, apathy and anhedonia, and impulsive-compulsive disturbances. Results The main results showed reduced interoceptive accuracy and sensibility in TD patients relative to both PIGD patients and healthy controls. Reduced interoceptive accuracy of TD group was a reliable result since their performance on the time estimation control task was comparable to that of both PIGD patients and healthy controls. Conclusions These findings demonstrate that the behavioural assessment of different aspects of interoceptive processing can provide with a further marker for subtyping patients with PD.

Background and purpose: Cognitive impairment is common in Parkinson's disease (PD), even in the early stages. We aimed to assess the relationship between insulin-like growth factor-1 (IGF-1) and cognitive functions in early, drug-naïve patients with PD. Methods: Serum IGF-1 was measured in 65 early, drug-naïve patients with PD that underwent a complete neuropsychological battery at baseline and after 2years. Linear regression analysis was used to evaluate the relationships between neuropsychological scores and IGF-1. Repeated-measures anova was applied to assess changes in neuropsychological variables over time. Results: At baseline, IGF-1 levels were related to phonological fluency. At follow-up, IGF-1 levels were associated with the Rey auditory verbal learning test (RAVLT) - immediate and delayed recall, Frontal Assessment Battery, verbal span and Benton judgement of the line orientation test. Patients with low IGF-1 levels at baseline showed a significantly faster decline of performances than patients with high IGF-1 levels on immediate and delayed recall of the RAVLT and interference task of the Stroop test. Conclusions: Low serum IGF-1 levels are related to poor performance on executive tasks in early, drug-naïve patients with PD, and may predict poor performance on attention/executive and verbal memory tasks after a 2-year follow-up. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.

Introduction Apathy is a neuropsychiatric symptom in Parkinson's Disease (PD) which has a negative impact on quality of life and might be related in part to damage of presynaptic dopaminergic system. Little is known about relationship between striatal dopamine levels and apathy in PD patients without dementia and/or depression. The aim of the present study was to investigate the relationship between “pure apathy” and striatal dopamine uptake in untreated, drug-naive PD patients without clinically significant dementia and/or depression. Methods Fourteen PD patients with pure apathy and 14 PD patients without apathy, matched for age, side of motor symptoms at onset, motor disability and disease duration, underwent both neuropsychological and behavioral examination including self-rated version of the Apathy Evaluation Scale (AES-S). All patients underwent 123 I-FP-CIT (DaT-SCAN) SPECT to assess dopamine transporter (DAT) striatal uptake. Results PD patients with apathy showed lower DAT levels in the striatum than non-apathetic patients. After Bonferroni correction the difference between groups was significant in the right caudate. Conclusions Apathy is associated with reduced striatal dopamine transporter levels, independent of motor disability and depression in non-demented PD patients. These findings suggest that dysfunction of dopaminergic innervation in the striatum and particularly in the right caudate may contribute to development of apathy in early PD.

Purpose: Apathy is associated with motor symptoms in Parkinson’s disease (PD); therefore, its evaluation could be influenced by motor disability. The Dimensional Apathy Scale (DAS) evaluates apathy excluding confounding effects of motor symptoms. The present study had three major aims: (a) to explore the psychometric properties of the DAS in non-demented PD patients; (b) to determine an optimal cut-off score of the DAS to identify apathetic PD patients; and (c) to determine a specific apathy profile in PD patients as compared to healthy controls (HC). Methods: One hundred and seven PD patients and 100 HC completed the DAS. To explore convergent and divergent validity of the DAS in PD, patients underwent the Apathy Evaluation Scale and tools for assessing depressive symptoms, anxiety and cognition. Clinical aspects were recorded. Receiver operating characteristic curve analyses were carried out to estimate the optimal cut-off score to identify clinically significant apathy. Results: The DAS scores showed high internal consistency and good evidence for convergent and discriminant validity. Maximum discrimination between apathetic and non-apathetic patients was obtained with a cut-off score of 28.5 (total score range: 0-72 with higher score indicating more severe apathy). Comparison between PD and HC groups revealed significant differences on total DAS, behavioural/cognitive initiation and emotional subscales. Conclusions: The DAS is a valid and reliable tool to assess multidimensional apathy in PD, independently of severity of motor symptoms. Reduced initiation of thought and behaviour and emotional blunting characterised PD patients, without confounding effects of motor disability.

OBJECTIVE: To characterize brain metabolic changes associated with mild cognitive impairment (MCI) in drug-naive patients with Parkinson disease (PD) using (18)F-fluorodeoxyglucose (FDG) and PET (FDG-PET). METHODS: This cross-sectional study included newly diagnosed patients with PD with MCI in single or multiple domain (PD-MCI; n =12) and without MCI (PD-nMCI; n =12), and healthy controls (n =12). The groups were matched for age. Moreover, the patient groups were matched for motor disability. All subjects underwent a FDG-PET study. Cerebral regional relative metabolic maps were compared in PD-MCI, PD-nMCI, and controls using regions of interest analysis (ROIs) and voxel-based analysis with statistical parametric mapping. RESULTS: ROIs and voxel-based analyses revealed significant relative hypometabolism in the prefrontal, superior/inferior parietal, and associative occipital cortices as well as in the striatum in patients with PD-MCI relative to controls (p < 0.05) and to a lesser extent in patients with PD-nMCI. In contrast, patients with PD-nMCI did not show significant metabolic changes as compared to controls. CONCLUSION: MCI in patients with PD is associated with cortical hypometabolism since the earliest stage, independent of therapy or motor disability. The early involvement of posterior cortical region, a pattern shared by advanced stages of PD-MCI and PD with dementia, could represent an early marker of dementia. The relevance of this pattern in predicting prodromal dementia has to be evaluated in longitudinal studies.

