scholarly journals Cross-frequency phase-amplitude coupling in repetitive movements in patients with Parkinson's disease

Author(s):  
Ruxue Gong ◽  
Christoph Mühlberg ◽  
Mirko Wegscheider ◽  
Christopher Fricke ◽  
Jost-Julian Rumpf ◽  
...  

Bradykinesia is a cardinal motor symptom in Parkinson's disease whose pathophysiology is incompletely understood. When signals are recorded from the cortex or scalp at rest, affected patients display enhanced phase-amplitude coupling between β (13-30Hz) and broadband γ (50-150Hz) oscillatory activities. However, it remains unclear whether and how abnormal phase-amplitude coupling is involved in slowing Parkinsonian movements during their execution. To address these questions, we analyzed high-density EEG signals recorded simultaneously with various motor activities and at rest in 19 patients with Parkinson's disease and 20 healthy controls. The motor tasks consisted of repetitive index finger pressing, and slow and fast tapping movements. Individual EEG source signals were computed for the premotor cortex, primary motor cortex, primary somatosensory cortex, and primary somatosensory complex. For the resting condition and the pressing task, phase-amplitude coupling averaged over the 4 motor regions and the entire movement period was larger in patients than in controls. In contrast, in all tapping tasks, state-related phase-amplitude coupling was similar between patients and controls. These findings were not aligned with motor performance and EMG data, which showed abnormalities in patients for tapping but not for pressing, suggesting that the strength of β-broadband γ phase-amplitude coupling during the movement period does not directly relate to Parkinsonian bradykinesia. Subsequently, we examined the dynamics of oscillatory EEG signals during motor transitions. When healthy controls performed the pressing task, dynamic phase-amplitude coupling increased shortly before pressing onset and decreased subsequently. A strikingly similar motif of coupling rise and decay was observed around the offset of pressing and around the onset of slow tapping, suggesting that such transient phase-amplitude coupling changes may be linked to transitions between different movement states - akin to preparatory states in dynamical systems theory of motor control. In patients, the modulation of phase-amplitude coupling was similar in (normally executed) pressing, but flattened in slow (abnormally executed) tapping compared to the controls. These deviations in phase-amplitude coupling around motor action transients may indicate dysfunctional evolution of neuronal population dynamics from the preparatory state to movement generation in Parkinson's disease. These findings may indicate that cross-frequency coupling is involved in the pathophysiology of bradykinesia in Parkinson's disease through its abnormal dynamic modulation.

Brain ◽  
2020 ◽  
Author(s):  
Ruxue Gong ◽  
Mirko Wegscheider ◽  
Christoph Mühlberg ◽  
Richard Gast ◽  
Christopher Fricke ◽  
...  

Abstract Abnormal phase-amplitude coupling between β and broadband-γ activities has been identified in recordings from the cortex or scalp of patients with Parkinson’s disease. While enhanced phase-amplitude coupling has been proposed as a biomarker of Parkinson’s disease, the neuronal mechanisms underlying the abnormal coupling and its relationship to motor impairments in Parkinson’s disease remain unclear. To address these issues, we performed an in-depth analysis of high-density EEG recordings at rest in 19 patients with Parkinson’s disease and 20 age- and sex-matched healthy control subjects. EEG signals were projected onto the individual cortical surfaces using source reconstruction techniques and separated into spatiotemporal components using independent component analysis. Compared to healthy controls, phase-amplitude coupling of Parkinson’s disease patients was enhanced in dorsolateral prefrontal cortex, premotor cortex, primary motor cortex and somatosensory cortex, the difference being statistically significant in the hemisphere contralateral to the clinically more affected side. β and γ signals involved in generating abnormal phase-amplitude coupling were not strictly phase-phase coupled, ruling out that phase-amplitude coupling merely reflects the abnormal activity of a single oscillator in a recurrent network. We found important differences for couplings between the β and γ signals from identical components as opposed to those from different components (originating from distinct spatial locations). While both couplings were abnormally enhanced in patients, only the latter were correlated with clinical motor severity as indexed by part III of the Movement Disorder Society Unified Parkinson’s Disease Rating Scale. Correlations with parkinsonian motor symptoms of such inter-component couplings were found in premotor, primary motor and somatosensory cortex, but not in dorsolateral prefrontal cortex, suggesting motor domain specificity. The topography of phase-amplitude coupling demonstrated profound differences in patients compared to controls. These findings suggest, first, that enhanced phase-amplitude coupling in Parkinson’s disease patients originates from the coupling between distinct neural networks in several brain regions involved in motor control. Because these regions included the somatosensory cortex, abnormal phase-amplitude coupling is not exclusively tied to the hyperdirect tract connecting cortical regions monosynaptically with the subthalamic nucleus. Second, only the coupling between β and γ signals from different components appears to have pathophysiological significance, suggesting that therapeutic approaches breaking the abnormal lateral coupling between neuronal circuits may be more promising than targeting phase-amplitude coupling per se.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zimple Kurlawala ◽  
Paul H. Shadowen ◽  
Joseph D. McMillan ◽  
Levi J Beverly ◽  
Robert P. Friedland

