Longitudinal assessment of autonomic dysfunction in early Parkinson's disease

Heart rate variability and autonomic nervous system imbalance: Potential biomarkers and detectable hallmarks of aging and inflammaging

The most cutting-edge issue in the research on aging is the quest for biomarkers that transcend molecular and cellular domains to encompass organismal-level implications. We recently hypothesized the role of Autonomic Nervous System (ANS) imbalance in this context. Studies on ANS functions during aging highlighted an imbalance towards heightened sympathetic nervous system (SNS) activity, instigating a proinflammatory milieu, and attenuated parasympathetic nervous system (PNS) function, which exerts anti-inflammatory effects via the cholinergic anti-inflammatory pathway (CAP) and suppression of the hypothalamic-pituitary-adrenal (HPA) axis. This scenario strongly suggests that ANS imbalance can fuel inflammaging, now recognized as one of the most relevant risk factors for age-related disease development. Recent recommendations have increasingly highlighted the need for actionable strategies to improve the quality of life for older adults by identifying biomarkers that can be easily measured, even in asymptomatic individuals. We advocate for considering ANS imbalance as a biomarker of aging and inflammaging. Measures of ANS imbalance, such as heart rate variability (HRV), are relatively affordable, non-invasive, and cost-effective, making this hallmark easily diagnosable. HRV gains renewed significance within the aging research landscape, offering a tangible link between pathophysiological perturbations and age-related health outcomes.

The effect of chronotropic incompetence on physiologic responses during progressive exercise in people with Parkinson's disease

PURPOSE

Heart rate (HR) response is likely to vary in people with Parkinson's disease (PD), particularly for those with chronotropic incompetence (CI). This study explores the impact of CI on HR and metabolic responses during cardiopulmonary exercise test (CPET) in people with PD, and its implications for exercise intensity prescription.

METHODS

Twenty-eight participants with mild PD and seventeen healthy controls underwent CPET to identify the presence or absence of CI. HR and metabolic responses were measured at submaximal (first (VT1) and second (VT2) ventilatory thresholds), and at peak exercise. Main outcome measures were HR, oxygen consumption (VO2), and changes in HR responses (HR/WR slope) to an increase in exercise demand.

RESULTS

CI was present in 13 (46%) PD participants (PDCI), who during CPET, exhibited blunted HR responses compared to controls and PD non-CI beyond 60% of maximal workload (p ≤ 0.05). PDCI presented a significantly lower HR at VT2, and peak exercise compared to PD non-CI and controls (p ≤ 0.001). VO2 was significantly lower in PDCI than PD non-CI and controls at VT2 (p = 0.003 and p = 0.036, respectively) and at peak exercise (p = 0.001 and p = 0.023, respectively).

CONCLUSION

Although poorly understood, the presence of CI in PD and its effect on HR and metabolic responses during incremental exercise is significant and important to consider when programming aerobic exercises.

The Relationship Between Autonomic Dysfunction and Mood Symptoms in De Novo Parkinson's Disease Patients Over Time

BACKGROUND

Autonomic dysfunction is prevalent in Parkinson's disease (PD) and can worsen quality of life. We examined: (a) whether specific autonomic symptoms were more strongly associated with anxiety or depression in PD and (b) whether overall autonomic dysfunction predicted mood trajectories over a 5-year period.

METHODS

Newly diagnosed individuals with PD (N = 414) from the Parkinson's Progression Markers Initiative completed self-report measures of depression, anxiety, and autonomic symptoms annually. Cross-sectional linear regressions examined relationships between specific autonomic subdomains (gastrointestinal, cardiovascular, thermoregulatory, etc.) and mood. Multilevel modeling examined longitudinal relationships with total autonomic load.

RESULTS

Gastrointestinal symptoms were associated with both higher anxiety (b = 1.04, 95% CI [.55, 1.53], P < .001) and depression (b = .24, 95% CI [.11, .37], P = .012), as were thermoregulatory symptoms (anxiety: b = 1.06, 95% CI [.46, 1.65], P = .004; depression: b = .25, 95% CI [.09, .42], P = .013), while cardiovascular (b = .36, 95% CI [.10, .62], P = .012) and urinary symptoms (b = .10, 95% CI [.01, .20], P = .037) were associated only with depression. Longitudinally, higher total autonomic load was associated with increases in both depression (b = .01, 95% CI [.00, .02], P = .015) and anxiety (b = .04, 95% CI [.01, .06], P < .001) over time, as well as occasion-to-occasion fluctuations (depression: b = .08, 95% CI [.05, .10], P < .001; anxiety: b = .24, 95% CI [.15, .32], P < .001).

CONCLUSION

Findings suggest autonomic dysfunction, particularly gastrointestinal and thermoregulatory symptoms, may be an indicator for elevated anxiety/depression and a potential treatment target early on in PD.

Association between autonomic dysfunction with motor and non-motor symptoms in patients with Parkinson's disease

To investigate the association between autonomic dysfunction (AutD) and motor as well as non-motor symptoms (NMS) in patients with Parkinson's disease (PD). Fifty-three PD patients were divided into two groups based on the number of domains affected by AutD: a multi-domain AutD group (AutD-M) and a single-domain AutD group (AutD-S), as evaluated using the Scale for Outcomes in Parkinson's disease-Autonomic (SCOPA-AUT), which assesses autonomic symptoms, one of the NMS. A comprehensive comparison was conducted between the two groups, including clinical measures such as clinical scales, quantitative evaluations of motor function and exercise capacity. Spearman correlation analysis was employed to investigate the relationship between AutD severity and PD symptoms. Additionally, we performed multiple linear regression model analysis to determine whether associations between SCOPA-AUT scores and clinical assessments remained significant after adjusting for Hoehn and Yahr stage, sex, and age. PD patients in the AutD-M group exhibited significantly more severe NMS and motor symptoms compared to those in the AutD-S group. In correlation analysis, SCOPA-AUT scores showed significant correlations with multiple clinical symptoms, such as most of the NMS, 10-MWT and CPET parameters. Furthermore, regression analysis also revealed that more pronounced fatigue, anxiety, depressive symptoms, worse walking speed and impaired exercise capacity were associated with higher SCOPA-AUT scores. The presence of AutD is correlated with emotional disturbances, decreased exercise endurance, and impaired gait function in patients with PD. Early management of AutD may prove beneficial in alleviating some NMS and motor symptoms in PD.

