scholarly journals The Influence of Dopamine on Automatic and Controlled Semantic Activation in Parkinson's Disease

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Wendy L. Arnott ◽  
David A. Copland ◽  
Helen J. Chenery ◽  
Bruce E. Murdoch ◽  
Peter A. Silburn ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Semantic Priming ◽  
Semantic Processing ◽  
Healthy Adult ◽  
Healthy Adults ◽  
Semantic Activation ◽  
Dopamine Depletion ◽  
Adult Participants ◽  
The Impact

Two semantic priming tasks, designed to isolate automatic and controlled semantic activation, were utilized to investigate the impact of dopamine depletion on semantic processing in Parkinson's disease (PD). Seven people with PD (tested whilst on and off levodopa medication) and seven healthy adults participated in the study. The healthy adult participants demonstrated intact automatic and controlled semantic activation. Aberrant controlled semantic activation was observed in the PD group on levodopa; however, automatic semantic activation was still evident. In contrast, automatic semantic activation was not evident in the PD group off levodopa. These results further clarify the impact of PD on semantic processing, demonstrating that dopamine depletion can cause disturbances in both automatic and controlled semantic activation.

scholarly journals The basal ganglia and semantic engagement: Potential insights from semantic priming in individuals with subcortical vascular lesions, Parkinson's disease, and cortical lesions

2003 ◽  
Vol 9 (7) ◽  
pp. 1041-1052 ◽  
Author(s):  
DAVID COPLAND
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Basal Ganglia ◽  
Semantic Priming ◽  
Semantic Processing ◽  
Semantic Network ◽  
Vascular Lesions ◽  
Cortical Lesions ◽  
The Impact ◽  
Prime Target

The impact of basal ganglia dysfunction on semantic processing was investigated by comparing the performance of individuals with nonthalamic subcortical (NS) vascular lesions, Parkinson's disease (PD), cortical lesions, and matched controls on a semantic priming task. Unequibiased lexical ambiguity primes were used in auditory prime-target pairs comprising 4 critical conditions; dominant related (e.g., bank–money), subordinate related (e.g., bank–river), dominant unrelated (e.g., foot–money) and subordinate unrelated (e.g., bat–river). Participants made speeded lexical decisions (word/nonword) on targets using a go–no-go response. When a short prime–target interstimulus interval (ISI) of 200 ms was employed, all groups demonstrated priming for dominant and subordinate conditions, indicating nonselective meaning facilitation and intact automatic lexical processing. Differences emerged at the long ISI (1250 ms), where control and cortical lesion participants evidenced selective facilitation of the dominant meaning, whereas NS and PD groups demonstrated a protracted period of nonselective meaning facilitation. This finding suggests a circumscribed deficit in the selective attentional engagement of the semantic network on the basis of meaning frequency, possibly implicating a disturbance of frontal–subcortical systems influencing inhibitory semantic mechanisms. (JINS, 2003, 9, 1041–1052.)

scholarly journals Dopamine Depletion Alters Macroscopic Network Dynamics in Parkinson’s Disease

2018 ◽  
Author(s):  
James M. Shine ◽  
Peter T. Bell ◽  
Elie Matar ◽  
Russell A. Poldrack ◽  
Simon J.G. Lewis ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Large Scale ◽  
Motor Symptom ◽  
Grey Matter Volume ◽  
Compensatory Mechanism ◽  
Dopamine Depletion ◽  
Network Integration ◽  
Whole Brain ◽  
The Impact

