Increased Anxiety After Stimulation of the Right Inferior Parietal Lobe and the Left Orbitofrontal Cortex

Sustained anxiety is a key symptom of anxiety disorders and may be associated with neural activation in the right inferior parietal lobe (rIPL), particularly under unpredictable threat. This finding suggests a moderating role of the rIPL in sustained anxiety, which we tested in the current study. We applied cathodal or sham transcranial direct current stimulation (tDCS) to the rIPL as a symptom provocation method in 22 healthy participants in a randomized, double-blind, crossover study, prior to two recordings of cerebral blood flow (CBF). In between, we applied a threat-of-shock paradigm with three conditions: unpredictable (U), predictable (P), or no electric shocks (N). We hypothesized increased anxiety under U, but not under P or N. Furthermore, we expected reduced CBF in the rIPL after tDCS compared to sham. As predicted, anxiety was higher in the U than the P and N conditions, and active tDCS augmented this effect. While tDCS did not alter CBF in the rIPL, it did attenuate the observed increase in brain regions that typically increase activation as a response to anxiety. These findings suggest that the rIPL moderates sustained anxiety as a gateway to brain regions crucial in anxiety. Alternatively, anodal tDCS over the left orbitofrontal cortex (lOFC) may have increased anxiety through disruption of OFC-amygdala interactions

Rey Visual Design Learning Test performance correlates with white matter structure

Objective: Studies exploring relation of visual memory to white matter are extensively lacking. The Rey Visual Design Learning Test (RVDLT) is an elementary motion, colour and word independent visual memory test. It avoids a significant contribution from as many additional higher order visual brain functions as possible to visual performance, such as three-dimensional, colour, motion or word-dependent brain operations. Based on previous results, we hypothesised that test performance would be related with white matter of dorsal hippocampal commissure, corpus callosum, posterior cingulate, superior longitudinal fascicle and internal capsule. Methods: In 14 healthy subjects, we measured intervoxel coherence (IC) by diffusion tensor imaging as an indication of connectivity and visual memory performance measured by the RVDLT. IC considers the orientation of the adjacent voxels and has a better signal-to-noise ratio than the commonly used fractional anisotropy index. Results: Using voxelwise linear regression analyses of the IC values, we found a significant and direct relationship between 11 clusters and visual memory test performance. The fact that memory performance correlated with white matter structure in left and right dorsal hippocampal commissure, left and right posterior cingulate, right callosal splenium, left and right superior longitudinal fascicle, right medial orbitofrontal region, left anterior cingulate, and left and right anterior limb of internal capsule emphasises our hypothesis. Conclusion: Our observations in healthy subjects suggest that individual differences in brain function related to the performance of a task of higher cognitive demands might partially be associated with structural variation of white matter region

Resting-state perfusion in motor and fronto-limbic areas is linked to diminished expression of emotion and speech in schizophrenia.

Negative symptoms (NS) are a core component of schizophrenia affecting community functioning and quality of life. We tested neural correlates of NS considering NS factors and consensus subdomains. We assessed NS using the Clinical Assessment Interview for Negative Symptoms and the Scale for Assessment of Negative Symptoms. Arterial spin labeling was applied to measure resting-state cerebral blood flow (rCBF) in 47 schizophrenia patients and 44 healthy controls. Multiple regression analyses calculated the relationship between rCBF and NS severity. We found an association between diminished expression (DE) and brain perfusion within the cerebellar anterior lobe and vermis, and the pre-, and supplementary motor area. Blunted affect was linked to fusiform gyrus and alogia to fronto-striatal rCBF. In contrast, motivation and pleasure was not associated with rCBF. These results highlight the key role of motor areas for DE. Considering NS factors and consensus subdomains may help identifying specific pathophysiological pathways of NS

Modulation of BOLD and Arterial Spin Labeling (ASL-CBF) Response in Patients with Transient Visual Impairment after Posterior Circulation Stroke*

Background and Purpose:: Blood oxygenation level-dependent (BOLD) signal and arterial spin labeling cerebral blood flow (ASL-CBF) changes, as detected by functional magnetic resonance imaging (fMRI) are closely related to neural activity. The aim of this case series study was to investigate modulations of the BOLD and ASL-CBF response in the primary visual cortex after posterior circulation stroke with transient visual impairment. Methods:: BOLD activity, resting CBF and task-related ASL-CBF response have been investigated 24-48 h after onset of transient visual symptoms in two patients who were treated conservatively, two patients who received thrombolysis after posterior circulation stroke, and five healthy controls with checkerboard stimulation and visual evoked potentials (VEPs). Results:: After normalization of transient visual symptoms the BOLD response and VEPs showed no hemispheric differences between patients and controls. The relative blood flow in the posterior cerebral arteries and the relative ASL-CBF response to checkerboard stimulation were reduced in three patients, compared to controls. In one patient who received intraarterial thrombolytic therapy, improvement of the relative CBF and ASL-CBF responses was observed, indicating early reperfusion. Conclusion:: In this case series of four patients, different CBF responses to conservative and thrombolytic therapy were observed, and early reperfusion after intraarterial thrombolysis was detected. Functional imaging, which makes use of the ASL-CBF technique, is feasible to measure early poststroke vascular changes, which are hardly detectable with BOLD-fMR

The Impact of Foehn Wind on Mental Distress among Patients in a Swiss Psychiatric Hospital.

