Search results for "fall"
showing 10 items of 964 documents
The applicability of SRTM in [18F]fallypride PET investigations: Impact of scan durations
2011
The high-affinity radioligand [18F]fallypride (FP) is frequently used for quantification of striatal/extrastriatal D2/3 receptors and the receptor occupancies of antipsychotics (APs). Its 110 minutes half-life allows long scan durations. However, the optimum scan duration is a matter of debate. This investigation focuses on scan-duration-related effects on simplified reference tissue model (SRTM) results and the time point of transient equilibrium in a large sample of dynamic FP positron emission tomography (PET) scans. Fifty drug-free and 50 AP-treated subjects underwent FP-PET scans (180 minutes scan duration). The binding potential ( BPND) of the putamen, thalamus, and temporal cortex w…
Dopamine D2/D3 receptor availability and venturesomeness.
2011
The construct of impulsivity is considered as a major trait of personality. There is growing evidence that the mesolimbic dopamine system plays an important role in the modulation of impulsivity and venturesomeness, the two key components within the impulsivity-construct. The aim of the present study was to explore an association between trait impulsivity measured with self-assessment and the dopaminergic neurotransmission as measured by positron emission tomography (PET) in a cohort of healthy male subjects. In vivo D2/D3 receptor availability was determined with [(18)F]fallypride PET in 18 non-smoking healthy subjects. The character trait impulsivity was measured using the Impulsiveness-V…
Lower limb muscle weakness predicts use of a multiple- versus single-step strategy to recover from forward loss of balance in older adults.
2012
BACKGROUND: Older adults compared with young adults have reduced strength and balance recovery ability. The purpose of the present study was to investigate whether age, sex, and/or lower limb strength predicted the stepping strategy used to recover from a forward loss of balance. METHODS: Ninety-five, community-dwelling, older adults, aged 65-90 years, participated in the study. Loss of balance was induced by releasing participants from a static forward lean. Participants performed four trials at three initial lean magnitudes and were subsequently classified as using a single- or multiple-step strategy. Isometric strength of the ankle, knee, and hip joint flexors and extensors was assessed …
Post-traumatic lethal carotid-cavernous fistula.
2006
The authors report about an unexpected death by traumatic lesion of the internal carotid artery in a 30-year-old man who had fallen two metres. The man suffered a fracture of the left maxillary sinus and a fracture of the right orbit with bilateral haemorrhage of the maxillary sinus. Surgical treatment was performed with favorable outcome. Clinically, there were no neurological symptoms but about 60 days after his accident, the man died from uncontrolled epistaxis. He was submitted to the autopsy that show a linear fracture in the left side of the turcic sella and lesion of the left internal carotid artery with carotid-cavernous fistula.
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…
Striatal and extrastriatal D2/D3-receptor-binding properties of ziprasidone: a positron emission tomography study with [18F]Fallypride and [11C]raclo…
2008
To elucidate the Batypicality( of ziprasidone, its striatal and extrastriatal D2/D3-receptor binding was characterized in patients with schizophrenia under steady-state conditions. These data were compared with striatal receptor occupancy values after single-dose ziprasidone ingestion in healthy controls. ( 18 F)fallypride positron emission tomography (PET) recordings were obtained in 15 patients under steady-state ziprasidone treatment at varying time points after the last dose. Binding potentials were calculated for striatal and extrastriatal regions. D2/D3-receptor occupancies were expressed relative to binding potentials in 8 unmedicated patients. In a parallel ( 11 C)raclopride-PET stu…
Kinematic analysis of motor strategies in frail aged adults during the Timed Up and Go: how to spot the motor frailty?
2015
Asma Hassani,1 Alexandre Kubicki,2,3 Vincent Brost,1 France Mourey,2,4 Fan Yang1 1Laboratoire LE2I CNRS 6306, Université de Bourgogne, Dijon, France; 2Institut National de la Santé et de la Recherche Médicale (INSERM), Cognition Action et Plasticité Sensori-Motrice, Campus Universitaire, Université de Bourgogne, Dijon, France; 3Centre Hospitalier Universitaire de Dijon, Hôpital de Champmaillot, Dijon, France; 4Faculté de Médecine, Université de Bourgogne, Dijon, France Objective: The purpose of this work was to analyze and compare the movement kinematics of sit-to-stand (STS) and back-to-sit (B…
Contributions of individual muscles to the sagittal- and frontal-plane angular accelerations of the trunk in walking.
2013
This study was conducted to analyze the unimpaired control of the trunk during walking. Studying the unimpaired control of the trunk reveals characteristics of good control. These characteristics can be pursued in the rehabilitation of impaired control. Impaired control of the trunk during walking is associated with aging and many movement disorders. This is a concern as it is considered to increase fall risk. Muscles that contribute to the trunk control in normal walking may also contribute to it under perturbation circumstances, attempting to prevent an impending fall. Knowledge of such muscles can be used to rehabilitate impaired control of the trunk. Here, angular accelerations of the t…
Vulnerability to psychotogenic effects of ketamine is associated with elevated D2/3-receptor availability.
2012
Previous positron emission tomography (PET) studies employing competition paradigms have shown either no change or substantial declines in striatal ( 11 C)-raclopride binding after challenge with psychotogenic doses of the N-methyl-D-aspartate antagonist ketamine. We sought to probe the relationship between the severity of ketamine-induced psychotic symptoms and altered dopamine D2/3 receptor availability throughout brain using the high affinity ligand ( 18 F)-fallypride (FP). PET recordings were obtained in a group of 10 healthy, young male volunteers, in a placebo condition, and in the course of an infusion with ketamine at a psychotomimetic dose. Administration of the Positive and Negati…
The striatal and extrastriatal D2/D3 receptor-binding profile of clozapine in patients with schizophrenia.
2005
Positron emission tomography (PET) studies reveal that clozapine at clinically used doses occupies less than 60% of D2/D3 dopamine receptors in human striatum. Here, the occupancy of D2/D3 dopamine receptors by clozapine in patients with schizophrenia was determined to test the hypothesis that clozapine binds preferentially to extrastriatal dopamine receptors. A total of 15 clozapine-treated inpatients with schizophrenia underwent a [18F]fallypride PET scan. Receptor occupancy was calculated as percent reduction in binding potential relative to unblocked values measured in seven normal volunteers. Mean D2/D3 receptor occupancy was statistically significantly higher in cortical (inferior tem…