Lateral trunk flexion is a very common clinical observation in patients affected by Parkinson's disease. Postural control is known to depend on vestibular, visual, and somatosensory information. The aim of this study was to investigate whether impairment of vestibular function can account for the postural alterations observed in parkinsonian patients with lateral trunk flexion. We evaluated vestibular function in 11 parkinsonian patients with lateral trunk flexion and in 11 age-, sex-, and disease duration-matched patients without lateral trunk flexion. The following vestibular tests were performed: infrared videonystagmography including fast and slow ocular movements, spontaneous-positional and evoked nystagmus search with and without visual fixation, fast positioning maneuvers, the bithermal caloric test, and the vibration test. A peripheral, unilateral vestibular hypofunction was identified in all patients with lateral trunk flexion. The vestibular hypofunction was ipsilateral to the leaning side and contralateral to the most affected parkinsonian side in all patients. In the control group, 7 subjects had no vestibular signs; 4 subjects had unilateral vestibular hypofunction without clinically evident lateral trunk flexion. Two of the latter patients subsequently developed lateral trunk flexion ipsilateral to the vestibular deficit and contralateral to the side most affected by Parkinson's disease. The processing of vestibular information was impaired in parkinsonian patients affected by lateral trunk flexion. The impairment was at least in part responsible for the patients' postural abnormality. We propose that the acronym PISA (Postural Imbalance Syndrome with vestibular Alterations) be used to describe the specific postural change observed in parkinsonian patients affected by a vestibular defect and lateral trunk flexion.

To explore the relationship between depression and cognitive impairment in non-demented PD patients, we evaluated neurological and neuropsychological asset in 65 patients with a diagnosis of major depressive disorder (dPD) according to DSM-IV criteria and 60 patients without depression (nPD). Compared with nPD patients, dPD patients had significantly higher scores on behavioral rating scales and performed worse on the Frontal Assessment Battery (FAB), Semantic Fluency Task, Copying Task (CT), and Stroop Test. Three dPD subgroups were identified based on the first two DSM-IV criteria: patients fulfilling criterion 1 (depressed mood; group 1); patients fulfilling criterion 2 (apathy/anhedonia; group 2); patients fulfilling criteria 1 and 2 (group 3). Patients of group 2 scored significantly lower than patients of group 1 on the CT, FAB and phonological fluency task. Patients of groups 2 and 3 scored significantly lower than nPD patients on visuoconstructional and frontal tasks. Similar results were obtained in dPD patients stratified in four subgroups based on cut-off scores of the Apathy Evaluation Scale and the Snaith Hamilton Pleasure Scale. In summary, PD patients with concomitant apathy and anhedonia may show more severe cognitive impairments. Since such patients are diagnosed to be affected by depression according to clinical DSM-IV criteria, we suggest that DSM-IV criteria may not distinguish an affective from a cognitive disorder in PD.

Introduction Anxiety disorders are common in Parkinson's Disease (PD) and their identification is relevant even at early stages. The Parkinson Anxiety Scale (PAS) evaluates anxiety in PD; it was used only in the original validation study in PD patients mainly at 2-3 stages of Hoehn & Yahr system (H&Y). The study aimed to investigate psychometric properties of observer-rated version of the PAS (OR-PAS), prevalence rate of anxiety and its features, compared with diagnostic criteria in early PD patients. Methods A sample of 101 PD patients with H&Y:1-2 underwent the OR-PAS. To assess convergent and divergent validity, PD patients underwent Beck Anxiety Inventory, and scales assessing depression, apathy, anhedonia and cognition. To diagnose anxiety disorders, Mini International Neuropsychiatric Inventory was used as gold standard. A "receiver operating characteristics" curve was obtained; positive and negative predictive values were calculated for different cut-off points of the OR-PAS and its subscales. Results There was no missing data, no floor and ceiling effects; mean score was 12.2 ± 10.1; Cronbach's alpha was 0.899. The OR-PAS showed good convergent and divergent validity. Maximum discrimination was obtained with a cut-off score of 8.5. The anxiety occurred in 59 patients (58.4%). Conclusion The OR-PAS is a reliable and valid screening instrument for assessing anxiety in patients at early PD. Anxiety was found in 58.4% of PD patients, demonstrating that anxiety occurs even at early stages.

Introduction Higher caffeine consumption has been associated with reduced risk of Parkinson's disease (PD), and with a more benign progression of motor and non-motor symptoms (NMS). The present observational cohort study investigated motor and non-motor correlates of caffeine consumption in de novo PD. Methods 79 newly diagnosed, drug naive PD patients have been included and followed up for 4 years. The total caffeine use was calculated with the Caffeine Consumption Questionnaire. Following study variables were recorded at baseline, and after 2 and 4 years: UPDRS part III, UPDRS part IV, l -dopa Equivalent Daily Dose (LEDD), NMS Questionnaire (NMSQuest), and the time occurring from PD diagnosis to the need for l -dopa treatment. Age, gender and disease duration were included as covariates in the statistical models. Results The average daily caffeine consumption was 296.1 ± 157.2 mg. At Cox regression models, higher caffeine consumption was associated with a lower rate of starting l -Dopa treatment (HR = 0.630; 95%CI = 0.382–0.996). At the mixed-effects linear regression models considering the whole study period, each additional espresso cup per day (50 mg of caffeine) was more likely associated with 5-point lower UPDRS part III total score (Coef = −0.01; 95%CI = −0.02 to 0.00), with 50% reduced LEDD (Coef = −0.01; 95%CI = −0.15 to 0.00; p = 0.021), and with 5-point lower NMSQuest total score (Coef = −0.01; 95%CI = −0.01 to 0.00), but not with UPDRS part IV total score (Coef = −0.00; 95%CI = −0.00 to 0.00). Conclusion Caffeine consumption was associated with a reduced accrual of motor and non-motor disability during 4-year follow-up in de novo PD, highlighting the rationale for using adenosine A2A antagonists since the early phases of PD.