Evaluation of Cardiovascular Autonomic Nervous System in Essential Tremor and Tremor Dominant Parkinson's Disease

(1) Background: The differential diagnosis of essential tremor (ET) and tremor-dominant Parkinson's disease (TDPD) can be challenging. Only a few studies have investigated the autonomic nervous system (ANS) in ET. However, some of these suggested that heart rate variability (HRV) might be useful in the differential diagnosis. (2) Methods: Demographic and clinical data, including medications and comorbidities, were collected from 15 TDPD patients, 19 ET patients, and 20 healthy controls. Assessment with the SCOPA-AUT questionnaire, 5 min HRV analysis in time and frequency domains, and evaluation of orthostatic hypotension (OH) with tilt test were performed. (3) Results: There were no significant differences between all groups on the SCOPA-AUT questionnaire. PD patients had OH more frequently and a larger drop in systolic blood pressure (SBP) during the tilt test than ET patients and controls. HRV was affected in PD, but not in ET and controls. Power in the low frequency band, the standard deviation of all normal RR intervals and SBP drop were potentially useful in differential diagnosis with AUCs of 0.83, 0.78, and 0.83, respectively. (4) Conclusions: Cardiovascular ANS dysfunction was present in TDPD, but not in ET and controls. HRV analysis and assessment of SBP drop may be potentially useful in the differential diagnosis of ET and TDPD.

Monitoring autonomic responses in Parkinson's disease individuals: non-linear and chaotic global metrics of heart rate variability

AIM

To examine and compare the autonomic responses, as assessed through the non-linear and chaotic global metrics of heart rate variability in two groups: the Parkinson's Disease Group (PDG) and the Control Group (CG), both at rest and during an active tilt test.

METHODS

The study encompassed 46 participants (PDG: n = 23; 73.73 ± 7.28 years old; CG: n = 23; 70.17 ± 8.20 years old). Initial data collection involved the acquisition of participant's characteristics. The autonomic modulation was estimated both at rest and during the active tilt test. For this assessment, we computed non-linear indices derived from five entropies (Approximate, Sample, Shannon, Renyi, Tsallis), Detrended Fluctuation Analysis and the seven chaotic global metrics (hsCFP1-hsCFP7).

RESULTS

At rest, the PDG exhibited lower values of hsCFP3 (0.818 ± 0.116 vs. 0.904 ± 0.065; p < 0.05) and Sample Entropy (0.720 ± 0.149 vs. 0.799 ± 0.171; p < 0.05). During the test, the PDG demonstrated lower values of ApEn, while the CG presented lower values of SampEn, hsCFP1, hsCFP3, hsCFP7, and higher values of hsCFP5. An interaction was observed, indicating that hsCFP1 and hsCFP3 exhibit differential behavior for the CG and PDG in response to the test.

CONCLUSION

subjects with PD exhibited reduced complexity of the RR interval series at rest, and a diminished autonomic response to the active tilt test when compared with the CG. The test, together with non-linear indices, may serve for assessing the Autonomic Nervous System in individuals with PD in a clinical setting. The interpretation of these data should be approached with caution, given the possible influences of pharmacotherapies and the inclusion of diabetic participants.

Baseline prevalence and longitudinal assessment of autonomic dysfunction in early Parkinson's disease

Autonomic dysfunction (AutD) is common and debilitating in Parkinson's disease (PD). Predictors of AutD are unclear, and data are limited on the biological relevance of AutD in PD. Here, we evaluated the baseline prevalence and 2-year longitudinal assessment of AutD in patients with de novo PD compared with healthy controls (HC). Moreover, we also assessed various variables that could predict longitudinal changes in AutD in early PD. Parkinson's Progression Markers Initiative (PPMI) was utilized to evaluate untreated PD participants at baseline and HC. Autonomic function was assessed using the 25-item Scale for Outcomes in Parkinson's Disease-Autonomic (SCOPA-AUT) score at baseline and 2 years. Clinical and biological variables were measured for their correlations with AuD for up to 2 years. Two hundred and ninety PD subjects and 170 HC were enrolled and followed for 2 years. SCOPA-AUT mean (SD) scores increased from baseline 8.49 ± 5.23 to 10.12 ± 5.77 at year 2 in PD subjects (p < 0.001) versus from 4.98 ± 3.34 to 5.03 ± 374 in HC (p = 0.496), with a significant difference between the groups (p < 0.001). Among them, 242 PD participants and 151 HC completed the SCOPA-AUT assessment, including sexual function. In the multivariate analysis, a higher baseline SCOPA-AUT score was associated with higher baseline MDS-UPDRS Part I scores (p < 0.001). Moreover, a longitudinal increase in autonomic function severity was associated with the white race (p = 0.010) at baseline. In contrast, there was no association with the CSF biomarkers. MDS-UPDRS Part I score may predict AuD in patients with early PD, which is correlated with nonmotor symptoms and race.

Setting the clinical context to non-motor symptoms reflected by Park-pain, Park-sleep, and Park-autonomic subtypes of Parkinson's disease

Non-motor symptoms (NMS) of Parkinson's disease (PD) are well described in both clinical practice and the literature, enabling their management and enhancing our understanding of PD. NMS can dominate the clinical pictures and NMS subtypes have recently been proposed, initially based on clinical observations, and later confirmed in data driven analyses of large datasets and in biomarker-based studies. In this chapter, we provide an update on what is known about three common subtypes of NMS in PD. The pain (Park-pain), sleep dysfunction (Park-sleep), and autonomic dysfunction (Park-autonomic), providing an overview of their individual classification, clinical manifestation, pathophysiology, diagnosis, and potential treatments.

Characteristics of fatigue in Parkinson’s disease: A longitudinal cohort study

Objective

To assess the prevalence, evolution, clinical characteristics, correlates and predictors of fatigue as well as to investigate the influence of comorbid fatigue on the longitudinal changes in motor and non-motor symptoms over a 2-year longitudinal follow-up period in a large cohort of patients with Parkinson’s disease (PD).

