Search results for "PARKINSON DISEASE"
showing 10 items of 223 documents
Cross-frequency coupling between gamma oscillations and deep brain stimulation frequency in Parkinson's disease.
2020
Abstract The disruption of pathologically enhanced beta oscillations is considered one of the key mechanisms mediating the clinical effects of deep brain stimulation on motor symptoms in Parkinson’s disease. However, a specific modulation of other distinct physiological or pathological oscillatory activities could also play an important role in symptom control and motor function recovery during deep brain stimulation. Finely tuned gamma oscillations have been suggested to be prokinetic in nature, facilitating the preferential processing of physiological neural activity. In this study, we postulate that clinically effective high-frequency stimulation of the subthalamic nucleus imposes cross-…
[18F]PR04.MZ PET/CT Imaging for Evaluation of Nigrostriatal Neuron Integrity in Patients With Parkinson Disease.
2020
Introduction Degeneration of dopaminergic, nigrostriatal neurons is the hallmark of Parkinson disease (PD), and PET quantification of dopamine transporters is a widely accepted method for differential diagnosis between idiopathic PD and essential tremor. [18F]PR04.MZ is a new PET tracer with excellent imaging properties allowing for precise quantification of striatal and extrastriatal dopamine transporter. Here we describe our initial experience with [18F]PR04.MZ PET/CT in a larger cohort of healthy controls and PD patients as a proof-of-concept study for this tracer. Methods Eighteen healthy subjects, 19 early PD patients (Hoehn-Yahr I–II), and 13 moderate-advanced PD patients (Hoehn-Yahr …
rTMS of supplementary motor area modulates therapy-induced dyskinesias in Parkinson disease
2005
The neural mechanisms and circuitry involved in levodopa-induced dyskinesia are unclear. Using repetitive transcranial magnetic stimulation (rTMS) over the supplementary motor area (SMA) in a group of patients with advanced Parkinson disease, the authors investigated whether modulation of SMA excitability may result in a modification of a dyskinetic state induced by continuous apomorphine infusion. rTMS at 1 Hz was observed to markedly reduce drug-induced dyskinesias, whereas 5-Hz rTMS induced a slight but not significant increase.
The "gender factor" in wearing-off among patients with parkinson's disease: A post hoc analysis of DEEP study
2014
Background. The early detection of wearing-off in Parkinson disease (DEEP) observational study demonstrated that women with Parkinson’s disease (PD) carry an increased risk (80.1%) for wearing-off (WO). This post hoc analysis of DEEP study evaluates gender differences on WO and associated phenomena.Methods. Patients on dopaminergic treatment for ≥1 year were included in this multicenter observational cross-sectional study. In a single visit, WO was diagnosed based on neurologist assessment as well as the use of the 19-item wearing-off questionnaire (WOQ-19); WO was defined for scores ≥2. Post hoc analyses were conducted to investigate gender difference for demographic and clinical features …
Large-scale replication and heterogeneity in Parkinson disease genetic loci
2012
Objective: Eleven genetic loci have reached genome-wide significance in a recent meta-analysis of genome-wide association studies in Parkinson disease (PD) based on populations of Caucasian descent. The extent to which these genetic effects are consistent across different populations is unknown. Methods: Investigators from the Genetic Epidemiology of Parkinson9s Disease Consortium were invited to participate in the study. A total of 11 SNPs were genotyped in 8,750 cases and 8,955 controls. Fixed as well as random effects models were used to provide the summary risk estimates for these variants. We evaluated between-study heterogeneity and heterogeneity between populations of different ances…
Involvement of Nitric Oxide in Nigrostriatal Dopaminergic System Degeneration : A Neurochemical Study.
2009
The present study was undertaken to explore the involvement of nitric oxide (NO) in the 6-hydroxydopamine (6-OHDA) experimental model of Parkinson's disease (PD) in rats. The effect of pharmacological manipulation of the NO system was evaluated on striatal dopamine (DA) level decrease produced by the toxin. 7-nitroindazole (7-NI, 50 mg/kg i.p.; n= 5) pretreatment significantly restored the striatal DA contents. Conversely, 40 mg/kg i.p. of molsidomine (MOL, n= 5), an NO donor, significantly worsened the neurodegeneration (n= 5) and completely counteracted the neuroprotective effect of 7-NI (n= 5). Thus, a crucial role for NO in 6-OHDA induced neurodegeneration is suggested together with a p…
7-nitroindazole protects striatal dopaminergic neurons against MPP+-induced degeneration: an in vivo microdialysis study.
2007
The neuropathological hallmark of Parkinson's disease (PD) is the selective degeneration of dopaminergic (DAergic) neurons in the substantia nigra pars compacta (SNc). In this study, using a microdialysis technique, we investigated whether an inhibitor of neuronal nitric oxide synthase (nNOS), 7-nitrindazole (7-NI), could protect against DAergic neuronal damage induced by in vivo infusion of 1-methyl-4-phenylpiridinium iodide (MPP(+)) in freely moving rats. Experiments were performed over 2 days in three groups of rats: (a) nonlesioned, (b) MPP(+)-lesioned, and (c) 7-NI pretreated MPP(+)-lesioned rats. On day 1, control rats were perfused with an artificial CSF, while 1 mM MPP(+) was infuse…
Gastric α-synuclein immunoreactive inclusions in Meissner's and Auerbach's plexuses in cases staged for Parkinson's disease-related brain pathology
2005
The progressive degenerative process associated with sporadic Parkinson's disease (sPD) is characterized by formation of alpha-synuclein-containing inclusion bodies in a few types of projection neurons in both the enteric and central nervous systems (ENS and CNS). In the brain, the process apparently begins in the brainstem (dorsal motor nucleus of the vagal nerve) and advances through susceptible regions of the basal mid-and forebrain until it reaches the cerebral cortex. Anatomically, all of the vulnerable brain regions are closely interconnected. Whether the pathological process begins in the brain or elsewhere in the nervous system, however, is still unknown. We therefore used immunocyt…
Neuroprotective Properties of Mildronate, a Small Molecule, in a Rat Model of Parkinson’s Disease
2010
Previously, we have found that mildronate [3-(2,2,2-trimethylhydrazinium) propionate dihydrate], a small molecule with charged nitrogen and oxygen atoms, protects mitochondrial metabolism that is altered by inhibitors of complex I and has neuroprotective effects in an azidothymidine-neurotoxicity mouse model. In the present study, we investigated the effects of mildronate in a rat model of Parkinson’s disease (PD) that was generated via a unilateral intrastriatal injection of the neurotoxin 6-hydroxydopamine (6‑OHDA). We assessed the expression of cell biomarkers that are involved in signaling cascades and provide neural and glial integration: the neuronal marker TH (tyrosine hydroxylase); …
The risky business of dopamine agonists in Parkinson disease and impulse control disorders
2011
Risk-taking behavior is characterized by pursuit of reward in spite of potential negative consequences. Dopamine neurotransmission along the mesocorticolimbic pathway is a potential modulator of risk behavior. In patients with Parkinson's disease (PD), impulse control disorder (ICD) can result from dopaminergic medication use, particularly dopamine agonists (DAA). Behaviors associated with ICD include hypersexuality as well as compulsive gambling, shopping, and eating, and these behaviors are potentially linked to alterations to risk processing. Using the Balloon Analogue Risk Task, we assessed the role of agonist therapy on risk-taking behavior in PD patients with (n = 22) and without (n =…