Both low serum uric acid (UA) levels and apathy are considered biomarkers of cognitive decline and dementia in Parkinson’s disease (PD). There is an urgent need to combine different biomarkers to predict disease course in PD. Data on the relationship between serum UA levels and apathy in PD are lacking. The aim of this study is to evaluate the relationship between serum UA levels and pure apathy in early, drug-naïve PD patients. Forty-nine early, drug-naïve PD patients were enrolled and stratified into two groups using the median serum UA levels at diagnosis (Group 1 serum UA ≤ 4.8 mg/dl; Group 2 serum UA > 4.8 mg/dl). The cohort was followed for the first 2 years of disease. Apathy was evaluated with the Apathy Evaluation Scale (AES). Patients with lower serum UA levels presented significant higher AES score compared to patients with higher serum UA levels. Regression analysis showed that baseline serum UA levels were significant determinants of AES scores at both baseline and 2-year follow up, irrespective of gender, age, attention/executive functions and dopamine replacement therapy when applicable. This is the first study showing a link between serum UA levels and apathy in non-demented, non-depressed, early, drug-naïve PD, being lower serum UA levels associated with greater apathy. Further follow up of our patients and replication of this observation in independent cohorts are needed to establish if this combination of biomarkers may help in characterizing a subgroup of PD patients at diagnosis.

BackgroundThe variability in the clinical phenotype of Parkinson's disease seems to suggest the existence of several subtypes of the disease. To test this hypothesis we performed a cluster analysis using data assessing both motor and non-motor symptoms in a large cohort of newly diagnosed untreated PD patients.MethodsWe collected data on demographic, motor, and the whole complex of non-motor symptoms from 100 consecutive newly diagnosed untreated outpatients. Statistical cluster analysis allowed the identification of different subgroups, which have been subsequently explored.ResultsThe data driven approach identified four distinct groups of patients, we have labeled: 1) Benign Pure Motor; 2) Benign mixed Motor-Non-Motor; 3) Non-Motor Dominant; and 4) Motor Dominant.ConclusionOur results confirmed the existence of different subgroups of early PD patients. Cluster analysis revealed the presence of distinct subtypes of patients profiled according to the relevance of both motor and non-motor symptoms. Identification of such subtypes may have important implications for generating pathogenetic hypotheses and therapeutic strategies.

Gender differences in brain structure and function may lead to differences in the clinical expression of neurological diseases, including Parkinson's disease (PD). Few studies reported gender-related differences in the burden of non-motor symptoms (NMS) in treated PD patients, but this matter has not been previously explored in drug-naïve PD patients. This study is to assess gender differences in the prevalence of NMS in a large sample of early, drug-naïve PD patients compared with age and sex-matched healthy controls. Two hundred early, drug-naïve PD patients and ninety-three age and sex-matched healthy controls were included in the study. Frequency of NMS was evaluated by means of the Non-Motor Symptoms Questionnaire. The difference in gender distribution of NMS was evaluated with the χ (2) exact test; multiple comparisons were corrected with the Benjamini-Hochberg method. Male PD patients complained of problems having sex and taste/smelling difficulties significantly more frequently than female PD patients. Furthermore, men with PD complained more frequently of dribbling, sadness/blues, loss of interest, anxiety, acting during dreams, and taste/smelling difficulties as compared to healthy control men, while female PD patients reported more frequently loss of interest and anxiety as compared with healthy control women. This study shows specific sex-related patterns of NMS in drug-naïve PD. In contrast with previous data, female PD patients did not present higher prevalence of mood symptoms as compared to male PD patients. Comparison with healthy controls showed that some NMS classically present in premotor and early stage of disease (i.e., acting out during dreams, taste/smelling difficulties) are more frequent in male than in female patients.

Background Anxiety is a common non-motor symptom among patients with Parkinson's disease (PD). Although the etiology of anxiety in PD is likely to be multifactorial, a dysfunction in the dopaminergic system might be implicated in its pathogenesis. The aim of our study was to investigate a possible dopaminergic mechanism involved in anxiety in newly diagnosed never-medicated PD patients using SPECT and 123I-FP-CIT as the dopamine transporter ligand. Methods Thirty-four newly diagnosed, untreated PD patients with asymmetric motor symptoms were included in the study: 17 patients with right- and 17 with left-motor onset, matched for age, disease duration and motor disability constituted the group. They were all evaluated for anxiety and depression and underwent an SPECT with 123I-FP-CIT. Dopamine transporter (DAT) availability values for right and left caudate and putamen were calculated and compared between patients with and without anxiety. Regression analyses were also performed in order to correlate DAT availability with the severity of the anxiety symptoms. Results Comparison between PD patients with and those without anxiety revealed significant differences of DAT availability in all the examined regions except the right putamen. In the group of patients considered as a whole, a significant correlation was found between increased anxiety severity and decreased DAT availability in right caudate. Conclusions We reported an association between nigrostriatal DAT availability deficits and anxiety symptoms in newly diagnosed, untreated PD patients. Our results suggest that hypofunction of the nigrostriatal dopaminergic system may represent one of the functional anomalies involved in anxiety in PD from the earliest stages of disease and irrespective of any therapy.