Psychiatric patients are particularly vulnerable to strong weather stimuli, such as foehn, a hot wind that occurs in the alps. However, there is a dearth of research regarding its impact on mental health. This study investigated the impact of foehn wind among patients of a psychiatric hospital located in a foehn area in the Swiss Alps. Analysis was based on anonymized datasets obtained from routine records on admission and discharge, including the Brief Symptom Checklist (BSCL) questionnaire, as well as sociodemographic parameters (age, sex, and diagnosis). Between 2013 and 2020, a total of 10,456 admission days and 10,575 discharge days were recorded. All meteorological data were extracted from the database of the Federal Office of Meteorology and Climatology of Switzerland. We estimated the effect of foehn on the BSCL items using a distributed lag model. Significant differences were found between foehn and non-foehn admissions in obsession-compulsion, interpersonal sensitivity, depression, anxiety, phobic anxiety, paranoid ideation, and general severity index (GSI) (p < 0.05). Our findings suggest that foehn wind events may negatively affect specific mental health parameters in patients. More research is needed to fully understand the impact of foehn's events on mental health

CBT Reduces CBF

Background: Imaging studies have provided evidence that cognitive‐behavioral therapy (CBT ) is able to change brain activation in phobic patients in response to threatening stimuli. The changes occurred in both emotion‐generating and modulatory regions. In this study, we use a data‐driven approach to explore resting state cerebral blood flow (CBF ) measured by arterial spin labeling (ASL ), before and after CBT. Methods: Eight female patients with spider phobia were scanned before and 1 month after an exposure‐based group therapy for spider phobia. Each MRI session consisted of an ASL resting state measurement acquired before and after a symptom provocation task involving the showing of spider pictures in the scanner. The first ASL acquisition measured anticipatory anxiety and the second measured postprocessing of phobia‐relevant stimuli. Results: Cognitive‐behavioral therapy significantly reduced spider phobic symptoms in all patients. Symptom reduction during anticipatory anxiety was accompanied by reduced bilateral CBF in the parahippocampal gyrus, ventral anterior thalamus, Brodmann area 8, and the anterior cingulate cortex. During postprocessing of phobia‐relevant stimuli, patients showed reduced CBF in the bilateral insula, components of the motor cortex, and areas associated with language functions. Conclusions: Longitudinal CBF dynamics following CBT were in concordance with results from several studies using BOLD fMRI to investigate the effects of psychotherapy on brain activity. CBF can be quantified by ASL , with the principal advantage of sensitivity to slow variations in neural activity and task independence. Therefore, ASL may be a suitable method for monitoring and evaluating the efficacy of psychotherapy or pharmacotherapy approaches

Lesions to Primary Sensory and Posterior Parietal Cortices Impair Recovery from Hand Paresis after Stroke

Neuroanatomical determinants of motor skill recovery after stroke are still poorly understood. Although lesion load onto the corticospinal tract is known to affect recovery, less is known about the effect of lesions to cortical sensorimotor areas. Here, we test the hypothesis that lesions of somatosensory cortices interfere with the capacity to recover motor skills after stroke

Cognitive outcome is related to functional thalamo-cortical connectivity after paediatric stroke.