Materials and methods

A total of 2,100 PD patients were enrolled from the Parkinson’s Disease &amp; Movement Disorders Multicenter Database and Collaborative Network in China (PD-MDCNC), and their motor and non-motor symptoms were assessed biennially using comprehensive scales, including the 16-item Parkinson Fatigue Scale (PFS-16). Each PD patient was categorized as PD with or without fatigue on the basis of a cut-off mean PFS-16 score of 3.3.

Results

The prevalence of fatigue in our cohort was 36.8%. Compared to PD patients without fatigue, PD patients with fatigue were more likely to be older, have a longer disease duration, and higher baseline levodopa equivalent daily dose (all p &lt; 0.05). Moreover, PD patients with fatigue showed more severe motor and non-motor phenotypes than those without fatigue. Overall, high total Unified Parkinson’s Disease Rating Scale (UPDRS) score (odds ratio [OR] = 1.016, 95% confidence interval [CI]: 1.009–1.024), Non-Motor Symptoms Scale score (OR = 1.022, 95% CI: 1.015–1.029), postural instability and gait difficulty (PIGD) subtype (OR = 1.586, 95% CI: 1.211–2.079), presence of excessive daytime sleepiness (EDS; OR = 1.343, 95% CI: 1.083–1.666), and wearing-off (OR = 1.282, 95% CI: 1.023–1.607) were significantly associated with fatigue in PD patients (all p &lt; 0.05). High total UPDRS score at baseline (OR = 1.014, 95% CI: 1.002–1.027, p = 0.028) increased the risk of developing fatigue during follow-up. Although significant, the odds ratios were low and confidence intervals were narrow. Analysis of disease progression showed significant group differences in motor and non-motor symptoms. In comparison with the never-fatigue group, the persistent-fatigue group showed significantly greater progression in motor, autonomic dysfunction, sleep, depression and cognitive symptoms (all p &lt; 0.05).

Conclusion

Increased disease severity, presence of the PIGD subtype, EDS, and wearing-off were associated with fatigue in PD patients. Significant subgroup-level differences were observed in the progression of motor and non-motor symptoms across different fatigue subgroups of PD patients.

Beyond shallow feelings of complex affect: Non-motor correlates of subjective emotional experience in Parkinson's disease

Affective disorders in Parkinson's disease (PD) concern several components of emotion. However, research on subjective feeling in PD is scarce and has produced overall varying results. Therefore, in this study, we aimed to evaluate the subjective emotional experience and its relationship with autonomic symptoms and other non-motor features in PD patients. We used a battery of film excerpts to elicit Amusement, Anger, Disgust, Fear, Sadness, Tenderness, and Neutral State, in 28 PD patients and 17 healthy controls. Self-report scores of emotion category, intensity, and valence were analyzed. In the PD group, we explored the association between emotional self-reported scores and clinical scales assessing autonomic dysregulation, depression, REM sleep behavior disorder, and cognitive impairment. Patient clustering was assessed by considering relevant associations. Tenderness occurrence and intensity of Tenderness and Amusement were reduced in the PD patients. Tenderness occurrence was mainly associated with the overall cognitive status and the prevalence of gastrointestinal symptoms. In contrast, the intensity and valence reported for the experience of Amusement correlated with the prevalence of urinary symptoms. We identified five patient clusters, which differed significantly in their profile of non-motor symptoms and subjective feeling. Our findings further suggest the possible existence of a PD phenotype with more significant changes in subjective emotional experience. We concluded that the subjective experience of complex emotions is impaired in PD. Non-motor feature grouping suggests the existence of disease phenotypes profiled according to specific deficits in subjective emotional experience, with potential clinical implications for the adoption of precision medicine in PD. Further research on larger sample sizes, combining subjective and physiological measures of emotion with additional clinical features, is needed to extend our findings.

The longitudinal progression of autonomic dysfunction in Parkinson's disease: A 7-year study

Background

Autonomic dysfunction, including gastrointestinal, cardiovascular, and urinary dysfunction, is often present in early Parkinson's Disease (PD). However, the knowledge of the longitudinal progression of these symptoms, and the connection between different autonomic domains, is limited. Furthermore, the relationship between the presence of autonomic symptoms in early-stage PD and olfactory dysfunction, a possible marker of central nervous system involvement, has not been fully investigated.

Objectives

We aimed to investigate the occurrence and progression of autonomic dysfunction in recently diagnosed (< 2 years) untreated PD patients and determine any coexistence of symptoms in individual patients. We also investigated the relationship between autonomic symptoms, olfactory dysfunction, and motor impairment.

Methods

Data were obtained from the Parkinson's Progression Markers Initiative (PPMI) database. Autonomic dysfunction was measured using the Scales for Outcomes in Parkinson's Disease (SCOPA-AUT). Symptom frequency and mean scores over 7 years were determined. The simultaneous occurrence of different autonomic symptoms was also examined. Finally, the relationships between SCOPA-AUT scores, olfactory dysfunction, and motor impairment were investigated using the University of Pennsylvania Smell Identification Test (UPSIT) and the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), respectively.

Results

Follow-up data were available for 7 years for 171 PD patients and for 5 years for 136 HCs. Mean SCOPA-AUT score increased significantly from baseline to the 7-year follow-up for each autonomic domain, except for female sexual dysfunction. Most patients reported three or more autonomic symptoms. Common clusters of symptoms were composed of combinations of gastrointestinal, urinary, thermoregulatory, and sexual dysfunction. At baseline, greater SCOPA-AUT total score was associated with lower UPSIT scores (r = -0.209, p = 0.006) and with greater total MDS-UDPRS III score (r = 0.218, p = 0.004).

Conclusions

Autonomic dysfunction, often with coexistence of autonomic manifestations, is common in early PD and progressively worsens over the first 7 years of disease, suggesting that these symptoms should be addressed with appropriate treatments early in the disease. The association between greater autonomic dysfunction and greater olfactory impairment, coupled with the association with more severe motor scores at baseline, indicates that patients who show more severe autonomic dysfunction could also have more severe involvement of the central nervous system at the time of diagnosis.

