Search results for "caudate"
showing 10 items of 53 documents
P13. Dendato-thalamo-cortical pathways in association with otolith dysfunction
2015
Introduction The processing of otolith information within the human cortex is still poorly understood (Lopez and Blanke, 2011). Two distinct anatomical otolith pathways within the thalamo-cortical vestibular network were proposed in patients with thalamic infarctions who presented with contra- or ipsiversive tilts of the subjective visual vertical (SVV) (Dieterich and Brandt, 1993; Baier et al., submitted for publication). Aim of this study was to investigate the dendato-thalamo-cortical pathways in association with otolith dysfunction by means of DTI (diffusion tensor imaging) based on the regions found in a recent patient study using statistical lesion-behavior mapping (Baier et al., subm…
Activation-Induced Rigidity in Neurologically and Cognitively Healthy Individuals Aged 18-90 Years: A Cross-Sectional Study.
2021
Background: Rigidity is a key clinical feature of Parkinson’s disease (PD), but in a very early phase of the disease it may be absent and can be enhanced through active movements of the arm contralateral to the one being tested. Objective: To evaluate in a large cohort of neurologically and cognitively healthy (NCH) subjects aged 18–90 years if activation-induced rigidity (AR) is present in all age classes, and if there are biological differences between subjects showing AR (AR+) and not showing AR (AR-). Methods: 2,228 NCH subjects categorized as young adult (18–44 years), adult (45–64 years), elderly (65–74 years), and old/oldest-old (75–90 years) were included in the analysis, and underw…
Nociceptive Primitive Reflexes in Neurologically and Cognitively Healthy Aging Subjects
2019
ABSTRACT:Background:To assess the prevalence of three nociceptive primitive reflexes (nPR), i.e., glabellar tap, snout reflex, and palmomental reflex, in neurologically and cognitively healthy (NCH) aging subjects.Objective:To investigate whether nPR are cross-sectionally associated with white matter hyperintensities (WMH), lacunes, atrophy of the caudate nuclei, and global brain atrophy.Methods:A total of 1246 NCH subjects aged 45–91 years were included in the study and underwent standard brain MRI. Atrophy of the caudate nuclei and global brain atrophy were assessed through the bicaudate ratio (BCr) and lateral ventricles to brain ratio (LVBr), respectively. WMH were assessed through visu…
Changes in latency of evoked potentials after caudate nucleus stimulation1
1984
Resume L'activation de la tete du noyau caude de chats qui avaient ete soumis a la section de la moelle epiniere a la hauteur de C 1 produit l'inhibition des potentiels evoques de la zone motrice (region pre-cruciale) et la reduction du temps de latence du maximum de l'onde lente negative. Les resultats de la reduction de latence sont discutes par rapport a la variation d'intensite de la stimulation declenchant l'activite du cortex moteur. On sougline enfin le role joue par le noyau caude dans le controle du systeme moteur.
Brain iron deposition after Ferumoxytol-enhanced MRI: A study of Porcine Brains
2020
Recent evidence of gadolinium deposition in the brain has raised safety concerns. Iron oxide nanoparticles are re-emerging as promising alternative MR contrast agents, because the iron core can be metabolized. However, long-term follow up studies of the brain after intravenous iron oxide administration have not been reported thus far. In this study, we investigated, if intravenously administered ferumoxytol nanoparticles are deposited in porcine brains. Methods: In an animal care and use committee-approved prospective case-control study, ten Gottingen minipigs received either intravenous ferumoxytol injections at a dose of 5 mg Fe/kg (n=4) or remained untreated (n=6). Nine to twelve months …
[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 …
Accumbens-caudate-septal circuit as a system for hippocampal regulation: involvement of a GABAergic neurotransmission.
1992
Hippocampal-based epileptiform activity may reach the basal ganglia via the nucleus accumbens. Previous data suggested that caudate nucleus is able to influence hippocampal epilepsy, probably sending a projection to the septum. In order to test the hypothesis of a retrograde activation of accumbens-caudate pathway in hippocampal regulation, we electrically stimulated both caudate nucleus and nucleus accumbens and studied modifications of hippocampal EEG in the feline focal epilepsy model. We also performed bilateral electrolytic lesion of nucleus accumbens and repeated caudate stimulation. Results showed that nucleus accumbens stimulation was ineffective in modifying hippocampal epilepsy; o…
Dopamine D2/3 receptor occupancy by quetiapine in striatal and extrastriatal areas
2010
Quetiapine is next to clozapine an antipsychotic agent that exerts hardly any extrapyramidal side-effects at clinical efficacious doses. Some previous receptor occupancy studies reported preferential extrastriatal D2/3 receptor (D2/3R)-binding properties of second-generation antipsychotics and suggested this as possible reason for improved tolerability. This positron emission tomography (PET) investigation was designed to compare the occupancy of dopamine D2/3Rs by quetiapine in striatal and extrastriatal brain regions. Therefore, a cohort of 16 quetiapine-treated psychotic patients underwent an [18F]fallypride (FP) PET scan. Due to the high affinity of FP and its comparatively long half-li…
Alterations in striatal neuropeptide mRNA produced by repeated administration of L-DOPA, ropinirole or bromocriptine correlate with dyskinesia induct…
2002
Chronic administration of L-DOPA to MPTP-treated common marmosets induces marked dyskinesia while repeated administration of equivalent antiparkisonian doses of ropinirole and bromocriptine produces only mild involuntary movements. The occurrence of dyskinesia has been associated with an altered balance between the direct and indirect striatal output pathways. Using in situ hybridisation histochemistry, we now compare the effects of these drug treatments on striatal preproenkephalin-A (PPE-A) and adenosine A(2a) receptor mRNA expression as markers of the indirect pathway and striatal preprotachykinin (PPT) mRNA and preproenkephalin-B (PPE-B, prodynorphin) mRNA expression as markers of the d…
Relationship between dopamine D2 receptor occupancy, clinical response, and drug and monoamine metabolites levels in plasma and cerebrospinal fluid. …
2009
Combining measurements of the monoamine metabolites in the cerebrospinal fluid (CSF) and neuroimaging can increase efficiency of drug discovery for treatment of brain disorders. To address this question, we examined five drug-naive patients suffering from schizophrenic disorder. Patients were assessed clinically, using the Positive and Negative Syndrome Scale (PANSS): at baseline and then at weekly intervals. Plasma and CSF levels of quetiapine and norquetiapine as well CSF 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxyindole-acetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were obtained at baseline and again after at least a 4 week medication trai…