Purpose: Diffuse cortical damage in relapsing-remitting multiple sclerosis (RRMS) is clinically relevant but cannot be directly assessed with conventional MRI. In this study, it was aimed to use diffusion tensor imaging (DTI) techniques with optimized intrinsic eddy current compensation to quantify and characterize cortical mean diffusivity (MD) and fractional anisotropy (FA) changes in RRMS and to analyze the distribution of these changes across the cortex. Materials and Methods: Three-Tesla MRI acquisition, mapping of the MD providing information about the integrity of microstructural barriers and of the FA reflecting axonal density and surface-based analysis with Freesurfer were performed for 24 RRMS patients and 25 control subjects. Results: Across the whole cortex, MD was increased in patients (p < 0.001), while surface-based analysis revealed focal cortical FA decreases. MD and FA changes were distributed inhomogeneously across the cortex, the MD increase being more widespread than the FA decrease. Cortical MD correlated with the Expanded Disability Status Scale (EDSS, r = 0.38, p = 0.03). Conclusion: Damage of microstructural barriers occurs inhomogeneously across the cortex in RRMS and might be spatially more widespread than axonal degeneration. The results and, in particular, the correlation with the clinical status indicate that DTI might be a promising technique for the monitoring of cortical damage under treatment in larger clinical studies.

Understanding the microstructural changes related to physiological aging of the cerebral cortex is pivotal to differentiate healthy aging from neurodegenerative processes. The aim of this study was to investigate the age-related global changes of cortical microstructure and regional patterns using multiparametric quantitative MRI (qMRI) in healthy subjects with a wide age range. 40 healthy participants (age range: 2 nd to 8 th decade) underwent high-resolution qMRI including T1, PD as well as T2, T2* and T2′ mapping at 3 Tesla. Cortical reconstruction was performed with the FreeSurfer toolbox, followed by tests for correlations between qMRI parameters and age. Cortical T1 values were negatively correlated with age (p=0.007) and there was a widespread age-related decrease of cortical T1 involving the frontal and the parietotemporal cortex, while T2 was correlated positively with age, both in frontoparietal areas and globally (p=0.004). Cortical T2′ values showed the most widespread associations across the cortex and strongest correlation with age (r= -0.724, p=0.0001). PD and T2* did not correlate with age. Multiparametric qMRI allows to characterize cortical aging, unveiling parameter-specific patterns. Quantitative T2′ mapping seems to be a promising imaging biomarker of cortical age-related changes, suggesting that global cortical iron deposition is a prominent process in healthy aging.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. Typical symptoms are an impaired vision, paresis or sensory disturbances. Conventional magnetic resonance imaging (MRI) techniques are required for the initial diagnosis and visualization of the lesion load, which is mainly located in the white matter. Previous studies assessing cognitive deficits and fatigue in MS patients indicate that also cortical damage is of high clinical relevance in these patients. Insight into cortical damage with conventional MRI techniques is limited. Therefore, in the present study, diffusion tensor imaging (DTI) was used to characterize cortical tissue remodeling in MS. Two tissue parameters were measured: the mean diffusivity (MD) and the fractional anisotropy (FA). Since previous DTI studies in MS reported inconsistent results, the question arose, whether MD and FA changes in patients with relapsingremitting MS (RRMS) can be detected using optimized DTI techniques and how they are distributed across the cortex. 24 patients with RRMS and 25 healthy control subjects participated in this study. MRI acquisition was performed with 3 Tesla MRI scanner. In addition, the clinical status was assessed using the Expanded Disability Status Scale (EDSS). An optimized DTI method with intrinsic eddy current compensation was used. MD and FA maps were created. Cortical parameter values were read and saved in surface-datasets. Global cortical FA/MD values were compared between groups. Furthermore, surface-based statistical comparisons were performed. We tested for correlations between the parameter(s) with significant global group differences and the EDSS. Increased global cortical MD values were observed in the patient group. Surface-based analysis unveiled MD increases particularly in temporal, occipital and parietal regions. Furthermore, the MD correlated significantly with the EDSS score. In addition, we observed focal cortical FA decreases in the temporal and occipital lobes. The MD correlates positively with the amount of diffusion in a certain area. Diffusion is limited by microstructural barriers. Accordingly, MD might quantify the integrity microstructural barriers. FA values are high inordered structures with directional diffusion such as fiber tracts. Therefore, reduced FA values in the occipital and temporal cortical might reflect axonal damage. Regions with MD increase were more widespread than areas with FA reduction. This finding might indicate that the cortical breakdown of microstructural barriers in MS patients is a more prominent and widespread cortical remodeling mechanism than the disruption of axonal structures. In addition, the observed correlation between cortical MD values and the EDSS highlights a potential relevance of DTI techniques for larger clinical studies.

Les analystes sont prompts à qualifier l’économie collaborative de transformation radicale du système capitaliste. Mais qu’en pensent ceux qui créent des entreprises au sein de ce secteur ? Quelles sont les priorités, les motivations des entrepreneurs, leur manière d’envisager l’organisation du travail comme l’impact de leurs initiatives sur les modes de consommation ?

Zusammenfassung„Black esophagus“ oder „akute Ösophagusnekrose“ (AÖN) ist eine seltene Erkrankung, die sich makroskopisch durch eine zirkumferente Schwarzverfärbung der Ösophagusmukosa mit abruptem Ende am gastroösophagealen Übergang auszeichnet. Die genaue Pathogenese ist unbekannt; es werden multifaktorielle Einflüsse wie z. B. Säurereflux, Ischämie und verringerte Schutzmechanismen der Mukosa als mögliche Ursachen diskutiert.Vorgestellt werden 2 Obduktionsfälle, die typische Befunde einer AÖN aufwiesen. Zusätzlich hatten Fall 1 eine Candida-Infektion und Fall 2 eine Appendizitis, sodass eine infektiöse Genese in beiden Fällen eine Rolle gespielt haben könnte.