Psychometric properties of the Autonomic Symptoms Checklist in the Lewy body disease module of the uniform dataset

INTRODUCTION

Autonomic dysfunction is an important feature of Lewy Body Dementia (DLB), but measurement of autonomic symptoms has been limited in both previous research and clinical practice. Accurate measurement of autonomic dysfunction has the potential to improve our understanding of the course and progression of DLB, given that autonomic symptoms typically precede cognitive impairment and are associated with functional impairment. The primary aim of this study was to examine the psychometric properties of the two versions (3.0 and 3.1) of the NACC LBD-module Autonomic Symptom Checklist (ASC).

METHODS

Psychometric analyses of the ASC (internal consistency, reliability, factor structure, and validity) were conducted on data acquired from 245 individuals with DLB from the NACC database. ASC V3.0 was contrasted on these attributes to V3.1.

RESULTS

Results suggested an underlying factor structure for the ASC, and confirmatory factor analysis (CFA) revealed 3 factors, which generally aligned with discrete autonomic systems. The ASC V3.0 and CFA-identified scales were comparable in terms of reliability, which were both improved relative to the ASC V3.1. In terms of ecological validity, CFA-identified items related to gastrointestinal/thermoregulation symptoms were significantly more associated with functional outcomes compared to the unitary ASC.

CONCLUSION

Findings underscore the importance of differentiation within the autonomic system. Future research into autonomic symptom classes and lab-based pathophysiological measurement of autonomic dysfunction in DLB has the potential to support early identification and inform treatment planning.

Prevalence of lower urinary tract symptoms, urinary incontinence and retention in Parkinson's disease: A systematic review and meta-analysis

Background

Lower urinary tract symptoms (LUTS) are common non-motor symptoms but are often overlooked in Parkinson's disease (PD). The prevalence of LUTS in PD is inconsistent among different studies.

Objective

To estimate the prevalence of LUTS, urinary incontinence, and urinary retention in PD patients, then, investigate potential sources of inconsistency in prevalence estimation.

Methods

We searched PubMed, EMBASE, and Web of Science databases from inception to May 2022. Studies reporting the prevalence of LUTS or LUTS subtypes in PD were included. Pooled prevalence of LUTS, LUTS subtypes, urinary incontinence, and urinary retention was calculated via random-effects models. Meta-regression and subgroup analyses were performed.

Results

Of 7,358 studies after duplicate removal, a total of 73 studies comprising 14,937 PD patients were included. The pooled prevalence of LUTS was 61% (95% CI 53–69; 27 studies; n = 5,179), while the pooled prevalence of storage symptoms and voiding symptoms was 59% (44–73; 9 studies; n = 798) and 24% (14–33; 11 studies; n = 886), respectively. The pooled prevalence of urinary incontinence, retention and post-void residual (PVR) volume ≥ 100 ml were 30% (95% CI 22–39; 21 studies; n = 6,054), 27% (17–37; 14 studies; n = 1,991), and 4% (1–7; 5 studies; n = 439), respectively. The prevalence of LUTS, urinary incontinence, or urinary retention was significantly associated with diagnostic methods.

Conclusion

LUTS and its subtypes present in a significant proportion of PD patients. It is necessary to use standardized and validated methods to detect and screen LUTS and its subtypes.

Systematic review registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022311233, Identifier: CRD42022311233.

Differential impact of individual autonomic domains on clinical outcomes in Parkinson's disease

INTRODUCTION

While autonomic failure is a well-known prognostic factor for more aggressive disease progression in Parkinson's disease (PD), with a three- to sevenfold higher risk of dementia and death within 10 years after the diagnosis, the individual impact of cardiovascular, gastrointestinal, urogenital, thermoregulatory, and pupillomotor autonomic domains on PD clinical outcomes remains unclear.

OBJECTIVES

We sought to determine the 5-year risk of developing dementia, falls, postural instability, dysarthria, and dysphagia in PD patients with and without autonomic impairment at baseline and to assess the joint and individual association of each autonomic domain on these key functional outcomes. In addition, we aimed to determine the impact of each autonomic domain on activities of daily living (ADLs) and health-related quality of life (HRQoL).

METHODS

We enrolled 65 consecutive PD patients in a 5-year cohort study involving standardized evaluations of autonomic symptoms, orthostatic hypotension, and motor and non-motor features, including cognitive function. Associations were estimated as odds ratio and adjusted for PD duration, age, and baseline motor impairment.

RESULTS

Cardiovascular dysautonomia was associated with a sevenfold higher risk of developing dementia (95%CI: 1.154-50.436; p = 0.035) and a fivefold higher risk of falls (95%CI: 1.099-18.949; p = 0.039), as well as significantly higher impairment in ADLs (p = 0.042) and HRQoL (p = 0.031). No relevant associations were found between the other autonomic domains and these outcomes.

CONCLUSIONS

Cardiovascular dysautonomia, but not other domains, showed an association with worse 5-year clinical outcomes in PD. Our data suggest a specific role for cardiovascular autonomic dysregulation in the pathogenic mechanisms of PD progression.

Postganglionic Sudomotor Assessment in Early Stage of Multiple System Atrophy and Parkinson Disease: A Morpho-functional Study

BACKGROUND AND OBJECTIVES

Sudomotor impairment has been recognized as a key feature in differentiating Parkinson disease (PD) and multiple system atrophy-parkinsonian type (MSA-P), with the latter characterized by diffuse anhidrosis in prospective study, including patients in late stage of disease. We aimed to evaluate morphologic and functional postganglionic sudomotor involvement in patients with newly diagnosed MSA-P and PD to identify possible biomarkers that might be of help in differentiating the 2 conditions in the early stage.

METHODS

One hundred patients with parkinsonism within 2 years from onset of motor symptoms were included in the study. At the time of recruitment, questionnaires to assess nonmotor, autonomic, and small fiber symptoms were administered, and patients underwent postganglionic sudomotor function assessment by the dynamic sweat test and punch skin biopsy from the distal leg. Skin samples were processed for indirect immunofluorescence with a panel of antibodies, including noradrenergic and cholinergic markers. The density of intraepidermal, sudomotor, and pilomotor nerve fibers was measured on confocal images with dedicated software. A follow-up visit 12 months after recruitment was performed to confirm the diagnosis.