Nonmotor symptoms (NMS) in Parkinson’s disease (PD) can start up to a decade before motor manifestations and strongly correlate with the quality of life. Understanding patterns of NMS can provide clues to the incipient site of PD pathology. Our goal was to systematically characterize the progression of NMS in PD (n = 489), compared to healthy controls, HC (n = 241), based on the sex of the subjects and laterality of motor symptom onset. Additionally, NMS experienced at the onset of PD were also compared to subjects with scans without dopaminergic deficit, SWEDD (n = 81). The Parkinson’s Progression Markers Initiative (PPMI) database was utilized to analyze several NMS scales. NMS experienced by PD and SWEDD cohorts were significantly higher than HC and both sex and laterality influenced several NMS scales at the onset of motor symptoms. Sex Differences. PD males experienced significant worsening of sexual, urinary, sleep, and cognitive functions compared to PD females. PD females reported significantly increased thermoregulatory dysfunction and anxious mood over 7 years and significantly more constipation during the first 4 years after PD onset. Laterality Differences. At onset, PD subjects with right-sided motor predominance reported significantly higher autonomic dysfunction. Subjects with left-sided motor predominance experienced significantly more anxious mood at onset which continued as Parkinson’s progressed. In conclusion, males experienced increased NMS burden in Parkinson’s disease. Laterality of motor symptoms did not significantly influence NMS progression, except anxious mood. We analyzed NMS in a large cohort of PD patients, and these data are valuable to improve PD patients’ quality of life by therapeutically alleviating nonmotor symptoms.


2019 ◽  
Author(s):  
Mikkel C. Vinding ◽  
Panagiota Tsitsi ◽  
Josefine Waldthaler ◽  
Robert Oostenveld ◽  
Martin Ingvar ◽  
...  

AbstractParkinson’s disease is characterized by a gradual loss of dopaminergic neurons, which are associated with altered neuronal activity in the beta band (13-30 Hz). Assessing beta band activity typically involves transforming the time-series to get the power of the signal in the frequency-domain. Such transformation assumes that the time-series can be reduced to a combination of steady-state sine-and cosine waves. However, recent studies have suggested that this approach masks relevant biophysical features in the beta band activity—for example, that the beta band exhibits transient bursts of high-amplitude activity.In an exploratory study we used magnetoencephalography (MEG) to record cortical beta band activity to characterize how spontaneous cortical beta bursts manifest in Parkinson’s patients ON and OFF dopaminergic medication, and compare this to matched healthy controls. From three minutes of MEG data, we extracted the time-course of beta band activity from the sensorimotor cortex and characterized high-amplitude epochs in the signal to test if they exhibited burst like properties. We then compared the rate, duration, inter-burst interval, and peak amplitude of the high-amplitude epochs between the Parkinson’s patients and healthy controls.Our results show that Parkinson’s patients OFF medication had a 6-17% lower beta bursts rate compared to healthy controls, while both the duration and the amplitude of the bursts were the same for Parkinson’s patients and healthy controls and medicated state of the Parkinson’s patients. These data thus support the view that beta bursts are fundamental underlying features of beta band activity, and show that changes in cortical beta band power in PD can be explained primarily by changes in the underlying burst rate. Importantly, our results also revealed a relationship between beta bursts rate and motor symptom severity in PD: a lower burst rate scaled with increased in severity of bradykinesia and postural/kinetic tremor. Beta burst rate might thus serve as neuromarker for Parkinson’s disease that can help in the assessment of symptom severity in Parkinson’s disease or evaluate treatment effectiveness.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Mikkel C Vinding ◽  
Panagiota Tsitsi ◽  
Josefine Waldthaler ◽  
Robert Oostenveld ◽  
Martin Ingvar ◽  
...  