Introduction In PD, Mild Cognitive Impairment (PD-MCI) occurs since early stages of disease. The aims were to assess presence of PD-MCI in untreated, drug-naive PD patients, and to follow-up the sample over 4 years to ascertain evolution of neurocognitive profile. Methods Seventy-six patients underwent neuropsychological testing at baseline (T0), and after 2 (T1:n = 62) and 4 years (T2:n = 55). Diagnosis of PD-MCI and PD-associated dementia (PDD) was made according to current consensus criteria. Results PD-MCI occurred in 25/76 patients (32.9%) at baseline, and 4 of them reverted from PD-MCI to Normal Cognition (Reverters), 7 remained stable (Non-Reverters) and 2 developed PDD at T2; 12 patients were lost to the follow-up. Among the 51 patients with normal cognition (PD-CN) at T0, 27 had normal cognition at T2 (5 of them were Reverters with respect to diagnosis at T1), 5 had MCI at T1 and T2 (Non-Reverters), 9 had MCI at T2 only, whereas 1 developed PDD; 9 patients were lost to the follow-up. At baseline, Reverters (n = 9) had younger age at onset and better performance on constructional visuospatial task than Non-Reverters (n = 12). Compared to patients without PD-MCI at all evaluations (n = 19), Reverters had poorer performance on verbal immediate recall and attention tasks and higher level of apathy at T0. Reduced performance on the Stroop Test at baseline predicted PD-MCI at T2. Conclusion Executive dysfunctions predicted development of PD-MCI after few years from onset. Reversal from PD-MCI to PD-CN was related to young age at onset and high level of apathy at baseline evaluation.

Background and purpose Oxidative stress is a central pathogenic mechanism of Parkinson's disease (PD), and the heme oxygenase (HO) bilirubin pathway is one of the main mammalian antioxidative defences. Indeed, there is growing evidence of HO−bilirubin upregulation from early phases of PD. Our aim was to investigate bilirubin as a possible biomarker of PD diagnosis and progression. Methods A cross-sectional case−control study was performed to evaluate differences in bilirubin levels between newly diagnosed, drug-naive PD subjects and controls. Afterwards, PD subjects were included in a 2-year longitudinal study to evaluate disease progression in relation to baseline bilirubin levels. Results Seventy-five de novo PD subjects were selected and matched with 75 controls by propensity score. Analysis of variance showed higher bilirubin levels in PD patients compared with controls (P

Introduction: Epidemiological studies report a 60-70% reduced risk of Parkinson's disease (PD) in smokers as compared to non-smokers. However, relationships between former smoking and PD have been poorly investigated. Methods: We recruited 116 de novo PD subjects, and investigated current, former and never smoking, and reasons for smoking cessation among former smokers. Two hundred and thirty-two controls were matched by Propensity Score. Results: PD subjects and controls were found to be current smokers (7.7 vs. 39.6%), former smokers (43.9 vs. 6.5%) and never smokers (48.2 vs. 53.9%). Logistic regression showed that current smokers were less likely to have PD (p

The variability in the clinical pheno- type of Parkinson's disease (PD) suggests the existence of several subtypes of the disease. Motor heterogeneity of PD is well established, but not nonmotor heterogeneity. At present, we are unable to predict the rate of progression of PD based on robust biomarkers. We aimed to examine the heterogeneity of PD by attempting to identify nonmotor fac- tors associated with the rate of motor progression and functional decline, as measured by the time to reach the need for levodopa therapy during the first 4 years from diagnosis in a cohort of de novo PD patients. The median time to introduction of L-dopa for patients with urinary symptoms was significantly shorter than that for those with- out (20 vs. 37 months; P 5 0.001). Cox's regression models showed that the urinary domain was associated with a higher probability of starting L-dopa (hazard ratio: 2.1; P 5 0.002). There was no influence of such confounders as sex, age, baseline motor features, use of dopamine ago- nists and/or monoamine oxidase B inhibitors, and total L- dopa equivalent daily dosage. Patients with urinary symp- toms had higher baseline and follow-up motor and nonmo- tor disturbances than those without. Our study suggests the existence of a subgroup of patients who show urinary symptoms along with an overall higher motor and nonmotor burden. Such patients are prone to manifest a rapid func- tional decline over the first 4 years of the disease. Urinary symptoms might be a clinical marker of severity as well as a possible nonmotor subtype of PD. V C 2015 International Parkinson and Movement Disorder Society

Objectives Mild cognitive impairment (MCI) is a common feature in Parkinson's disease (PD). We performed an exploratory study to investigate dopaminergic nigrostriatal innervation and its cognitive correlates in early untreated PD patients with MCI as compared to cognitively intact patients. Patients and methods A consecutive series of 34-de-novo, drug-naive patients with PD were enrolled. They underwent [123-I] FP-CIT SPECT and comprehensive neuropsychological battery. MCI was identified in 15 of 34 patients with PD. Results The two groups did not show any statistically significant difference in age, sex, disease duration, education, lateralization, and H&Y and Hospital Anxiety and Depression Scale scores. Logistic regression analysis showed that UPDRS-III was weakly associated with MCI (P = 0.034). Partial correlation analysis controlling for UPDRS-III and age suggested that in PD patients with MCI reduced V3″ values in the more affected caudate were correlated with reduced performances in frontal assessment battery, Trail Making Test: part B minus Part A and copy task of the Rey–Osterrieth complex figure test. Reduced V3″ values in the more and less affected putamen were significantly related with reduced performance in frontal assessment battery and in copy task of Rey–Osterrieth complex figure test, respectively. No correlation was found between neuropsychological scores and DAT availability in PD patients without MCI. Conclusions Although preliminary, our results suggest that striatal dopamine depletion may contribute to some cognitive deficit in early never treated PD patients with MCI.

