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BioRxiv : the Preprint Server For... May 2024Striatal Cholinergic Interneurons (CIN) are drivers of L-Dopa induced Dyskinesias (LID). However, what signaling pathways elicit aberrant CIN activity remains unclear....
BACKGROUND
Striatal Cholinergic Interneurons (CIN) are drivers of L-Dopa induced Dyskinesias (LID). However, what signaling pathways elicit aberrant CIN activity remains unclear. CIN express D2 and D5 receptors suggesting repeated activation of these receptors in response to L-Dopa could promote LID. While the role of D5 in this process has recently been probed, little is known about the role of D2.
METHOD
Mice with CIN-specific D2 ablation (D2 KO) underwent unilateral 6-OHDA lesion and chronic L-Dopa dosing, throughout which LID severity was quantified. The effect of D2 KO on histological markers of LID severity and CIN activity were also quantified postmortem.
RESULTS
D2 KO attenuated LID across L-Dopa doses, reduced expression of histological LID marker p-ERK, and prevented L-Dopa-induced increases in CIN activity marker p-rpS6 in the dorsolateral striatum.
CONCLUSION
The activation of D2 specifically on CIN is a key driver of LID.
PubMed: 38765986
DOI: 10.1101/2024.05.10.593604 -
Scientific Reports May 2024Aspiration pneumonia is the leading cause of death in patients with Parkinson's disease. The incidence of silent aspiration is high in such patients owing to decreased... (Clinical Trial)
Clinical Trial
Aspiration pneumonia is the leading cause of death in patients with Parkinson's disease. The incidence of silent aspiration is high in such patients owing to decreased pharyngeal and laryngeal sensation; thus, interventions for this condition may help prevent pneumonia. In this single-arm, open-label study, we used a cervical percutaneous interferential current stimulation device to activate pharyngeal and laryngeal sensory nerves. We evaluated its effectiveness in patients with Hoehn-Yahr stages 2-4 Parkinson's disease. The primary endpoint was the proportion of patients with a normal cough reflex after consuming 1% citric acid at the end of the intervention compared with baseline measurements. In total, 25 patients received neck percutaneous interferential current stimulation for 20 min twice weekly for 8 weeks. Afterward, the proportion of patients with a normal cough reflex after 1% citric acid consumption increased significantly (p = 0.001), whereas other indicators, such as tongue pressure, peak expiratory flow, and penetration or aspiration during videofluoroscopic examination, remained unchanged. A longer duration of illness, higher Unified Parkinson's Disease Rating Scale total scores, and higher levodopa equivalent daily doses were significantly associated with improved cough test outcomes. Hence, cervical percutaneous interferential current stimulation significantly improved cough reflexes and may improve silent aspiration. Trial Registration: Japan Registry of Clinical Trials, jRCTs062220013, first registered 09/05/2022.
Topics: Humans; Parkinson Disease; Female; Male; Aged; Cough; Citric Acid; Middle Aged; Pneumonia, Aspiration; Electric Stimulation Therapy
PubMed: 38762573
DOI: 10.1038/s41598-024-62460-x -
Cell Reports. Medicine Jun 2024Levodopa-induced dyskinesia (LID) is an intractable motor complication arising in Parkinson's disease with the progression of disease and chronic treatment of levodopa....
Levodopa-induced dyskinesia (LID) is an intractable motor complication arising in Parkinson's disease with the progression of disease and chronic treatment of levodopa. However, the specific cell assemblies mediating dyskinesia have not been fully elucidated. Here, we utilize the activity-dependent tool to identify three brain regions (globus pallidus external segment [GPe], parafascicular thalamic nucleus, and subthalamic nucleus) that specifically contain dyskinesia-activated ensembles. An intensity-dependent hyperactivity in the dyskinesia-activated subpopulation in GPe (GPe) is observed during dyskinesia. Optogenetic inhibition of GPe significantly ameliorates LID, whereas reactivation of GPe evokes dyskinetic behavior in the levodopa-off state. Simultaneous chemogenetic reactivation of GPe and another previously reported ensemble in striatum fully reproduces the dyskinesia induced by high-dose levodopa. Finally, we characterize GPe as a subset of prototypic neurons in GPe. These findings provide theoretical foundations for precision medication and modulation of LID in the future.
Topics: Levodopa; Globus Pallidus; Dyskinesia, Drug-Induced; Animals; Neurons; Male; Optogenetics; Mice; Parkinson Disease; Humans; Subthalamic Nucleus
PubMed: 38759649
DOI: 10.1016/j.xcrm.2024.101566 -
Journal of Neurosciences in Rural... 2024For this observational study, we evaluated the clinical profile of Parkinsonian features in multiple system atrophy (MSA), as there is no clarity about the specifics of...