Abstract Parkinson’s disease is characterized by a gradual loss of dopaminergic neurons, which is associated with altered neuronal activity in the beta-band (13–30 Hz). Assessing beta-band activity typically involves transforming the time-series to get the power of the signal in the frequency domain. Such transformation assumes that the time-series can be reduced to a combination of steady-state sine- and cosine waves. However, recent studies have suggested that this approach masks relevant biophysical features in the beta-band—for example, that the beta-band exhibits transient bursts of high-amplitude activity. In an exploratory study, we used magnetoencephalography to record beta-band activity from the sensorimotor cortex, to characterize how spontaneous cortical beta bursts manifest in Parkinson’s patients on and off dopaminergic medication, and compare this to matched healthy controls. We extracted the time-course of beta-band activity from the sensorimotor cortex and characterized bursts in the signal. We then compared the burst rate, duration, inter-burst interval and peak amplitude between the Parkinson’s patients and healthy controls. Our results show that Parkinson’s patients off medication had a 5–17% lower beta bursts rate compared to healthy controls, while both the duration and the amplitude of the bursts were the same for healthy controls and medicated state of the Parkinson’s patients. These data thus support the view that beta bursts are fundamental underlying features of beta-band activity, and show that changes in cortical beta-band power in Parkinson’s disease can be explained—primarily by changes in the underlying burst rate. Importantly, our results also revealed a relationship between beta burst rate and motor symptom severity in Parkinson’s disease: a lower burst rate scaled with increased severity of bradykinesia and postural/kinetic tremor. Beta burst rate might thus serve as a neuromarker for Parkinson’s disease that can help in the assessment of symptom severity in Parkinson’s disease or in the evaluation of treatment effectiveness.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Gian Pal ◽  
Vivian Ramirez ◽  
Phillip A. Engen ◽  
Ankur Naqib ◽  
Christopher B. Forsyth ◽  
...  

AbstractOlfactory dysfunction is a pre-motor symptom of Parkinson’s disease (PD) that appears years prior to diagnosis and can affect quality of life in PD. Changes in microbiota community in deep nasal cavity near the olfactory bulb may trigger the olfactory bulb-mediated neuroinflammatory cascade and eventual dopamine loss in PD. To determine if the deep nasal cavity microbiota of PD is significantly altered in comparison to healthy controls, we characterized the microbiota of the deep nasal cavity using 16S rRNA gene amplicon sequencing in PD subjects and compared it to that of spousal and non-spousal healthy controls. Correlations between microbial taxa and PD symptom severity were also explored. Olfactory microbial communities of PD individuals were more similar to those of their spousal controls than to non-household controls. In direct comparison of PD and spousal controls and of PD and non-spousal controls, significantly differently abundant taxa were identified, and this included increased relative abundance of putative opportunistic-pathobiont species such as Moraxella catarrhalis. M. catarrhalis was also significantly correlated with more severe motor scores in PD subjects. This proof-of-concept study provides evidence that potential pathobionts are detected in the olfactory bulb and that a subset of changes in the PD microbiota community could be a consequence of unique environmental factors associated with PD living. We hypothesize that an altered deep nasal microbiota, characterized by a putative pro-inflammatory microbial community, could trigger neuroinflammation in PD.