Background and purpose Apathy may be either a symptom of major depression or a behavioral disturbance occurring in concomitance with depression or alone in Parkinson's disease (PD). The aim of the present study was to determine the progression of cognitive impairment in drug-naive untreated PD patients with or without clinically significant apathy. Methods Sixty-two PD patients with a disease duration

Background Diagnosing Parkinson's disease (PD) and tracking its progression may require the combination of reliable biomarkers. Among them, both serum uric acid (UA) and dopamine transporter (DaT) binding deserve more investigations. Aims of the study We aimed to investigate the relationship between serum UA levels and DaT availability in newly diagnosed, drug-naive PD patients, by means of semiquantitative [(123) I]FP-CIT-SPECT. Methods We recruited 52 newly diagnosed, drug-naive PD patients, and performed serum UA dosage and [(123) I]FP-CIT-SPECT. Results Pearson's correlation analysis showed that UA levels were significantly higher in patients with higher averaged, ipsilateral and contralateral DaT binding in caudate, putamen, and striatum. Conclusions We showed, for the first time, by regional semiquantitative analysis of DaT binding in PD patients that UA levels significantly correlates with the severity of dopaminergic impairment in caudate, putamen, and striatum. This study broadens our knowledge on the importance of UA as a biomarker of PD.

Background: Longitudinal studies on healthy participants have shown that subjective memory impairment (defined as subjective cognitive complaints with normal cognitive objective performance) might be a strong predictor of mild cognitive impairment (MCI). Parkinson disease (PD) also manifests cognitive disturbances, but whether subjective memory complaints may predict the development of MCI in PD has not yet been explored. Methods: We prospectively screened newly diagnosed, untreated patients with PD in order to evaluate whether subjective memory complaints may predict development of MCI over a 2-year follow-up evaluation. Results: We enrolled 76 de novo untreated patients with PD. Of the 76 patients, 23 (30.3%) complained memory issues. Among the patients cognitively unimpaired at baseline, those with subjective complaints were more likely to develop MCI at follow-up. The regression model confirmed that presence of subjective memory complaints at baseline was an independent predictor of development of MCI at follow-up. Discussion: This is the first prospective study to explore the relationship between subjective and objective cognitive deficits in newly diagnosed, untreated patients. Our results provide preliminary evidence that subjective memory complaints might predict future development of MCI.

Background and purpose Uric acid (UA) has been studied extensively as a valuable biomarker of Parkinson's disease (PD), but its relationship with non-motor symptoms (NMS) in de novo PD has been poorly investigated. Our aim was to evaluate the usefulness of baseline serum UA as a marker of NMS progression in newly diagnosed PD. Methods Sixty-nine newly diagnosed PD patients were enrolled. At baseline, all patients completed the NMS questionnaire (NMSQuest), and serum UA levels were measured. After 2 years, the NMSQuest was completed again and patients were categorized into four groups: NMS improvement (domain involvement at baseline but not at 2-year follow-up visit), NMS absence (domain not involved at baseline or 2-year follow-up visits), NMS presence (domain involvement both at baseline and 2-year follow-up visits) and NMS worsening (domain not involved at baseline but involved at 2-year follow-up). Results anova with post hoc Bonferroni correction showed that patients with NMS absence presented significantly higher UA values than patients with NMS presence with regard to the attention/memory (P = 0.023), depression/anxiety (P = 0.028) and cardiovascular domains (P = 0.002), whilst no differences were found with regard to both the NMS improvement and worsening groups. In addition, multinomial regression analysis showed that the lowest tertile of NMS progression presented higher UA levels (P = 0.023; odds ratio 0.488) compared with patients with greater NMS progression. Conclusions This is the first report of a relationship between serum UA and presence/progression of multiple NMS in de novo PD, providing additional evidence of the reliability of UA as a biomarker of PD and opening new insights on PD neuroprotection.

Background We recently showed specific sex-related patterns of non motor symptoms (NMS) in early, drug-naive PD patients. However, to date studies investigating gender-related effects of dopaminergic treatment on NMS in early PD are lacking. Methods In the present study, we first report a prospective assessment of gender-related differences in the spectrum of NMS before (baseline) and after starting dopaminergic therapy (2-year follow-up) in a large cohort of newly diagnosed PD patients. Differences in NMS frequency between baseline and follow-up were evaluated by McNemar test. Spearman's rank test was employed to explore interactions between NMS and drug treatment. Results One-hundred and thirty four PD patients (86M and 48W) were included in the present study. At 2-year follow-up, Sadness/blues presented a significant percentage reduction as compared to baseline in both sexes, while Urgency, Daytime sleepiness, Weight change and Sex drive presented a significant percentage increase only in men. At follow up men complained of a greater number of NMS as compared to women. Occurrence of Weight change was related to therapy in both sexes. Male gender was found to be a risk factor for developing Dribbling and Nocturia, irrespective of therapy and clinical features. Conclusions In conclusion, our study showed that mood symptoms improved after the introduction of therapy in both sexes, while men appeared to be more prone to develop some NMS possibly linked to dopaminergic treatment.

Background Non-motor symptoms are very common among patients with Parkinson9s disease since the earliest stage, but little is known about their progression and their relationship with dopaminergic replacement therapy. Methods We studied non-motor symptoms before and after 2 years from dopaminergic therapy introduction in ninety-one newly diagnosed previously untreated PD patients. Results At baseline, nearly all patients (97.8%) referred at least one non-motor symptom. At follow-up, only few non-motor symptoms significantly changed. Particularly, depression and concentration became less frequent, while weight change significantly increased after introduction of dopamine agonists. Conclusions We reported for the first time a 2-year prospective study on non-motor symptoms before and after starting therapy in newly diagnosed PD patients. Even if non-motor symptoms are very frequent in early stage, they tend to remain stable during the early phase of disease, being only few non-motor symptoms affected from dopaminergic therapy and, specifically, by the use of dopamine agonists.

