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Abstract Acoustic myography (AMG) noninvasively probes muscle activity. We explored whether AMG captures abnormal motor activity in patients with Parkinson's disease (PD) and how this activity is modulated by antiparkinsonian medication. Twenty patients with PD underwent AMG of the biceps, triceps, extensor carpi radialis longus, and adductor policis muscles of the more affected arm during active and passive movements, using a mobile AMG device (CURO, Denmark). AMG and assessment of motor symptoms were performed in a pragmatic off‐medication state, as well as one and 3 h after oral intake of 200 mg levodopa. Three AMG parameters were calculated using the CURO analysis system. Motor efficiency was expressed by the E‐score, muscle fiber recruitment by the temporal T‐score, spatial summation by the S‐score, and S/T ratio. Twenty age‐ and sex‐matched healthy subjects served as controls. Group mean values were statistically compared using unpaired two‐tailed adjusted t‐test and ANOVA with Tukey´s correction for multiple comparison (p ≤ 0.05). For the biceps and extensor carpi radialis longus muscles, the active movement S:T ratio was lower in PD relative to healthy controls. The E‐score was also lower during active and passive flexion/extension movements in the off‐medication state. No significant between‐group differences in the AMG scores were noted for the triceps muscle during active or passive movements. The active S:T ratio and the E‐score during active elbow flexion and extension may offer a useful means to quickly assess abnormal motor activity and the effect of drug treatment in PD.

Abstract Background Intracellular deposition of alpha‐synuclein (α‐syn) as Lewy bodies and Lewy neurites is a central event in the pathogenesis of Parkinson's disease (PD) and other α‐synucleinopathies. Transgenic mouse models overexpressing human α‐syn, are useful research tools in preclinical studies of pathogenetic mechanisms. Such mice develop α‐syn inclusions as well as neurodegeneration with a topographical distribution that varies depending on the choice of promoter and which form of α‐syn that is overexpressed. Moreover, they display motor symptoms and cognitive disturbances that to some extent resemble the human conditions. Purpose One of the main motives for assessing behavior in these mouse models is to evaluate the potential of new treatment strategies, including their impact on motor and cognitive symptoms. However, due to a high within‐group variability with respect to such features, the behavioral studies need to be applied with caution. In this review, we discuss how to make appropriate choices in the experimental design and which tests that are most suitable for the evaluation of PD‐related symptoms in such studies. Methods We have evaluated published results on two selected transgenic mouse models overexpressing wild type (L61) and mutated (A30P) α‐syn in the context of their validity and utility for different types of behavioral studies. Conclusions By applying appropriate behavioral tests, α‐syn transgenic mouse models provide an appropriate experimental platform for studies of symptoms related to PD and other α‐synucleinopathies.

Abstract Introduction Bradyphrenia is a key cognitive feature in Parkinson's disease (PD). There is no consensus on whether information processing speed is impaired or not beyond motor performance. Objective This study aims to explore which perceptual, motor, or cognitive components of information processing are involved in the slowdown affecting cognitive performance. Methods The study included 48 patients with PD (age: 63, 3 ± 8, 18; HY I‐III; UPDRS 15,46 ± 7,76) and 53 healthy controls (age: 60,09 ± 12,83). Five reaction time (RT) tasks were administered to all participants. The average RT in each of the tasks and the percentage of correct answers were measured. Patients with PD were in "ON state" at the time of the evaluation. Perceptual, motor, and cognitive components were isolated by means of a series of ANCOVAs. Results As expected, the motor component was slowed down in patients with PD. Moreover, while patients with PD showed slower RT than controls in all tasks, differences between groups did not exponentially increase with the increasing task complexity. ANCOVA analyses also revealed that the perceptual and sustained alert component resulted to be slowed down, with no differences being found in any of the remaining isolated cognitive components (i.e., response strategy‐inhibition, decisional, visual search, or interference control). Conclusions The results revealed that slowness of information processing in PD was mainly associated with an impaired processing speed of the motor and perceptual‐alertness components analyzed. The results may help designing new neurorehabilitation strategies, focusing on the improvement of perceptual and alertness mechanisms.

Background: The known impairments of the cardiovascular system in Parkinson´s disease (PD) are caused by autonomic dysfunction and manifested mainly in postural hypotension, chronotropic insufficiency, and reduced heart rate variability. Other dysfunctions, mainly stress response, arrhythmia occurrence, and heart morphology changes, are still the subject of research., Objectives: To assess the heart rate and blood pressure reaction during exercise, advanced measurements of heart volumes and mass using cardiac magnetic resonance (CMR), and occurrence of arrhythmias in PD patients., Methods: Thirty PD patients (19 men, mean age 57.5 years) without known cardiac comorbidities underwent bicycle ergometry, electrocardiogram Holter monitoring and CMR. Exercise and CMR parameters were compared with controls (24 subjects for ergometry, 20 for CMR)., Results: PD patients had lower baseline systolic blood pressure (SBP) (117.8 vs. 128.3 mmHg, p < 0.01), peak SBP (155.8 vs. 170.8 mmHg, p < 0.05), and lower heart rate increase (49.7 vs. 64.3 beats per minute, p < 0.01). PD patients had higher indexed left and right ventricular end-diastolic volumes (68.5 vs. 57.3, p = 0.003 and 73.5 vs. 61.0 mL/m 2 , respectively) and also indexed left and right ventricular end-systolic volumes (44.1 vs. 39.0, p = 0.013 and 29.0 vs. 22.0 mL/m 2 , p = 0.013, respectively). A high prevalence of atrial fibrillation (8 subjects, 26.7%) was found., Conclusions: This novel study combining functional and structural approaches showed that PD is linked with weaker blood pressure and heart rate reaction during exercise, increased myocardial mass and heart volumes compared to controls, and a high prevalence of atrial fibrillation., (© 2023 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Background: Parkinson´s disease (PD) has a large phenotypic variability, which may, at least partly, be genetically driven including alterations of gene products. Candidates might not only be proteins associated with disease risk but also pathways that play a role in aging., Objective: To evaluate phenotype-modifying effects of genetic variants in Klotho, a longevity gene., Methods: We analyzed two longitudinal cohorts: one local cohort comprising 459 PD patients who underwent genotyping for the KL-VS haplotype in Klotho including a subgroup of 125 PD patients and 50 healthy controls who underwent biochemical cerebrospinal fluid (CSF) analyses of Klotho and fibroblast growth factor 23 as well as vitamin D metabolites. The second cohort comprised 297 patients from the Parkinson's Progression Markers Initiative (PPMI) for validation of genetic-clinical findings., Results: PD patients carrying the KL-VS haplotype demonstrated a shorter interval between PD onset and onset of cognitive impairment (both cohorts) and higher Unified Parkinson´s Disease Rating Scale part III (UPDRS III) scores (PPMI). CSF protein levels of Klotho and fibroblast growth factor 23 were lower in PD patients irrespective of gender compared to controls. Moreover, low CSF levels of Klotho were associated with higher scores in the UPDRS III and Hoehn and Yahr Scale., Conclusions: Our results indicate that genetic variants in Klotho together with its corresponding CSF protein profiles are associated with aspects of disease severity in PD. These findings suggest that pathways associated with aging might be targets for future biomarker research in PD., (© 2021 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)