AbstractParkinson’s disease is primarily characterised by diminished dopaminergic function, however the impact of these impairments on large-scale brain dynamics remains unclear. It has been difficult to disentangle the direct effects of Parkinson’s disease from compensatory changes that reconfigure the functional signature of the whole brain network. To examine the causal role of dopamine depletion in network-level topology, we investigated time-varying network structure in 37 individuals with idiopathic Parkinson’s disease, both ‘On’ and ‘Off’ dopamine replacement therapy, along with 50 age-matched, healthy control subjects using resting-state functional MRI. By tracking dynamic network-level topology, we found that the Parkinson’s disease ‘Off’ state was associated with greater network-level integration than in the ‘On’ state. The extent of integration in the ‘Off’ state inversely correlated with motor symptom severity, suggesting that a shift toward a more integrated network topology may be a compensatory mechanism associated with preserved motor function in the dopamine depleted ‘Off’ state. Furthermore, we were able to demonstrate that measures of both cognitive and brain reserve (i.e., premorbid intelligence and whole brain grey matter volume) had a positive relationship with the relative increase in network integration observed in the dopaminergic ‘Off’ state. This suggests that each of these factors plays an important role in promoting network integration in the dopaminergic ‘Off’ state. Our findings provide a mechanistic basis for understanding the PD ‘Off’ state and provide a further conceptual link with network-level reconfiguration. Together, our results highlight the mechanisms responsible for pathological and compensatory change in Parkinson’s disease.

scholarly journals Assessment of Sit-to-Stand Transfers during Daily Life Using an Accelerometer on the Lower Back

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6618
Author(s):  
Lukas Adamowicz ◽  
F. Isik Karahanoglu ◽  
Christopher Cicalo ◽  
Hao Zhang ◽  
Charmaine Demanuele ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Daily Life ◽  
Healthy Adults ◽  
Group Differences ◽  
Sit To Stand ◽  
Lower Back ◽  
Age Related ◽  
Related Group ◽  
The Impact

The ability to perform sit-to-stand (STS) transfers has a significant impact on the functional mobility of an individual. Wearable technology has the potential to enable the objective, long-term monitoring of STS transfers during daily life. However, despite several recent efforts, most algorithms for detecting STS transfers rely on multiple sensing modalities or device locations and have predominantly been used for assessment during the performance of prescribed tasks in a lab setting. A novel wavelet-based algorithm for detecting STS transfers from data recorded using an accelerometer on the lower back is presented herein. The proposed algorithm is independent of device orientation and was validated on data captured in the lab from younger and older healthy adults as well as in people with Parkinson’s disease (PwPD). The algorithm was then used for processing data captured in free-living conditions to assess the ability of multiple features extracted from STS transfers to detect age-related group differences and assess the impact of monitoring duration on the reliability of measurements. The results show that performance of the proposed algorithm was comparable or significantly better than that of a commercially available system (precision: 0.990 vs. 0.868 in healthy adults) and a previously published algorithm (precision: 0.988 vs. 0.643 in persons with Parkinson’s disease). Moreover, features extracted from STS transfers at home were able to detect age-related group differences at a higher level of significance compared to data captured in the lab during the performance of prescribed tasks. Finally, simulation results showed that a monitoring duration of 3 days was sufficient to achieve good reliability for measurement of STS features. These results point towards the feasibility of using a single accelerometer on the lower back for detection and assessment of STS transfers during daily life. Future work in different patient populations is needed to evaluate the performance of the proposed algorithm, as well as assess the sensitivity and reliability of the STS features.

Coexistent Osteoarthritis and Parkinson’s Disease: Data from the Parkinson’s Foundation Outcomes Project

2020 ◽  
Vol 10 (4) ◽  
pp. 1601-1610
Author(s):  
Jaimie A. Roper ◽  
Abigail C. Schmitt ◽  
Hanzhi Gao ◽  
Ying He ◽  
Samuel Wu ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Study Data ◽  
Functional Mobility ◽  
Quality Improvement Initiative ◽  
Timed Up And Go ◽  
Mobility Performance ◽  
Risk Of Mortality ◽  
The Impact