Background A relation between the side of motor onset and cognitive impairment in early PD has been reported, suggesting that the asymmetric degeneration affecting subcortical regions may play a pivotal role in lateralized cognitive function. However, evidences are controversial and all previous studies were performed on treated patients, though it is known that dopaminergic therapy can affect cognition in PD. Methods Sixty-nine early untreated PD patients underwent an extensive neuropsychological battery exploring memory, visuospatial and attention/executive functions. Patients were divided with respect of the side of onset (right vs. left) and further grouped according to motor phenotype (tremor vs. rigidity-bradykinesia). Multivariate analysis of variance has been carried out to compare clinical and neuropsychological data between subgroups. Results There were no differences in any neuropsychological task between right-sided and left-sided onset subgroups, irrespective of tremor dominant or rigid-bradykinetic phenotype. Age at onset was significantly higher in patients with any cognitive impairment as compared with patients without (66.7 ± 3.2 vs. 56.3 ± 6.8 years, p = 0.001). Conclusion Side of motor onset is not a major determinant for developing lateralized cognitive deficits in newly diagnosed untreated PD patients.

The objective of this study was to evaluate hearing impairment in patients affected by Parkinson's disease compared with hearing scores observed in normal age- and sex-matched controls. One hundred eighteen consecutive patients with a clinical diagnosis of Parkinson's disease were screened. Severity of motor symptoms and staging were measured with the Unified Parkinson's Disease Rating Scale (section III) and the Hoehn and Yahr scale. Audiometric evaluation consisted of a comprehensive audiologic case history and questionnaire, visual otoscopic examination, acoustic immittance measures (tympanogram and acoustic reflexes), pure tone audiometry, and measurement of brain stem auditory-evoked potentials. Healthy age- and sex-matched subjects were selected as the control group. One hundred six of 118 patients were enrolled. Pure tone audiometry revealed age-dependent high-frequency hearing loss in patients with Parkinson's disease compared with both normative values and values for healthy age- and sex-matched controls (75/106 [71%], χ(2) = 5.959, P = .02; 92/106 [86.8%] vs 60/106 [56.6%], χ(2) = 23.804, P < .001, respectively). Pure tone audiometry scores correlated with Hoehn and Yahr scale scores (P < .05). Brain stem auditory-evoked potentials were normal in all patients. Our patients with Parkinson's disease showed age-dependent peripheral, unilateral, or bilateral hearing impairment. Whether these auditory deficits are intrinsic to Parkinson's disease or secondary to a more complex impaired processing of sensorial inputs occurring over the course of illness remains to be determined. Because α-synuclein is located predominately in the efferent neuronal system within the inner ear, it could affect susceptibility to noise-induced hearing loss or presbycusis. It is feasible that the natural aging process combined with neurodegenerative changes intrinsic to Parkinson's disease might interfere with cochlear transduction mechanisms, thus anticipating presbycusis.

The Parkinson Progression Marker Initiative (PPMI) is a comprehensive observational, international, multi-center study designed to identify PD progression biomarkers both to improve understanding of disease etiology and course and to provide crucial tools to enhance the likelihood of success of PD modifying therapeutic trials. The PPMI cohort will comprise 400 recently diagnosed PD and 200 healthy subjects followed longitudinally for clinical, imaging and biospecimen biomarker assessment using standardized data acquisition protocols at twenty-one clinical sites. All study data will be integrated in the PPMI study database and will be rapidly and publically available through the PPMI web site- www.ppmi-info.org. Biological samples including longitudinal collection of blood, cerebrospinal fluid (CSF) and urine will be available to scientists by application to an independent PPMI biospecimen review committee also through the PPMI web site. PPMI will rely on a partnership of government, PD foundations, industry and academics working cooperatively. This approach is crucial to enhance the potential for success of this ambitious strategy to develop PD progression biomarkers that will accelerate research in disease modifying therapeutics.

Little is known about the relationship between cognitive dysfunctions and the non-motor complex in subjects with newly diagnosed untreated Parkinson's disease (PD). The aim of this study was to explore the association between non-motor symptoms (NMS) and cognitive dysfunctions in an incident cohort of de novo, drug-naive, PD patients. Sixty-six non-demented, early, untreated PD patients completed a semi-structured interview on NMS and a battery of neuropsychological tests that assess verbal memory, visuospatial abilities, and attention/executive functions. Scores were age- and education-corrected. Patients who failed at least two tests for each cognitive domain were diagnosed as having mild cognitive impairment (MCI). All but three (95.4%) PD patients complained of at least one NMS. A total of 37.8% was diagnosed with MCI. There was a relationship between sleep-NMS and cognitive dysfunctions. Specifically, both REM behavioral sleep disorders (RBD) and insomnia were associated with lower scores on several cognitive tests. Moreover, RBD was closely related to MCI. NMS and MCI are very common even in the early phase of PD, before patients are treated. Given the correlation between sleep disturbances and cognitive impairment, it is possible that sleep symptoms in PD patients might be considered as an early marker of dementia.

Parkinson’s disease (PD) is a common neurodegenerative disorder with a progressive disabling course. Health-related quality of life (HrQoL) in Italian patients with PD has not been evaluated. The objective of this study was to evaluate HrQol of an Italian cohort of PD patients and to provide a comprehensive analysis of HrQoL determinants. We performed a cross-sectional survey of 70 outpatients with idiopathic PD recruited in the department of Neurology, Napoli University, Italy. Clinical data included the Unified PD Rating Scale (UPDRS), motor and non-motor symptoms. The generic instrument EuroQol (EQ-5D and EQ-VAS) was used to evaluate HrQol. Factors influencing HrQol were assessed by multivariate regression analysis. Severe problems in at least one dimension of the EQ-5D were experienced by 60% of PD patients versus 4.7% in general Italian population. The dimensions most affected were mobility, pain/discomfort and anxiety/depression with only 17.4%, 18.8% and 17.4% of patients, respectively, reporting no problems in these dimensions. The mean EQ-VAS score was 54.20 ± 18.38. Independent determinants of reduced HrQoL were increased UPDRS scores, motor fluctuations, dyskinesias, depression and dementia. PD strongly affects HrQol in Italian patients. The results of this study should be considered in the development of national healthcare programmes aimed at improvement of the HrQoL in Italian patients with PD. In particular, these programmes should concentrate not only on motor but also on non-motor manifestations of PD.