2021 ◽  
pp. 1-9
Author(s):  
Laura P. Hughes ◽  
Marilia M.M. Pereira ◽  
Deborah A. Hammond ◽  
John B. Kwok ◽  
Glenda M. Halliday ◽  
...  

Background: Reduced activity of lysosomal glucocerebrosidase is found in brain tissue from Parkinson’s disease patients. Glucocerebrosidase is also highly expressed in peripheral blood monocytes where its activity is decreased in Parkinson’s disease patients, even in the absence of GBA mutation. Objective: To measure glucocerebrosidase activity in cryopreserved peripheral blood monocytes from 30 Parkinson’s disease patients and 30 matched controls and identify any clinical correlation with disease severity. Methods: Flow cytometry was used to measure lysosomal glucocerebrosidase activity in total, classical, intermediate, and non-classical monocytes. All participants underwent neurological examination and motor severity was assessed by the Movement Disorders Society Unified Parkinson’s Disease Rating Scale. Results: Glucocerebrosidase activity was significantly reduced in the total and classical monocyte populations from the Parkinson’s disease patients compared to controls. GCase activity in classical monocytes was inversely correlated to motor symptom severity. Conclusion: Significant differences in monocyte glucocerebrosidase activity can be detected in Parkinson’s disease patients using cryopreserved mononuclear cells and monocyte GCase activity correlated with motor features of disease. Being able to use cryopreserved cells will facilitate the larger multi-site trials needed to validate monocyte GCase activity as a Parkinson’s disease biomarker.


2021 ◽  
Author(s):  
Natalia Pelizari Novaes ◽  
Joana Bisol Balardin ◽  
Fabiana Campos Hirata ◽  
Luciano Melo ◽  
Edson Amaro ◽  
...  

2021 ◽  
pp. 1-5
Author(s):  
Trine HØrmann Thomsen ◽  
Susanna M. Wallerstedt ◽  
Kristian Winge ◽  
Filip Bergquist

People with Parkinson’s disease (PwP) have been suggested to be more vulnerable to negative psychological and psycho-social effects of the COVID-19 pandemic. Our aim was to assess the potential impact of the COVID-19 pandemic in PwP. A Danish/Swedish cohort of 67 PwP was analysed. Health-related quality of life (HRQL), depression, anxiety, apathy, sleep and motor symptom-scores were included in the analysis. Additionally, the Danish participants provided free-text descriptions of life during the pandemic. Overall, the participants reported significantly better HRQL during the COVID-19 period compared with before. Reduced social pressure may be part of the explanation. Despite worsened anxiety, night sleep improved.


2021 ◽  
Vol 11 (7) ◽  
pp. 895
Author(s):  
Karolina A. Bearss ◽  
Joseph F. X. DeSouza

Parkinson’s disease (PD) is a neurodegenerative disease that has a fast progression of motor dysfunction within the first 5 years of diagnosis, showing an annual motor rate of decline of the Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) between 5.2 and 8.9 points. We aimed to determine both motor and non-motor PD symptom progression while participating in dance classes once per week over a period of three years. Longitudinal data was assessed for a total of 32 people with PD using MDS-UPDRS scores. Daily motor rate of decline was zero (slope = 0.000146) in PD-Dancers, indicating no motor impairment, whereas the PD-Reference group showed the expected motor decline across three years (p < 0.01). Similarly, non-motor aspects of daily living, motor experiences of daily living, and motor complications showed no significant decline. A significant group (PD-Dancers and PD-Reference) by days interaction showed that PD who train once per week have less motor impairment (M = 18.75) than PD-References who do not train (M = 24.61) over time (p < 0.05). Training is effective at slowing both motor and non-motor PD symptoms over three years as shown in decreased scores of the MDS-UPDRS.


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