OBJECTIVES
For this observational study, we evaluated the clinical profile of Parkinsonian features in multiple system atrophy (MSA), as there is no clarity about the specifics of these features in this disease compared to progressive supranuclear palsy (PSP) and Parkinson's disease (PD).
MATERIALS AND METHODS
Here, we selected 57 patients with MSA based on standard criteria and grouped them into two categories - Parkinsonian variant of MSA (MSA-P) and cerebellar variant of MSA (MSA-C). However, researchers did not distinguish among patients based on the nature of extrapyramidal syndrome or levodopa responsiveness. Then, we examined the patients at the time of their first visit to outpatient clinics or indoor wards and recorded and analyzed the specific extrapyramidal features or their variations.
RESULTS
The extrapyramidal features including levodopa responsiveness were highly variable among MSA-C as well as MSA-P patients. A subset of patients presented with features resembling PSP (symmetry [56.1%], axial rigidity [52.6%], backward falls [28.1%], and down-gaze restriction [17.5%]), while others presented with features resembling PD (asymmetry [43.9%], tremors [71.9%], and peripheral rigidity [40.4%]). After grouping patients based on predominant extrapyramidal features, 36.8% of patients had PD-like, 19.3% had PSP-like, and 43.9 % had mixed presentation. Moreover, 86% of patients had a perceptible levodopa response, including a sustained response for more than six months in 64% of patients.
CONCLUSION
Extrapyramidal features in MSA patients may be PD-like, PSP-like, or mixed. Moreover, an initial presentation resembling PSP or PD may be deceptive and one must follow it up for MSA.
PubMed: 38746510
DOI: 10.25259/JNRP_445_2023 -
Neurobiology of Disease Jul 2024Parkinson's disease (PD) is characterized by the disruption of repetitive, concurrent and sequential motor actions due to compromised timing-functions principally...
Parkinson's disease (PD) is characterized by the disruption of repetitive, concurrent and sequential motor actions due to compromised timing-functions principally located in cortex-basal ganglia (BG) circuits. Increasing evidence suggests that motor impairments in untreated PD patients are linked to an excessive synchronization of cortex-BG activity at beta frequencies (13-30 Hz). Levodopa and subthalamic nucleus deep brain stimulation (STN-DBS) suppress pathological beta-band reverberation and improve the motor symptoms in PD. Yet a dynamic tuning of beta oscillations in BG-cortical loops is fundamental for movement-timing and synchronization, and the impact of PD therapies on sensorimotor functions relying on neural transmission in the beta frequency-range remains controversial. Here, we set out to determine the differential effects of network neuromodulation through dopaminergic medication (ON and OFF levodopa) and STN-DBS (ON-DBS, OFF-DBS) on tapping synchronization and accompanying cortical activities. To this end, we conducted a rhythmic finger-tapping study with high-density EEG-recordings in 12 PD patients before and after surgery for STN-DBS and in 12 healthy controls. STN-DBS significantly ameliorated tapping parameters as frequency, amplitude and synchrony to the given auditory rhythms. Aberrant neurophysiologic signatures of sensorimotor feedback in the beta-range were found in PD patients: their neural modulation was weaker, temporally sluggish and less distributed over the right cortex in comparison to controls. Levodopa and STN-DBS boosted the dynamics of beta-band modulation over the right hemisphere, hinting to an improved timing of movements relying on tactile feedback. The strength of the post-event beta rebound over the supplementary motor area correlated significantly with the tapping asynchrony in patients, thus indexing the sensorimotor match between the external auditory pacing signals and the performed taps. PD patients showed an excessive interhemispheric coherence in the beta-frequency range during the finger-tapping task, while under DBS-ON the cortico-cortical connectivity in the beta-band was normalized. Ultimately, therapeutic DBS significantly ameliorated the auditory-motor coupling of PD patients, enhancing the electrophysiological processing of sensorimotor feedback-information related to beta-band activity, and thus allowing a more precise cued-tapping performance.