RESULTS

We recruited 57 patients with PD (M/F 36/21, age 63.5 ± 9.4 years) and 43 patients with MSA-P (M/F 27/16, age 62.3 ± 9.0 years). Clinical scales and questionnaires showed a more severe clinical picture in patients with MSA-P compared to those with PD. Sweating output and intraepidermal, pilomotor, and sudomotor nerve densities, compared to controls, were lower in both groups but with a greater impairment in patients with MSA-P. Pilomotor and sudomotor nerve density correlated with sweating function and with nonmotor clinical symptoms. A composite sudomotor parameter defined as the arithmetic product of sweat production multiplied by the density of sudomotor fibers efficiently separated the 2 populations; the receiver operating characteristics curve showed an area under the curve of 0.83.

DISCUSSION

Dynamic sweat test and the quantification of cutaneous autonomic nerves proved to be a sensitive morpho-functional approach to assess the postganglionic component of the sudomotor pathway, revealing a more severe involvement in MSA-P than in PD early in the disease course. This approach can be applied to differentiate the 2 conditions early.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that postganglionic sudomotor morpho-functional assessment accurately distinguish patients with PD from patients with MSA-P.

Pathophysiology and Symptomatology of Drooling in Parkinson’s Disease

Drooling can present in patients with Parkinson’s disease (PD), and it is manifested as an excessive pooling of saliva inside the oral cavity. Currently, the exact pathophysiological mechanism of drooling in PD is not yet fully explicated. Thus, it becomes crucial to understand if some clinical characteristics may emphasize drooling or if they are just concomitant. In PD, excessive drooling has been associated with a higher burden of non-motor symptoms, such as cognitive impairment, sleep problems, autonomic dysfunction, constipation and orthostatic hypotension, and of worse severity of motor fluctuations and bradykinesia. PD patients with excessive drooling also showed a reduction of striatal DAT availability at DaTSCAN imaging. Excessive drooling in patients with Parkinson’s cannot be attributed to a single factor but to a mixture of factors, including but not limited to impaired nigrostriatal pathways.

Neurodegeneration in the centrally-projecting Edinger-Westphal nucleus contributes to the non-motor symptoms of Parkinson's disease in the rat

BACKGROUND

The neuropathological background of major depression and anxiety as non-motor symptoms of Parkinson's disease is much less understood than classical motor symptoms. Although, neurodegeneration of the Edinger-Westphal nucleus in human Parkinson's disease is a known phenomenon, its possible significance in mood status has never been elucidated. In this work we aimed at investigating whether neuron loss and alpha-synuclein accumulation in the urocortin 1 containing (UCN1) cells of the centrally-projecting Edinger-Westphal (EWcp) nucleus is associated with anxiety and depression-like state in the rat.

METHODS

Systemic chronic rotenone administration as well as targeted leptin-saporin-induced lesions of EWcp/UCN1 neurons were conducted. Rotarod, open field and sucrose preference tests were performed to assess motor performance and mood status. Multiple immunofluorescence combined with RNAscope were used to reveal the functional-morphological changes. Two-sample Student's t test, Spearman's rank correlation analysis and Mann-Whitney U tests were used for statistics.

RESULTS

In the rotenone model, besides motor deficit, an anxious and depression-like phenotype was detected. Well-comparable neuron loss, cytoplasmic alpha-synuclein accumulation as well as astro- and microglial activation were observed both in the substantia nigra pars compacta and EWcp. Occasionally, UCN1-immunoreactive neuronal debris was observed in phagocytotic microglia. UCN1 peptide content of viable EWcp cells correlated with dopaminergic substantia nigra cell count. Importantly, other mood status-related dopaminergic (ventral tegmental area), serotonergic (dorsal and median raphe) and noradrenergic (locus ceruleus and A5 area) brainstem centers did not show remarkable morphological changes. Targeted partial selective EWcp/UCN1 neuron ablation induced similar mood status without motor symptoms.

CONCLUSIONS

Our findings collectively suggest that neurodegeneration of urocortinergic EWcp contributes to the mood-related non-motor symptoms in toxic models of Parkinson's disease in the rat.

Motor and non-motor circuit disturbances in early Parkinson disease: which happens first?

For the last two decades, pathogenic concepts in Parkinson disease (PD) have revolved around the toxicity and spread of α-synuclein. Thus, α-synuclein would follow caudo-rostral propagation from the periphery to the central nervous system, first producing non-motor manifestations (such as constipation, sleep disorders and hyposmia), and subsequently impinging upon the mesencephalon to account for the cardinal motor features before reaching the neocortex as the disease evolves towards dementia. This model is the prevailing theory of the principal neurobiological mechanism of disease. Here, we scrutinize the temporal evolution of motor and non-motor manifestations in PD and suggest that, even though the postulated bottom-up mechanisms are likely to be involved, early involvement of the nigrostriatal system is a key and prominent pathophysiological mechanism. Upcoming studies of detailed clinical manifestations with newer neuroimaging techniques will allow us to more closely define, in vivo, the role of α-synuclein aggregates with respect to neuronal loss during the onset and progression of PD.

Autonomic and Depression Symptoms in Parkinson's Disease: Clinical Evidence for Overlapping Physiology

BACKGROUND

Autonomic dysfunction and depression are common non-motor symptoms of Parkinson's disease (PD) that confer poorer prognosis. These PD symptoms may have overlapping pathophysiologic underpinnings.

OBJECTIVE

To investigate associations between autonomic and depression symptoms in early PD, and their evolution over time.

METHODS

We obtained data from the Parkinson's Progression Markers Initiative, a prospective open-access database of early PD. Regression analyses were used to model effects of depression on autonomic symptoms in controls and in PD at baseline, visit 6 (24 months after baseline), and visit 12 (60 months after baseline), correcting for multiple comparisons.

RESULTS

Data from 421 people with PD at baseline, 360 at visit 6, 300 at visit 12, and 193 controls were included. When controlling for age, depression, and anti-hypertensive medications, depression predicted autonomic symptoms in all groups. Accounting for motor symptoms did not alter these associations. When comparing groups, the influence of depression on autonomic symptoms was stronger in all PD groups compared to controls, and strongest in PD at visit 12. Depression predicted the presence of orthostatic hypotension only in the PD group at visit 12.

CONCLUSION

We demonstrated the important impact of depression on autonomic symptoms in early and middle stages of PD, which are independent of motor symptoms. Though the physiologic basis of these two PD symptoms are not fully understood, our findings add to pathologic evidence of a shared mechanistic substrate, separate from that responsible for PD motor symptoms. These findings may influence clinical management and development of novel therapies.