Background: The impact of concurrent osteoarthritis on mobility and mortality in individuals with Parkinson’s disease is unknown. Objective: We sought to understand to what extent osteoarthritis severity influenced mobility across time and how osteoarthritis severity could affect mortality in individuals with Parkinson’s disease. Methods: In a retrospective observational longitudinal study, data from the Parkinson’s Foundation Quality Improvement Initiative was analyzed. We included 2,274 persons with Parkinson’s disease. The main outcomes were the effects of osteoarthritis severity on functional mobility and mortality. The Timed Up and Go test measured functional mobility performance. Mortality was measured as the osteoarthritis group effect on survival time in years. Results: More individuals with symptomatic osteoarthritis reported at least monthly falls compared to the other groups (14.5% vs. 7.2% without reported osteoarthritis and 8.4% asymptomatic/minimal osteoarthritis, p = 0.0004). The symptomatic group contained significantly more individuals with low functional mobility (TUG≥12 seconds) at baseline (51.5% vs. 29.0% and 36.1%, p < 0.0001). The odds of having low functional mobility for individuals with symptomatic osteoarthritis was 1.63 times compared to those without reported osteoarthritis (p < 0.0004); and was 1.57 times compared to those with asymptomatic/minimal osteoarthritis (p = 0.0026) after controlling pre-specified covariates. Similar results hold at the time of follow-up while changes in functional mobility were not significant across groups, suggesting that osteoarthritis likely does not accelerate the changes in functional mobility across time. Coexisting symptomatic osteoarthritis and Parkinson’s disease seem to additively increase the risk of mortality (p = 0.007). Conclusion: Our results highlight the impact and potential additive effects of symptomatic osteoarthritis in persons with Parkinson’s disease.

Association of the Non-Motor Burden with Patterns of Striatal Dopamine Loss in de novo Parkinson’s Disease

2020 ◽  
Vol 10 (4) ◽  
pp. 1541-1549
Author(s):  
Seok Jong Chung ◽  
Sangwon Lee ◽  
Han Soo Yoo ◽  
Yang Hyun Lee ◽  
Hye Sun Lee ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
De Novo ◽  
Early Stage ◽  
Striatal Dopamine ◽  
Motor Deficits ◽  
Dopamine Depletion ◽  
Severe Motor ◽  
Severe Group ◽  
Striatal Dopamine Depletion

Background: Striatal dopamine deficits play a key role in the pathogenesis of Parkinson’s disease (PD), and several non-motor symptoms (NMSs) have a dopaminergic component. Objective: To investigate the association between early NMS burden and the patterns of striatal dopamine depletion in patients with de novo PD. Methods: We consecutively recruited 255 patients with drug-naïve early-stage PD who underwent 18F-FP-CIT PET scans. The NMS burden of each patient was assessed using the NMS Questionnaire (NMSQuest), and patients were divided into the mild NMS burden (PDNMS-mild) (NMSQuest score <6; n = 91) and severe NMS burden groups (PDNMS-severe) (NMSQuest score >9; n = 90). We compared the striatal dopamine transporter (DAT) activity between the groups. Results: Patients in the PDNMS-severe group had more severe parkinsonian motor signs than those in the PDNMS-mild group, despite comparable DAT activity in the posterior putamen. DAT activity was more severely depleted in the PDNMS-severe group in the caudate and anterior putamen compared to that in the PDMNS-mild group. The inter-sub-regional ratio of the associative/limbic striatum to the sensorimotor striatum was lower in the PDNMS-severe group, although this value itself lacked fair accuracy for distinguishing between the patients with different NMS burdens. Conclusion: This study demonstrated that PD patients with severe NMS burden exhibited severe motor deficits and relatively diffuse dopamine depletion throughout the striatum. These findings suggest that the level of NMS burden could be associated with distinct patterns of striatal dopamine depletion, which could possibly indicate the overall pathological burden in PD.