Hyperhomocysteinaemia was reported in patients with Parkinson's disease (PD) treated with l-Dopa. The increase in plasma concentration of this sulfur compound arises from the massive methylation of the drug operated by the enzyme catechol-O-methyltransferase (COMT), which acts as a powerful sink of methyl groups. The contemporary occurrence of C677T polymorphism in homozygosity, leading to a temperature-labile variant of the MTHFR enzyme, induces an even more marked increase in tHcy. Here we show that l-Dopa administration in hyperhomocysteinemic PD patients is able to lower intracellular concentration of S-Adenosylmethionine (AdoMet) in erythrocytes (RBC), while the occurrence of hyperhomocysteinaemia causes a significant increase in S-Adenosylhomocysteine (AdoHcy) level. In patients with PD treated with l-Dopa and hyperhomocysteinemic, the remarkable decrease in AdoMet and the concurrent increase in AdoHcy concentration both contribute to significantly lower the transmethylation potential ([AdoMet]/[AdoHcy]), a useful index of the effectiveness of methyl group transfer by methyltransferases. This decrease could indeed contribute to partly attenuate, through a self-limiting kinetic mechanism, the tendency of developing drug resistance, partly mediated in these patients by COMT upregulation. Our results also support the conclusion that COMT inhibitors (entacapone or tolcapone), when administered in PD patients treated with l-Dopa, may potentiate the endogenous AdoHcy-dependent COMT inhibition mechanism already operative in a variable fashion.

Multiple system atrophy call be classified into two main types, a Parkinsonian (MSA-P) and a cerebellar (MSA-C) variant based on clinical presentation. We obtained diffusion-weighted magnetic resonance imaging (DWI) in 9 MSA-P and 12 MSA-C patients and 11 controls, and correlated DWI changes with disease duration and severity. We found that Trace (D) values in the entire and anterior putamen were significantly higher in MSA-P than in MSA-C patients and controls, whereas Trace (D) values in the cerebellum and middle cerebellar peduncle (MCP) were significantly higher in MSA-C than in MSA-P patients and controls. Increased disease duration was significantly correlated with increased Trace (D) values in pons of MSA-P patients, and in cerebellum and MCP of MSA-C patients. Both UMSARS and UPDRS motor scores positively correlated with entire and posterior putaminal Trace (D) values in MSA-P patients. The diffusivity changes parallel phenotypical and pathologic differences between MSA-P and MSA-C patients, suggesting that DWI is a feasible tool for in vivo evaluation of neurodegeneration in MSA. Based on our findings, Trace (D) measurements in the putamen and pons in MSA-P patients and in the cerebellum and MCP in MSA-C patients could serve as quantitative markers for microstructural damage in the course of disease.

The arginine growth hormone (GH) stimulation test differentiates the Parkinsonian variant of multiple system atrophy (MSA-P) from idiopathic Parkinson's disease (PD). Our aim was to evaluate the accuracy of the arginine GH stimulation test in distinguishing between PSP, MSA-P, and PD. We measured the GH response to arginine in serum samples of 26 MSA-P, 23 PSP, and 26 PD patients, and in 80 healthy controls. We used ANOVA followed by the Bonferroni test to compare GH values and peaks among groups. We used receiver operating characteristic curve analysis to establish the arginine cut-off level that best differentiated between MSA-P, PSP, and PD. The GH peak was significantly lower (P0.01) in MSA-P (1.46 +/- 0.29 microg/L) than in both PD (8.74 +/- 0.98 microg/L) and PSP (6.64 +/- 0.82 microg/L) patients, and controls (8.59 +/- 0.44 microg/L). Growth hormone peaked later in PSP patients than in PD patients and controls. At a cut-off level of 4 microg/L, arginine test distinguished MSA-P from PD with a sensitivity of 92% and a specificity of 96%, and MSA-P from PSP with a sensitivity of 78% and a specificity of 96%. The GH response to arginine differentiates MSA-P from PD and PSP with a good diagnostic accuracy. The neuroendocrine response to arginine of PSP patients differed from that of MSA-P patients, but was not identical to that of normal controls and PD patients. Our results suggest that the impairment of the central mechanisms modulating GH release differs between PSP and MSA-P.

We evaluated tolerability and the efficacy of continuous infusion of apomorphine hydrochloride on involuntary movements and mood disorder in Huntington's disease (HD) patients in a pilot, single center, double-blind, randomized, crossover, and controlled versus placebo study. Nine patients with a molecular diagnosis of HD were screened for response to acute apomorphine injection. Four of them, not ameliorating at the acute test, were discontinued. Five patients, responding to acute apomorphine, received continuous infusion of either apomorphine or placebo for 5 days. After 2 days of washout, the alternative treatment was administered. Primary endpoint measures were scores of the Unified Huntington's Disease Rating Scale (UHDRS "motor section") and of the Abnormal Involuntary Movement Scale (AIMS). Secondary endpoint measures were the Hamilton Depression Rating Scale (HAD) score and safety parameters. Both UHDRS and AIMS scores significantly decreased in all patients after apomorphine. The beneficial effect of apomorphine was recorded throughout the 5 treatment days. The HAD score did not change after infusion of either treatment. No serious adverse events were reported by either group during the study. Our results suggest that continuous infusion of apomorphine might be considered for the treatment of involuntary movements in some HD patients.