Topics: Humans; Parkinson Disease; Male; Female; Middle Aged; Deep Brain Stimulation; Aged; Beta Rhythm; Motor Cortex; Cortical Synchronization; Levodopa; Fingers; Subthalamic Nucleus; Antiparkinson Agents; Electroencephalography
PubMed: 38740349
DOI: 10.1016/j.nbd.2024.106529 -
Medicine May 2024We investigated the correlation of orthostatic hypotension (OH) in Parkinson disease (PD) with the disease course and severity, and its possible impact on quality of... (Observational Study)
Observational Study
We investigated the correlation of orthostatic hypotension (OH) in Parkinson disease (PD) with the disease course and severity, and its possible impact on quality of life. 171 PD patients were recruited and divided into the PD-NOH (n = 91) and PD-OH groups (n = 80). Clinical data were collected. The severity and quality of life of PD patients were evaluated. The impact of disease severity was analyzed using logistic regression analysis. The ROC curve was plotted. There were significant differences (P < .05) between PD-NOH and PD-OH groups in terms of the disease course, non-motor symptoms (somnipathy), Hoehn&Yahr stage, LEDD score, RBDSQ score, PDQ-39 score, MMSE score, MoCA, MDS-UPDRS Part III scores during off- and on-periods, and NMSS score. Hoehn&Yahr stage (OR 4.950, 95% CI 1.516-16.157, P = .008) was closely associated with the risk of OH in PD. PDQ-39 score (OR 1.079, 95% CI 1.033-1.127, P = .001) in PD patients with OH further decreased. Patients with PD-OH experienced severe impairment in 4 dimensions of quality of life, including motor function, cognitive function, physical discomfort, and activities of daily living. Different clinical symptoms of PD-OH were positively correlated with PDQ39 subscales. The area under the ROC curve of the Hoehn&Yahr stage in predicting the occurrence of OH was 0.679 (95% CI 0.600-0.758), and that of the Hoehn&Yahr stage combined with levodopa equivalent dose, and MDS-UPDRS Part III score during off-period was 0.793 (95% CI 0.727-0.862). Higher Hoehn&Yahr stage is associated with increased risk of OH in PD patients, and deteriorated quality of life of PD patients. Patients with different OH symptoms are affected in different dimensions of their quality of life. The Hoehn & Yahr stage can independently predict the risk of OH in PD patients.
Topics: Humans; Parkinson Disease; Quality of Life; Hypotension, Orthostatic; Male; Female; Aged; Middle Aged; Severity of Illness Index; Disease Progression
PubMed: 38728450
DOI: 10.1097/MD.0000000000038169 -
Journal of Parkinson's Disease 2024Gait issues, including reduced speed, stride length and freezing of gait (FoG), are disabling in advanced phases of Parkinson's disease (PD), and their treatment is...
BACKGROUND
Gait issues, including reduced speed, stride length and freezing of gait (FoG), are disabling in advanced phases of Parkinson's disease (PD), and their treatment is challenging. Levodopa/carbidopa intestinal gel (LCIG) can improve these symptoms in PD patients with suboptimal control of motor fluctuations, but it is unclear if continuous dopaminergic stimulation can further improve gait issues, independently from reducing Off-time.
OBJECTIVE
To analyze before (T0) and after 3 (T1) and 6 (T2) months of LCIG initiation: a) the objective improvement of gait and balance; b) the improvement of FoG severity; c) the improvement of motor complications and their correlation with changes in gait parameters and FoG severity.
METHODS
This prospective, longitudinal 6-months study analyzed quantitative gait parameters using wearable inertial sensors, FoG with the New Freezing of Gait Questionnaire (NFoG-Q), and motor complications, as per the MDS-UPDRS part IV scores.
RESULTS
Gait speed and stride length increased and duration of Timed up and Go and of sit-to-stand transition was significantly reduced comparing T0 with T2, but not between T0-T1. NFoG-Q score decreased significantly from 19.3±4.6 (T0) to 11.8±7.9 (T1) and 8.4±7.6 (T2) (T1-T0 p = 0.018; T2-T0 p < 0.001). Improvement of MDS-UPDRS-IV (T0-T2, p = 0.002, T0-T1 p = 0.024) was not correlated with improvement of gait parameters and NFoG-Q from T0 to T2. LEDD did not change significantly after LCIG initiation.
CONCLUSION
Continuous dopaminergic stimulation provided by LCIG infusion progressively ameliorates gait and alleviates FoG in PD patients over time, independently from improvement of motor fluctuations and without increase of daily dosage of dopaminergic therapy.
Topics: Humans; Levodopa; Parkinson Disease; Male; Aged; Female; Middle Aged; Gait Disorders, Neurologic; Longitudinal Studies; Gels; Carbidopa; Prospective Studies; Drug Combinations; Antiparkinson Agents
PubMed: 38728203
DOI: 10.3233/JPD-240003 -
BMC Chemistry May 2024An electroanalytical methodology was developed by direct differential pulse voltammetric (DPV) measurement of Levodopa (LD), Carbidopa (CD) and Entacapone (ENT) mixture...