A New Series Of 1,3-Dimethylxanthine Based Adenosine A2a Receptor Antagonists As A Non-Dopaminergic Treatment Of Parkinson’s Disease

2020 ◽  
Vol 17 ◽  
Author(s):  
Suman Rohilla ◽  
Ranju Bansal ◽  
Puneet Chauhan ◽  
Sonja Kachler ◽  
Karl-Norbert Klotz
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Molecular Docking ◽  
Binding Affinity ◽  
Docking Studies ◽  
Binding Modes ◽  
Molecular Docking Studies ◽  
In Silico Docking ◽  
Adenosine A2a Receptor Antagonists ◽  
The Impact

Background: Adenosine receptors (AR) have emerged as competent and innovative nondopaminergic targets for the development of potential drug candidates and thus constitute an effective and safer treatment approach for Parkinson’s disease (PD). Xanthine derivatives are considered as potential candidates for the treatment Parkinson’s disease due to their potent A2A AR antagonistic properties. Objective: The objectives of the work are to study the impact of substituting N7-position of 8-m/pchloropropoxyphenylxanthine structure on in vitro binding affinity of compounds with various AR subtypes, in vivo antiparkinsonian activity and binding modes of newly synthesized xanthines with A2A AR in molecular docking studies. Methods: Several new 7-substituted 8-m/p-chloropropoxyphenylxanthine analogues have been prepared. Adenosine receptor binding assays were performed to study the binding interactions with various subtypes and perphenazine induced rat catatonia model was used for antiparkinsonian activity. Molecular docking studies were performed using Schrödinger molecular modeling interface. Results: 8-para-substituted xanthine 9b bearing an N7-propyl substituent displayed the highest affinity towards A2A AR (Ki = 0.75 µM) with moderate selectivity versus other AR subtypes. 7-Propargyl analogue 9d produced significantly longlasting antiparkinsonian effects and also produced potent and selective binding affinity towards A2A AR. In silico docking studies further highlighted the crucial structural components required to develop xanthine derived potential A2A AR ligands as antiparkinsonian agents. Conclusion: A new series of 7-substituted 8-m/p-chloropropoxyphenylxanthines having good affinity for A2A AR and potent antiparkinsonian activity has been developed.

Appendectomy Does Not Increase the Risk of Future Emergence of Parkinson’s Disease: A Meta-analysis

2021 ◽  
pp. 000313482198903
Author(s):  
Mitsuru Ishizuka ◽  
Norisuke Shibuya ◽  
Kazutoshi Takagi ◽  
Hiroyuki Hachiya ◽  
Kazuma Tago ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Meta Analysis ◽  
Cochrane Library ◽  
Random Effects Models ◽  
Significant Difference ◽  
The Cochrane Library ◽  
The Impact ◽  
The Relationship ◽  
Observation Period

Objective To explore the impact of appendectomy history on emergence of Parkinson’s disease (PD). Background Although there are several studies to investigate the relationship between appendectomy history and emergence of PD, the results are still controversial. Methods We performed a comprehensive electronic search of the literature (the Cochrane Library, PubMed, and the Web of Science) up to April 2020 to identify studies that had employed databases allowing comparison of emergence of PD between patients with and those without appendectomy history. To integrate the impact of appendectomy history on emergence of PD, a meta-analysis was performed using random-effects models to calculate the risk ratio (RR) and 95% confidence interval (CI) for the selected studies, and heterogeneity was analyzed using I2 statistics. Results Four studies involving a total of 6 080 710 patients were included in this meta-analysis. Among 1 470 613 patients with appendectomy history, 1845 (.13%) had emergences of PD during the observation period, whereas among 4 610 097 patients without appendectomy history, 6743 (.15%) had emergences of PD during the observation period. These results revealed that patients with appendectomy history and without appendectomy had almost the same emergence of PD (RR, 1.02; 95% CI, .87-1.20; P = .83; I2 = 87%). Conclusion This meta-analysis has demonstrated that there was no significant difference in emergence of PD between patients with and those without appendectomy history.

scholarly journals Impact of DaTscan Imaging on Clinical Decision Making in Clinically Uncertain Parkinson’s Disease