Objective Multiple system atrophy (MSA) may be difficult to distinguish from idiopathic Parkinson's disease (PD). Our aim was to evaluate the accuracy of the arginine growth hormone (GH) stimulation test in distinguishing between MSA and PD in large populations of patients. Methods We measured the GH response to arginine in 69 MSA (43 MSAp [parkinsonism as the main motor feature] and 26 MSAc [cerebellar features predominated]) patients, 35 PD patients, and 90 healthy control subjects. We used receiver-operating curve analysis to establish the arginine cutoff value that best differentiated between MSA and PD. Results The GH response to arginine was significantly lower (p < 0.01) in MSA than in either PD patients or control subjects. At a cutoff level of 4μg/L, arginine distinguished MSAp from PD with a sensitivity and specificity of 91% and MSAc from PD with a sensitivity of 96% and specificity of 91%. The arginine test had a positive predictive value for MSA of 95%. The GH response to arginine was not affected by disease duration or severity, MSA motor subtype, pyramidal signs, response to dopaminergic therapy, or magnetic resonance imaging findings. Interpretation The GH response to arginine differentiates MSA from PD with a high diagnostic accuracy. The results suggest an impairment of cholinergic central systems modulating GH release in MSA. Ann Neurol 2006

Spastic paraplegia type 4 is caused by mutations in the gene that encodes spastin (SPG4), a member of the AAA protein family. A cohort of 34 unrelated Italian patients with pure spastic paraplegia, of which 18 displayed autosomal dominant inheritance and 16 were apparently sporadic, were screened for mutations in the SPG4 gene by denaturing high performance liquid chromatography. We identified a previously reported mutation in a sporadic patient with pure hereditary spastic paraplegia. We also identified eight unrelated patients with pure autosomal dominant hereditary spastic paraplegia carrying five novel mutations in the SPG4 gene (one missense mutation, c.1304 C>T; one nonsense mutation, c.807C>A; two frameshift mutations, c.1281dupT, c.1514_1515insATA; and one splicing mutation, c.1322-2A>C). The frequency for SPG4 mutations detected in autosomal dominant hereditary spastic paraplegia was 44.4%. This study contributes to expand the spectrum of SPG4 mutations in Italian population.

OBJECTIVE Restless legs syndrome (RLS) is a common neurologic condition characterized by uncomfortable and unpleasant sensations in the legs, occurring primarily at rest, which are usually worse in the evening and are alleviated by movement. RLS is present in 20-40% of patients with renal failure. This study was a 14-week open, randomized, crossover trial of ropinirole vs. levodopa sustained release (SR) in 11 patients with RLS on chronic hemodialysis. METHODS Eleven patients (7 men, 4 women) were enrolled in the study. They received either levodopa SR or ropinirole for 6 weeks, followed by a washout week, then the alternate treatment for 6 weeks. Patients rated the severity of RLS by means of a 6-item questionnaire developed by the International Restless Legs Study Group (6-item IRLS), by the Clinical Global Impression (CGI) scale, and by sleep diaries. RESULTS Under treatment with levodopa SR, 1 patient presented severe vomiting, leading to study discontinuation. The 10 patients who completed the study reported a 33.5% improvement (from 16.7 +/- 3.2 to 11.1 +/- 4; P < 0.001) of the 6-item IRLS scores during levodopa SR treatment and a 73.5% improvement (from 16.6 +/- 2.8 to 4.4 +/- 3.8; P < 0.001) during ropinirole treatment. By the end of the study the mean levodopa SR dosage was 190 mg/d and the mean ropinirole dosage was 1.45 mg/d. Ropinirole was superior to levodopa SR in reducing 6-item IRLS scores (P < 0.001) and in increasing sleep time (P < 0.001). The patient CGI scale showed a significant difference favoring ropinirole (P < 0.01). There was no significant carryover or period effect for any outcome measure. Four patients reported a complete reversion of RLS symptoms during ropinirole treatment at doses ranging from 0.25-2 mg/d. CONCLUSIONS These results suggest that ropinirole is more effective than levodopa SR in the treatment of RLS in patients on chronic hemodialysis.

STUDY OBJECTIVES: Restless legs syndrome (RLS) prevalence estimates range from 0% to 52% in Parkinson disease (PD), but the causal relationship between the two disorders is still debated. The present study aims to evaluate RLS prevalence in de novo PD subjects, its incidence during the first 4 years from diagnosis, and possible relationships with clinical, laboratory, and neuroradiological data. METHODS: One hundred nine newly diagnosed, drug-naïve PD subjects were evaluated at the time of PD diagnosis, and after 2- and 4-years. RLS diagnosis was performed with the RLS Diagnostic Index at each visit. Motor features, additional non-motor symptoms (NMS), and concomitant dopaminergic and nondopaminergic treatments were also gathered. Moreover, at baseline, 65 subjects were randomly selected to undergo a FP-CIT SPECT to study dopamine transporter availability. RESULTS: RLS prevalence rose from 4.6% at baseline evaluation to 6.5% after 2 years and to 16.3% after 4 years (P = 0.007). A multinomial logistic stepwise regression model selected NMS Questionnaire items more likely to be associated with RLS at diagnosis (insomnia, OR = 15.555; P = 0.040) and with occurrence of RLS during follow-up (dizziness, OR = 1.153; P = 0.022; and daytime sleepiness; OR = 9.557; P = 0.001), as compared to patients without RLS. Older age was more likely associated to increased RLS occurrence during follow-up in a random effect logistic regression model (OR = 1.187; P = 0.036). A multinomial logistic stepwise model found increased dopaminergic transporter availability of affected caudate and putamen to be more likely associated with RLS presence at diagnosis (n = 5; OR = 75.711; P = 0.077), and RLS occurrence during follow-up (n = 16; OR = 12.004; P = 0.059), respectively, as compared to patients without RLS (n = 88). CONCLUSIONS: RLS is present since PD diagnosis, and increases in prevalence during the course of PD. PD subjects with RLS have higher age at PD onset, more preserved dopaminergic pathways, and worse sleep and cardiovascular disturbances.