Search results for "Gyrus"
showing 10 items of 277 documents
Neural mechanisms of training an auditory event‐related potential task in a brain–computer interface context
2019
Effective use of brain-computer interfaces (BCIs) typically requires training. Improved understanding of the neural mechanisms underlying BCI training will facilitate optimisation of BCIs. The current study examined the neural mechanisms related to training for electroencephalography (EEG)-based communication with an auditory event-related potential (ERP) BCI. Neural mechanisms of training in 10 healthy volunteers were assessed with functional magnetic resonance imaging (fMRI) during an auditory ERP-based BCI task before (t1) and after (t5) three ERP-BCI training sessions outside the fMRI scanner (t2, t3, and t4). Attended stimuli were contrasted with ignored stimuli in the first-level fMRI…
The Functional Role of Large-scale Brain Network Coordination in Placebo-induced Anxiolysis
2018
Abstract Anxiety reduction through mere expectation of anxiolytic treatment effects (placebo anxiolysis) has enormous clinical importance. Recent behavioral and electrophysiological data suggest that placebo anxiolysis involves reduced vigilance and enhanced internalization of attention; however, the underlying neurobiological mechanisms are not yet clear. Given the fundamental function of intrinsic connectivity networks (ICNs) in basic cognitive processes, we investigated ICN activity patterns associated with externally and internally directed mental states under the influence of an anxiolytic placebo medication. Based on recent findings, we specifically analyzed the functional role of the…
Central nervous system involvement in late-onset Pompe disease: clues from neuroimaging and neuropsychological analysis
2018
Background and purpose Late-onset Pompe disease (LOPD) is a rare, multisystem disorder that is well established to mainly impair skeletal muscle function. Systematic studies exploring brain functions in LOPD are lacking. The aim of this study was to detect morphological and functional brain alterations as well as neuropsychological impairment in LOPD. Methods We studied 21 patients (10 male, mean age 49 ± 18.4 years) with defined diagnosis of LOPD, divided into two groups: one with pre-symptomatic hyperCKemia with no muscle weakness and the second with limb-girdle muscle weakness. All patients underwent 3T magnetic resonance imaging (MRI) to obtain morphological/angiographic evaluation as w…
Interictal Hyperperfusion in the Higher Visual Cortex in Patients With Episodic Migraine.
2019
Background Migraine pathophysiology is complex and probably involves cortical and subcortical alterations. Structural and functional brain imaging studies indicate alterations in the higher order visual cortex in patients with migraine. Arterial spin labeling magnetic resonance imaging (ASL-MRI) is a non-invasive imaging method for assessing changes in cerebral blood flow (CBF) in vivo. Objective To examine if interictal CBF differs between patients with episodic migraine (EM) with or without aura and healthy controls (HC). Methods We assessed interictal CBF using 2D pseudo-continuous ASL-MRI on a 3 Tesla Philips scanner (University Hospital Zurich, Switzerland) in EM (N = 17, mean age 32.7…
Reward anticipation revisited- evidence from an fMRI study in euthymic bipolar I patients and healthy first-degree relatives.
2017
Abstract Background Symptomatic phases in bipolar disorder (BD) are hypothesized to result from a hypersensitive behavioral activation system (BAS) being sensitive to potential rewards. However, studies on the neuronal underpinnings of reward anticipation in BD are scarce with contradictory findings and possibly confounded by effects of dopaminergic medication, necessitating further research on dysfunctional motivation in BD. Moreover, its role as vulnerability marker for BD is unclear. Methods Functional imaging was conducted in 16 euthymic BD-I patients free from dopaminergic medication and 19 healthy first-degree relatives using a monetary incentive delay task and compared to parallelize…
Structural brain correlates of IQ changes in bipolar disorder
2006
Background. There is increasing evidence that cognitive deficits are present in bipolar disorder (BP), but their neural correlates have not been fully explored. The aim of this study is to correlate structural brain abnormalities with cognitive performance in BP and to explore differences between clinical subtypes. Method. Thirty-six BP patients (13 men, 23 women) with a mean age of 39 years (range 21–63 years) underwent neuropsychological testing and imaging. Twenty-five patients had bipolar disorder I (BP I) and 11 had bipolar disorder II (BP II). Patients with co-morbid psychiatric diagnosis, drug and alcohol abuse or systemic illness were excluded. Correlations between cognitive perform…
Lithium prevents grey matter atrophy in patients with bipolar disorder: an international multicenter study
2020
AbstractBackgroundLithium (Li) is the gold standard treatment for bipolar disorder (BD). However, its mechanisms of action remain unknown but include neurotrophic effects. We here investigated the influence of Li on cortical and local grey matter (GM) volumes in a large international sample of patients with BD and healthy controls (HC).MethodsWe analyzed high-resolution T1-weighted structural magnetic resonance imaging scans of 271 patients with BD type I (120 undergoing Li) and 316 HC. Cortical and local GM volumes were compared using voxel-wise approaches with voxel-based morphometry and SIENAX using FSL. We used multiple linear regression models to test the influence of Li on cortical an…
Functional MRI of galvanic vestibular stimulation with alternating currents at different frequencies.
2004
Abstract Functional MRI was performed in 28 healthy volunteers to study the effects of galvanic vestibular stimulation with alternating currents (AC-GVS) of different frequencies on brain activation patterns. The aims of this study were (1) to identify specific areas within the vestibular cortical network that are involved in the processing of frequency-specific aspects by correlation analyses, (2) to determine the optimal frequency for stimulation of the vestibular system with respect to perception, and (3) to analyze whether different frequencies of AC-GVS are mediated in different cortical areas or different sites within the vestibular cortex. AC-GVS was performed using sinusoidal stimul…
Childhood methylphenidate treatment of ADHD and response to affective stimuli
2009
Neural correlates of emotional dysregulation in attention-deficit/hyperactivity disorder (ADHD) and persisting influence of Methylphenidate (MPH) still remain insufficiently understood. Decreased activation in the subgenual cingulate and the ventral striatum were found during the perception of positive and negative affective pictures in drug-naïve males with ADHD during childhood (n=10). Males with ADHD during childhood treated with MPH (n=10) did not show any significant differences compared to healthy controls (n=10). Further prospective studies need to clarify direct and indirect mechanisms of MPH treatment that may contribute to emotional processing, which is dysfunctional in males with…
Functional correlates of vertical gaze palsy and other ocular motor deficits in PSP: An FDG-PET study
2014
Abstract Objective To determine the functional correlates of vertical gaze palsy and other ocular motor deficits in patients with progressive supranuclear palsy (PSP) using [ 18 F]fluorodeoxyglucose (FDG-)PET. Methods Twenty-six patients with PSP underwent clinical examination of vertical gaze combined with FDG-PET scans to assess regional cerebral glucose metabolism as a marker of neuronal activity. Of these, eighteen PSP patients were also investigated by electrical nystagmography to determine horizontal ocular motor deficits. Statistical parametric mapping analyses were performed to correlate regional neuronal activity with ocular motor functions. Results In categorical comparisons, pati…