2021 ◽  
pp. 1-5
Author(s):  
Jonathan R. Isaacson ◽  
Salima Brillman ◽  
Nisha Chhabria ◽  
Stuart H. Isaacson
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Clinical Diagnosis ◽  
Clinical Decision Making ◽  
Photon Emission ◽  
Case Series ◽  
Emission Computed Tomography ◽  
Medication Therapy ◽  
Clinical Scenarios ◽  
The Impact

Background: The diagnosis of Parkinson’s disease (PD) is primarily clinical, but in cases of diagnostic uncertainty, evaluation of nigrostriatal dopaminergic degeneration (NSDD) by imaging of the dopamine transporter using DaTscan with single-photon emission computed tomography (SPECT) brain imaging may be helpful. Objective/Methods: In the current paper, we describe clinical scenarios for which DaTscan imaging was used in a prospective case series of 201 consecutive patients in whom a movement disorder specialist ordered DaTscan imaging to clarify NSDD. We describe the impact of DaTscan results on changing or confirming pre-DaTscan clinical diagnosis and on post-DaTscan treatment changes. Results/Conclusion: DaTscan imaging can be useful in several clinical scenarios to determine if NSDD is present. These include in patients with early subtle symptoms, suboptimal response to levodopa, prominent action tremor, drug-induced parkinsonism, and in patients with lower extremity or other less common parkinsonism clinical presentations. We also found DaTscan imaging to be useful to determine underlying NSDD in patients with PD diagnosis for 3-5 years but without apparent clinical progression or development of motor fluctuations. Overall, in 201 consecutive patients with clinically questionable NSDD, DaTscan was abnormal in 58.7% of patients, normal in 37.8%, and inconclusive in 3.5%. DaTscan imaging changed clinical diagnosis in 39.8% of patients and led to medication therapy changes in 70.1% of patients.

scholarly journals Validation of Cognitive Rehabilitation as a Balance Rehabilitation Strategy in Patients with Parkinson’s Disease: Study Protocol for a Randomized Controlled Trial

Medicina ◽  
2021 ◽  
Vol 57 (4) ◽  
pp. 314
Author(s):  
Aida Arroyo-Ferrer ◽  
Francisco José Sánchez-Cuesta ◽  
Yeray González-Zamorano ◽  
María Dolores del Castillo ◽  
Carolina Sastre-Barrios ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cognitive Therapy ◽  
Cognitive Processing ◽  
Processing Speed ◽  
Cognitive Rehabilitation ◽  
Neurodegenerative Disorder ◽  
Control Group ◽  
Motor Symptoms ◽  
The Impact

Background: Parkinson’s disease (PD) is the second most common neurodegenerative disorder. This disease is characterized by motor symptoms, such as bradykinesia, tremor, and rigidity. Although balance impairment is characteristic of advanced stages, it can be present with less intensity since the beginning of the disease. Approximately 60% of PD patients fall once a year and 40% recurrently. On the other hand, cognitive symptoms affect up to 20% of patients with PD in early stages and can even precede the onset of motor symptoms. There are cognitive requirements for balance and can be challenged when attention is diverted or reduced, linking a worse balance and a higher probability of falls with a slower cognitive processing speed and attentional problems. Cognitive rehabilitation of attention and processing speed can lead to an improvement in postural stability in patients with Parkinson’s. Methods: We present a parallel and controlled randomized clinical trial (RCT) to assess the impact on balance of a protocol based on cognitive rehabilitation focused on sustained attention through the NeuronUP platform (Neuronup SI, La Rioja, Spain) in patients with PD. For 4 weeks, patients in the experimental group will receive cognitive therapy three days a week while the control group will not receive any therapy. The protocol has been registered at trials.gov NCT04730466. Conclusions: Cognitive therapy efficacy on balance improvement may open the possibility of new rehabilitation strategies for prevention of falls in PD, reducing morbidity, and saving costs to the health care system.

Sign in / Sign up

Export Citation Format

Share Document