Self-Reported Visual Complaints in People with Parkinson's Disease: A Systematic Review

BACKGROUND

Scientific research increasingly focuses on visual symptoms of people with Parkinson's disease (PD). However, this mostly involves functional measures, whereas self-reported data are equally important for guiding clinical care.

OBJECTIVE

This review provides an overview of the nature and prevalence of self-reported visual complaints by people with PD, compared to healthy controls.

METHODS

A systematic literature search was performed. Studies from three databases (PubMed, PsycInfo, and Web of Science) were screened for eligibility. Only studies that reported results of visual self-reports in people with idiopathic PD were included.

RESULTS

One hundred and thirty-nine eligible articles were analyzed. Visual complaints ranged from function-related complaints (e.g., blurred vision, double vision, increased sensitivity to light or changes in contrast sensitivity) to activity-related complaints (e.g., difficulty reading, reaching, or driving). Visual complaints were more prevalent in people with PD compared to healthy controls. The presence of visual complaints leads to a reduced quality of life (QoL). Increased prevalence and severity of visual complaints in people with PD are related to longer disease duration, higher disease severity, and off-state.

CONCLUSION

A large proportion of people with PD have visual complaints, which negatively affect QoL. Complaints are diverse in nature, and specific and active questioning by clinicians is advised to foster timely recognition, acknowledgement, and management of these complaints.

Characteristics of Autonomic Dysfunction in Parkinson's Disease: A Large Chinese Multicenter Cohort Study

Autonomic dysfunction (AutD) is one of the non-motor symptoms (NMSs) in Parkinson's disease (PD). To investigate the prevalence and clinical features of AutD in Chinese patients with PD, a large multicenter cohort of 2,556 individuals with PD were consecutively involved in the Parkinson's Disease and Movement Disorders Multicenter Database and Collaborative Network in China (PD-MDCNC) between January 1, 2017, and December 31, 2019. The assessment of AutD was performed using the Scale for Outcomes in Parkinson's Disease for Autonomic Symptoms (SCOPA-AUT). The evaluation of motor symptoms and other NMSs were performed using well-established scales recommended by the Movement Disorder Society. We found that out of 2,556 patients with PD, 2,333 patients with PD (91.28%) had AutD. Compared with the group of patients with PD without AutD, the group of patients with PD with AutD had older age, older age of onset, longer disease duration, more severe motor symptoms, motor complications, and more frequent NMSs. As for partial correlation analysis, the total SCOPA-AUT score was significantly and positively associated with motor severity scales [Unified Parkinson's Disease Rating Scale (UPDRS) total score] and some of the NMSs [Rapid Eye Movement Sleep Behavior Disorder Questionnaire (RBD), Epworth Sleepiness Scale, Hamilton Depression Scale], Fatigue Severity Scale, and Parkinson's disease questionnaire. PD Sleep Scale was significantly and negatively correlated with AutD. With logistic regression analysis for potentially related factors, age, UPDRS total score, RBD, hyposmia, depression, and fatigue may be associated with PD with AutD. In conclusion, our multicenter cohort study reported the high prevalence of AutD in Chinese PD and revealed the associated factors of PD with AutD.

Neuro-Immunity and Gut Dysbiosis Drive Parkinson's Disease-Induced Pain

Parkinson's disease (PD) is the second most common neurodegenerative disorder, affecting 1-2% of the population aged 65 and over. Additionally, non-motor symptoms such as pain and gastrointestinal dysregulation are also common in PD. These impairments might stem from a dysregulation within the gut-brain axis that alters immunity and the inflammatory state and subsequently drives neurodegeneration. There is increasing evidence linking gut dysbiosis to the severity of PD's motor symptoms as well as to somatosensory hypersensitivities. Altogether, these interdependent features highlight the urgency of reviewing the links between the onset of PD's non-motor symptoms and gut immunity and whether such interplays drive the progression of PD. This review will shed light on maladaptive neuro-immune crosstalk in the context of gut dysbiosis and will posit that such deleterious interplays lead to PD-induced pain hypersensitivity.

A Neurologist's Practical Approach to Cognitive Impairment

The global prevalence of dementia is expected to triple by the year 2050. This impending health care crisis has led to new heights of public awareness and general concern regarding cognitive impairment. Subsequently, clinicians are seeing more and more people presenting with cognitive concerns. It is important that clinicians meet these concerns with a strategy promoting accurate diagnoses. We have diagramed and described a practical approach to cognitive impairment. Through an algorithmic approach, we determine the presence and severity of cognitive impairment, systematically evaluate domains of function, and use this information to determine the next steps in evaluation. We also discuss how to proceed when cognitive impairment is associated with motor abnormalities or rapid progression.

Heterogeneity of prodromal Parkinson symptoms in siblings of Parkinson disease patients

A prodromal phase of Parkinson's disease (PD) may precede motor manifestations by decades. PD patients' siblings are at higher risk for PD, but the prevalence and distribution of prodromal symptoms are unknown. The study objectives were (1) to assess motor and non-motor features estimating prodromal PD probability in PD siblings recruited within the European PROPAG-AGEING project; (2) to compare motor and non-motor symptoms to the well-established DeNoPa cohort. 340 PD siblings from three sites (Bologna, Seville, Kassel/Goettingen) underwent clinical and neurological evaluations of PD markers. The German part of the cohort was compared with German de novo PD patients (dnPDs) and healthy controls (CTRs) from DeNoPa. Fifteen (4.4%) siblings presented with subtle signs of motor impairment, with MDS-UPDRS-III scores not clinically different from CTRs. Symptoms of orthostatic hypotension were present in 47 siblings (13.8%), no different to CTRs (p = 0.072). No differences were found for olfaction and overall cognition; German-siblings performed worse than CTRs in visuospatial-executive and language tasks. 3/147 siblings had video-polysomnography-confirmed REM sleep behavior disorder (RBD), none was positive on the RBD Screening Questionnaire. 173/300 siblings had <1% probability of having prodromal PD; 100 between 1 and 10%, 26 siblings between 10 and 80%, one fulfilled the criteria for prodromal PD. According to the current analysis, we cannot confirm the increased risk of PD siblings for prodromal PD. Siblings showed a heterogeneous distribution of prodromal PD markers and probability. Additional parameters, including strong disease markers, should be investigated to verify if these results depend on validity and sensitivity of prodromal PD criteria, or if siblings' risk is not elevated.

