Search results for "cortex"
showing 10 items of 1827 documents
Estimation of the dimensionality of sleep-EEG data in schizophrenics
1993
Deterministic chaos could be regarded as a healthy flexibility of the human brain necessary for correct neuronal operations. Several investigations have demonstrated that in healthy subjects the dimensionality of REM sleep is much higher than that of slow wave sleep (SWS). We investigated the sleep-EEG of schizophrenic patients with methods from nonlinear system theory in order to estimate the dynamic properties of CNS. We hypothesized that schizophrenics would reveal alterations of their dynamic EEG features indicating impaired information processing. In 11 schizophrenic patients, the EEG's dimensionality during sleep stages II and REM was reduced. We suggest that such lower dimensional ch…
Differential pathophysiological mechanisms of reduced P300 amplitude in schizophrenia and depression: a single trial analysis
1997
In order to address basic mechanisms behind a reduced averaged P300 wave in schizophrenia and depression, 17 unmedicated schizophrenic and 11 unmedicated depressive subjects were tested in an 'oddball paradigm' against healthy controls matched for gender and age. The amplitude distributions of single trials' maximum positive deflections after stimulation (P300) for both target and nontarget stimuli were determined, which served as a basis for calculating the discrimination index d'. This index characterizes differences in the electrophysiological responses to target and nontarget stimuli of a subject being engaged in a discrimination task. As a main result d' was significantly lower for sch…
Neurodevelopmental subtypes of bipolar disorder are related to cortical folding patterns: An international multicenter study
2018
Objectives Brain sulcation is an indirect marker of neurodevelopmental processes. Studies of the cortical sulcation in bipolar disorder have yielded mixed results, probably due to high variability in clinical phenotype. We investigated whole-brain cortical sulcation in a large sample of selected patients with high neurodevelopmental load. Methods A total of 263 patients with bipolar disorder I and 320 controls were included in a multicentric magnetic resonance imaging (MRI) study. All subjects underwent high-resolution T1-weighted brain MRI. Images were processed with an automatized pipeline to extract the global sulcal index (g-SI) and the local sulcal indices (l-SIs) from 12 a priori dete…
Subchronic haloperidol downregulates dopamine synthesis capacity in the brain of schizophrenic patients in vivo
2003
Udgivelsesdato: 2003-Apr The antipsychotic effect of neuroleptics cannot be attributed entirely to acute blockade of postsynaptic D(2)-like dopamine (DA) receptors, but may arise in conjunction with the delayed depolarization block of the presynaptic neurons and reduced DA synthesis capacity. Whereas the phenomenon of depolarization block is well established in animals, it is unknown if a similar phenomenon occurs in humans treated with neuroleptics. We hypothesized that haloperidol treatment should result in decreased DA synthesis capacity. We used 6-[(18)F]fluoro-L-dopa (FDOPA) and positron emission tomography (PET) in conjunction with compartmental modeling to measure the relative activi…
Left orbitofrontal and superior temporal gyrus structural changes associated to suicidal behavior in patients with schizophrenia.
2008
Suicidal attempts are relatively frequent and clinically relevant in patients with schizophrenia. Recent studies have found gray matter differences in suicidal and non-suicidal depressive patients. However, no previous neuroimaging study has investigated possible structural abnormalities associated to suicidal behaviors in patients with schizophrenia. A whole-brain magnetic resonance voxel-based morphometric examination was performed on 37 male patients meeting the DSM-IV criteria for schizophrenia. Thirteen (35.14%) patients had attempted suicide. A non-parametric permutation test was computed to perform the comparability between groups. An analysis of covariance (AnCova) model was constru…
Reslizumab as add-on therapy in patients with refractory asthma
2020
### Key messages #### What is the key question? #### What is the bottom line? #### Why read on? Asthma is a common disease, affecting an estimated 334 million people worldwide, with considerable impact on quality of life and high associated costs.1–3 Asthma severity is assessed retrospectively from the level of treatment required to control symptoms and exacerbations. Approximately 5%–10% of patients with asthma are believed to suffer from severe disease.4 Patients with severe asthma typically require ongoing maintenance therapy with high-dose inhaled corticosteroid (ICS)/long-acting beta-agonist (LABA).2 Furthermore, systemic corticosteroids (SCS) are often required for potentially life-th…
A randomized, double-blind study to compare the efficacy and safety of two doses of mometasone furoate delivered via Breezhaler® or Twisthaler® in pa…
2019
Abstract Introduction Mometasone furoate (MF) is the inhaled corticosteroid (ICS) component in the long-acting β2-agonist (LABA)/ICS fixed-dose combination of indacaterol/MF, delivered via Breezhaler®, in development for asthma. MF at low (80 μg) and high (320 μg) doses delivered via Breezhaler® is expected to be comparable to MF at low (200 μg) and high (800 μg) doses respectively, delivered via Twisthaler®. Methods This was a randomized, double-blind, double-dummy, four-week, parallel-group study of 739 adolescents and adults with persistent asthma. Eligible patients were receiving ICS treatment up to the maximum dose per day on a stable regimen for at least four weeks before screening. T…
Omalizumab in patients with severe persistent allergic asthma in a real-life setting in Germany
2009
Omalizumab is a humanized monoclonal anti-immunoglobulin E (IgE) antibody indicated in Europe for the treatment of uncontrolled severe persistent allergic (IgE-mediated) asthma despite optimal therapy with inhaled corticosteroids and long-acting beta(2) agonists. Between 2005 and 2007 280 patients (58% female, mean age 44+/-16 yrs., 46% on oral corticosteroids, median serum IgE level 235IU/ml) who met the EU criteria for add-on therapy with anti-IgE were treated prospectively with omalizumab by 134 physicians as part of a post-marketing surveillance trial and were followed-up for 6 months. The median follow-up time was 195 days, the patients were treated with a median dose of 450mg omalizum…
Human dopamine receptor D2/D3 availability predicts amygdala reactivity to unpleasant stimuli
2009
r r Abstract: Dopamine (DA) modulates the response of the amygdala. However, the relation between dopa- minergic neurotransmission in striatal and extrastriatal brain regions and amygdala reactivity to affective stimuli has not yet been established. To address this issue, we measured DA D2/D3 receptor (DRD2/3) availability in twenty-eight healthy men (nicotine-dependent smokers and never-smokers) using positron emission tomography with ( 18 F)fallypride. In the same group of participants, amygdala response to unpleasant visual stimuli was determined using blood oxygen level-dependent (BOLD) functional mag- netic resonance imaging. The effects of DRD2/3 availability in emotion-related brain …
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…