Sebastian Scheliga

Smoking is a major risk factor of cardiovascular diseases, notably peripheral arterial disease (PAD). Despite this link, research on smoking cessation interventions in PAD patients remains scarce and inconclusive regarding the efficacy of such interventions. Therefore, elucidating it is crucial and should address both individuals who smoke that are motivated to quit and individuals who smoke heavily lacking the motivation to quit. The Aachen Smoking Cessation and Harm Reduction (ASCHR) trial is a prospective randomized controlled study (RCT) on the benefits of telemedical-psychological support for smoking cessation in patients with PAD, funded by the “Innovation Fund” of the Joint Federal Committee in Germany. This trial aims to scientifically assess the efficacy, feasibility, acceptance, and efficiency of a multi-stage smoking cessation program based on the recommendations of the German guideline for smoking cessation tailored to patients with PAD, compared to a control group receiving no intervention. Central to the program is psychological counseling utilizing motivational interviewing techniques, delivered through telemedicine via video consultations. The primary endpoint of the ASCHR trial is the smoking cessation rate after 8 months of intervention, with a secondary endpoint evaluating sustained abstinence at a further 6 months follow-up. Smoking cessation is defined as a carbon monoxide level in exhaled air of less than 6 ppm. We hypothesize that the group receiving the multi-stage cessation program will yield a cessation rate at least 10 percentage points higher than that of usual care. Anticipating a dropout rate of around 35%, the planned sample size is at least N = 1032 study participants. Should the trial demonstrate significant positive outcomes, efforts should be made to integrate the program into routine care in Germany, potentially offering a promising base for future smoking cessation support among PAD patients.

Background: The lead symptom of small fibre neuropathy (SFN) is neuropathic pain. Recent functional magnetic resonance imaging (fMRI) studies have indicated central changes in SFN patients of different etiologies. However, less is known about brain functional connectivity during acute pain processing in idiopathic SFN.Methods: We conducted fMRI with thermal heat pain application (left volar forearm) in 32 idiopathic SFN patients and 31 healthy controls. We performed functional connectivity analyses with right supplementary motor area (SMA), left insula, and left caudate nucleus (CN) as seed regions, respectively. Since pathogenic gain‐of‐function variants in voltage gated sodium channels (Nav) have been linked to SFN pathophysiology, explorative connectivity analyses were performed in a homogenous subsample of patients carrying rare heterozygous missense variants.Results: For right SMA, we found significantly higher connectivity with the right thalamus in SFN patients compared to controls. This connectivity correlated significantly with intraepidermal nerve fibre density, suggesting a link between peripheral and central pain processing. We found significantly reduced connections between right SMA and right middle frontal gyrus in patients with Nav variants. Likewise, connectivity between left CN and right frontal pole was decreased.Conclusions: Aberrant functional connectivity in SFN is in line with previous research on other chronic pain syndromes. Functional connectivity changes may be linked to SFN, highlighting the need to determine if they result from peripheral changes causing abnormal somatosensory processing. This understanding may be crucial for assessing their impact on painful symptoms and therapy response.Significance statement: We found increased functional connectivity between SMA and thalamus during painful stimulation in patients with idiopathic SFN. Connectivity correlated significantly with intraepidermal nerve fibre density, suggesting a link between peripheral and central pain processing. Our findings emphasize the importance of investigating functional connectivity changes as a potential feature of SFN.

Psychotic symptoms may be traced back to sensory sensitivity. Thereby, visual motion (VM) processing particularly has been suggested to be impaired in schizophrenia (SCZ). In healthy brains, VM underlies predictive processing within hierarchically structured systems. However, less is known about predictive VM processing in SCZ. Therefore, we performed fMRI during a VM paradigm with three conditions of varying predictability, i.e., predictable-, random-, and arbitrary motion. The study sample comprised 17 SCZ patients and 23 healthy controls. We calculated general linear model (GLM) analysis to assess group differences in VM processing across motion conditions. Here, we identified significantly lower activity in right temporoparietal junction (TPJ) for SCZ patients. Therefore, right TPJ was set as seed for connectivity analyses. For patients, across conditions we identified increased connections to higher regions, namely medial prefrontal cortex, or paracingulate gyrus. Healthy subjects activated sensory regions as area V5, or superior parietal lobule. Since TPJ operates as hub modulating network shifts, aberrant functional connectivity with higher structures may thus reflect a compensatory mechanism co-occurring to impaired TPJ activity in SCZ. In sum, these altered neural patterns provide a framework for future studies focusing on predictive VM processing to identify potential biomarkers of psychosis.

Previous fMRI research identified superior temporal sulcus as central integration area for audiovisual stimuli. However, less is known about a general multisensory integration network across senses. Therefore, we conducted activation likelihood estimation meta-analysis with multiple sensory modalities to identify a common brain network. We included 49 studies covering all Aristotelian senses i.e., auditory, visual, tactile, gustatory, and olfactory stimuli. Analysis revealed significant activation in bilateral superior temporal gyrus, middle temporal gyrus, thalamus, right insula, and left inferior frontal gyrus. We assume these regions to be part of a general multisensory integration network comprising different functional roles. Here, thalamus operate as first subcortical relay projecting sensory information to higher cortical integration centers in superior temporal gyrus/sulcus while conflict-processing brain regions as insula and inferior frontal gyrus facilitate integration of incongruent information. We additionally performed meta-analytic connectivity modelling and found each brain region showed co-activations within the identified multisensory integration network. Therefore, by including multiple sensory modalities in our meta-analysis the results may provide evidence for a common brain network that supports different functional roles for multisensory integration.