Longitudinal Changes in Parkinson's Disease Symptoms with and Without Rapid Eye Movement Sleep Behavior Disorder: The Oxford Discovery Cohort Study

BACKGROUND

Parkinson's disease (PD) comorbid with rapid eye movement sleep behavior disorder (RBD) may show more severe motor and nonmotor symptoms, suggesting a distinct PD subtype.

OBJECTIVE

The aim of this study was to investigate the impact of RBD on the longitudinal change of motor and nonmotor symptoms in patients with PD.

METHODS

Patients with early PD (diagnosed within 3.5 years) recruited from 2010 to 2019 were followed every 18 months in the Oxford Parkinson's Disease Centre Discovery cohort. At each visit, we used standard questionnaires and measurements to assess demographic features and motor and nonmotor symptoms (including RBD, daytime sleepiness, mood, autonomic symptoms, cognition, and olfaction). Data were analyzed with linear mixed effects and Cox regression models. Possible RBD (pRBD) was longitudinally determined according to RBD Screening Questionnaire scores.

RESULTS

A total of 923 patients were recruited (mean age: 67.1 ± 9.59 years; 35.9% female), and 788 had follow-up assessment(s) (mean: 4.8 ± 1.98 years, range: 1.3-8.3). Among them, 33.3% were identified as pRBD (PD + pRBD). Patients with PD + pRBD had more severe baseline symptoms and showed faster progression on Movement Disorder Society-Unified Parkinson's Disease Rating Scale parts I and III, Purdue Pegboard test, and Beck Depression Inventory scores. Moreover, PD + pRBD was associated with an increased level of risk for mild cognitive impairment (hazard ratio [HR] = 1.36, 95% confidence interval [CI]: 1.01-1.83), freezing of gait (HR = 1.42, 95% CI: 1.10-1.86), and frequent falling (HR = 1.62, 95% CI: 1.02-2.60).

CONCLUSIONS

Patients with PD + pRBD progress faster on motor, mood, and cognitive symptoms, confirming a more aggressive PD subtype that can be identified at baseline and has major clinical implications. © 2021 International Parkinson and Movement Disorder Society.

The Relationship Between Anxiety Disorders and Parkinson's Disease: Clinical and Therapeutic Issues

PURPOSE OF REVIEW

This paper seeks to describe anxiety's different symptomatologic presentations in Parkinson's disease (PD), its longitudinal course and predictors, as well as its motor and non-motor correlates. It also reviews the available screening tools and different treatment modalities.

RECENT FINDINGS

In PD, longitudinal predictors of anxiety are mostly non-motor non-dopaminergic symptoms. The longitudinal course of anxiety is mainly a stable one. The Parkinson Anxiety Scale and the Geriatric Anxiety Scale are the 2 recommended screening tools. A third of PD patients suffer from an anxiety disorder at any time point. It can precede or follow PD motor symptoms. Anxiety is associated with demographic, disease-related motor and non-motor features. There is a lack of studies evaluating psychotropic treatment of anxiety in PD. Adjustment of dopaminergic treatment is indicated when anxiety is associated with motor fluctuations. DBS can be useful as well as CBT and body-mind interventions.

Potential treatment of Parkinson's disease using new-generation carbon nanotubes: a biomolecular in silico study

Background: One of the underlying mechanisms of Parkinson's disease is the aggregation of α-synuclein proteins, including amyloids and Lewy bodies in the brain. Aim: To study the inhibitory effect of doped carbon nanotubes (CNTs) on amyloid aggregation. Materials & methods: Molecular dynamics tools were utilized to simulate the influence of CNTs doped with phosphorus, nitrogen and bromine and nitrogen on the formation of α-synuclein amyloid. Results: The CNTs exhibited strong interactions with α-synuclein, with phosphorus-doped CNTs having the most substantial interactions. Conclusion: Doped-CNTs, especially phosphorus-doped carbon nanotube could effectively prevent α-synuclein amyloid formation, thus, it could be considered as a potential treatment for Parkinson's disease. However, further in vitro and clinical investigations are required.

Clinical features associated with drooling in Parkinson's disease

INTRODUCTION

Drooling is characterized by an excessive pooling of saliva in the oral cavity. The exact pathophysiological mechanism of drooling in Parkinson's disease (PD) is not yet fully understood.

OBJECTIVE

To identify the relationship between drooling and other clinical features in people diagnosed with PD.

METHOD

Research on the topic was carried out on the PubMed and ScienceDirect electronic databases. Articles published between March 2015 and March 2020 were selected. Search terms and inclusion and exclusion criteria were previously defined. The articles included met those requirements.

RESULTS

Sixteen articles were included for analysis. The prevalence of drooling varies between 9.26 and 70% and can occur at any stage of the disease. Higher prevalence of drooling is related to disease duration, disease severity, older age, male, levodopa equivalent dose, hypomimia, dysphagia, dysarthria, cognition, sleep, non-dominant tremor, motor fluctuations, bradykinesia, more symmetric pattern, gastrointestinal and urinary problems, sexual dysfunction, obstipation, and orthostatic hypotension. However, it is not related to hallucinations, rapid eye movement sleep behavior disorder, akinetic-rigid PD, mixed, nor dyskinesias.

CONCLUSION

Drooling is not caused by a single factor; it is influenced and related to several clinical features. Some clinical factors participate in the onset of drooling while others are concomitant.

Autonomic Dysfunctions in Parkinson's Disease: Prevalence, Clinical Characteristics, Potential Diagnostic Markers, and Treatment

Parkinson's disease (PD) is a common neurodegenerative disease in the middle-aged and the elderly. Symptoms of autonomic dysfunctions are frequently seen in PD patients, severely affecting the quality of life. This review summarizes the epidemiology, clinical manifestations, and treatment options of autonomic dysfunctions. The clinical significance of autonomic dysfunctions in PD early diagnosis and differential diagnosis is also discussed.