An electroanalytical methodology was developed by direct differential pulse voltammetric (DPV) measurement of Levodopa (LD), Carbidopa (CD) and Entacapone (ENT) mixture using bare glassy carbon electrode (GCE) in Britton Robinson (BR) buffer (pH = 2.0). A multivariate calibration model was then applied to the exported preprocessed voltammetric data using partial least square (PLS) as a chemometric tool. Additionally, the model was cross-validated and the number of latent variables (LVs) were determined to produce a reliable model for simultaneous quantitation of the three drugs either in their synthetic mixtures or in their marketed pharmaceutical formulation with high accuracy and precision. Data preprocessing was used to tackle the problem of lacking bi-linearity which is commonly found in electrochemical data. The proposed chemometric model was able to provide fast and reliable technique for quantitative determination of antiparkinson drugs in their dosage forms. This was successfully achieved by utilizing sixteen mixtures as calibration set and nine mixtures as validation set. The percent recoveries for LD, CD and ENT were found to be 100.05% ± 1.28%, 100.04% ± 0.53% and 99.99% ± 1.25%, respectively. The obtained results of the proposed method were statistically compared to those of a previously reported High Performance Liquid Chromatography (HPLC) methodology. Finally, the presented analytical method strongly supports green analytical chemistry regarding the minimization of potentially dangerous chemicals and solvents, as well as reducing energy utilization and waste generation.
PubMed: 38725000
DOI: 10.1186/s13065-024-01189-0 -
Case Reports in Neurological Medicine 2024Infantile dystonia-parkinsonism type 2 (PKDYS2) is a rare inherited autosomal recessive movement disorder with onset in infancy. The disease is associated with a...
Infantile dystonia-parkinsonism type 2 (PKDYS2) is a rare inherited autosomal recessive movement disorder with onset in infancy. The disease is associated with a mutation in the solute carrier family 18 member A2 gene (). There are reports of trials with dopaminergic drugs and the condition of patients given levodopa almost always worsens and dopamine agonists give varying degrees of benefit to some. Here, we report a PKDYS2 patient with a new variant in the gene who underwent multiple trials of pharmacotherapy. The abnormalities in development and neurological examination of the case were first noted at the age of 2 months, and after a series of treatment attempts (e.g., with antiepileptics) and diagnostic procedures, the diagnosis of PKDYS2 was determined when whole exome sequencing (WES) at age 6, revealed a homozygous pathologic variant NM_003054.4:c.1107dup, p.(Val370Serfs91) in the gene. The patient then received treatment with multiple dopaminergic drugs (e.g., levodopa, pramipexole, and methylphenidate). The patient with PKDYS2 harbored a new variant in The phenotype of the patient resembles that of some previously reported patients with PKDYS2. The patient received minor benefits from certain dopaminergic drugs, such as pramipexole, but side effects led to the discontinuation of tested medications.
PubMed: 38716424
DOI: 10.1155/2024/4767647 -
Translational Neuroscience Jan 2024Freezing of gait (FOG) in Parkinson's disease (PD) has a poorly understood pathophysiology, which hinders treatment development. Recent work showed a dysfunctional...
BACKGROUND
Freezing of gait (FOG) in Parkinson's disease (PD) has a poorly understood pathophysiology, which hinders treatment development. Recent work showed a dysfunctional fronto-striato-limbic circuitry at rest in PD freezers compared to non-freezers in the dopamine "OFF" state. While other studies found that dopaminergic replacement therapy alters functional brain organization in PD, the specific effect of dopamine medication on fronto-striato-limbic functional connectivity in freezers remains unclear.
OBJECTIVE
To evaluate how dopamine therapy alters resting state functional connectivity (rsFC) of the fronto-striato-limbic circuitry in PD freezers, and whether the degree of connectivity change is related to freezing severity and anxiety.
METHODS
Twenty-three PD FOG patients underwent MRI at rest (rsfMRI) in their clinically defined "OFF" and "ON" dopaminergic medication states. A seed-to-seed based analysis was performed between a priori defined limbic circuitry ROIs. Functional connectivity was compared between OFF and ON states. A secondary correlation analyses evaluated the relationship between Hospital Anxiety and Depression Scale (HADS)-Anxiety) and FOG Questionnaire with changes in rsFC from OFF to ON.
RESULTS
PD freezers' OFF compared to ON showed increased functional coupling between the right hippocampus and right caudate nucleus, and between the left putamen and left posterior parietal cortex (PPC). A negative association was found between HADS-Anxiety and the rsFC change from OFF to ON between the left amygdala and left prefrontal cortex, and left putamen and left PPC.
CONCLUSION
These findings suggest that dopaminergic medication partially modulates the frontoparietal-limbic-striatal circuitry in PD freezers, and that the influence of medication on the amygdala, may be related to clinical anxiety in freezer.
PubMed: 38708096
DOI: 10.1515/tnsci-2022-0336