The thalamus has complex connections with the cortex and is involved in various cognitive processes. Despite increasing interest in the thalamus and the underlying thalamo-cortical interaction, little is known about thalamo-cortical connections after paediatric arterial ischaemic stroke. Therefore, the aim of this study was to investigate thalamo-cortical connections and their association with cognitive performance after arterial ischaemic stroke. Twenty patients in the chronic phase after paediatric arterial ischaemic stroke (≥2 years after diagnosis, diagnosed <16 years; aged 5-23 years, mean: 15.1 years) and 20 healthy controls matched for age and sex were examined in a cross-sectional study design. Cognitive performance (selective attention, inhibition, working memory, and cognitive flexibility) was evaluated using standardized neuropsychological tests. Resting-state functional magnetic resonance imaging was used to examine functional thalamo-cortical connectivity. Lesion masks were integrated in the preprocessing pipeline to ensure that structurally damaged voxels did not influence functional connectivity analyses. Cognitive performance (selective attention, inhibition, and working memory) was significantly reduced in patients compared to controls. Network analyses revealed significantly lower thalamo-cortical connectivity for the motor, auditory, visual, default mode network, salience, left/right executive, and dorsal attention network in patients compared with controls. Interestingly, analyses additionally revealed higher thalamo-cortical connectivity in some subdivisions of the thalamus for the default mode network (medial nuclei), motor (lateral nuclei), dorsal attention (anterior nuclei), and the left executive network (posterior nuclei) in patients compared with controls. Increased and decreased thalamo-cortical connectivity strength within the same networks was, however, found in different thalamic subdivisions. Thus, alterations in thalamo-cortical connectivity strength after paediatric stroke seem to point in both directions, with stronger as well as weaker thalamo-cortical connectivity in patients compared with controls. Multivariate linear regression, with lesion size and age as covariates, revealed significant correlations between cognitive performance (selective attention, inhibition, and working memory) and the strength of thalamo-cortical connectivity in the motor, auditory, visual, default mode network, posterior default mode network, salience, left/right executive, and dorsal attention network after childhood stroke. Our data suggest that the interaction between different sub-nuclei of the thalamus and several cortical networks relates to post-stroke cognition. The variability in cognitive outcomes after paediatric stroke might partly be explained by functional thalamo-cortical connectivity strength

Associations of resting-state perfusion and auditory verbal hallucinations with and without emotional content in schizophrenia.

Auditory Verbal Hallucinations (AVH) are highly prevalent in patients with schizophrenia. AVH with high emotional content lead to particularly poor functional outcome. Increasing evidence shows that AVH are associated with alterations in structure and function in language and memory related brain regions. However, neural correlates of AVH with emotional content remain unclear. In our study (n = 91), we related resting-state cerebral perfusion to AVH and emotional content, comparing four groups: patients with AVH with emotional content (n = 13), without emotional content (n = 14), without hallucinations (n = 20) and healthy controls (n = 44). Patients with AVH and emotional content presented with increased perfusion within the amygdala and the ventromedial and dorsomedial prefrontal cortex (vmPFC/ dmPFC) compared to patients with AVH without emotional content. In addition, patients with any AVH showed hyperperfusion within the anterior cingulate gyrus, the vmPFC/dmPFC, the right hippocampus, and the left pre- and postcentral gyrus compared to patients without AVH. Our results indicate metabolic alterations in brain areas critical for the processing of emotions as key for the pathophysiology of AVH with emotional content. Particularly, hyperperfusion of the amygdala may reflect and even trigger emotional content of AVH, while hyperperfusion of the vmPFC/dmPFC cluster may indicate insufficient top-down amygdala regulation in patients with schizophrenia

Neuronal current imaging of epileptic activity: An MRI study in patients with a first unprovoked epileptic seizure.

OBJECTIVE This study evaluates the performance of the novel MRI sequence stimulus-induced rotary saturation (SIRS) to map responses to interictal epileptic activity in the human cortex. Spin-lock pulses have been applied to indirectly detect neuronal activity through magnetic field perturbations. Following initial reports about the feasibility of the method in humans and animals with epilepsy, we aimed to investigate the diagnostic yield of spin-lock MR pulses in comparison with scalp-EEG in first seizure patients. METHODS We employed a novel method for measurements of neuronal activity through the detection of a resonant oscillating field, stimulus-induced rotary saturation contrast (SIRS) at spin-lock frequencies of 120 and 240 Hz acquired at a single 3T MRI system. Within a prospective observational study, we conducted SIRS experiments in 55 patients within 7 days after a suspected first unprovoked epileptic seizure and 61 healthy control subjects. In this study, we report on the analysis of data from a single 3T MRI system, encompassing 35 first seizure patients and 31 controls. RESULTS The SIRS method was applicable in all patients and healthy controls at frequencies of 120 and 240 Hz. We did not observe any significant age- or sex-related differences. Specificity of SIRS at 120 Hz was 90.3% and 93.5% at 240 Hz. Sensitivity was 17.1% at 120 Hz and 40.0% at 240 Hz. SIGNIFICANCE SIRS targets neuronal oscillating magnetic fields in patients with epilepsy. The coupling of presaturated spins to epilepsy-related magnetic field perturbations may serve as a-at this stage experimental-diagnostic test in first seizure patients to complement EEG findings as a standard screening test. PLAIN LANGUAGE SUMMARY Routine diagnostic tests carry several limitations when applied after a suspected first seizure. SIRS is a noninvasive MRI method to enable time-sensitive diagnosis of image correlates of epileptic activity with increased sensitivity compared to routine EEG