Clinical and Epidemiological Aspects of Parkinson's Disease in the South of Western Siberia

Background: The article is devoted to one of the most common neurodegenerative diseases in the world-Parkinson's disease (PD), the prevalence of which in Russia reaches 140-150 people per 100,000 people. The clinical and anamnestic profile of a patient with PD is presented, the prevalence of motor and non-motor symptoms is reflected, and a comparative characteristic of the neurological deficit in the Siberian population of patients with other cohorts of patients with Parkinson's disease in different countries and ethnic groups is presented. Methods: We studied 140 patients with Parkinson's disease. A comprehensive assessment of neurological status was performed using the "Unified Parkinson's Disease Rating Scale (UPDRS)." In addition, we used the Beck Depression and MoCA scale test. Assessment of the presence and severity of olfactory dysfunction was performed using the Sniffin Stick odor identification test. The stage of PD was evaluated according to the classification of M. M. Hoehn and M. D. Yahr. Results: The cohort of the study was dominated by overweight patients with a higher level of education, with concomitant arterial hypertension, coronary heart disease, and dyslipidemia. The severity of motor and most non-motor symptoms directly correlates with the duration of PD and the stage of the disease. The predominant form of the disease was a mixed form, which was also noted in research cohorts in Canada and the UK. The Siberian cohort tends to be more prevalent in hyposmia, daytime sleepiness, orthostatic hypotension, and depressive and REM disorders. Conclusion: Our data show the importance of a comprehensive assessment of both motor and non-motor neurological deficits as well as the analysis of comorbid disorders and risk factors for the occurrence and progression of Parkinson's disease. They also show the prevalence of certain motor and non-motor symptoms in the Siberian cohort of patients with Parkinson's disease.

Lower Urinary Tract and Gastrointestinal Dysfunction Are Common in Early Parkinson's Disease

Purpose

Autonomic dysfunction is a common nonmotor feature and early manifestation of Parkinsons disease (PD). Autonomic dysfunction in PD is associated with a worse prognosis. We sought to characterize autonomic dysfunction and identify associated factors in patients with early PD.

Methods

An observational, cross-sectional, descriptive, and analytical study was conducted to evaluate patients with early PD from the Parkinsons Progression Markers Initiative. We utilized the Scales for Outcomes in Parkinsons Disease-Autonomic dysfunction questionnaire to determine the prevalence and frequencies of autonomic symptomatology. The cohort was grouped into high and low dysautonomic scores. A regression model identified variables that independently explained dysautonomic scores in our early PD cohort.

Results

414 PD patients had a mean age of 61.1 (SD 9.7) years at diagnosis and mean disease duration of 6.7 (SD 6.6) months. Among all patients, 43.7% (181/414) had high dysautonomic scores. Urinary and gastrointestinal symptoms were the most prevalent and frequently reported dysautonomic symptoms. Patients with fatigue (beta = 4.28, p < 0.001), probable rapid eye movement sleep behavior disorder (beta = 2.71, p < 0.001), excessive daytime sleepiness (beta = 1.88,p=0.039), impulsivity and compulsivity (beta = 2.42, p < 0.001), and increasing age (beta = 1.05, p < 0.001) were more likely to have high dysautonomic scores.

Conclusion

Lower urinary tract and gastrointestinal symptoms are prevalent and frequent in early PD patients. Fatigue, sleep disorders, impulsivity and compulsivity, and age are predictors of autonomic dysfunction. Autonomic symptoms predominated in this group of early PD patients in the disease course and were associated with more severe disease.

Autonomic Dysfunction in Parkinson's Disease

Recognition of the importance of nonmotor dysfunction as a component of Parkinson's disease has exploded over the past three decades. Autonomic dysfunction is a frequent and particularly important nonmotor feature because of the broad clinical spectrum it covers. Cardiovascular, gastrointestinal, urinary, sexual, and thermoregulatory abnormalities all can appear in the setting of Parkinson's disease. Cardiovascular dysfunction is characterized most prominently by orthostatic hypotension. Gastrointestinal dysfunction can involve virtually all levels of the gastrointestinal tract. Urinary dysfunction can entail either too frequent voiding or difficulty voiding. Sexual dysfunction is frequent and frustrating for both patient and partner. Alterations in sweating and body temperature are not widely recognized but often are present. Autonomic dysfunction can significantly and deleteriously impact quality of life for individuals with Parkinson's disease. Because effective treatment for many aspects of autonomic dysfunction is available, it is vitally important that assessment of autonomic dysfunction be a regular component of the neurologic history and exam and that appropriate treatment be initiated and maintained.

Autonomic dysfunction is associated with neuropsychological impairment in Lewy body disease

OBJECTIVE

This study aimed to analyze the association of autonomic dysfunction with cognition, depression, apathy, and fatigue in Lewy body disease (LBD).

METHODS

We included 61 patients [49 with idiopathic Parkinson's disease, 7 with dementia with Lewy bodies, and 5 E46K-SNCA mutation carriers] and 22 healthy controls. All participants underwent a comprehensive battery of neuropsychological and clinical measures, autonomic symptom assessment with the SCOPA-AUT, analysis of non-invasive hemodynamic parameters during deep breathing, the Valsalva maneuver, and a 20-min tilt test, and electrochemical skin conductance measurement at rest (Sudoscan). Student's t tests were used to assess group differences, and bivariate correlations and stepwise linear regressions to explore associations between autonomic function, cognition, depression, apathy, and fatigue.

RESULTS

Compared to controls, patients who had significant impairment (p < 0.05) in cognition, higher depression, apathy, and fatigue, more autonomic symptoms and objective autonomic dysfunction, reduced deep breathing heart rate variability [expiratory-to-inspiratory (E/I) ratio], prolonged pressure recovery time, and lower blood pressure in Valsalva late phase II and phase IV, while 24.1% had orthostatic hypotension in the tilt test. Autonomic parameters significantly correlated with cognitive and neuropsychiatric outcomes, systolic blood pressure during the Valsalva maneuver predicting apathy and depression. The E/I ratio was the main predictor of cognitive performance (17.6% for verbal fluency to 32.8% for visual memory).

CONCLUSION

Cardiovascular autonomic dysfunction is associated with cognitive and neuropsychiatric impairment in LBD, heart rate variability during deep breathing and systolic blood pressure changes during the Valsalva procedure are the main predictors of neuropsychological performance and depression/apathy symptoms, respectively.